/* ===== 基础变量与重置 ===== */
:root {
    --primary: #2563eb;
    --primary-dark: #1d4ed8;
    --primary-light: #dbeafe;
    --success: #16a34a;
    --success-light: #dcfce7;
    --warning: #d97706;
    --warning-light: #fef3c7;
    --danger: #dc2626;
    --danger-light: #fee2e2;
    --gray-50: #f8fafc;
    --gray-100: #f1f5f9;
    --gray-200: #e2e8f0;
    --gray-300: #cbd5e1;
    --gray-400: #94a3b8;
    --gray-500: #64748b;
    --gray-600: #475569;
    --gray-700: #334155;
    --gray-800: #1e293b;
    --gray-900: #0f172a;
    --radius: 8px;
    --shadow-sm: 0 1px 2px 0 rgb(0 0 0 / 0.05);
    --shadow: 0 1px 3px 0 rgb(0 0 0 / 0.1), 0 1px 2px -1px rgb(0 0 0 / 0.1);
    --shadow-md: 0 4px 6px -1px rgb(0 0 0 / 0.1), 0 2px 4px -2px rgb(0 0 0 / 0.1);
    --shadow-lg: 0 10px 15px -3px rgb(0 0 0 / 0.1), 0 4px 6px -4px rgb(0 0 0 / 0.1);
    --header-height: 60px;
    --sidebar-width: 280px;
    --transition: all 0.2s ease;
}

* { margin: 0; padding: 0; box-sizing: border-box; }

html { font-size: 16px; }

body {
    font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, "Helvetica Neue", Arial, "Noto Sans SC", sans-serif;
    color: var(--gray-800);
    background: var(--gray-50);
    line-height: 1.6;
    -webkit-font-smoothing: antialiased;
}

.hidden { display: none !important; }

/* ===== 按钮系统 ===== */
.btn-primary, .btn-secondary, .btn-danger, .btn-text {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    gap: 6px;
    padding: 10px 20px;
    border-radius: var(--radius);
    font-size: 14px;
    font-weight: 500;
    cursor: pointer;
    border: none;
    transition: var(--transition);
    white-space: nowrap;
}

.btn-primary {
    background: var(--primary);
    color: white;
}
.btn-primary:hover { background: var(--primary-dark); }

.btn-secondary {
    background: white;
    color: var(--gray-700);
    border: 1px solid var(--gray-300);
}
.btn-secondary:hover { background: var(--gray-50); border-color: var(--gray-400); }

.btn-danger {
    background: var(--danger);
    color: white;
}
.btn-danger:hover { background: #b91c1c; }

.btn-text {
    background: transparent;
    color: var(--gray-500);
    padding: 6px 12px;
}
.btn-text:hover { color: var(--gray-700); }

.btn-sm { padding: 6px 14px; font-size: 13px; }

/* ===== 表单 ===== */
.form-group { margin-bottom: 16px; }
.form-group label {
    display: block;
    margin-bottom: 6px;
    font-size: 14px;
    font-weight: 500;
    color: var(--gray-700);
}
.form-group input,
.form-group textarea,
.form-group select {
    width: 100%;
    padding: 10px 14px;
    border: 1px solid var(--gray-300);
    border-radius: var(--radius);
    font-size: 14px;
    transition: var(--transition);
    font-family: inherit;
}
.form-group input:focus,
.form-group textarea:focus,
.form-group select:focus {
    outline: none;
    border-color: var(--primary);
    box-shadow: 0 0 0 3px var(--primary-light);
}

/* ===== 页面框架 ===== */
.page {
    min-height: 100vh;
}

/* ===== 登录页 ===== */
#auth-page {
    display: flex;
    align-items: center;
    justify-content: center;
    background: linear-gradient(135deg, #1e3a5f 0%, #2563eb 100%);
    padding: 40px 20px;
}

.auth-container {
    display: grid;
    grid-template-columns: 1fr 1fr;
    max-width: 960px;
    width: 100%;
    background: white;
    border-radius: 16px;
    overflow: hidden;
    box-shadow: var(--shadow-lg);
}

.auth-brand {
    background: linear-gradient(135deg, #1e3a5f 0%, #2563eb 100%);
    color: white;
    padding: 60px 48px;
    display: flex;
    flex-direction: column;
    justify-content: center;
}
.auth-brand h1 {
    font-size: 32px;
    font-weight: 700;
    margin-bottom: 12px;
}
.auth-brand p {
    font-size: 16px;
    opacity: 0.9;
    margin-bottom: 24px;
}
.auth-brand-badge {
    display: inline-block;
    background: rgba(255,255,255,0.15);
    backdrop-filter: blur(4px);
    padding: 8px 16px;
    border-radius: 20px;
    font-size: 13px;
    font-weight: 500;
    width: fit-content;
}

.auth-form-wrapper {
    padding: 60px 48px;
    display: flex;
    flex-direction: column;
    justify-content: center;
}
.auth-form-wrapper h2 {
    font-size: 24px;
    margin-bottom: 24px;
    color: var(--gray-800);
}

@media (max-width: 768px) {
    .auth-container { grid-template-columns: 1fr; }
    .auth-brand { padding: 40px 24px; }
    .auth-form-wrapper { padding: 40px 24px; }
}

/* ===== 顶部导航 ===== */
.app-header {
    position: fixed;
    top: 0; left: 0; right: 0;
    height: var(--header-height);
    background: white;
    border-bottom: 1px solid var(--gray-200);
    display: flex;
    align-items: center;
    justify-content: space-between;
    padding: 0 32px;
    z-index: 100;
    box-shadow: var(--shadow-sm);
}

.header-brand {
    display: flex;
    align-items: center;
    gap: 10px;
    font-weight: 600;
    font-size: 16px;
    color: var(--gray-800);
}
.logo-icon { font-size: 20px; }

.header-nav {
    display: flex;
    gap: 8px;
}
.nav-link {
    padding: 8px 16px;
    border-radius: var(--radius);
    font-size: 14px;
    font-weight: 500;
    color: var(--gray-500);
    text-decoration: none;
    transition: var(--transition);
}
.nav-link:hover { color: var(--gray-700); background: var(--gray-100); }
.nav-link.active { color: var(--primary); background: var(--primary-light); }

.header-user {
    display: flex;
    align-items: center;
    gap: 12px;
    font-size: 14px;
    color: var(--gray-600);
}

/* ===== 主内容区 ===== */
.app-main {
    margin-top: var(--header-height);
    min-height: calc(100vh - var(--header-height));
    padding: 32px;
    max-width: 1280px;
    margin-left: auto;
    margin-right: auto;
}

.page-header {
    margin-bottom: 28px;
}
.page-header h2 {
    font-size: 24px;
    font-weight: 600;
    color: var(--gray-800);
    margin-bottom: 6px;
}
.page-header p {
    color: var(--gray-500);
    font-size: 14px;
}

/* ===== 项目总览页 ===== */
.progress-summary {
    display: grid;
    grid-template-columns: repeat(4, 1fr);
    gap: 16px;
    margin-bottom: 32px;
}
.progress-card {
    background: white;
    border-radius: var(--radius);
    padding: 24px;
    text-align: center;
    box-shadow: var(--shadow);
    border: 1px solid var(--gray-200);
}
.progress-value {
    font-size: 32px;
    font-weight: 700;
    color: var(--primary);
    margin-bottom: 4px;
}
.progress-label {
    font-size: 13px;
    color: var(--gray-500);
}

.projects-grid {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: 20px;
}

.project-card {
    background: white;
    border-radius: var(--radius);
    border: 1px solid var(--gray-200);
    padding: 24px;
    cursor: pointer;
    transition: var(--transition);
    position: relative;
}
.project-card:hover:not(.locked) {
    box-shadow: var(--shadow-md);
    border-color: var(--primary);
    transform: translateY(-2px);
}
.project-card.locked {
    opacity: 0.55;
    cursor: not-allowed;
    filter: grayscale(0.4);
}
.project-card.completed {
    border-color: var(--success);
}
.project-card.completed::after {
    content: "✓";
    position: absolute;
    top: 16px;
    right: 16px;
    width: 24px;
    height: 24px;
    background: var(--success);
    color: white;
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 14px;
    font-weight: 700;
}

.project-header {
    display: flex;
    align-items: center;
    gap: 10px;
    margin-bottom: 12px;
}
.project-num {
    width: 32px;
    height: 32px;
    border-radius: 8px;
    background: var(--primary-light);
    color: var(--primary);
    display: flex;
    align-items: center;
    justify-content: center;
    font-weight: 700;
    font-size: 14px;
}
.project-title {
    font-size: 16px;
    font-weight: 600;
    color: var(--gray-800);
}
.project-desc {
    font-size: 13px;
    color: var(--gray-500);
    margin-bottom: 16px;
    line-height: 1.5;
}
.project-meta {
    display: flex;
    align-items: center;
    gap: 12px;
    font-size: 13px;
    color: var(--gray-400);
    margin-bottom: 12px;
}
.project-tags {
    display: flex;
    gap: 6px;
    flex-wrap: wrap;
}
.project-tag {
    font-size: 12px;
    padding: 2px 8px;
    border-radius: 4px;
    background: var(--gray-100);
    color: var(--gray-500);
}
.project-tag.key { background: #fef3c7; color: #92400e; }
.project-tag.diff { background: #fee2e2; color: #991b1b; }
.project-tag.core { background: #dbeafe; color: #1e40af; }

.project-progress {
    margin-top: 12px;
}
.project-progress-bar {
    height: 6px;
    background: var(--gray-100);
    border-radius: 3px;
    overflow: hidden;
}
.project-progress-fill {
    height: 100%;
    background: var(--primary);
    border-radius: 3px;
    transition: width 0.3s ease;
}
.project-progress-text {
    font-size: 12px;
    color: var(--gray-400);
    margin-top: 6px;
    text-align: right;
}

.project-score {
    margin-top: 10px;
    font-size: 13px;
    color: var(--gray-600);
}

@media (max-width: 1024px) {
    .projects-grid { grid-template-columns: repeat(2, 1fr); }
}
@media (max-width: 640px) {
    .projects-grid { grid-template-columns: 1fr; }
    .progress-summary { grid-template-columns: repeat(2, 1fr); }
}

/* ===== 课程学习页布局 ===== */
.learning-layout {
    display: flex;
    gap: 24px;
    min-height: calc(100vh - var(--header-height) - 64px);
}

.learning-sidebar {
    width: var(--sidebar-width);
    flex-shrink: 0;
    background: white;
    border-radius: var(--radius);
    border: 1px solid var(--gray-200);
    box-shadow: var(--shadow);
    overflow: hidden;
    display: flex;
    flex-direction: column;
    max-height: calc(100vh - var(--header-height) - 64px);
    position: sticky;
    top: calc(var(--header-height) + 32px);
}

.sidebar-header {
    padding: 16px 20px;
    border-bottom: 1px solid var(--gray-200);
}
.sidebar-header h3 { font-size: 15px; font-weight: 600; }

.sidebar-content {
    overflow-y: auto;
    flex: 1;
    padding: 8px;
}

.toc-project {
    margin-bottom: 4px;
}
.toc-project-header {
    display: flex;
    align-items: center;
    gap: 8px;
    padding: 10px 12px;
    border-radius: 6px;
    cursor: pointer;
    font-weight: 600;
    font-size: 14px;
    color: var(--gray-700);
    transition: var(--transition);
}
.toc-project-header:hover { background: var(--gray-100); }
.toc-project-header.active { background: var(--primary-light); color: var(--primary); }
.toc-project-header .toc-arrow {
    font-size: 12px;
    transition: transform 0.2s;
    color: var(--gray-400);
}
.toc-project-header.expanded .toc-arrow { transform: rotate(90deg); }

.toc-tasks {
    padding-left: 12px;
    display: none;
}
.toc-tasks.expanded { display: block; }

.toc-task {
    padding: 8px 12px 8px 28px;
    border-radius: 6px;
    cursor: pointer;
    font-size: 13px;
    color: var(--gray-600);
    position: relative;
    transition: var(--transition);
}
.toc-task:hover { background: var(--gray-50); color: var(--gray-800); }
.toc-task.active { background: var(--primary-light); color: var(--primary); font-weight: 500; }
.toc-task .task-status {
    position: absolute;
    left: 10px;
    top: 50%;
    transform: translateY(-50%);
    width: 6px;
    height: 6px;
    border-radius: 50%;
    background: var(--gray-300);
}
.toc-task.done .task-status { background: var(--success); }
.toc-task .task-lock {
    position: absolute;
    right: 10px;
    top: 50%;
    transform: translateY(-50%);
    font-size: 11px;
    color: var(--gray-400);
}

.learning-content {
    flex: 1;
    min-width: 0;
}
.learning-main {
    background: white;
    border-radius: var(--radius);
    border: 1px solid var(--gray-200);
    box-shadow: var(--shadow);
    padding: 32px;
    min-height: 100%;
}

/* 学习内容样式 */
.content-header {
    margin-bottom: 24px;
    padding-bottom: 20px;
    border-bottom: 1px solid var(--gray-200);
}
.content-header h2 {
    font-size: 22px;
    font-weight: 600;
    color: var(--gray-800);
    margin-bottom: 8px;
}
.content-header .content-breadcrumb {
    font-size: 13px;
    color: var(--gray-400);
}

.content-body h3 {
    font-size: 18px;
    font-weight: 600;
    color: var(--gray-800);
    margin: 28px 0 12px;
    padding-bottom: 8px;
    border-bottom: 1px solid var(--gray-100);
}
.content-body h4 {
    font-size: 15px;
    font-weight: 600;
    color: var(--gray-700);
    margin: 20px 0 10px;
}
.content-body p {
    margin-bottom: 12px;
    font-size: 14px;
    line-height: 1.8;
    color: var(--gray-600);
}
.content-body ul, .content-body ol {
    margin: 12px 0 12px 20px;
    font-size: 14px;
    color: var(--gray-600);
}
.content-body li { margin-bottom: 6px; }

.content-body .highlight-box {
    background: var(--primary-light);
    border-left: 4px solid var(--primary);
    padding: 16px 20px;
    border-radius: 0 var(--radius) var(--radius) 0;
    margin: 16px 0;
    font-size: 14px;
    color: var(--gray-700);
}

.content-body .warn-box {
    background: var(--warning-light);
    border-left: 4px solid var(--warning);
    padding: 16px 20px;
    border-radius: 0 var(--radius) var(--radius) 0;
    margin: 16px 0;
    font-size: 14px;
    color: var(--gray-700);
}

/* 代码块 */
.code-block-wrapper {
    margin: 16px 0;
    border-radius: var(--radius);
    overflow: hidden;
    border: 1px solid var(--gray-200);
}
.code-header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: 8px 16px;
    background: var(--gray-100);
    border-bottom: 1px solid var(--gray-200);
}
.code-lang {
    font-size: 12px;
    font-weight: 600;
    color: var(--gray-500);
    text-transform: uppercase;
}
.code-copy-btn {
    padding: 4px 12px;
    font-size: 12px;
    background: white;
    border: 1px solid var(--gray-300);
    border-radius: 4px;
    cursor: pointer;
    color: var(--gray-600);
    transition: var(--transition);
}
.code-copy-btn:hover { background: var(--gray-50); }
.code-copy-btn.copied { background: var(--success-light); color: var(--success); border-color: var(--success); }

pre {
    background: var(--gray-900);
    color: #e2e8f0;
    padding: 20px;
    overflow-x: auto;
    font-size: 13px;
    line-height: 1.6;
    font-family: "SF Mono", Monaco, "Cascadia Code", "Roboto Mono", Consolas, "Courier New", monospace;
}
code {
    font-family: "SF Mono", Monaco, "Cascadia Code", "Roboto Mono", Consolas, "Courier New", monospace;
    font-size: 0.92em;
}
:not(pre) > code {
    background: var(--gray-100);
    padding: 2px 6px;
    border-radius: 4px;
    color: var(--danger);
    font-size: 0.9em;
}

/* 表格 */
.content-table {
    width: 100%;
    border-collapse: collapse;
    margin: 16px 0;
    font-size: 14px;
}
.content-table th,
.content-table td {
    border: 1px solid var(--gray-200);
    padding: 10px 14px;
    text-align: left;
}
.content-table th {
    background: var(--gray-50);
    font-weight: 600;
    color: var(--gray-700);
}
.content-table tr:nth-child(even) { background: var(--gray-50); }

/* 知识点标签 */
.knowledge-tag {
    display: inline-flex;
    align-items: center;
    gap: 4px;
    font-size: 12px;
    padding: 2px 8px;
    border-radius: 4px;
    font-weight: 500;
}
.knowledge-tag.key { background: #fef3c7; color: #92400e; }
.knowledge-tag.diff { background: #fee2e2; color: #991b1b; }
.knowledge-tag.core { background: #dbeafe; color: #1e40af; }

/* 测验入口 */
.quiz-entry {
    margin: 24px 0;
    padding: 20px;
    background: linear-gradient(135deg, var(--primary-light) 0%, #eff6ff 100%);
    border-radius: var(--radius);
    border: 1px solid #bfdbfe;
    display: flex;
    align-items: center;
    justify-content: space-between;
}
.quiz-entry-info h4 {
    margin: 0 0 4px;
    font-size: 15px;
    color: var(--gray-800);
}
.quiz-entry-info p {
    margin: 0;
    font-size: 13px;
    color: var(--gray-500);
}

/* 学习导航 */
.content-nav {
    display: flex;
    justify-content: space-between;
    margin-top: 32px;
    padding-top: 20px;
    border-top: 1px solid var(--gray-200);
}

/* ===== 测评考核页 ===== */
.assessment-layout {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 24px;
}
.assessment-section h3 {
    font-size: 16px;
    font-weight: 600;
    margin-bottom: 16px;
    color: var(--gray-800);
}
.assessment-list {
    display: flex;
    flex-direction: column;
    gap: 12px;
}
.assessment-item {
    background: white;
    border: 1px solid var(--gray-200);
    border-radius: var(--radius);
    padding: 16px 20px;
    display: flex;
    align-items: center;
    justify-content: space-between;
    transition: var(--transition);
}
.assessment-item:hover { border-color: var(--primary); box-shadow: var(--shadow); }
.assessment-item-info h4 {
    font-size: 14px;
    font-weight: 600;
    color: var(--gray-800);
    margin-bottom: 4px;
}
.assessment-item-info p {
    font-size: 13px;
    color: var(--gray-500);
}
.assessment-item-score {
    font-size: 20px;
    font-weight: 700;
    color: var(--primary);
}
.assessment-item-score.empty { color: var(--gray-300); }

@media (max-width: 768px) {
    .assessment-layout { grid-template-columns: 1fr; }
}

/* ===== 弹窗 ===== */
.modal {
    position: fixed;
    inset: 0;
    z-index: 200;
    display: flex;
    align-items: center;
    justify-content: center;
}
.modal-overlay {
    position: absolute;
    inset: 0;
    background: rgba(0,0,0,0.5);
    backdrop-filter: blur(4px);
}
.modal-content {
    position: relative;
    background: white;
    border-radius: 12px;
    box-shadow: var(--shadow-lg);
    width: 90%;
    max-width: 640px;
    max-height: 85vh;
    display: flex;
    flex-direction: column;
    z-index: 1;
}
.modal-content.modal-large { max-width: 900px; }
.modal-header {
    display: flex;
    align-items: center;
    justify-content: space-between;
    padding: 20px 24px;
    border-bottom: 1px solid var(--gray-200);
}
.modal-header h3 { font-size: 18px; font-weight: 600; }
.modal-close {
    background: none;
    border: none;
    font-size: 24px;
    color: var(--gray-400);
    cursor: pointer;
    line-height: 1;
}
.modal-close:hover { color: var(--gray-700); }
.modal-body {
    padding: 24px;
    overflow-y: auto;
    flex: 1;
}
.modal-footer {
    padding: 16px 24px;
    border-top: 1px solid var(--gray-200);
    display: flex;
    justify-content: flex-end;
    gap: 10px;
}

/* 测验弹窗内容 */
.quiz-question {
    margin-bottom: 24px;
}
.quiz-question-text {
    font-size: 16px;
    font-weight: 500;
    color: var(--gray-800);
    margin-bottom: 16px;
    line-height: 1.6;
}
.quiz-options {
    display: flex;
    flex-direction: column;
    gap: 10px;
}
.quiz-option {
    padding: 12px 16px;
    border: 1px solid var(--gray-200);
    border-radius: var(--radius);
    cursor: pointer;
    font-size: 14px;
    transition: var(--transition);
    display: flex;
    align-items: center;
    gap: 10px;
}
.quiz-option:hover { background: var(--gray-50); border-color: var(--gray-300); }
.quiz-option.selected {
    border-color: var(--primary);
    background: var(--primary-light);
}
.quiz-option.correct {
    border-color: var(--success);
    background: var(--success-light);
}
.quiz-option.wrong {
    border-color: var(--danger);
    background: var(--danger-light);
}
.quiz-option input[type="radio"] { cursor: pointer; }

.quiz-result {
    margin-top: 16px;
    padding: 16px;
    border-radius: var(--radius);
    font-size: 14px;
}
.quiz-result.correct { background: var(--success-light); color: #166534; }
.quiz-result.wrong { background: var(--danger-light); color: #991b1b; }
.quiz-result-title { font-weight: 600; margin-bottom: 6px; }

/* 单元测试 */
.exam-question {
    margin-bottom: 28px;
    padding-bottom: 20px;
    border-bottom: 1px solid var(--gray-100);
}
.exam-question:last-child { border-bottom: none; }
.exam-q-header {
    display: flex;
    align-items: center;
    gap: 8px;
    margin-bottom: 12px;
}
.exam-q-num {
    width: 28px;
    height: 28px;
    border-radius: 50%;
    background: var(--primary-light);
    color: var(--primary);
    display: flex;
    align-items: center;
    justify-content: center;
    font-weight: 700;
    font-size: 13px;
    flex-shrink: 0;
}
.exam-q-type {
    font-size: 12px;
    padding: 2px 8px;
    border-radius: 4px;
    background: var(--gray-100);
    color: var(--gray-500);
}
.exam-question-text {
    font-size: 15px;
    color: var(--gray-800);
    margin-bottom: 12px;
    line-height: 1.6;
}
.exam-options { display: flex; flex-direction: column; gap: 8px; }
.exam-option {
    padding: 10px 14px;
    border: 1px solid var(--gray-200);
    border-radius: var(--radius);
    cursor: pointer;
    font-size: 14px;
    transition: var(--transition);
    display: flex;
    align-items: center;
    gap: 8px;
}
.exam-option:hover { background: var(--gray-50); }
.exam-option.selected { border-color: var(--primary); background: var(--primary-light); }
.exam-option.correct { border-color: var(--success); background: var(--success-light); }
.exam-option.wrong { border-color: var(--danger); background: var(--danger-light); }

.exam-textarea {
    width: 100%;
    min-height: 120px;
    padding: 12px;
    border: 1px solid var(--gray-300);
    border-radius: var(--radius);
    font-family: monospace;
    font-size: 13px;
    resize: vertical;
}

.exam-timer {
    font-size: 14px;
    font-weight: 600;
    color: var(--warning);
    background: var(--warning-light);
    padding: 4px 12px;
    border-radius: 20px;
}
.exam-timer.urgent { color: var(--danger); background: var(--danger-light); animation: pulse 1s infinite; }

@keyframes pulse {
    0%, 100% { opacity: 1; }
    50% { opacity: 0.7; }
}

.exam-results {
    text-align: center;
    padding: 40px;
}
.exam-score-circle {
    width: 120px;
    height: 120px;
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    margin: 0 auto 20px;
    font-size: 36px;
    font-weight: 700;
}
.exam-score-circle.pass { background: var(--success-light); color: var(--success); }
.exam-score-circle.fail { background: var(--danger-light); color: var(--danger); }

/* ===== 学习数据中心 ===== */
.data-center-grid {
    display: grid;
    grid-template-columns: repeat(2, 1fr);
    gap: 20px;
}
.data-card {
    background: white;
    border-radius: var(--radius);
    border: 1px solid var(--gray-200);
    padding: 24px;
    box-shadow: var(--shadow);
}
.data-card.full-width { grid-column: 1 / -1; }
.data-card h3 {
    font-size: 16px;
    font-weight: 600;
    margin-bottom: 16px;
    color: var(--gray-800);
}

.progress-detail-item {
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: 10px 0;
    border-bottom: 1px solid var(--gray-100);
    font-size: 14px;
}
.progress-detail-item:last-child { border-bottom: none; }

.score-table {
    width: 100%;
    border-collapse: collapse;
    font-size: 14px;
}
.score-table th,
.score-table td {
    text-align: left;
    padding: 10px;
    border-bottom: 1px solid var(--gray-100);
}
.score-table th { color: var(--gray-500); font-weight: 500; }

.wrong-q-item {
    padding: 16px;
    background: var(--gray-50);
    border-radius: var(--radius);
    margin-bottom: 12px;
}
.wrong-q-title { font-weight: 500; margin-bottom: 8px; color: var(--gray-800); }
.wrong-q-answer { font-size: 13px; color: var(--gray-500); }
.wrong-q-answer .correct { color: var(--success); font-weight: 500; }
.wrong-q-answer .wrong { color: var(--danger); }

.analysis-chart {
    display: flex;
    align-items: flex-end;
    gap: 16px;
    height: 160px;
    padding-top: 20px;
}
.chart-bar-wrapper {
    flex: 1;
    display: flex;
    flex-direction: column;
    align-items: center;
    gap: 8px;
}
.chart-bar {
    width: 100%;
    max-width: 60px;
    background: var(--primary);
    border-radius: 4px 4px 0 0;
    transition: height 0.5s ease;
    min-height: 4px;
}
.chart-bar-label {
    font-size: 12px;
    color: var(--gray-500);
    text-align: center;
}
.chart-bar-value {
    font-size: 13px;
    font-weight: 600;
    color: var(--primary);
}

/* ===== 设置页 ===== */
.settings-grid {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 20px;
}
.settings-card {
    background: white;
    border-radius: var(--radius);
    border: 1px solid var(--gray-200);
    padding: 24px;
    box-shadow: var(--shadow);
}
.settings-card h3 {
    font-size: 16px;
    font-weight: 600;
    margin-bottom: 20px;
    color: var(--gray-800);
}
.settings-actions {
    display: flex;
    flex-direction: column;
    gap: 12px;
}
.settings-actions button { width: 100%; justify-content: center; }

@media (max-width: 768px) {
    .settings-grid { grid-template-columns: 1fr; }
    .data-center-grid { grid-template-columns: 1fr; }
}

/* ===== Toast ===== */
.toast {
    position: fixed;
    bottom: 32px;
    left: 50%;
    transform: translateX(-50%);
    background: var(--gray-800);
    color: white;
    padding: 12px 24px;
    border-radius: var(--radius);
    font-size: 14px;
    z-index: 300;
    box-shadow: var(--shadow-lg);
    animation: toastIn 0.3s ease;
}
@keyframes toastIn {
    from { opacity: 0; transform: translateX(-50%) translateY(20px); }
    to { opacity: 1; transform: translateX(-50%) translateY(0); }
}

/* ===== 响应式学习页 ===== */
@media (max-width: 900px) {
    .learning-layout { flex-direction: column; }
    .learning-sidebar {
        width: 100%;
        max-height: 300px;
        position: static;
    }
    .app-main { padding: 20px; }
    .header-nav { display: none; }
}

/* ===== 滚动条 ===== */
::-webkit-scrollbar { width: 6px; height: 6px; }
::-webkit-scrollbar-track { background: transparent; }
::-webkit-scrollbar-thumb { background: var(--gray-300); border-radius: 3px; }
::-webkit-scrollbar-thumb:hover { background: var(--gray-400); }

/* ===== 标记标签 ===== */
.tag {
    display: inline-flex;
    align-items: center;
    gap: 4px;
    font-size: 12px;
    padding: 2px 8px;
    border-radius: 4px;
    font-weight: 500;
    margin-right: 4px;
}
.tag-difficulty { background: #fee2e2; color: #991b1b; }
.tag-key { background: #fef3c7; color: #92400e; }
.tag-core { background: #dbeafe; color: #1e40af; }

/* 学习页底部测验 */
.task-quiz-section {
    margin-top: 32px;
    padding: 24px;
    background: linear-gradient(135deg, #eff6ff 0%, #f8fafc 100%);
    border-radius: var(--radius);
    border: 1px solid #bfdbfe;
}
.task-quiz-section h4 {
    margin: 0 0 16px;
    color: var(--primary);
}

/* 空状态 */
.empty-state {
    text-align: center;
    padding: 60px 20px;
    color: var(--gray-400);
}
.empty-state-icon { font-size: 48px; margin-bottom: 16px; }
.empty-state-title { font-size: 16px; font-weight: 500; margin-bottom: 8px; color: var(--gray-600); }
.empty-state-desc { font-size: 14px; }