/* ========== Reset & Base ========== */
*, *::before, *::after { box-sizing: border-box; margin: 0; padding: 0; }
html { scroll-behavior: smooth; }
body {
    font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", "PingFang SC", "Microsoft YaHei", "Helvetica Neue", Arial, sans-serif;
    background: #f4f7fb;
    color: #2c3e50;
    line-height: 1.8;
    font-size: 15px;
}
a { text-decoration: none; color: inherit; }

/* ========== Layout ========== */
.app-wrapper {
    display: flex;
    min-height: 100vh;
}

/* ========== Left Sidebar ========== */
.sidebar {
    position: fixed;
    top: 0;
    left: 0;
    width: 250px;
    height: 100vh;
    background: #1a3a5c;
    color: #c8d6e5;
    overflow-y: auto;
    z-index: 100;
    display: flex;
    flex-direction: column;
    box-shadow: 2px 0 12px rgba(0,0,0,0.15);
}
.sidebar-header {
    padding: 20px 16px 14px;
    border-bottom: 1px solid rgba(255,255,255,0.08);
    text-align: center;
}
.sidebar-header h2 {
    font-size: 17px;
    color: #fff;
    font-weight: 700;
    letter-spacing: 1px;
}
.sidebar-header .sub {
    font-size: 12px;
    color: #8ba4c0;
    margin-top: 2px;
}
.sidebar-nav { flex: 1; padding: 8px 0; }
.sidebar-nav .nav-part {
    padding: 10px 16px 4px;
    font-size: 11px;
    font-weight: 600;
    color: #6a8fbb;
    text-transform: uppercase;
    letter-spacing: 1px;
}
.sidebar-nav a {
    display: block;
    padding: 7px 16px 7px 22px;
    font-size: 13px;
    color: #b0c7de;
    border-left: 3px solid transparent;
    transition: all 0.2s;
    cursor: pointer;
}
.sidebar-nav a:hover {
    background: rgba(255,255,255,0.06);
    color: #fff;
}
.sidebar-nav a.active {
    background: rgba(44,111,170,0.3);
    color: #fff;
    border-left-color: #2c6faa;
    font-weight: 600;
}
.sidebar-nav a .ch-num {
    display: inline-block;
    width: 22px;
    color: #6a8fbb;
    font-size: 12px;
}
.sidebar-nav a.active .ch-num { color: #8fc1f0; }
.sidebar-nav a .priority-dot {
    display: inline-block;
    font-size: 11px;
    margin-left: 4px;
}
.sidebar-nav a .priority-dot.high { color: #f39c12; }
.sidebar-nav a .priority-dot.low { color: #7f8c8d; }
.sidebar-nav a .priority-dot.drop { color: #95a5a6; }

/* ========== Right Content ========== */
.main-content {
    margin-left: 250px;
    flex: 1;
    padding: 0;
    min-height: 100vh;
}

/* ========== Top Banner ========== */
.top-banner {
    background: linear-gradient(135deg, #1a3a5c 0%, #2c6faa 50%, #1a3a5c 100%);
    color: #fff;
    padding: 36px 40px 30px;
    text-align: center;
    position: relative;
}
.top-banner h1 {
    font-size: 26px;
    font-weight: 800;
    letter-spacing: 2px;
}
.top-banner p {
    margin-top: 6px;
    font-size: 14px;
    color: #b0cfe8;
    letter-spacing: 1px;
}
.top-banner .target-badge {
    display: inline-block;
    margin-top: 10px;
    background: rgba(255,255,255,0.15);
    border: 1px solid rgba(255,255,255,0.25);
    border-radius: 20px;
    padding: 4px 20px;
    font-size: 13px;
    font-weight: 600;
    color: #ffd700;
}

/* ========== Content Wrapper ========== */
.content-wrap {
    padding: 30px 36px 60px;
    max-width: 960px;
}

/* ========== Part Title ========== */
.part-title {
    font-size: 22px;
    font-weight: 700;
    color: #1a3a5c;
    border-left: 5px solid #2c6faa;
    padding-left: 16px;
    margin: 40px 0 24px;
}
.part-title:first-of-type { margin-top: 0; }
.part-title .part-score {
    font-size: 14px;
    font-weight: 400;
    color: #7f8c8d;
    margin-left: 10px;
}

/* ========== Chapter Card ========== */
.chapter-card {
    background: #fff;
    border-radius: 10px;
    box-shadow: 0 2px 12px rgba(0,0,0,0.06);
    padding: 28px 30px;
    margin-bottom: 28px;
    border: 1px solid #eef3f9;
    transition: box-shadow 0.2s;
}
.chapter-card:hover {
    box-shadow: 0 4px 20px rgba(44,111,170,0.10);
}
.chapter-card .ch-header {
    display: flex;
    align-items: center;
    justify-content: space-between;
    flex-wrap: wrap;
    margin-bottom: 16px;
}
.chapter-card .ch-title {
    font-size: 19px;
    font-weight: 700;
    color: #1a3a5c;
}
.chapter-card .ch-title .ch-score {
    font-size: 14px;
    font-weight: 400;
    color: #7f8c8d;
    margin-left: 8px;
}
.chapter-card .ch-stars {
    font-size: 16px;
    letter-spacing: 2px;
}
.chapter-card .ch-stars.star-high { color: #f39c12; }
.chapter-card .ch-stars.star-mid { color: #e67e22; }
.chapter-card .ch-stars.star-low { color: #95a5a6; }
.chapter-card .ch-stars .drop-label {
    font-size: 12px;
    color: #e74c3c;
    background: #fde8e8;
    padding: 2px 10px;
    border-radius: 4px;
    margin-left: 6px;
    font-weight: 600;
}

/* ========== Section tags ========== */
.section-tag {
    display: inline-block;
    font-size: 13px;
    font-weight: 600;
    padding: 2px 14px;
    border-radius: 4px;
    margin-bottom: 12px;
}
.section-tag.tag-core { background: #eaf2fb; color: #2c6faa; }
.section-tag.tag-must { background: #fef7e6; color: #d68910; }
.section-tag.tag-example { background: #eafaf1; color: #1e8449; }
.section-tag.tag-tip { background: #f5eef8; color: #7d3c98; }
.section-tag.tag-warn { background: #fdedec; color: #c0392b; }

/* ========== Content blocks ========== */
.ch-content { margin-top: 10px; }
.ch-content p { margin-bottom: 8px; }
.ch-content ul, .ch-content ol { padding-left: 22px; margin-bottom: 10px; }
.ch-content li { margin-bottom: 4px; }

/* ========== KaTeX 渲染后的样式微调 ========== */
.ch-content code { font-size: 0.95em; }
.ch-content .katex { font-size: 1.05em; }
.ch-content .katex-display {
    margin: 10px 0 !important;
    overflow-x: auto;
    overflow-y: hidden;
}
.ch-content p .katex,
.ch-content li .katex { margin: 0 2px; }
.ch-content code .katex { font-size: inherit; }

/* ========== Chart Card (数学图示) ========== */
.chart-card {
    background: #ffffff;
    border: 1px solid #e3e8ee;
    border-radius: 8px;
    padding: 12px 14px;
    margin: 14px 0;
    box-shadow: 0 1px 3px rgba(0, 0, 0, 0.04);
}
.chart-card .chart-title {
    font-weight: 700;
    color: #2c3e50;
    font-size: 14px;
    margin-bottom: 8px;
}
.math-svg {
    display: block;
    width: 100%;
    height: auto;
    max-width: 480px;
    margin: 0 auto;
}
.proof-block {
    background: #f0f7ff;
    border-left: 4px solid #5dade2;
    border-radius: 6px;
    padding: 12px 16px;
    margin: 12px 0;
    font-size: 14px;
    line-height: 1.8;
}
.proof-block .proof-label {
    font-weight: 700;
    color: #2874a6;
    margin-bottom: 6px;
}
.proof-block .step {
    margin: 4px 0;
    padding-left: 8px;
}
.proof-block .step-eq {
    font-family: 'Cambria Math', 'STIX Two Math', serif;
    color: #1a5276;
}
.proof-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(360px, 1fr));
    gap: 14px;
    margin: 14px 0;
}

/* ========== Must-know card ========== */
.must-card {
    background: #fefbea;
    border-left: 4px solid #f1c40f;
    border-radius: 6px;
    padding: 14px 18px;
    margin: 14px 0;
}
.must-card .must-label {
    font-weight: 700;
    color: #b7950b;
    font-size: 14px;
    margin-bottom: 6px;
}
.must-card table {
    width: 100%;
    border-collapse: collapse;
    font-size: 14px;
    margin-top: 6px;
}
.must-card table th,
.must-card table td {
    padding: 6px 10px;
    border: 1px solid #e8dcc8;
    text-align: left;
}
.must-card table th {
    background: #f5edd6;
    font-weight: 600;
    color: #7a5f0a;
}

/* ========== Example card ========== */
.example-card {
    background: #f8fdf9;
    border-left: 4px solid #27ae60;
    border-radius: 6px;
    padding: 14px 18px;
    margin: 14px 0;
}
.example-card .example-label {
    font-weight: 700;
    color: #1e8449;
    font-size: 14px;
    margin-bottom: 6px;
}
.example-card .example-question {
    font-weight: 600;
    margin-bottom: 4px;
}
.example-card .example-solution {
    color: #2c3e50;
}
.example-card .example-hint {
    background: #eef6f1;
    padding: 8px 12px;
    border-radius: 4px;
    margin-top: 6px;
    font-size: 14px;
    color: #1a5c3a;
    border-left: 3px solid #27ae60;
}
.example-card .example-hint::before {
    content: "💡小白解析：";
    font-weight: 600;
}

/* ========== Formula box ========== */
.formula-box {
    background: #f0f6fc;
    border: 1px solid #d6e4f0;
    border-radius: 6px;
    padding: 12px 18px;
    margin: 10px 0;
    text-align: center;
    font-size: 16px;
    font-weight: 500;
    color: #1a3a5c;
    font-family: "Times New Roman", "Cambria Math", serif;
}

/* ========== Inline math/code chips ========== */
/* 统一内联公式（如 <code>x_n e^{x_{n+1}} = e^{x_n} − 1</code>）的样式，
   让它与 .formula-box 视觉协调：浅色衬底 + 暖色强调 + 衬线字。 */
code {
    font-family: "Cambria Math", "Latin Modern Math", "STIX Two Math",
                 "Times New Roman", "Cambria", Georgia, serif;
    font-size: 0.95em;
    font-style: normal;
    font-weight: 500;
    line-height: 1;
    color: #b03a2e;
    background: linear-gradient(180deg, #fff5f1 0%, #fdecea 100%);
    border: 1px solid #f5c6b8;
    border-radius: 4px;
    padding: 2px 7px;
    margin: 0 1px;
    white-space: nowrap;
    transition: all 0.15s ease;
}
code:hover {
    background: linear-gradient(180deg, #ffe8e2 0%, #f9d4cb 100%);
    border-color: #e89379;
}
/* 嵌套的 sub/sup 不要被外层 code 的 line-height 拉得太高 */
code sub, code sup {
    line-height: 0;
    font-size: 0.75em;
}

/* ========== 浮动小标题（badge 在顶部的标签样式，不挤压正文） ========== */
.tag-float {
    position: relative;
    border-radius: 10px;
    padding: 12px 18px 16px;
    margin: 16px 0;
    background: rgba(255, 255, 255, 0.85);
    border: 1px solid #e1e9f3;
    box-shadow: 0 2px 8px rgba(0, 0, 0, 0.05);
    backdrop-filter: blur(4px);
    -webkit-backdrop-filter: blur(4px);
}
.tag-float::before {
    display: inline-block;
    padding: 4px 12px;
    margin-bottom: 8px;
    border-radius: 6px;
    text-align: center;
    font-weight: 700;
    font-size: 12px;
    color: #fff;
    letter-spacing: 1px;
    box-shadow: 0 2px 4px rgba(0, 0, 0, 0.1);
}
.tag-float.t-example::before   { content: "📌 例题";     background: linear-gradient(135deg, #2c6faa, #1a5276); }
.tag-float.t-summary::before   { content: "🧠 解法总结"; background: linear-gradient(135deg, #27ae60, #1e8449); }
.tag-float.t-tip::before       { content: "💡 小白技巧"; background: linear-gradient(135deg, #f39c12, #d68910); }
.tag-float.t-warn::before      { content: "⚠️ 防粗心";   background: linear-gradient(135deg, #e74c3c, #c0392b); }
.tag-float.t-formula::before   { content: "📐 公式卡片"; background: linear-gradient(135deg, #8e44ad, #6c3483); }
.tag-float.t-strategy::before  { content: "🎯 应试策略"; background: linear-gradient(135deg, #16a085, #0e6655); }

.tag-float .tf-title { font-weight: 700; font-size: 15px; color: #1a3a5c; margin: 2px 0 6px; }
.tag-float .tf-body  { font-size: 14px; color: #34495e; line-height: 1.85; }
.tag-float .tf-body code { background: #f0f3f7; padding: 1px 6px; border-radius: 3px; color: #c0392b; }
.tag-float ul { padding-left: 20px; margin: 6px 0; }
.tag-float li { margin-bottom: 3px; }

/* ========== inline chip 标签 ========== */
.chip {
    display: inline-block;
    font-size: 12px;
    padding: 1px 10px;
    border-radius: 12px;
    margin: 0 4px 4px 0;
    font-weight: 600;
    letter-spacing: 0.5px;
}
.chip.exam  { background: #fdecea; color: #c0392b; }
.chip.trick { background: #fef5e7; color: #d68910; }
.chip.key   { background: #e8f5e9; color: #1e8449; }
.chip.formula { background: #eaf2fb; color: #2c6faa; }

/* ========== 右侧「本页要点」悬浮导航（固定在右，毛玻璃半透明） ========== */
.outline-panel {
    position: fixed;
    top: 100px;
    right: 24px;
    width: 180px;
    background: rgba(255, 255, 255, 0.78);
    border: 1px solid rgba(214, 228, 240, 0.6);
    border-radius: 10px;
    padding: 14px 14px 12px;
    box-shadow: 0 4px 18px rgba(0, 0, 0, 0.08);
    backdrop-filter: blur(10px);
    -webkit-backdrop-filter: blur(10px);
    z-index: 90;
    max-height: calc(100vh - 140px);
    overflow-y: auto;
}
.outline-panel .op-title {
    font-size: 13px;
    font-weight: 700;
    color: #1a3a5c;
    margin-bottom: 10px;
    padding-bottom: 6px;
    border-bottom: 1px dashed #d6e4f0;
}
.outline-panel a {
    display: block;
    font-size: 12px;
    color: #4a6580;
    padding: 5px 6px;
    border-radius: 4px;
    margin-bottom: 2px;
    cursor: pointer;
    line-height: 1.5;
    transition: all 0.15s;
}
.outline-panel a:hover {
    background: #f0f6fc;
    color: #1a3a5c;
    transform: translateX(-2px);
}
.outline-panel a.active {
    background: #eaf2fb;
    color: #2c6faa;
    font-weight: 600;
}

@media (max-width: 1200px) {
    .outline-panel { display: none; }
}

/* ========== Drop section style ========== */
.chapter-card.drop-card {
    opacity: 0.75;
    border-left: 4px solid #bdc3c7;
}
.chapter-card.drop-card:hover { opacity: 0.85; }

/* ========== Loading/Await UI ========== */
.chapter-loading {
    text-align: center;
    padding: 60px 20px;
    color: #95a5a6;
}
.chapter-loading .spinner {
    display: inline-block;
    width: 32px;
    height: 32px;
    border: 3px solid #eef3f9;
    border-top-color: #2c6faa;
    border-radius: 50%;
    animation: spin 0.8s linear infinite;
    margin-bottom: 12px;
}
@keyframes spin {
    to { transform: rotate(360deg); }
}

/* ========== Back to top ========== */
.back-to-top {
    position: fixed;
    bottom: 30px;
    right: 30px;
    width: 44px;
    height: 44px;
    border-radius: 50%;
    background: #2c6faa;
    color: #fff;
    border: none;
    font-size: 20px;
    cursor: pointer;
    box-shadow: 0 3px 10px rgba(44,111,170,0.35);
    transition: opacity 0.3s, transform 0.2s;
    opacity: 0;
    transform: translateY(10px);
    pointer-events: none;
    z-index: 200;
    display: flex;
    align-items: center;
    justify-content: center;
}
.back-to-top.show {
    opacity: 1;
    transform: translateY(0);
    pointer-events: auto;
}
.back-to-top:hover {
    background: #1a4d7a;
    transform: translateY(-2px);
}

/* ========== Chapter nav buttons ========== */
.chapter-nav {
    display: flex;
    justify-content: space-between;
    margin-top: 24px;
    padding-top: 16px;
    border-top: 1px solid #eef3f9;
}
.chapter-nav button {
    background: #2c6faa;
    color: #fff;
    border: none;
    padding: 8px 20px;
    border-radius: 6px;
    font-size: 14px;
    cursor: pointer;
    transition: background 0.2s;
}
.chapter-nav button:hover {
    background: #1a4d7a;
}
.chapter-nav button:disabled {
    background: #bdc3c7;
    cursor: not-allowed;
}

/* ========== 右侧导航中的 Part 标题样式 ========== */
.outline-wrap a.outline-part {
    display: block;
    background: linear-gradient(135deg, #eaf2fb, #f0f6fc);
    border-left: 3px solid #2c6faa;
    color: #1a3a5c;
    font-weight: 700;
    font-size: 13px;
    padding: 6px 10px;
    margin: 8px 0 4px;
    border-radius: 4px;
    line-height: 1.4;
}
.outline-wrap a.outline-part:hover {
    background: linear-gradient(135deg, #d6e4f5, #e8f0f9);
    color: #1a3a5c;
}
.outline-wrap a.outline-part.active {
    background: linear-gradient(135deg, #2c6faa, #1a3a5c);
    color: #fff;
    border-left-color: #f39c12;
}

/* ========== 章节导览目录 (Nav TOC) ========== */
.nav-toc {
    background: linear-gradient(135deg, #f0f6fc 0%, #e8f0f9 100%);
    border: 1px solid #c8d8eb;
    border-radius: 8px;
    padding: 14px 18px 16px;
    margin: 14px 0 22px;
    box-shadow: 0 1px 3px rgba(26, 58, 92, 0.06);
}
.nav-toc .toc-title {
    font-size: 15px;
    font-weight: 700;
    color: #1a3a5c;
    margin-bottom: 8px;
    display: flex;
    align-items: center;
    gap: 6px;
}
.nav-toc .toc-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(220px, 1fr));
    gap: 6px 14px;
    font-size: 13px;
}
.nav-toc .toc-grid a {
    display: flex;
    align-items: baseline;
    gap: 6px;
    padding: 4px 6px;
    border-radius: 4px;
    color: #2c3e50;
    transition: background 0.15s;
    line-height: 1.6;
}
.nav-toc .toc-grid a:hover {
    background: rgba(44, 111, 170, 0.08);
    color: #2c6faa;
}
.nav-toc .toc-grid .toc-num {
    display: inline-block;
    min-width: 22px;
    color: #2c6faa;
    font-weight: 700;
    font-size: 12px;
}
.nav-toc .toc-grid .toc-text {
    flex: 1;
}
.nav-toc .toc-grid .toc-tag {
    font-size: 10px;
    padding: 1px 5px;
    border-radius: 3px;
    background: #fef5e7;
    color: #d68910;
    font-weight: 600;
    white-space: nowrap;
}

/* ========== 分节标题 (Part Divider) ========== */
.part-divider {
    display: flex;
    align-items: center;
    gap: 12px;
    margin: 32px 0 18px;
    padding: 0;
    scroll-margin-top: 20px;
}
.part-divider .pd-num {
    flex-shrink: 0;
    width: 36px;
    height: 36px;
    border-radius: 50%;
    background: linear-gradient(135deg, #2c6faa, #1a3a5c);
    color: #fff;
    font-weight: 700;
    font-size: 16px;
    display: flex;
    align-items: center;
    justify-content: center;
    box-shadow: 0 2px 6px rgba(26, 58, 92, 0.2);
}
.part-divider .pd-text {
    flex: 1;
}
.part-divider .pd-name {
    font-size: 17px;
    font-weight: 700;
    color: #1a3a5c;
    line-height: 1.3;
}
.part-divider .pd-desc {
    font-size: 12px;
    color: #7f8c8d;
    margin-top: 2px;
}
.part-divider.p1 .pd-num { background: linear-gradient(135deg, #2c6faa, #1a3a5c); }
.part-divider.p2 .pd-num { background: linear-gradient(135deg, #8e44ad, #6c3483); }
.part-divider.p3 .pd-num { background: linear-gradient(135deg, #16a085, #0e6655); }
.part-divider.p4 .pd-num { background: linear-gradient(135deg, #d68910, #b7950b); }
.part-divider.p5 .pd-num { background: linear-gradient(135deg, #c0392b, #922b21); }
.part-divider.p6 .pd-num { background: linear-gradient(135deg, #c0392b, #922b21); }
.part-divider.p7 .pd-num { background: linear-gradient(135deg, #c0392b, #922b21); }
.part-divider.p8 .pd-num { background: linear-gradient(135deg, #c0392b, #922b21); }
.part-divider.p9 .pd-num { background: linear-gradient(135deg, #27ae60, #1e8449); }

/* ========== 跨章节标记 (Cross-chapter badge) ========== */
.cross-ch-badge {
    display: inline-block;
    font-size: 11px;
    font-weight: 700;
    padding: 2px 8px;
    border-radius: 10px;
    margin-left: 8px;
    vertical-align: middle;
    letter-spacing: 0.5px;
}
.cross-ch-badge.ch02 {
    background: #fdecea;
    color: #c0392b;
    border: 1px solid #f5b7b1;
}
.cross-ch-badge.ch03 {
    background: #eafaf1;
    color: #1e8449;
    border: 1px solid #a9dfbf;
}
.cross-ch-badge.ch04 {
    background: #fef5e7;
    color: #d68910;
    border: 1px solid #fad7a0;
}
.cross-ch-badge::before {
    content: "🔗 ";
    font-size: 10px;
}

/* ========== 章节 Tab 切换（笔记 / 练习） ========== */
.ch-tabs {
    display: flex;
    gap: 4px;
    margin: 0 0 16px;
    padding: 4px;
    background: #f0f3f7;
    border-radius: 8px;
    width: fit-content;
}
.ch-tabs .ch-tab {
    background: transparent;
    border: none;
    padding: 8px 18px;
    font-size: 14px;
    font-weight: 600;
    color: #5a6b80;
    border-radius: 6px;
    cursor: pointer;
    transition: all 0.2s;
    font-family: inherit;
}
.ch-tabs .ch-tab:hover { color: #1a3a5c; background: rgba(44,111,170,0.08); }
.ch-tabs .ch-tab.active {
    background: linear-gradient(135deg, #2c6faa, #1a3a5c);
    color: #fff;
    box-shadow: 0 2px 6px rgba(26,58,92,0.2);
}

/* 练习模式：隐藏笔记区域，仅显示 .ch-practice（tab 栏保持可见）*/
.ch-content.practice-mode > :not(.ch-tabs):not(.ch-practice) { display: none; }
.ch-content.practice-mode .ch-practice { display: block; }
.ch-content:not(.practice-mode) .ch-practice { display: none; }

/* ========== 练习卡片（知识卡形式） ========== */
.ch-practice {
    padding: 4px 0 20px;
}
.ch-practice .practice-header {
    background: linear-gradient(135deg, #fef7e6, #fef0d2);
    border-left: 4px solid #d68910;
    padding: 12px 16px;
    border-radius: 6px;
    margin-bottom: 18px;
    color: #7a5a0a;
    font-size: 14px;
    line-height: 1.7;
}
.ch-practice .practice-header strong { color: #5a4500; }

.problem-card {
    background: #fff;
    border: 1px solid #e3e8ee;
    border-left: 4px solid #2c6faa;
    border-radius: 8px;
    padding: 16px 20px;
    margin: 0 0 18px;
    box-shadow: 0 1px 3px rgba(0,0,0,0.04);
    transition: box-shadow 0.2s;
}
.problem-card:hover { box-shadow: 0 3px 12px rgba(44,111,170,0.12); }
.problem-card .pc-head {
    display: flex;
    align-items: center;
    gap: 10px;
    margin-bottom: 8px;
}
.problem-card .pc-num {
    flex-shrink: 0;
    width: 28px;
    height: 28px;
    border-radius: 50%;
    background: linear-gradient(135deg, #2c6faa, #1a3a5c);
    color: #fff;
    font-weight: 700;
    font-size: 13px;
    display: flex;
    align-items: center;
    justify-content: center;
}
.problem-card .pc-type {
    font-size: 12px;
    font-weight: 600;
    padding: 2px 10px;
    background: #fef5e7;
    color: #d68910;
    border-radius: 10px;
}
.problem-card .pc-question {
    font-size: 15px;
    color: #2c3e50;
    line-height: 1.9;
    margin: 10px 0 4px;
    padding: 10px 14px;
    background: #fafbfc;
    border-radius: 6px;
    border-left: 3px solid #e3e8ee;
}
.problem-card .pc-hints {
    margin-top: 12px;
}
.problem-card .pc-hints summary {
    cursor: pointer;
    user-select: none;
    color: #2c6faa;
    font-weight: 600;
    font-size: 14px;
    padding: 6px 0;
    list-style: none;
    display: inline-flex;
    align-items: center;
    gap: 6px;
}
.problem-card .pc-hints summary::-webkit-details-marker { display: none; }
.problem-card .pc-hints summary::before {
    content: "💡";
    font-size: 16px;
}
.problem-card .pc-hints[open] summary::before { content: "📖"; }
.problem-card .pc-hints ol {
    margin: 10px 0 0;
    background: #f0f6fc;
    padding: 12px 18px 12px 40px;
    border-radius: 6px;
    border-left: 3px solid #5dade2;
}
.problem-card .pc-hints ol li {
    font-size: 14px;
    color: #34495e;
    line-height: 1.8;
    margin-bottom: 6px;
}
.problem-card .pc-hints ol li:last-child { margin-bottom: 0; }
.problem-card .pc-hints ol li strong { color: #1a3a5c; }

/* ========== 考研倒计时条 ========== */
.countdown-bar {
    background: linear-gradient(135deg, #1a3a5c 0%, #2c6faa 50%, #1a4d80 100%);
    color: #fff;
    padding: 14px 28px;
    display: flex;
    align-items: center;
    gap: 22px;
    box-shadow: 0 2px 8px rgba(26, 58, 92, 0.2);
    position: sticky;
    top: 0;
    z-index: 50;
    flex-wrap: wrap;
}
.countdown-bar.urgent { background: linear-gradient(135deg, #c0392b 0%, #e74c3c 50%, #c0392b 100%); animation: cbPulse 2s ease-in-out infinite; }
.countdown-bar.warning { background: linear-gradient(135deg, #b7950b 0%, #d68910 50%, #b7950b 100%); }
.countdown-bar.critical { background: linear-gradient(135deg, #922b21 0%, #c0392b 50%, #641e16 100%); animation: cbPulse 1.2s ease-in-out infinite; }
.countdown-bar.exam-day { background: linear-gradient(135deg, #8e44ad 0%, #9b59b6 50%, #8e44ad 100%); }
.countdown-bar.exam-over { background: linear-gradient(135deg, #2c3e50 0%, #34495e 50%, #2c3e50 100%); }
@keyframes cbPulse {
    0%, 100% { box-shadow: 0 2px 8px rgba(231, 76, 60, 0.3); }
    50% { box-shadow: 0 4px 18px rgba(231, 76, 60, 0.6); }
}
.cb-left {
    display: flex;
    align-items: center;
    gap: 12px;
    flex-shrink: 0;
}
.cb-icon {
    font-size: 30px;
    line-height: 1;
}
.cb-info { line-height: 1.3; }
.cb-title {
    font-size: 15px;
    font-weight: 700;
    color: #ffd700;
    letter-spacing: 1px;
}
.cb-date {
    font-size: 12px;
    color: #b0cfe8;
    margin-top: 2px;
}
.cb-units {
    display: flex;
    align-items: center;
    gap: 6px;
    background: rgba(0, 0, 0, 0.18);
    padding: 8px 16px;
    border-radius: 10px;
    border: 1px solid rgba(255, 255, 255, 0.12);
}
.cb-unit {
    display: flex;
    flex-direction: column;
    align-items: center;
    min-width: 48px;
}
.cb-num {
    font-size: 26px;
    font-weight: 800;
    color: #fff;
    font-family: "Courier New", "Consolas", monospace;
    line-height: 1.1;
    letter-spacing: 1px;
    text-shadow: 0 1px 2px rgba(0, 0, 0, 0.3);
    min-width: 36px;
    text-align: center;
}
.cb-unit-label {
    font-size: 10px;
    color: #b0cfe8;
    margin-top: 1px;
    letter-spacing: 1px;
}
.cb-sep {
    color: rgba(255, 255, 255, 0.4);
    font-size: 20px;
    font-weight: 700;
    padding-bottom: 12px;
}
.cb-progress-wrap {
    display: flex;
    align-items: center;
    gap: 8px;
    min-width: 160px;
    flex: 1;
    max-width: 240px;
}
.cb-progress-bar {
    flex: 1;
    height: 8px;
    background: rgba(0, 0, 0, 0.25);
    border-radius: 4px;
    overflow: hidden;
    border: 1px solid rgba(255, 255, 255, 0.1);
}
.cb-progress-fill {
    height: 100%;
    background: linear-gradient(90deg, #ffd700 0%, #ff8c00 100%);
    border-radius: 4px;
    transition: width 0.5s ease;
}
.cb-progress-text {
    font-size: 12px;
    color: #ffd700;
    font-weight: 700;
    min-width: 36px;
    text-align: right;
}
.cb-settings {
    background: rgba(255, 255, 255, 0.1);
    border: 1px solid rgba(255, 255, 255, 0.2);
    color: #fff;
    width: 32px;
    height: 32px;
    border-radius: 50%;
    cursor: pointer;
    font-size: 14px;
    transition: all 0.2s;
    flex-shrink: 0;
}
.cb-settings:hover { background: rgba(255, 255, 255, 0.2); transform: rotate(90deg); }

@media (max-width: 768px) {
    .countdown-bar { padding: 10px 16px; gap: 10px; }
    .cb-left { gap: 8px; }
    .cb-icon { font-size: 22px; }
    .cb-title { font-size: 13px; }
    .cb-date { font-size: 10px; }
    .cb-units { padding: 4px 8px; gap: 3px; }
    .cb-num { font-size: 18px; }
    .cb-unit-label { font-size: 9px; }
    .cb-sep { font-size: 14px; }
    .cb-progress-wrap { display: none; }
}
@media (max-width: 480px) {
    .cb-date { display: none; }
}

/* ========== 掌握程度追踪：紧凑按钮 + 折叠面板 ========== */

/* 顶部紧凑按钮（题目右侧） */
.problem-card .pc-head {
    gap: 8px;
}
.pc-mastery-toggle {
    margin-left: auto;
    display: inline-flex;
    align-items: center;
    gap: 5px;
    padding: 4px 12px;
    background: #f0f6fc;
    color: #4a6580;
    border: 1px solid #d6e4f0;
    border-radius: 14px;
    font-size: 12px;
    font-weight: 600;
    cursor: pointer;
    transition: all 0.18s;
    white-space: nowrap;
    user-select: none;
}
.pc-mastery-toggle:hover {
    background: #e1ecf7;
    transform: translateY(-1px);
    box-shadow: 0 2px 6px rgba(44,111,170,0.15);
}
.pc-mastery-toggle.open {
    background: #2c6faa;
    color: #fff;
    border-color: #2c6faa;
}
.pc-mastery-toggle.strong { background: #27ae60; color: #fff; border-color: #27ae60; }
.pc-mastery-toggle.strong.open { background: #1e8449; border-color: #1e8449; }
.pc-mastery-toggle.weak   { background: #e67e22; color: #fff; border-color: #e67e22; }
.pc-mastery-toggle.weak.open { background: #ca6f1e; border-color: #ca6f1e; }
.pc-mastery-icon { font-size: 13px; }
.pc-mastery-arrow {
    font-size: 10px;
    line-height: 1;
    transition: transform 0.2s;
    opacity: 0.7;
}
.pc-mastery-toggle.open .pc-mastery-arrow { transform: rotate(180deg); }

/* 折叠面板（默认隐藏） */
.pc-mastery-panel {
    margin-top: 12px;
    background: linear-gradient(180deg, #f8fafc 0%, #f1f5f9 100%);
    border: 1px solid #d6e4f0;
    border-radius: 8px;
    padding: 14px 16px;
    animation: pcMasterySlideIn 0.25s ease-out;
}
.pc-mastery-panel[hidden] { display: none; }
@keyframes pcMasterySlideIn {
    from { opacity: 0; transform: translateY(-6px); }
    to   { opacity: 1; transform: translateY(0); }
}
.pc-mastery-form {
    padding-bottom: 10px;
    border-bottom: 1px dashed #cdd9e5;
    margin-bottom: 10px;
}
.pc-mastery-row {
    display: flex;
    align-items: center;
    gap: 10px;
    margin-bottom: 8px;
    font-size: 13px;
    flex-wrap: wrap;
}
.pc-mastery-row > label {
    min-width: 56px;
    color: #34495e;
    font-weight: 600;
}
.pc-mastery-range {
    flex: 1;
    min-width: 180px;
    -webkit-appearance: none;
    height: 6px;
    border-radius: 3px;
    background: linear-gradient(to right, #e74c3c 0%, #f39c12 50%, #27ae60 100%);
    outline: none;
    cursor: pointer;
}
.pc-mastery-range::-webkit-slider-thumb {
    -webkit-appearance: none;
    width: 18px;
    height: 18px;
    border-radius: 50%;
    background: #2c6faa;
    border: 2px solid #fff;
    box-shadow: 0 1px 4px rgba(0,0,0,0.2);
    cursor: pointer;
}
.pc-mastery-range::-moz-range-thumb {
    width: 18px;
    height: 18px;
    border-radius: 50%;
    background: #2c6faa;
    border: 2px solid #fff;
    cursor: pointer;
}
.pc-mastery-value {
    min-width: 40px;
    text-align: right;
    font-weight: 700;
    color: #1a3a5c;
}
.pc-mastery-date,
.pc-mastery-note {
    padding: 6px 10px;
    border: 1px solid #cdd9e5;
    border-radius: 4px;
    font-size: 13px;
    background: #fff;
    color: #2c3e50;
    font-family: inherit;
}
.pc-mastery-date { min-width: 140px; }
.pc-mastery-note { flex: 1; min-width: 180px; }
.pc-mastery-date:focus,
.pc-mastery-note:focus {
    outline: none;
    border-color: #2c6faa;
    box-shadow: 0 0 0 2px rgba(44,111,170,0.15);
}
.pc-mastery-actions {
    display: flex;
    gap: 8px;
    margin-top: 6px;
}
.pc-mastery-save {
    background: #2c6faa;
    color: #fff;
    border: none;
    padding: 7px 18px;
    border-radius: 5px;
    font-size: 13px;
    font-weight: 600;
    cursor: pointer;
    transition: all 0.2s;
}
.pc-mastery-save:hover { background: #1a4d80; transform: translateY(-1px); }
.pc-mastery-save:disabled { background: #95a5a6; cursor: not-allowed; transform: none; }
.pc-mastery-close {
    background: #ecf0f1;
    color: #4a6580;
    border: 1px solid #cdd9e5;
    padding: 7px 14px;
    border-radius: 5px;
    font-size: 13px;
    cursor: pointer;
    transition: all 0.2s;
}
.pc-mastery-close:hover { background: #d6e4f0; }
.pc-mastery-history {
    margin-top: 4px;
}
.pc-history-title {
    font-size: 13px;
    color: #4a6580;
    font-weight: 600;
    margin-bottom: 8px;
}
.pc-history-list {
    list-style: none;
    padding: 0;
    margin: 0;
    max-height: 200px;
    overflow-y: auto;
}
.pc-history-item {
    display: flex;
    align-items: center;
    gap: 10px;
    padding: 6px 10px;
    margin-bottom: 4px;
    background: #fff;
    border: 1px solid #e8eef4;
    border-radius: 4px;
    font-size: 12px;
}
.pc-history-item .hi-date {
    color: #34495e;
    font-weight: 600;
    min-width: 90px;
}
.pc-history-item .hi-bar {
    flex: 1;
    height: 6px;
    background: #ecf0f1;
    border-radius: 3px;
    overflow: hidden;
    position: relative;
}
.pc-history-item .hi-bar-fill {
    height: 100%;
    border-radius: 3px;
    transition: width 0.3s;
}
.pc-history-item .hi-pct {
    min-width: 38px;
    text-align: right;
    font-weight: 700;
}
.pc-history-item .hi-note {
    flex: 1;
    min-width: 60px;
    color: #7f8c8d;
    font-style: italic;
}
.pc-history-item .hi-delete {
    background: #e74c3c;
    color: #fff;
    border: none;
    width: 22px;
    height: 22px;
    border-radius: 50%;
    cursor: pointer;
    font-size: 12px;
    line-height: 1;
    transition: all 0.2s;
}
.pc-history-item .hi-delete:hover { background: #c0392b; transform: scale(1.1); }
.pc-history-empty {
    font-size: 12px;
    color: #95a5a6;
    text-align: center;
    padding: 8px;
    font-style: italic;
}
.pc-mastery-toast {
    position: fixed;
    top: 80px;
    right: 30px;
    background: #27ae60;
    color: #fff;
    padding: 10px 22px;
    border-radius: 6px;
    font-size: 13px;
    box-shadow: 0 4px 16px rgba(0,0,0,0.2);
    z-index: 1000;
    opacity: 0;
    transform: translateX(20px);
    transition: all 0.3s;
}
.pc-mastery-toast.show { opacity: 1; transform: translateX(0); }
.pc-mastery-toast.error { background: #e74c3c; }
.pc-mastery-toast.info { background: #3498db; }

@media (max-width: 576px) {
    .pc-mastery-row { flex-direction: column; align-items: stretch; gap: 4px; }
    .pc-mastery-row > label { min-width: 0; }
    .pc-mastery-date, .pc-mastery-note { width: 100%; min-width: 0; }
    .pc-history-item { flex-wrap: wrap; }
    .pc-mastery-toggle { font-size: 11px; padding: 3px 8px; }
}

/* ========== 公式速查 Tab 样式 ========== */
.ch-formulas {
    margin-top: 16px;
}
.ch-formulas[hidden], .practice-mode ~ .ch-formulas { display: none; }
.formulas-mode ~ .ch-content > .ch-formulas { display: block; }
.formulas-mode ~ .ch-content > .ch-hints { display: none; }

.formulas-header {
    background: linear-gradient(135deg, #fff8e1 0%, #fef7e0 100%);
    border-left: 4px solid #f39c12;
    border-radius: 8px;
    padding: 16px 20px;
    margin-bottom: 20px;
}
.formulas-title {
    font-size: 20px;
    font-weight: 700;
    color: #b7950b;
    margin-bottom: 6px;
}
.formulas-subtitle {
    font-size: 13px;
    color: #7a5f0a;
}
.formulas-toc {
    display: flex;
    flex-wrap: wrap;
    gap: 8px;
    margin-top: 12px;
}
.formulas-toc-item {
    display: inline-block;
    padding: 4px 12px;
    background: #fff;
    border: 1px solid #f1c40f;
    border-radius: 14px;
    color: #b7950b;
    font-size: 12px;
    text-decoration: none;
    transition: all 0.2s;
}
.formulas-toc-item:hover {
    background: #f1c40f;
    color: #fff;
    transform: translateY(-1px);
}
.formulas-empty {
    margin-top: 12px;
    padding: 10px 14px;
    background: #fff;
    border-radius: 6px;
    color: #7a5f0a;
    font-size: 13px;
}

.formula-section {
    background: #fff;
    border-radius: 8px;
    padding: 16px 20px;
    margin-bottom: 18px;
    box-shadow: 0 1px 6px rgba(0,0,0,0.05);
    border: 1px solid #eef3f9;
}
.formula-section-title {
    font-size: 16px;
    font-weight: 700;
    color: #1a3a5c;
    margin: 0 0 12px;
    padding-bottom: 8px;
    border-bottom: 2px solid #eaf2fb;
    display: flex;
    align-items: center;
    gap: 8px;
    flex-wrap: wrap;
}
.formula-importance {
    font-size: 12px;
    color: #d68910;
    font-weight: 600;
    background: #fef7e0;
    padding: 2px 8px;
    border-radius: 10px;
    margin-left: auto;
    letter-spacing: 1px;
}
.formula-item {
    background: #f8fafc;
    border-left: 3px solid #5dade2;
    border-radius: 6px;
    padding: 10px 14px;
    margin-bottom: 10px;
    transition: all 0.2s;
}
.formula-item:hover {
    background: #eef6fb;
    border-left-color: #2c6faa;
}
.formula-item-head {
    display: flex;
    align-items: center;
    gap: 8px;
    margin-bottom: 4px;
    flex-wrap: wrap;
}
.formula-name {
    font-size: 14px;
    font-weight: 700;
    color: #1a3a5c;
}
.formula-tag {
    font-size: 10px;
    padding: 1px 8px;
    border-radius: 8px;
    font-weight: 600;
    text-transform: uppercase;
    letter-spacing: 0.5px;
}
.formula-tag.core { background: #eaf2fb; color: #2c6faa; }
.formula-tag.must { background: #fef7e6; color: #d68910; }
.formula-tag.warn { background: #fdedec; color: #c0392b; }
.formula-tag.tip { background: #f5eef8; color: #7d3c98; }
.formula-formula {
    background: #fff;
    padding: 8px 12px;
    border-radius: 4px;
    margin: 6px 0;
    border: 1px dashed #d6e4f0;
    font-family: "Cambria Math", "STIX Two Math", serif;
    color: #1a5276;
    font-size: 15px;
    text-align: center;
    overflow-x: auto;
}
.formula-formula .katex { font-size: 1em; }
.formula-proof {
    font-size: 13px;
    color: #4a5568;
    margin-top: 6px;
    padding: 6px 10px;
    background: #f7fafc;
    border-radius: 4px;
    border-left: 2px solid #a0aec0;
    line-height: 1.6;
}
.proof-tag {
    display: inline-block;
    background: #4a5568;
    color: #fff;
    font-size: 10px;
    font-weight: 700;
    padding: 1px 6px;
    border-radius: 3px;
    margin-right: 6px;
    vertical-align: 1px;
    letter-spacing: 0.5px;
}
.formula-note {
    font-size: 12px;
    color: #7a5f0a;
    margin-top: 4px;
    padding: 4px 8px;
    background: #fff8e1;
    border-radius: 4px;
    border-left: 2px solid #f1c40f;
    line-height: 1.5;
}

@media (max-width: 576px) {
    .formulas-title { font-size: 16px; }
    .formula-section { padding: 12px 14px; }
    .formula-item { padding: 8px 10px; }
    .formula-formula { font-size: 13px; padding: 6px 8px; }
    .formula-importance { margin-left: 0; }
}

/* ========== 番茄钟（悬浮按钮 + 弹窗）========== */
.pomo-float {
    position: fixed;
    bottom: 24px;
    right: 24px;
    z-index: 1000;
}
.pomo-float-btn {
    position: relative;
    width: 72px;
    height: 72px;
    border: none;
    background: linear-gradient(135deg, #ff6347 0%, #e74c3c 100%);
    border-radius: 50%;
    cursor: pointer;
    box-shadow: 0 4px 16px rgba(231, 76, 60, 0.4);
    transition: all 0.3s;
    display: flex;
    align-items: center;
    justify-content: center;
    flex-direction: column;
    color: #fff;
    overflow: hidden;
}
.pomo-float-btn:hover {
    transform: scale(1.05);
    box-shadow: 0 6px 24px rgba(231, 76, 60, 0.55);
}
.pomo-float-btn.running { animation: pomoPulse 2s ease-in-out infinite; }
.pomo-float-btn.break { background: linear-gradient(135deg, #2ecc71 0%, #27ae60 100%); box-shadow: 0 4px 16px rgba(39, 174, 96, 0.4); }
.pomo-float-btn.break.running { animation: pomoPulseGreen 2s ease-in-out infinite; }
@keyframes pomoPulse {
    0%, 100% { box-shadow: 0 4px 16px rgba(231, 76, 60, 0.4); }
    50% { box-shadow: 0 4px 28px rgba(231, 76, 60, 0.7); }
}
@keyframes pomoPulseGreen {
    0%, 100% { box-shadow: 0 4px 16px rgba(39, 174, 96, 0.4); }
    50% { box-shadow: 0 4px 28px rgba(39, 174, 96, 0.7); }
}
.pomo-ring {
    position: absolute;
    top: 0; left: 0;
    width: 100%; height: 100%;
    transform: rotate(-90deg);
}
.pomo-ring-bg {
    fill: none;
    stroke: rgba(255, 255, 255, 0.2);
    stroke-width: 4;
}
.pomo-ring-fg {
    fill: none;
    stroke: rgba(255, 255, 255, 0.9);
    stroke-width: 4;
    stroke-linecap: round;
    stroke-dasharray: 175.93; /* 2π·28 */
    stroke-dashoffset: 175.93;
    transition: stroke-dashoffset 0.5s linear;
}
.pomo-float-icon {
    font-size: 22px;
    line-height: 1;
    margin-bottom: 2px;
}
.pomo-float-time {
    font-size: 12px;
    font-weight: 700;
    font-family: "Courier New", monospace;
    line-height: 1;
    text-shadow: 0 1px 2px rgba(0,0,0,0.3);
}

/* 弹窗面板 */
.pomo-panel {
    position: absolute;
    bottom: 84px;
    right: 0;
    width: 380px;
    max-height: 80vh;
    overflow-y: auto;
    background: #fff;
    border-radius: 12px;
    box-shadow: 0 8px 32px rgba(0,0,0,0.18);
    padding: 18px;
    border: 1px solid #f0e0e0;
    animation: pomoPanelSlideIn 0.3s ease-out;
}
.pomo-panel[hidden] { display: none; }
@keyframes pomoPanelSlideIn {
    from { opacity: 0; transform: translateY(-10px); }
    to   { opacity: 1; transform: translateY(0); }
}
.pomo-panel-head {
    display: flex;
    align-items: center;
    justify-content: space-between;
    margin-bottom: 14px;
    padding-bottom: 10px;
    border-bottom: 1px solid #f0e0e0;
}
.pomo-panel-title {
    font-size: 16px;
    font-weight: 700;
    color: #c0392b;
}
.pomo-close {
    background: #ecf0f1;
    border: none;
    width: 26px; height: 26px;
    border-radius: 50%;
    cursor: pointer;
    color: #4a5568;
    font-size: 12px;
}
.pomo-close:hover { background: #c0392b; color: #fff; }
.pomo-section {
    margin-bottom: 14px;
}
.pomo-section-label {
    font-size: 12px;
    font-weight: 700;
    color: #4a5568;
    margin-bottom: 8px;
    padding-left: 6px;
    border-left: 3px solid #e74c3c;
}
.pomo-presets {
    display: flex;
    flex-wrap: wrap;
    gap: 6px;
}
.pomo-preset {
    background: #fff5f3;
    border: 1px solid #fadbd8;
    border-radius: 6px;
    padding: 6px 10px;
    font-size: 12px;
    cursor: pointer;
    color: #c0392b;
    font-weight: 600;
    transition: all 0.2s;
}
.pomo-preset:hover { background: #fadbd8; transform: translateY(-1px); }
.pomo-preset.active {
    background: #e74c3c;
    color: #fff;
    border-color: #c0392b;
}
.pomo-preset .preset-icon { font-size: 14px; margin-right: 4px; }

/* 大圆环 */
.pomo-circle-wrap {
    position: relative;
    width: 200px;
    height: 200px;
    margin: 8px auto 14px;
}
.pomo-big-ring {
    width: 100%;
    height: 100%;
    transform: rotate(-90deg);
}
.pomo-big-ring-bg {
    fill: none;
    stroke: #f0e0e0;
    stroke-width: 8;
}
.pomo-big-ring-fg {
    fill: none;
    stroke: #e74c3c;
    stroke-width: 8;
    stroke-linecap: round;
    stroke-dasharray: 565.48; /* 2π·90 */
    stroke-dashoffset: 565.48;
    transition: stroke-dashoffset 0.8s linear, stroke 0.3s;
}
.pomo-circle-wrap.break .pomo-big-ring-fg { stroke: #27ae60; }
.pomo-time-display {
    position: absolute;
    top: 50%; left: 50%;
    transform: translate(-50%, -50%);
    font-size: 42px;
    font-weight: 800;
    font-family: "Courier New", monospace;
    color: #2c3e50;
    letter-spacing: 2px;
}
.pomo-state-display {
    position: absolute;
    bottom: 30px;
    left: 50%;
    transform: translateX(-50%);
    font-size: 13px;
    color: #7f8c8d;
    font-weight: 600;
}

/* 控制按钮 */
.pomo-controls {
    display: grid;
    grid-template-columns: 1fr 1fr 1fr;
    gap: 6px;
    margin-bottom: 14px;
}
.pomo-btn {
    border: none;
    padding: 8px 10px;
    border-radius: 6px;
    font-size: 13px;
    font-weight: 600;
    cursor: pointer;
    transition: all 0.2s;
    background: #ecf0f1;
    color: #4a5568;
}
.pomo-btn:hover { background: #d6e4f0; transform: translateY(-1px); }
.pomo-btn-primary {
    background: #e74c3c;
    color: #fff;
    grid-column: span 2;
    padding: 10px;
    font-size: 14px;
}
.pomo-btn-primary:hover { background: #c0392b; }
.pomo-btn-secondary { background: #95a5a6; color: #fff; }
.pomo-btn-secondary:hover { background: #7f8c8d; }
.pomo-btn-tertiary { background: #bdc3c7; color: #fff; }
.pomo-btn-tertiary:hover { background: #95a5a6; }

/* 统计 */
.pomo-stats {
    display: grid;
    grid-template-columns: 1fr 1fr 1fr;
    gap: 8px;
    margin-bottom: 14px;
    padding: 10px;
    background: #fff5f3;
    border-radius: 8px;
}
.pomo-stat-item {
    text-align: center;
}
.pomo-stat-num {
    font-size: 20px;
    font-weight: 800;
    color: #c0392b;
}
.pomo-stat-label {
    font-size: 11px;
    color: #7f8c8d;
    margin-top: 2px;
}

/* 自定义时长 */
.pomo-custom-row {
    display: flex;
    gap: 8px;
    align-items: center;
    flex-wrap: wrap;
    font-size: 12px;
}
.pomo-custom-row label {
    display: flex;
    align-items: center;
    gap: 4px;
    color: #4a5568;
}
.pomo-custom-row input {
    width: 56px;
    padding: 4px 6px;
    border: 1px solid #cdd9e5;
    border-radius: 4px;
    text-align: center;
}
.pomo-btn-mini {
    padding: 4px 12px;
    background: #e74c3c;
    color: #fff;
    border: none;
    border-radius: 4px;
    font-size: 11px;
    font-weight: 600;
    cursor: pointer;
}
.pomo-btn-mini:hover { background: #c0392b; }

/* 设置 */
.pomo-settings {
    background: #f8f9fa;
    padding: 10px;
    border-radius: 6px;
}
.pomo-toggle {
    display: flex;
    align-items: center;
    justify-content: space-between;
    font-size: 12px;
    color: #4a5568;
    padding: 4px 0;
    gap: 8px;
}
.pomo-toggle span { flex: 1; }
.pomo-toggle input[type=range] { flex: 1; max-width: 100px; }
.pomo-toggle select {
    padding: 3px 6px;
    border: 1px solid #cdd9e5;
    border-radius: 3px;
    font-size: 12px;
    background: #fff;
}

/* 历史 */
.pomo-history {
    max-height: 120px;
    overflow-y: auto;
    background: #fafafa;
    padding: 8px;
    border-radius: 6px;
    font-size: 12px;
}
.pomo-history-item {
    display: flex;
    justify-content: space-between;
    padding: 4px 6px;
    border-bottom: 1px dashed #ecf0f1;
    color: #4a5568;
}
.pomo-history-item:last-child { border-bottom: none; }
.pomo-history-empty { color: #95a5a6; font-style: italic; padding: 6px; text-align: center; }

.pomo-footer {
    margin-top: 12px;
    padding-top: 10px;
    border-top: 1px dashed #f0e0e0;
    color: #7f8c8d;
    font-size: 11px;
    text-align: center;
}

/* 完成时屏幕闪一下 */
@keyframes pomoFlash {
    0%, 100% { background: rgba(255, 255, 255, 0); }
    50% { background: rgba(231, 76, 60, 0.1); }
}
.pomo-flash { animation: pomoFlash 0.4s ease 3; }

@media (max-width: 480px) {
    .pomo-float { top: 12px; right: 16px; }
    .pomo-float-btn { width: 60px; height: 60px; }
    .pomo-panel { width: 320px; right: -16px; }
}

/* ========== Responsive ========== */
@media (max-width: 768px) {
    .sidebar { width: 200px; }
    .main-content { margin-left: 200px; }
    .content-wrap { padding: 20px 18px 40px; }
    .chapter-card { padding: 20px 18px; }
    .top-banner { padding: 24px 18px; }
    .top-banner h1 { font-size: 20px; }
}
@media (max-width: 576px) {
    .sidebar { width: 170px; }
    .sidebar-nav a { font-size: 12px; padding: 5px 10px 5px 14px; }
    .main-content { margin-left: 170px; }
    .content-wrap { padding: 14px 12px 30px; }
    .chapter-card { padding: 16px 14px; }
    .chapter-card .ch-title { font-size: 16px; }
    .top-banner h1 { font-size: 17px; }
    .must-card table { font-size: 12px; }

/* ============================================================
   真题精练模块样式
   ============================================================ */

/* 侧边栏专题区 */
.sidebar-nav .nav-part-special {
    background: linear-gradient(135deg, #ff7675 0%, #e74c3c 100%);
    color: #fff !important;
    margin: 4px 8px;
    padding: 8px 12px;
    border-radius: 6px;
    letter-spacing: 1px;
    font-weight: 700;
    text-align: center;
}
.sidebar-nav .nav-special-item {
    background: rgba(231, 76, 60, 0.15) !important;
    color: #fff !important;
    border-left: 3px solid #e74c3c !important;
    font-weight: 600;
    margin: 2px 8px;
    border-radius: 0 6px 6px 0;
}
.sidebar-nav .nav-special-item:hover {
    background: rgba(231, 76, 60, 0.3) !important;
}
.sidebar-nav .nav-special-item.active {
    background: rgba(231, 76, 60, 0.4) !important;
    border-left-color: #fff !important;
}
.sidebar-nav .nav-special-item .ch-num {
    color: #e74c3c;
    font-size: 14px;
}

/* 真题模块顶部 */
.zhenti-header {
    background: linear-gradient(135deg, #1a3a5c 0%, #2c6faa 100%) !important;
    color: #fff !important;
    border-radius: 8px;
    padding: 16px 20px !important;
    margin-bottom: 16px;
}
.zhenti-header .ch-title { color: #fff !important; }
.zhenti-header .ch-score { color: #ffd700 !important; }
.zhenti-header .ch-stars { color: #ffd700 !important; }

/* 介绍区 */
.zhenti-intro {
    background: linear-gradient(135deg, #f5f7fa 0%, #e8eef5 100%);
    padding: 16px 20px;
    border-radius: 8px;
    border-left: 4px solid #2c6faa;
    margin-bottom: 16px;
}
.zhenti-intro ul {
    margin: 8px 0 8px 20px;
    line-height: 1.9;
}
.zhenti-intro ul li {
    margin-bottom: 4px;
}

/* 总览卡片 - 行式布局 */
.zhenti-overview {
    margin-bottom: 16px;
}
.zhenti-stat-row {
    display: flex;
    gap: 10px;
    margin-bottom: 10px;
}
.zhenti-stat-card {
    flex: 1;
    min-width: 0;
    background: #fff;
    border-radius: 8px;
    padding: 12px 8px;
    box-shadow: 0 2px 6px rgba(0,0,0,0.06);
    text-align: center;
    border-top: 3px solid var(--accent, #3498db);
    transition: transform 0.2s, box-shadow 0.2s;
}
.zhenti-stat-card:hover {
    transform: translateY(-2px);
    box-shadow: 0 4px 12px rgba(0,0,0,0.1);
}
.zhenti-stat-card .zs-icon {
    font-size: 20px;
    margin-bottom: 2px;
}
.zhenti-stat-card .zs-num {
    font-size: 20px;
    font-weight: 700;
    color: #1a3a5c;
    line-height: 1.2;
}
.zhenti-stat-card .zs-label {
    font-size: 11px;
    color: #6a8fbb;
    margin-top: 2px;
}

/* 板块分布条 */
.zhenti-part-row {
    display: flex;
    align-items: center;
    gap: 8px;
    background: #fff;
    padding: 8px 14px;
    border-radius: 8px;
    box-shadow: 0 2px 6px rgba(0,0,0,0.06);
}
.zrp-label {
    font-size: 12px;
    white-space: nowrap;
    min-width: 64px;
}
.zrp-label strong {
    font-size: 14px;
}
.zrp-bar {
    flex: 1;
    height: 8px;
    background: #f0f4f8;
    border-radius: 4px;
    overflow: hidden;
    min-width: 40px;
}
.zrp-fill {
    height: 100%;
    border-radius: 4px;
    transition: width 0.6s ease;
}

/* Tabs */
.zhenti-tabs {
    display: flex;
    gap: 4px;
    background: #fff;
    padding: 6px;
    border-radius: 8px;
    box-shadow: 0 2px 6px rgba(0,0,0,0.06);
    margin-bottom: 12px;
    overflow-x: auto;
}
.zhenti-tab {
    flex: 1;
    padding: 10px 14px;
    background: transparent;
    border: none;
    border-radius: 6px;
    font-size: 14px;
    font-weight: 600;
    color: #6a8fbb;
    cursor: pointer;
    transition: all 0.2s;
    white-space: nowrap;
}
.zhenti-tab:hover {
    background: #f4f7fb;
    color: #1a3a5c;
}
.zhenti-tab.active {
    background: linear-gradient(135deg, #2c6faa 0%, #1a3a5c 100%);
    color: #fff;
    box-shadow: 0 2px 6px rgba(44, 111, 170, 0.3);
}

/* 筛选栏 */
.zhenti-filters {
    background: #fff;
    padding: 14px 16px;
    border-radius: 8px;
    box-shadow: 0 2px 6px rgba(0,0,0,0.06);
    margin-bottom: 12px;
}
.filter-row {
    display: flex;
    flex-wrap: wrap;
    gap: 16px;
    margin-bottom: 8px;
}
.filter-row:last-child { margin-bottom: 0; }
.filter-group {
    flex: 1;
    min-width: 280px;
}
.filter-group-search { flex-basis: 100%; }
.filter-label {
    display: block;
    font-size: 12px;
    font-weight: 600;
    color: #6a8fbb;
    margin-bottom: 6px;
}
.filter-pills {
    display: flex;
    flex-wrap: wrap;
    gap: 6px;
}
.filter-pill {
    padding: 6px 12px;
    background: #f4f7fb;
    border: 1px solid #e0e8f0;
    border-radius: 16px;
    font-size: 12px;
    color: #4a5568;
    cursor: pointer;
    transition: all 0.2s;
}
.filter-pill:hover {
    background: #e8eef5;
    border-color: #c8d6e5;
}
.filter-pill.active {
    background: linear-gradient(135deg, #2c6faa 0%, #1a3a5c 100%);
    color: #fff;
    border-color: #1a3a5c;
    font-weight: 600;
}
.filter-input {
    width: 100%;
    padding: 8px 12px;
    border: 1px solid #e0e8f0;
    border-radius: 6px;
    font-size: 13px;
    background: #fafbfc;
}
.filter-input:focus {
    outline: none;
    border-color: #2c6faa;
    box-shadow: 0 0 0 2px rgba(44, 111, 170, 0.1);
    background: #fff;
}

/* 内容区 */
.zhenti-content-area {
    background: transparent;
}
.zhenti-loading {
    text-align: center;
    padding: 60px 20px;
    color: #6a8fbb;
}
.zhenti-empty {
    text-align: center;
    padding: 60px 20px;
    background: #fff;
    border-radius: 8px;
    box-shadow: 0 2px 6px rgba(0,0,0,0.06);
}
.zhenti-empty .empty-icon {
    font-size: 48px;
    margin-bottom: 12px;
}
.zhenti-empty .empty-text {
    font-size: 16px;
    font-weight: 600;
    color: #1a3a5c;
    margin-bottom: 4px;
}
.zhenti-empty .empty-tip {
    font-size: 13px;
    color: #95a5a6;
}

/* 列表头部 */
.zhenti-list-header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: 10px 16px;
    background: #fff;
    border-radius: 8px;
    box-shadow: 0 2px 6px rgba(0,0,0,0.06);
    margin-bottom: 10px;
}
.zlh-info {
    font-size: 13px;
    color: #4a5568;
}
.zlh-info strong {
    color: #2c6faa;
    font-size: 16px;
}
.zlh-actions {
    display: flex;
    gap: 6px;
}

/* 按钮 */
.zbtn {
    padding: 6px 14px;
    background: #f4f7fb;
    border: 1px solid #e0e8f0;
    border-radius: 6px;
    font-size: 13px;
    color: #4a5568;
    cursor: pointer;
    transition: all 0.2s;
    font-family: inherit;
}
.zbtn:hover {
    background: #e8eef5;
    border-color: #c8d6e5;
}
.zbtn-primary {
    background: linear-gradient(135deg, #2c6faa 0%, #1a3a5c 100%);
    color: #fff;
    border-color: #1a3a5c;
    font-weight: 600;
}
.zbtn-primary:hover {
    background: linear-gradient(135deg, #1a3a5c 0%, #0f2540 100%);
}
.zbtn-ghost {
    background: transparent;
    border-color: transparent;
}
.zbtn-ghost:hover {
    background: #f4f7fb;
    border-color: #e0e8f0;
}
.zbtn:disabled {
    opacity: 0.6;
    cursor: not-allowed;
}

/* 题目卡片 */
.zhenti-question-list {
    display: flex;
    flex-direction: column;
    gap: 12px;
}
.zhenti-card {
    background: #fff;
    border-radius: 8px;
    box-shadow: 0 2px 6px rgba(0,0,0,0.06);
    overflow: hidden;
    transition: box-shadow 0.2s;
}
.zhenti-card:hover {
    box-shadow: 0 4px 12px rgba(0,0,0,0.1);
}
.zc-head {
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: 10px 14px;
    background: linear-gradient(90deg, #f5f7fa 0%, #ffffff 100%);
    border-bottom: 1px solid #e8eef5;
    cursor: pointer;
    user-select: none;
}
.zc-head-left {
    display: flex;
    align-items: center;
    gap: 6px;
    flex-wrap: wrap;
}
.zc-head-right {
    display: flex;
    align-items: center;
    gap: 8px;
}
.zc-year {
    padding: 2px 8px;
    background: #1a3a5c;
    color: #fff;
    border-radius: 4px;
    font-size: 12px;
    font-weight: 700;
}
.zc-num {
    padding: 2px 8px;
    background: #2c6faa;
    color: #fff;
    border-radius: 4px;
    font-size: 11px;
    font-weight: 600;
}
.zc-part {
    padding: 2px 8px;
    border-radius: 4px;
    font-size: 11px;
    font-weight: 600;
}
.zc-part-高数 { background: #d4edda; color: #155724; }
.zc-part-线代 { background: #fff3cd; color: #856404; }
.zc-part-概率 { background: #f8d7da; color: #721c24; }
.zc-type {
    padding: 2px 8px;
    background: #e8eef5;
    color: #4a5568;
    border-radius: 4px;
    font-size: 11px;
}
.zc-score {
    font-size: 11px;
    color: #6a8fbb;
    font-weight: 600;
}
.zc-difficulty {
    color: #f39c12;
    font-size: 12px;
    letter-spacing: 1px;
}
.zc-mastery {
    padding: 3px 10px;
    color: #fff;
    border-radius: 12px;
    font-size: 11px;
    font-weight: 600;
}
.zc-mastery.none {
    background: #95a5a6;
}
.zc-toggle {
    color: #6a8fbb;
    font-size: 14px;
    transition: transform 0.2s;
}
.zhenti-card.collapsed .zc-body {
    display: none;
}

.zc-body {
    padding: 14px 16px;
}
.zc-question {
    margin-bottom: 12px;
}
.zq-label {
    font-size: 12px;
    font-weight: 700;
    color: #1a3a5c;
    margin-bottom: 6px;
}
.zq-text {
    line-height: 1.8;
    color: #2c3e50;
    font-size: 14px;
}
.q-options {
    margin-top: 10px;
    display: flex;
    flex-direction: column;
    gap: 4px;
}
.q-option {
    padding: 6px 10px;
    background: #f8fafc;
    border: 1px solid #e0e8f0;
    border-radius: 4px;
    font-size: 13px;
    color: #4a5568;
}

.zc-meta {
    margin: 12px 0;
    padding: 10px 12px;
    background: #f8fafc;
    border-radius: 6px;
    border-left: 3px solid #2c6faa;
}
.q-tpoints, .q-kpoints {
    margin-bottom: 6px;
    line-height: 1.8;
}
.q-tpoints:last-child, .q-kpoints:last-child { margin-bottom: 0; }
.qt-label, .qk-label, .qe-label {
    font-size: 12px;
    font-weight: 700;
    color: #1a3a5c;
    margin-right: 4px;
}
.qt-chip {
    display: inline-block;
    padding: 2px 8px;
    background: #e8eef5;
    color: #2c6faa;
    border-radius: 12px;
    font-size: 11px;
    margin: 2px 4px 2px 0;
}
.qk-chip {
    display: inline-block;
    padding: 2px 10px;
    background: #d4edda;
    color: #155724;
    border-radius: 12px;
    font-size: 11px;
    margin: 2px 4px 2px 0;
    cursor: pointer;
    transition: all 0.2s;
    text-decoration: none;
}
.qk-chip:hover {
    background: #c3e6cb;
    transform: translateY(-1px);
    box-shadow: 0 2px 4px rgba(0,0,0,0.1);
}

.zc-actions {
    display: flex;
    gap: 8px;
    margin: 12px 0;
    flex-wrap: wrap;
}

.zc-solution {
    margin-top: 12px;
    padding: 14px;
    background: linear-gradient(135deg, #fff9e6 0%, #fffbf0 100%);
    border-radius: 6px;
    border-left: 4px solid #f39c12;
}
.zs-head {
    font-size: 14px;
    font-weight: 700;
    color: #1a3a5c;
    margin-bottom: 10px;
}
.zs-steps {
    margin-left: 20px;
    line-height: 1.8;
    font-size: 13px;
}
.zs-step {
    margin-bottom: 12px;
    padding-left: 4px;
}
.zs-step-title {
    font-weight: 700;
    color: #1a3a5c;
    margin-bottom: 4px;
}
.zs-step-content {
    color: #4a5568;
}
.zs-formula {
    margin: 6px 0;
    padding: 6px 10px;
    background: #fff;
    border-radius: 4px;
    border-left: 3px solid #2c6faa;
}
.zs-answer {
    margin-top: 14px;
    padding: 10px 12px;
    background: linear-gradient(90deg, #d4edda 0%, #c3e6cb 100%);
    border-radius: 6px;
    border: 1px solid #28a745;
}
.zsa-label {
    font-weight: 700;
    color: #155724;
    margin-right: 4px;
}
.zsa-value {
    color: #155724;
    font-weight: 600;
    font-size: 15px;
}
.q-errors {
    margin-top: 10px;
    padding: 10px;
    background: #fff5f5;
    border-radius: 4px;
    border-left: 3px solid #e74c3c;
}
.qe-label {
    color: #e74c3c;
}
.q-errors ul {
    margin: 6px 0 0 20px;
    font-size: 12px;
    color: #721c24;
    line-height: 1.7;
}

/* 掌握度面板 */
.zc-mastery-panel {
    margin-top: 12px;
    padding: 14px;
    background: #f0f4f8;
    border-radius: 6px;
    border: 1px solid #d0dae5;
}
.zmp-inner {
    display: flex;
    flex-direction: column;
    gap: 8px;
}
.zmp-row {
    display: flex;
    align-items: center;
    gap: 10px;
}
.zmp-row label {
    width: 60px;
    font-size: 12px;
    font-weight: 600;
    color: #4a5568;
}
.zmp-row input[type=range] {
    flex: 1;
    max-width: 240px;
}
.zmp-row input[type=date], .zmp-row input[type=text] {
    flex: 1;
    padding: 6px 8px;
    border: 1px solid #c8d6e5;
    border-radius: 4px;
    font-size: 12px;
    font-family: inherit;
}
.zmp-value {
    width: 50px;
    text-align: right;
    font-weight: 700;
    color: #1a3a5c;
}
.zmp-actions {
    display: flex;
    gap: 8px;
    margin-top: 4px;
}
.zmp-history {
    margin-top: 8px;
    padding-top: 8px;
    border-top: 1px dashed #c8d6e5;
}
.zmp-history-title {
    font-size: 12px;
    font-weight: 700;
    color: #1a3a5c;
    margin-bottom: 6px;
}
.zmp-history-list {
    list-style: none;
    padding: 0;
    margin: 0;
    max-height: 200px;
    overflow-y: auto;
}
.zmp-history-item {
    display: flex;
    align-items: center;
    gap: 8px;
    padding: 5px 8px;
    background: #fff;
    border-radius: 4px;
    margin-bottom: 4px;
    font-size: 12px;
}
.zh-date {
    width: 70px;
    color: #4a5568;
    font-family: monospace;
}
.zh-bar {
    flex: 1;
    height: 6px;
    background: #e0e8f0;
    border-radius: 3px;
    overflow: hidden;
}
.zh-bar-fill {
    height: 100%;
    transition: width 0.3s;
}
.zh-pct {
    width: 40px;
    text-align: right;
    font-weight: 700;
}
.zh-note {
    color: #6a8fbb;
    font-style: italic;
    max-width: 200px;
    overflow: hidden;
    text-overflow: ellipsis;
    white-space: nowrap;
}
.zh-delete {
    padding: 2px 6px;
    background: transparent;
    border: none;
    color: #95a5a6;
    cursor: pointer;
    font-size: 11px;
}
.zh-delete:hover {
    color: #e74c3c;
}
.zmp-empty {
    color: #95a5a6;
    font-size: 12px;
    text-align: center;
    padding: 10px;
}

/* 考点分类 */
.zhenti-kp-overview {
    margin-bottom: 16px;
}
.zkp-card {
    background: linear-gradient(135deg, #fff9e6 0%, #fffbf0 100%);
    padding: 14px 16px;
    border-radius: 8px;
    border-left: 4px solid #f39c12;
}
.zkp-title {
    font-size: 16px;
    font-weight: 700;
    color: #1a3a5c;
    margin-bottom: 4px;
}
.zkp-desc {
    font-size: 13px;
    color: #4a5568;
}
.zhenti-kp-grid {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 16px;
}
@media (max-width: 900px) {
    .zhenti-kp-grid { grid-template-columns: 1fr; }
}
.zkp-section {
    background: #fff;
    border-radius: 8px;
    padding: 14px;
    box-shadow: 0 2px 6px rgba(0,0,0,0.06);
}
.zkp-section-title {
    font-size: 14px;
    font-weight: 700;
    color: #1a3a5c;
    padding-bottom: 8px;
    margin-bottom: 10px;
    border-bottom: 1px solid #e8eef5;
}
.zkp-item {
    display: flex;
    align-items: center;
    gap: 8px;
    padding: 8px 10px;
    background: #f8fafc;
    border-radius: 4px;
    margin-bottom: 6px;
    cursor: pointer;
    transition: all 0.2s;
}
.zkp-item:hover {
    background: #e8eef5;
    transform: translateX(2px);
}
.zkp-name {
    flex: 1;
    font-size: 13px;
    color: #2c3e50;
}
.zkp-count {
    padding: 2px 8px;
    background: #2c6faa;
    color: #fff;
    border-radius: 10px;
    font-size: 11px;
    font-weight: 600;
}
.zkp-arrow {
    color: #6a8fbb;
    font-size: 14px;
}
.zkp-chapter-group {
    margin-bottom: 14px;
}
.zkp-chapter-label {
    font-size: 12px;
    font-weight: 700;
    color: #6a8fbb;
    margin: 8px 0 6px;
    padding-left: 4px;
}
.kkp-item {
    background: #f0fff4;
}
.kkp-item:hover { background: #d4edda; }
.zkp-more {
    text-align: center;
    color: #6a8fbb;
    font-size: 12px;
    padding: 8px;
}

/* 错题本 */
.zhenti-wrongbook {
    display: flex;
    flex-direction: column;
    gap: 16px;
}
.zwb-header {
    background: linear-gradient(135deg, #fff5f5 0%, #ffe6e6 100%);
    padding: 14px 16px;
    border-radius: 8px;
    border-left: 4px solid #e74c3c;
}
.zwb-title {
    font-size: 16px;
    font-weight: 700;
    color: #1a3a5c;
    margin-bottom: 4px;
}
.zwb-desc {
    font-size: 13px;
    color: #4a5568;
}
.zwb-stats {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: 10px;
}
.zwb-section {
    background: #fff;
    border-radius: 8px;
    padding: 14px;
    box-shadow: 0 2px 6px rgba(0,0,0,0.06);
}
.zwb-section-title {
    font-size: 15px;
    font-weight: 700;
    color: #1a3a5c;
    margin-bottom: 10px;
    padding-bottom: 8px;
    border-bottom: 1px solid #e8eef5;
}
.zwb-hint {
    font-size: 12px;
    color: #f39c12;
    margin-bottom: 10px;
    padding: 8px 12px;
    background: #fff9e6;
    border-radius: 4px;
}
.zwb-empty {
    text-align: center;
    padding: 40px 20px;
    background: #fff;
    border-radius: 8px;
    box-shadow: 0 2px 6px rgba(0,0,0,0.06);
}

/* 模考模式弹窗 */
.zhenti-modal {
    position: fixed;
    inset: 0;
    background: rgba(0,0,0,0.6);
    z-index: 9999;
    display: flex;
    justify-content: center;
    align-items: flex-start;
    padding: 40px 20px;
    overflow-y: auto;
}
.zhenti-modal[hidden] { display: none; }
.zhenti-modal-content {
    background: #fff;
    border-radius: 12px;
    width: 100%;
    max-width: 720px;
    box-shadow: 0 20px 50px rgba(0,0,0,0.3);
    overflow: hidden;
    animation: zhentiModalIn 0.25s ease-out;
}
.zhenti-modal-large {
    max-width: 900px;
}
.zhenti-modal-medium {
    max-width: 700px;
}
@keyframes zhentiModalIn {
    from { opacity: 0; transform: translateY(-20px); }
    to   { opacity: 1; transform: translateY(0); }
}
.zhenti-modal-header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: 14px 20px;
    background: linear-gradient(135deg, #1a3a5c 0%, #2c6faa 100%);
    color: #fff;
}
.zhenti-modal-title {
    font-size: 16px;
    font-weight: 700;
}
.zhenti-modal-close {
    padding: 4px 10px;
    background: transparent;
    border: 1px solid rgba(255,255,255,0.3);
    border-radius: 4px;
    color: #fff;
    cursor: pointer;
    font-size: 14px;
}
.zhenti-modal-close:hover {
    background: rgba(255,255,255,0.2);
}
.zhenti-modal-body {
    padding: 20px;
    max-height: calc(100vh - 200px);
    overflow-y: auto;
}

/* 模考设置 */
.mock-setup {
    padding: 20px;
}
.mock-desc {
    font-size: 14px;
    color: #4a5568;
    margin-bottom: 16px;
    padding: 12px;
    background: #f0f4f8;
    border-radius: 6px;
    border-left: 3px solid #2c6faa;
}
.mock-desc strong {
    color: #1a3a5c;
}
.mock-config-row {
    display: flex;
    align-items: center;
    gap: 12px;
    margin-bottom: 12px;
}
.mock-config-row label {
    width: 100px;
    font-size: 13px;
    font-weight: 600;
    color: #4a5568;
}
.mock-config-row select {
    flex: 1;
    padding: 8px 10px;
    border: 1px solid #c8d6e5;
    border-radius: 4px;
    font-size: 13px;
    background: #fff;
}
.mock-start-btn {
    width: 100%;
    padding: 12px;
    background: linear-gradient(135deg, #27ae60 0%, #1e8449 100%);
    color: #fff;
    border: none;
    border-radius: 6px;
    font-size: 15px;
    font-weight: 700;
    cursor: pointer;
    margin-top: 16px;
    transition: all 0.2s;
}
.mock-start-btn:hover {
    transform: translateY(-2px);
    box-shadow: 0 4px 12px rgba(39, 174, 96, 0.3);
}
.mock-tip {
    margin-top: 14px;
    padding: 10px;
    background: #fff9e6;
    border-radius: 4px;
    font-size: 12px;
    color: #856404;
}

/* 模考进行中 */
.mock-running {
    padding: 0;
}
.mock-running-head {
    display: flex;
    align-items: center;
    gap: 16px;
    padding: 12px 20px;
    background: #f8fafc;
    border-bottom: 1px solid #e0e8f0;
}
.mock-progress-info {
    font-size: 14px;
    font-weight: 700;
    color: #1a3a5c;
}
.mock-timer {
    margin-left: auto;
    font-size: 22px;
    font-weight: 700;
    color: #1a3a5c;
    font-family: monospace;
    padding: 4px 12px;
    background: #fff;
    border-radius: 4px;
    border: 1px solid #e0e8f0;
}
.mock-timer.urgent {
    color: #fff;
    background: #e74c3c;
    border-color: #e74c3c;
    animation: mockTimerPulse 1s infinite;
}
@keyframes mockTimerPulse {
    0%, 100% { opacity: 1; }
    50% { opacity: 0.7; }
}
.mock-submit-btn {
    padding: 6px 14px;
    background: #e74c3c;
    color: #fff;
    border: none;
    border-radius: 4px;
    font-size: 13px;
    font-weight: 600;
    cursor: pointer;
}
.mock-submit-btn:hover {
    background: #c0392b;
}

.mock-question-area {
    padding: 20px;
    min-height: 200px;
}
.mock-q-card {
    background: #f8fafc;
    padding: 16px;
    border-radius: 6px;
    border-left: 4px solid #2c6faa;
}
.mq-head {
    display: flex;
    justify-content: space-between;
    align-items: center;
    margin-bottom: 12px;
    flex-wrap: wrap;
    gap: 6px;
}
.mq-num {
    font-size: 14px;
    font-weight: 700;
    color: #1a3a5c;
}
.mq-meta {
    font-size: 11px;
    color: #6a8fbb;
}
.mq-question {
    line-height: 1.8;
    color: #2c3e50;
    font-size: 14px;
    margin-bottom: 12px;
}
.mock-options {
    display: flex;
    flex-direction: column;
    gap: 8px;
}
.mock-option {
    display: flex;
    align-items: center;
    gap: 8px;
    padding: 8px 12px;
    background: #fff;
    border: 2px solid #e0e8f0;
    border-radius: 6px;
    cursor: pointer;
    transition: all 0.2s;
    font-size: 13px;
}
.mock-option:hover {
    background: #f0f4f8;
    border-color: #c8d6e5;
}
.mock-option.checked {
    background: #d4edda;
    border-color: #28a745;
}
.mock-textarea {
    margin-top: 12px;
}
.mock-textarea textarea {
    width: 100%;
    padding: 10px;
    border: 1px solid #c8d6e5;
    border-radius: 4px;
    font-size: 13px;
    font-family: inherit;
    resize: vertical;
}

.mock-nav {
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: 12px 20px;
    background: #f8fafc;
    border-top: 1px solid #e0e8f0;
}
.mock-nav-btn {
    padding: 8px 16px;
    background: #2c6faa;
    color: #fff;
    border: none;
    border-radius: 4px;
    font-size: 13px;
    cursor: pointer;
}
.mock-nav-btn:hover {
    background: #1a3a5c;
}
.mock-nav-btn:disabled {
    background: #c8d6e5;
    cursor: not-allowed;
}
.mock-question-dots {
    display: flex;
    gap: 6px;
}
.mock-dot {
    width: 28px;
    height: 28px;
    border-radius: 50%;
    background: #e0e8f0;
    color: #6a8fbb;
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 12px;
    font-weight: 600;
    cursor: pointer;
    transition: all 0.2s;
}
.mock-dot:hover { background: #c8d6e5; }
.mock-dot.active {
    background: #2c6faa;
    color: #fff;
}
.mock-dot.answered {
    background: #27ae60;
    color: #fff;
}

/* 模考结果 */
.mock-result {
    padding: 20px;
}
.mock-result-head {
    margin-bottom: 16px;
}
.mock-result-title {
    font-size: 18px;
    font-weight: 700;
    color: #1a3a5c;
    text-align: center;
}
.mock-result-stats {
    margin-bottom: 16px;
}
.mrs-grid {
    display: grid;
    grid-template-columns: repeat(4, 1fr);
    gap: 10px;
}
@media (max-width: 600px) {
    .mrs-grid { grid-template-columns: repeat(2, 1fr); }
}
.mock-result-detail {
    max-height: 400px;
    overflow-y: auto;
}
.mrd-title {
    font-size: 14px;
    font-weight: 700;
    color: #1a3a5c;
    margin-bottom: 10px;
    padding-bottom: 6px;
    border-bottom: 1px solid #e0e8f0;
}
.mrd-item {
    padding: 12px;
    background: #f8fafc;
    border-radius: 6px;
    margin-bottom: 8px;
    border-left: 4px solid #c8d6e5;
}
.mrd-item.correct { border-left-color: #27ae60; }
.mrd-item.wrong { border-left-color: #e74c3c; }
.mrd-item.skipped { border-left-color: #95a5a6; }
.mrd-head {
    display: flex;
    justify-content: space-between;
    margin-bottom: 6px;
}
.mrd-num {
    font-weight: 700;
    color: #1a3a5c;
}
.mrd-status {
    font-size: 12px;
    font-weight: 600;
}
.mrd-item.correct .mrd-status { color: #27ae60; }
.mrd-item.wrong .mrd-status { color: #e74c3c; }
.mrd-item.skipped .mrd-status { color: #95a5a6; }
.mrd-q-text {
    font-size: 13px;
    color: #4a5568;
    line-height: 1.7;
    margin-bottom: 6px;
}
.mrd-answer-row {
    font-size: 12px;
    margin-top: 4px;
}
.mrd-label {
    color: #6a8fbb;
    margin-right: 4px;
}
.mrd-user {
    color: #2c3e50;
    font-weight: 600;
}
.mrd-ans {
    color: #27ae60;
    font-weight: 600;
}
.mock-result-actions {
    display: flex;
    gap: 10px;
    margin-top: 16px;
    justify-content: center;
}
.mock-action-btn {
    padding: 10px 20px;
    background: #f4f7fb;
    border: 1px solid #c8d6e5;
    border-radius: 6px;
    font-size: 13px;
    cursor: pointer;
}
.mock-action-btn.primary {
    background: linear-gradient(135deg, #2c6faa 0%, #1a3a5c 100%);
    color: #fff;
    border-color: #1a3a5c;
}

/* 答案弹窗内容 */
.am-question {
    line-height: 1.8;
    color: #2c3e50;
    font-size: 14px;
    margin-bottom: 10px;
}
.am-options {
    display: flex;
    flex-direction: column;
    gap: 4px;
    margin-bottom: 10px;
}
.am-option {
    padding: 6px 10px;
    background: #f8fafc;
    border: 1px solid #e0e8f0;
    border-radius: 4px;
    font-size: 13px;
}
.am-divider {
    height: 1px;
    background: #e0e8f0;
    margin: 12px 0;
}
.am-answer-row {
    padding: 10px 12px;
    background: linear-gradient(90deg, #d4edda 0%, #c3e6cb 100%);
    border-radius: 6px;
    margin-bottom: 14px;
}
.am-label {
    color: #155724;
    font-weight: 700;
    margin-right: 4px;
}
.am-value {
    color: #155724;
    font-weight: 600;
}
.am-actions {
    display: flex;
    gap: 10px;
}

/* 统计页 */
.zhenti-stats {
    display: flex;
    flex-direction: column;
    gap: 16px;
}
.zst-section {
    background: #fff;
    border-radius: 8px;
    padding: 16px;
    box-shadow: 0 2px 6px rgba(0,0,0,0.06);
}
.zst-title {
    font-size: 15px;
    font-weight: 700;
    color: #1a3a5c;
    margin-bottom: 12px;
    padding-bottom: 8px;
    border-bottom: 1px solid #e8eef5;
}
.zst-grid {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(140px, 1fr));
    gap: 10px;
    margin-bottom: 14px;
}
.zst-progress {
    margin-top: 8px;
}
.zst-bar {
    height: 14px;
    background: #f4f7fb;
    border-radius: 4px;
    overflow: hidden;
    margin-bottom: 4px;
    display: flex;
}
.zst-bar-fill {
    height: 100%;
    transition: width 0.6s ease;
}
.zst-bar-fill.mastered { background: #27ae60; }
.zst-bar-fill.mid { background: #f39c12; }
.zst-bar-fill.weak { background: #e74c3c; }
.zst-legend {
    display: flex;
    gap: 16px;
    font-size: 12px;
    color: #4a5568;
    margin-top: 4px;
}
.zl-item {
    display: flex;
    align-items: center;
    gap: 4px;
}
.zl-dot {
    width: 10px;
    height: 10px;
    border-radius: 50%;
}
.zst-part-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(180px, 1fr));
    gap: 12px;
}
.zst-part-card {
    padding: 12px;
    background: #f8fafc;
    border-radius: 6px;
    border-left: 3px solid #2c6faa;
}
.zsp-name {
    font-size: 14px;
    font-weight: 700;
    color: #1a3a5c;
    margin-bottom: 6px;
}
.zsp-numbers {
    display: flex;
    flex-direction: column;
    gap: 2px;
    font-size: 12px;
    color: #4a5568;
    margin-bottom: 8px;
}
.zsp-numbers strong {
    font-size: 14px;
}
.zsp-progress {
    height: 8px;
    background: #e0e8f0;
    border-radius: 4px;
    overflow: hidden;
    margin-bottom: 4px;
}
.zsp-fill {
    height: 100%;
    background: linear-gradient(90deg, #2c6faa 0%, #1abc9c 100%);
    transition: width 0.6s ease;
}
.zsp-pct {
    font-size: 12px;
    color: #6a8fbb;
    text-align: right;
}

.zst-year-list {
    display: flex;
    flex-direction: column;
    gap: 6px;
}
.zsy-row {
    display: flex;
    align-items: center;
    gap: 10px;
}
.zsy-year {
    width: 60px;
    font-weight: 700;
    color: #1a3a5c;
}
.zsy-bar {
    flex: 1;
    height: 10px;
    background: #f4f7fb;
    border-radius: 5px;
    overflow: hidden;
}
.zsy-fill {
    height: 100%;
    background: linear-gradient(90deg, #2c6faa 0%, #1abc9c 100%);
    transition: width 0.6s ease;
}
.zsy-info {
    width: 60px;
    text-align: center;
    font-size: 12px;
    color: #4a5568;
}
.zsy-pct {
    width: 50px;
    text-align: right;
    font-size: 12px;
    font-weight: 700;
    color: #2c6faa;
}

.zst-weak-list {
    display: flex;
    flex-direction: column;
    gap: 6px;
}
.zwk-item {
    display: flex;
    align-items: center;
    gap: 10px;
    padding: 8px 10px;
    background: #fff5f5;
    border-radius: 4px;
    cursor: pointer;
    transition: all 0.2s;
}
.zwk-item:hover {
    background: #ffe6e6;
    transform: translateX(2px);
}
.zwk-name {
    flex: 1;
    font-size: 13px;
    color: #2c3e50;
}
.zwk-count {
    font-size: 11px;
    color: #6a8fbb;
}
.zwk-bar {
    width: 100px;
    height: 8px;
    background: #f4f7fb;
    border-radius: 4px;
    overflow: hidden;
}
.zwk-fill {
    height: 100%;
    transition: width 0.6s ease;
}
.zwk-pct {
    width: 40px;
    text-align: right;
    font-size: 12px;
    font-weight: 700;
}
.zwk-hint {
    margin-top: 10px;
    font-size: 12px;
    color: #6a8fbb;
    text-align: center;
}

/* Toast */
.zhenti-toast {
    position: fixed;
    top: 100px;
    left: 50%;
    transform: translateX(-50%) translateY(-20px);
    padding: 10px 20px;
    background: #27ae60;
    color: #fff;
    border-radius: 6px;
    font-size: 14px;
    z-index: 99999;
    box-shadow: 0 4px 12px rgba(0,0,0,0.2);
    opacity: 0;
    transition: all 0.3s;
    pointer-events: none;
}
.zhenti-toast.show {
    opacity: 1;
    transform: translateX(-50%) translateY(0);
}
.zhenti-toast.error {
    background: #e74c3c;
}

/* 响应式 */
@media (max-width: 768px) {
    .zhenti-stat-row { flex-wrap: wrap; }
    .zhenti-stat-card { flex-basis: calc(50% - 5px); min-width: calc(50% - 5px); }
    .zhenti-part-row { flex-wrap: wrap; }
    .zhenti-part-row .zrp-label { min-width: 48px; font-size: 11px; }
    .zst-grid { grid-template-columns: repeat(2, 1fr); }
    .filter-group { min-width: 100%; }
    .mock-running-head { flex-wrap: wrap; }
    .mock-question-dots { order: 3; flex-basis: 100%; justify-content: center; }
    .zst-year-list .zsy-row { flex-wrap: wrap; }
    .zwk-item { flex-wrap: wrap; }
}
}