/* ==================================================================
   全局样式 / 设计令牌
   现代主流风格：浅灰背景 + 主题蓝（#2563eb），圆角 12px，柔和阴影。
   ================================================================== */
:root {
    --color-bg: #f5f7fb;
    --color-bg-elev: #ffffff;
    --color-border: #e5e7eb;
    --color-border-strong: #d1d5db;
    --color-text: #111827;
    --color-text-secondary: #4b5563;
    --color-text-muted: #9ca3af;
    --color-primary: #2563eb;
    --color-primary-hover: #1d4ed8;
    --color-primary-soft: #dbeafe;
    --color-success: #10b981;
    --color-success-soft: #d1fae5;
    --color-danger: #ef4444;
    --color-danger-soft: #fee2e2;
    --color-warning: #f59e0b;
    --color-warning-soft: #fef3c7;
    --color-info: #3b82f6;

    --radius-sm: 6px;
    --radius: 10px;
    --radius-lg: 16px;
    --shadow-sm: 0 1px 2px rgba(15, 23, 42, .06);
    --shadow: 0 4px 12px rgba(15, 23, 42, .08);
    --shadow-lg: 0 12px 32px rgba(15, 23, 42, .14);

    --header-h: 60px;
    --sidebar-w: 240px;

    --duration: .18s;
}

* {
    box-sizing: border-box;
}

html, body {
    margin: 0;
    padding: 0;
    height: 100%;
    background: var(--color-bg);
    color: var(--color-text);
    font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", "PingFang SC",
        "Hiragino Sans GB", "Microsoft YaHei", sans-serif;
    font-size: 14px;
    line-height: 1.6;
    -webkit-font-smoothing: antialiased;
}

a {
    color: var(--color-primary);
    text-decoration: none;
}

a:hover {
    color: var(--color-primary-hover);
}

button {
    font: inherit;
    cursor: pointer;
}

img {
    max-width: 100%;
    height: auto;
}

/* ============== 通用按钮 ============== */
.btn {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    gap: 6px;
    height: 36px;
    padding: 0 16px;
    border: 1px solid transparent;
    border-radius: var(--radius);
    background: var(--color-bg-elev);
    color: var(--color-text);
    font-size: 14px;
    font-weight: 500;
    transition: all var(--duration);
    user-select: none;
}

.btn:hover {
    background: #f3f4f6;
}

.btn:active {
    transform: translateY(1px);
}

.btn:disabled {
    opacity: .5;
    cursor: not-allowed;
}

.btn-primary {
    background: var(--color-primary);
    color: #fff;
    border-color: var(--color-primary);
}

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

.btn-outline {
    background: transparent;
    border-color: var(--color-border-strong);
    color: var(--color-text);
}

.btn-outline:hover {
    border-color: var(--color-primary);
    color: var(--color-primary);
    background: var(--color-primary-soft);
}

.btn-danger {
    background: var(--color-danger);
    color: #fff;
    border-color: var(--color-danger);
}

.btn-danger:hover {
    background: #dc2626;
    border-color: #dc2626;
}

.btn-ghost {
    background: transparent;
    border-color: transparent;
    color: var(--color-text-secondary);
}

.btn-ghost:hover {
    background: #f3f4f6;
}

.btn-sm {
    height: 30px;
    padding: 0 12px;
    font-size: 13px;
}

.btn-lg {
    height: 44px;
    padding: 0 20px;
    font-size: 15px;
}

/* ============== 表单控件 ============== */
.form-group {
    margin-bottom: 16px;
}

.form-label {
    display: block;
    margin-bottom: 6px;
    font-size: 13px;
    color: var(--color-text-secondary);
    font-weight: 500;
}

.form-input,
.form-select,
.form-textarea {
    display: block;
    width: 100%;
    height: 38px;
    padding: 0 12px;
    border: 1px solid var(--color-border-strong);
    border-radius: var(--radius);
    background: var(--color-bg-elev);
    color: var(--color-text);
    font-size: 14px;
    transition: all var(--duration);
    outline: none;
}

.form-textarea {
    height: auto;
    min-height: 80px;
    padding: 8px 12px;
    line-height: 1.5;
    resize: vertical;
}

.form-input:focus,
.form-select:focus,
.form-textarea:focus {
    border-color: var(--color-primary);
    box-shadow: 0 0 0 3px var(--color-primary-soft);
}

/* 禁用浏览器自带的搜索/历史外观 */
.form-input::-webkit-search-decoration,
.form-input::-webkit-search-cancel-button,
.form-input::-webkit-search-results-button,
.form-input::-webkit-search-results-decoration {
    -webkit-appearance: none;
    display: none;
}

/* ============== 卡片 ============== */
.card {
    background: var(--color-bg-elev);
    border: 1px solid var(--color-border);
    border-radius: var(--radius-lg);
    box-shadow: var(--shadow-sm);
    padding: 20px;
}

/* ============== 标签 ============== */
.tag {
    display: inline-flex;
    align-items: center;
    height: 22px;
    padding: 0 8px;
    border-radius: 999px;
    font-size: 12px;
    background: #f3f4f6;
    color: var(--color-text-secondary);
}

.tag-primary {
    background: var(--color-primary-soft);
    color: var(--color-primary);
}

.tag-success {
    background: var(--color-success-soft);
    color: #047857;
}

.tag-danger {
    background: var(--color-danger-soft);
    color: #b91c1c;
}

.tag-warning {
    background: var(--color-warning-soft);
    color: #b45309;
}

/* ============== 顶部导航 ============== */
.app-header {
    position: sticky;
    top: 0;
    height: var(--header-h);
    background: var(--color-bg-elev);
    border-bottom: 1px solid var(--color-border);
    display: flex;
    align-items: center;
    padding: 0 24px;
    z-index: 100;
    backdrop-filter: saturate(180%) blur(8px);
    background-color: rgba(255, 255, 255, .85);
}

.app-logo {
    display: flex;
    align-items: center;
    gap: 8px;
    font-weight: 700;
    font-size: 16px;
    color: var(--color-text);
}

.app-logo .logo-mark {
    width: 28px;
    height: 28px;
    border-radius: 8px;
    background: linear-gradient(135deg, var(--color-primary), #6366f1);
    display: flex;
    align-items: center;
    justify-content: center;
    color: #fff;
    font-weight: 700;
    font-size: 14px;
}

.app-nav {
    display: flex;
    align-items: center;
    gap: 4px;
    margin-left: 36px;
    flex: 1;
}

.app-nav a {
    height: 36px;
    padding: 0 14px;
    border-radius: var(--radius);
    display: inline-flex;
    align-items: center;
    color: var(--color-text-secondary);
    font-size: 14px;
    transition: all var(--duration);
}

.app-nav a:hover {
    background: #f3f4f6;
    color: var(--color-text);
}

.app-nav a.active {
    background: var(--color-primary-soft);
    color: var(--color-primary);
}

.app-userbox {
    display: flex;
    align-items: center;
    gap: 12px;
    margin-left: auto;
}

.user-avatar {
    width: 32px;
    height: 32px;
    border-radius: 50%;
    background: linear-gradient(135deg, #818cf8, #6366f1);
    color: #fff;
    display: inline-flex;
    align-items: center;
    justify-content: center;
    font-size: 13px;
    font-weight: 600;
    overflow: hidden;
    flex: 0 0 auto;
}
.user-avatar img {
    width: 100%;
    height: 100%;
    object-fit: cover;
    display: block;
}

/* ============== 容器 ============== */
.app-main {
    max-width: 1200px;
    margin: 0 auto;
    padding: 24px;
}

.page-title {
    margin: 0 0 4px;
    font-size: 22px;
    font-weight: 700;
}

.page-subtitle {
    margin: 0 0 20px;
    color: var(--color-text-secondary);
    font-size: 13px;
}

/* ============== 表格 ============== */
.table {
    width: 100%;
    border-collapse: separate;
    border-spacing: 0;
    font-size: 14px;
}

.table th,
.table td {
    padding: 12px 14px;
    text-align: left;
    border-bottom: 1px solid var(--color-border);
}

.table th {
    background: #f9fafb;
    font-weight: 600;
    color: var(--color-text-secondary);
    font-size: 13px;
}

.table tbody tr:hover {
    background: #f9fafb;
}

/* ============== Modal ============== */
.modal-mask {
    position: fixed;
    inset: 0;
    background: rgba(15, 23, 42, .45);
    backdrop-filter: blur(2px);
    z-index: 1000;
    display: flex;
    align-items: center;
    justify-content: center;
    opacity: 0;
    pointer-events: none;
    transition: opacity var(--duration);
}

.modal-mask.show {
    opacity: 1;
    pointer-events: auto;
}

.modal {
    background: var(--color-bg-elev);
    border-radius: var(--radius-lg);
    box-shadow: var(--shadow-lg);
    min-width: 360px;
    max-width: calc(100vw - 48px);
    max-height: calc(100vh - 48px);
    display: flex;
    flex-direction: column;
    transform: scale(.96);
    transition: transform var(--duration);
}

.modal-mask.show .modal {
    transform: scale(1);
}

.modal-header {
    padding: 18px 20px;
    border-bottom: 1px solid var(--color-border);
    display: flex;
    align-items: center;
    gap: 12px;
}

.modal-title {
    margin: 0;
    font-size: 16px;
    font-weight: 600;
}

.modal-close {
    margin-left: auto;
    width: 28px;
    height: 28px;
    border-radius: 6px;
    border: 0;
    background: transparent;
    color: var(--color-text-muted);
    cursor: pointer;
}

.modal-close:hover {
    background: #f3f4f6;
    color: var(--color-text);
}

.modal-body {
    padding: 20px;
    overflow: auto;
    flex: 1;
}

.modal-footer {
    padding: 14px 20px;
    border-top: 1px solid var(--color-border);
    display: flex;
    justify-content: flex-end;
    gap: 10px;
}

/* ============== Toast ============== */
.toast-wrap {
    position: fixed;
    top: 24px;
    left: 50%;
    transform: translateX(-50%);
    z-index: 2000;
    display: flex;
    flex-direction: column;
    gap: 8px;
    pointer-events: none;
}

.toast {
    min-width: 220px;
    max-width: 360px;
    padding: 10px 16px;
    border-radius: var(--radius);
    background: rgba(17, 24, 39, .94);
    color: #fff;
    font-size: 14px;
    box-shadow: var(--shadow-lg);
    display: flex;
    align-items: center;
    gap: 8px;
    animation: toast-in .25s ease-out;
}

.toast.success {
    background: var(--color-success);
}

.toast.error {
    background: var(--color-danger);
}

.toast.warning {
    background: var(--color-warning);
}

@keyframes toast-in {
    from { transform: translateY(-12px); opacity: 0; }
    to   { transform: translateY(0); opacity: 1; }
}

/* ============== Loading ============== */
.loader {
    display: inline-block;
    width: 16px;
    height: 16px;
    border: 2px solid #e5e7eb;
    border-top-color: var(--color-primary);
    border-radius: 50%;
    animation: spin .8s linear infinite;
}

.loader-lg {
    width: 36px;
    height: 36px;
    border-width: 3px;
}

@keyframes spin {
    to { transform: rotate(360deg); }
}

.loading-block {
    display: flex;
    align-items: center;
    justify-content: center;
    padding: 60px 20px;
    color: var(--color-text-muted);
    flex-direction: column;
    gap: 12px;
}

/* ============== Empty ============== */
.empty-block {
    display: flex;
    flex-direction: column;
    align-items: center;
    justify-content: center;
    padding: 60px 20px;
    color: var(--color-text-muted);
    gap: 8px;
}

.empty-block .icon {
    font-size: 36px;
}

/* ============== 工具类 ============== */
.flex { display: flex; }
.flex-1 { flex: 1; }
.items-center { align-items: center; }
.justify-between { justify-content: space-between; }
.gap-8 { gap: 8px; }
.gap-12 { gap: 12px; }
.gap-16 { gap: 16px; }
.mt-8 { margin-top: 8px; }
.mt-12 { margin-top: 12px; }
.mt-16 { margin-top: 16px; }
.mt-20 { margin-top: 20px; }
.mb-8 { margin-bottom: 8px; }
.mb-16 { margin-bottom: 16px; }
.text-muted { color: var(--color-text-muted); }
.text-secondary { color: var(--color-text-secondary); }
.text-success { color: var(--color-success); }
.text-danger { color: var(--color-danger); }
.text-bold { font-weight: 600; }
.text-center { text-align: center; }
.text-right { text-align: right; }
.fs-12 { font-size: 12px; }
.fs-13 { font-size: 13px; }
.fs-16 { font-size: 16px; }
.fs-18 { font-size: 18px; }

/* ============== 网格 ============== */
.paper-grid {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(300px, 1fr));
    gap: 16px;
    margin-top: 20px;
}

.paper-pager {
    display: flex;
    justify-content: center;
    align-items: center;
    flex-wrap: wrap;
    gap: 6px;
    margin-top: 24px;
}

/* ============== 题库分类 Tabs ============== */
.exam-tabs {
    display: flex;
    flex-wrap: wrap;
    gap: 8px;
    margin: 12px 0 4px;
    padding: 6px;
    background: var(--color-bg-elev);
    border: 1px solid var(--color-border);
    border-radius: var(--radius-lg);
    box-shadow: var(--shadow-sm);
}
.exam-tab {
    appearance: none;
    -webkit-appearance: none;
    background: transparent;
    border: 1px solid transparent;
    color: var(--color-text-secondary);
    padding: 6px 16px;
    border-radius: 999px;
    font-size: 14px;
    line-height: 22px;
    cursor: pointer;
    transition: background var(--duration), color var(--duration), border-color var(--duration);
    white-space: nowrap;
}
.exam-tab:hover {
    background: var(--color-primary-soft);
    color: var(--color-primary);
}
.exam-tab.active {
    background: var(--color-primary);
    border-color: var(--color-primary);
    color: #fff;
}
.exam-tab.active:hover {
    background: var(--color-primary-hover);
    border-color: var(--color-primary-hover);
    color: #fff;
}

.paper-card {
    background: var(--color-bg-elev);
    border: 1px solid var(--color-border);
    border-radius: var(--radius-lg);
    padding: 20px;
    box-shadow: var(--shadow-sm);
    transition: all var(--duration);
    cursor: pointer;
    display: flex;
    flex-direction: column;
    gap: 12px;
}

.paper-card:hover {
    transform: translateY(-2px);
    box-shadow: var(--shadow);
    border-color: var(--color-primary);
}

.paper-card .paper-meta {
    display: flex;
    gap: 8px;
    flex-wrap: wrap;
}

.paper-card .paper-name {
    font-size: 16px;
    font-weight: 600;
    margin: 0;
}

.paper-card .paper-progress {
    display: flex;
    flex-direction: column;
    gap: 6px;
}

.progress-bar {
    height: 6px;
    background: #f3f4f6;
    border-radius: 4px;
    overflow: hidden;
}

.progress-bar > .fill {
    height: 100%;
    background: linear-gradient(90deg, var(--color-primary), #6366f1);
    border-radius: 4px;
    transition: width .3s;
}

/* ============== 题号宫格 ============== */
.qno-grid {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(40px, 1fr));
    gap: 8px;
}

.qno-cell {
    height: 36px;
    border-radius: 8px;
    border: 1px solid var(--color-border);
    background: #fff;
    color: var(--color-text-secondary);
    font-size: 13px;
    cursor: pointer;
    transition: all var(--duration);
}

.qno-cell:hover {
    border-color: var(--color-primary);
    color: var(--color-primary);
}

.qno-cell.correct {
    background: var(--color-success-soft);
    color: #047857;
    border-color: var(--color-success-soft);
}

.qno-cell.wrong {
    background: var(--color-danger-soft);
    color: #b91c1c;
    border-color: var(--color-danger-soft);
}

.qno-cell.answered {
    background: var(--color-primary-soft);
    color: var(--color-primary);
    border-color: var(--color-primary-soft);
}

.qno-cell.current {
    border: 2px solid var(--color-primary);
    color: var(--color-primary);
    font-weight: 600;
}

/* ============== 刷题页 ============== */
.quiz-layout {
    display: grid;
    grid-template-columns: 1fr 280px;
    gap: 20px;
    align-items: start;
}

@media (max-width: 900px) {
    .quiz-layout {
        grid-template-columns: 1fr;
    }
}

.quiz-card {
    background: var(--color-bg-elev);
    border: 1px solid var(--color-border);
    border-radius: var(--radius-lg);
    padding: 28px 32px;
    box-shadow: var(--shadow-sm);
}

.quiz-meta {
    display: flex;
    align-items: center;
    gap: 8px;
    flex-wrap: wrap;
    margin-bottom: 16px;
}

.quiz-shared {
    background: #fafbff;
    border: 1px solid #e0e7ff;
    border-left: 3px solid var(--color-primary);
    padding: 14px 16px;
    border-radius: var(--radius);
    margin-bottom: 18px;
    color: var(--color-text-secondary);
    font-size: 13.5px;
    line-height: 1.8;
}

.quiz-stem {
    font-size: 16px;
    line-height: 1.85;
    color: var(--color-text);
    margin-bottom: 20px;
    word-break: break-word;
}

.quiz-options {
    display: flex;
    flex-direction: column;
    gap: 10px;
}

.option-row {
    display: flex;
    align-items: flex-start;
    gap: 12px;
    padding: 14px 16px;
    border: 1px solid var(--color-border);
    border-radius: var(--radius);
    background: #fff;
    cursor: pointer;
    transition: all var(--duration);
    user-select: none;
}

.option-row:hover {
    border-color: var(--color-primary);
    background: var(--color-primary-soft);
}

.option-row.selected {
    border-color: var(--color-primary);
    background: var(--color-primary-soft);
}

.option-row.correct {
    border-color: var(--color-success);
    background: var(--color-success-soft);
}

.option-row.wrong {
    border-color: var(--color-danger);
    background: var(--color-danger-soft);
}

.option-row .opt-letter {
    width: 26px;
    height: 26px;
    border-radius: 50%;
    border: 1px solid var(--color-border-strong);
    display: inline-flex;
    align-items: center;
    justify-content: center;
    font-weight: 600;
    font-size: 13px;
    background: #fff;
    flex-shrink: 0;
}

.option-row.selected .opt-letter,
.option-row.correct .opt-letter,
.option-row.wrong .opt-letter {
    color: #fff;
}

.option-row.selected .opt-letter {
    background: var(--color-primary);
    border-color: var(--color-primary);
}

.option-row.correct .opt-letter {
    background: var(--color-success);
    border-color: var(--color-success);
}

.option-row.wrong .opt-letter {
    background: var(--color-danger);
    border-color: var(--color-danger);
}

.option-row .opt-text {
    flex: 1;
    word-break: break-word;
}

.quiz-actions {
    display: flex;
    gap: 12px;
    margin-top: 24px;
    padding-top: 20px;
    border-top: 1px dashed var(--color-border);
    align-items: center;
}

.quiz-feedback {
    margin-top: 16px;
    padding: 12px 14px;
    border-radius: var(--radius);
}

.quiz-feedback.success {
    background: var(--color-success-soft);
    color: #047857;
}

.quiz-feedback.error {
    background: var(--color-danger-soft);
    color: #b91c1c;
}

.quiz-feedback.info {
    background: var(--color-primary-soft);
    color: var(--color-primary);
}

/* ============== 登录/注册 ============== */
.auth-page {
    min-height: 100vh;
    display: flex;
    align-items: center;
    justify-content: center;
    background: linear-gradient(135deg, #eef2ff 0%, #f5f7fb 60%);
    padding: 24px;
}

.auth-card {
    background: #fff;
    border-radius: 20px;
    box-shadow: var(--shadow-lg);
    width: 100%;
    max-width: 420px;
    padding: 36px 32px;
}

.auth-title {
    margin: 0 0 6px;
    font-size: 22px;
    font-weight: 700;
    text-align: center;
}

.auth-subtitle {
    text-align: center;
    color: var(--color-text-muted);
    font-size: 13px;
    margin-bottom: 24px;
}

.auth-tabs {
    display: flex;
    background: #f3f4f6;
    border-radius: var(--radius);
    padding: 4px;
    margin-bottom: 20px;
}

.auth-tabs > button {
    flex: 1;
    height: 32px;
    border: 0;
    border-radius: 8px;
    background: transparent;
    color: var(--color-text-secondary);
    font-weight: 500;
    cursor: pointer;
}

.auth-tabs > button.active {
    background: #fff;
    color: var(--color-primary);
    box-shadow: var(--shadow-sm);
}

/* ============== 后台 ============== */
.admin-layout {
    display: grid;
    grid-template-columns: 220px 1fr;
    min-height: calc(100vh - var(--header-h));
}

.admin-sidebar {
    background: #fff;
    border-right: 1px solid var(--color-border);
    padding: 20px 14px;
}

.admin-sidebar a {
    display: flex;
    align-items: center;
    gap: 8px;
    height: 36px;
    padding: 0 12px;
    border-radius: var(--radius);
    color: var(--color-text-secondary);
    margin-bottom: 4px;
}

.admin-sidebar a:hover {
    background: #f3f4f6;
    color: var(--color-text);
}

.admin-sidebar a.active {
    background: var(--color-primary-soft);
    color: var(--color-primary);
}

.admin-content {
    padding: 24px;
}

.stat-grid {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(200px, 1fr));
    gap: 16px;
}

.stat-card {
    background: #fff;
    border: 1px solid var(--color-border);
    border-radius: var(--radius-lg);
    padding: 18px 20px;
    box-shadow: var(--shadow-sm);
}

.stat-card .label {
    color: var(--color-text-muted);
    font-size: 13px;
    margin-bottom: 6px;
}

.stat-card .value {
    font-size: 26px;
    font-weight: 700;
    color: var(--color-text);
}

.stat-card .value .suffix {
    font-size: 14px;
    font-weight: 500;
    color: var(--color-text-muted);
    margin-left: 2px;
}

/* ============== 概览分组 / 图表卡 ============== */
.stat-section {
    margin-bottom: 24px;
}

.stat-section-title {
    font-size: 15px;
    font-weight: 600;
    color: var(--color-text);
    margin: 8px 0 12px;
    padding-left: 8px;
    border-left: 3px solid var(--color-primary);
    line-height: 1.2;
    display: flex;
    align-items: center;
    gap: 12px;
}

/* 标题右侧的时间范围胶囊切换组 */
.range-switch {
    margin-left: auto;
    display: inline-flex;
    align-items: center;
    padding: 3px;
    background: #f1f3f8;
    border: 1px solid var(--color-border);
    border-radius: 999px;
    box-shadow: inset 0 1px 1px rgba(15, 23, 42, 0.04);
}

.range-switch .range-btn {
    appearance: none;
    -webkit-appearance: none;
    border: none;
    outline: none;
    background: transparent;
    color: var(--color-text-muted, #6b7280);
    font-size: 12.5px;
    font-weight: 500;
    line-height: 1;
    padding: 6px 14px;
    border-radius: 999px;
    cursor: pointer;
    transition: background-color .18s ease, color .18s ease, box-shadow .18s ease, transform .18s ease;
    white-space: nowrap;
}

.range-switch .range-btn:hover:not(.active) {
    color: var(--color-text);
    background: rgba(79, 70, 229, 0.06);
}

.range-switch .range-btn:active {
    transform: scale(0.97);
}

.range-switch .range-btn.active {
    background: #ffffff;
    color: var(--color-primary);
    box-shadow:
        0 1px 2px rgba(15, 23, 42, 0.08),
        0 0 0 1px rgba(79, 70, 229, 0.18);
}

.range-switch .range-btn:focus-visible {
    box-shadow:
        0 0 0 2px #fff,
        0 0 0 4px rgba(79, 70, 229, 0.45);
}

/* 图表加载中状态（切换 range 时使用） */
.chart-loading {
    position: relative;
    opacity: 0.55;
    pointer-events: none;
    transition: opacity .15s ease;
}
.chart-loading::after {
    content: '';
    position: absolute;
    top: 50%;
    left: 50%;
    width: 22px;
    height: 22px;
    margin: -11px 0 0 -11px;
    border-radius: 50%;
    border: 2px solid rgba(79, 70, 229, 0.18);
    border-top-color: var(--color-primary);
    animation: rangeSpin .7s linear infinite;
}
@keyframes rangeSpin {
    to { transform: rotate(360deg); }
}

@media (max-width: 720px) {
    .stat-section-title {
        flex-wrap: wrap;
    }
    .range-switch {
        margin-left: 0;
    }
    .range-switch .range-btn {
        padding: 5px 10px;
        font-size: 12px;
    }
}

.chart-grid {
    display: grid;
    grid-template-columns: repeat(2, minmax(0, 1fr));
    gap: 16px;
}

.chart-card {
    background: #fff;
    border: 1px solid var(--color-border);
    border-radius: var(--radius-lg);
    padding: 16px 18px;
    box-shadow: var(--shadow-sm);
    display: flex;
    flex-direction: column;
}

.chart-card-wide {
    grid-column: 1 / -1;
}

.chart-card .chart-title {
    font-size: 14px;
    font-weight: 600;
    color: var(--color-text);
    margin-bottom: 10px;
}

.chart-card .chart-title-with-action {
    display: flex;
    align-items: center;
    justify-content: space-between;
    gap: 8px;
}

.chart-card .chart-title-select {
    font-size: 12px;
    font-weight: 500;
    color: var(--color-text);
    background: var(--color-bg, #fff);
    border: 1px solid var(--color-border, #e5e7eb);
    border-radius: 6px;
    padding: 3px 8px;
    line-height: 1.4;
    max-width: 160px;
    cursor: pointer;
    outline: none;
    transition: border-color .15s, box-shadow .15s;
}

.chart-card .chart-title-select:hover {
    border-color: var(--color-primary, #4f46e5);
}

.chart-card .chart-title-select:focus {
    border-color: var(--color-primary, #4f46e5);
    box-shadow: 0 0 0 2px rgba(79, 70, 229, 0.15);
}

.chart-card .chart-body {
    position: relative;
    height: 260px;
}

.chart-card-wide .chart-body {
    height: 300px;
}

@media (max-width: 1100px) {
    .chart-grid {
        grid-template-columns: 1fr;
    }
    .chart-card-wide {
        grid-column: 1;
    }
}

/* ============== 工具栏 ============== */
.toolbar {
    display: flex;
    align-items: center;
    gap: 12px;
    margin-bottom: 16px;
    flex-wrap: wrap;
}

.toolbar .search-input {
    width: 240px;
}

/* 滚动条美化 */
::-webkit-scrollbar {
    width: 8px;
    height: 8px;
}
::-webkit-scrollbar-thumb {
    background: #d1d5db;
    border-radius: 8px;
}
::-webkit-scrollbar-thumb:hover {
    background: #9ca3af;
}

/* ============ 答案 / 解析 弹窗 ============ */
.analysis-modal-body {
    font-size: 14px;
    line-height: 1.85;
    color: var(--color-text);
    max-height: 70vh;
    overflow-y: auto;
    padding-right: 4px;
}

.analysis-modal-body .analysis-meta {
    display: flex;
    flex-wrap: wrap;
    gap: 8px;
    margin-bottom: 16px;
    padding-bottom: 12px;
    border-bottom: 1px dashed var(--color-border);
}

.analysis-modal-body .analysis-section-title {
    font-size: 14px;
    font-weight: 600;
    color: var(--color-text);
    margin: 4px 0 10px;
    display: flex;
    align-items: center;
    gap: 6px;
}

.analysis-modal-body .analysis-text {
    color: var(--color-text-secondary);
    word-break: break-word;
}

/* 申论"分段块"渲染（reference / demonstrate / zstz 三个独立小模块）。
   - 段卡片之间留较大间距，方便视觉区分；
   - 段内文字行距加大到 1.85，匹配粉笔网页阅读节奏；
   - 段内图片紧跟文字下方，独占一行。 */
.analysis-modal-body .shenlun-section {
    margin-top: 28px;
    padding-top: 16px;
    border-top: 1px solid var(--color-border);
}
.analysis-modal-body .shenlun-section:first-child {
    margin-top: 4px;
    padding-top: 0;
    border-top: none;
}
.analysis-modal-body .shenlun-section-title {
    font-size: 15px;
    font-weight: 600;
    color: var(--color-text);
    margin: 0 0 12px;
    display: flex;
    align-items: center;
    gap: 6px;
}
.analysis-modal-body .shenlun-section-text {
    color: var(--color-text-secondary);
    line-height: 1.85;
    word-break: break-word;
}
.analysis-modal-body .shenlun-section-images {
    margin-top: 12px;
    display: flex;
    flex-direction: column;
    gap: 12px;
}
.analysis-modal-body .shenlun-section-image img {
    max-width: 100%;
    border-radius: 6px;
    border: 1px solid var(--color-border);
    background: #fff;
    display: block;
}

.analysis-modal-body .analysis-img {
    margin: 8px 0;
}

.analysis-modal-body .analysis-img img {
    max-width: 100%;
    border-radius: 6px;
    border: 1px solid var(--color-border);
    background: #fff;
}

/* 行内公式图：让公式像普通字符一样融入文本流（仿粉笔效果）。
   - max-height 限定到约一行字高，避免高图把行高撑爆；
   - vertical-align:middle 与文字基线居中对齐；
   - 不加边框/背景，避免破坏正文阅读节奏。 */
.inline-formula-img {
    display: inline-block;
    max-height: 1.4em;
    vertical-align: middle;
    margin: 0 2px;
    background: transparent;
}

/* 启发式：图片加载完成后若 naturalWidth ≥ 60px，会被打上 .is-block，
   视为图形推理/概念图等"块级图"，按原尺寸展示，不再压成行内公式。
   - max-width: 100% 防止超宽溢出容器；
   - height: auto 保持原始比例。 */
.inline-formula-img.is-block {
    display: block;
    max-height: none;
    width: auto;
    height: auto;
    max-width: 100%;
    margin: 6px 0;
    vertical-align: baseline;
}

/* ============ AI 详解 双 Tab ============ */
.analysis-modal-body .analysis-tabs {
    display: flex;
    gap: 4px;
    margin: 8px 0 12px;
    border-bottom: 1px solid var(--color-border);
}

.analysis-modal-body .analysis-tab {
    appearance: none;
    background: transparent;
    border: 0;
    padding: 8px 14px;
    cursor: pointer;
    font-size: 14px;
    color: var(--color-text-secondary);
    border-bottom: 2px solid transparent;
    transition: color .15s ease, border-color .15s ease;
}

.analysis-modal-body .analysis-tab:hover {
    color: var(--color-text);
}

.analysis-modal-body .analysis-tab.is-active {
    color: var(--color-primary);
    border-bottom-color: var(--color-primary);
    font-weight: 600;
}

.analysis-modal-body .ai-summary {
    padding: 10px 12px;
    background: #fff8e6;
    border-left: 3px solid #f5a623;
    border-radius: 4px;
    margin-bottom: 14px;
    color: var(--color-text);
    line-height: 1.6;
}

.analysis-modal-body .ai-kps {
    display: flex;
    flex-wrap: wrap;
    gap: 6px;
    margin: 4px 0 10px;
}

.analysis-modal-body .ai-options {
    display: flex;
    flex-direction: column;
    gap: 8px;
}

.analysis-modal-body .ai-opt-row {
    display: flex;
    gap: 10px;
    align-items: flex-start;
    padding: 8px 10px;
    background: #f8fafd;
    border: 1px solid var(--color-border);
    border-radius: 6px;
}

.analysis-modal-body .ai-opt-letter {
    flex: 0 0 28px;
    height: 28px;
    line-height: 28px;
    text-align: center;
    border-radius: 50%;
    background: var(--color-primary);
    color: #fff;
    font-weight: 700;
    font-size: 13px;
}

.analysis-modal-body .ai-opt-text {
    flex: 1;
    color: var(--color-text-secondary);
    line-height: 1.7;
    word-break: break-word;
}

.analysis-modal-body .ai-meta-foot {
    margin-top: 14px;
    padding-top: 10px;
    border-top: 1px dashed var(--color-border);
    line-height: 1.6;
}

.analysis-modal-body .ai-empty {
    text-align: center;
    padding: 28px 12px;
}

.analysis-modal-body .ai-empty .ai-empty-tip {
    margin-bottom: 16px;
    line-height: 1.7;
}

.analysis-modal-body .ai-pane-loading {
    padding: 20px;
    text-align: center;
}

/* ========== 粉笔导入面板 ========== */
a.link {
    color: var(--color-primary);
    text-decoration: none;
}
a.link:hover {
    text-decoration: underline;
}
.fb-item:hover {
    background: var(--color-bg, #fafbfd);
}
.fb-item:last-child {
    border-bottom: none !important;
}

/* 粉笔导入：第 1 步「科目」切换胶囊 */
.fb-tabs {
    display: inline-flex;
    align-items: center;
    padding: 3px;
    background: #f1f3f8;
    border: 1px solid var(--color-border);
    border-radius: 999px;
    box-shadow: inset 0 1px 1px rgba(15, 23, 42, 0.04);
}
.fb-tabs .fb-tab {
    appearance: none;
    -webkit-appearance: none;
    border: none;
    outline: none;
    background: transparent;
    color: var(--color-text-muted, #6b7280);
    font-size: 13px;
    font-weight: 500;
    line-height: 1;
    padding: 7px 18px;
    border-radius: 999px;
    cursor: pointer;
    transition: background-color .18s ease, color .18s ease, box-shadow .18s ease, transform .18s ease;
    white-space: nowrap;
}
.fb-tabs .fb-tab:hover:not(.active) {
    color: var(--color-text);
    background: rgba(79, 70, 229, 0.06);
}
.fb-tabs .fb-tab:active {
    transform: scale(0.97);
}
.fb-tabs .fb-tab.active {
    background: #ffffff;
    color: var(--color-primary);
    box-shadow:
        0 1px 2px rgba(15, 23, 42, 0.08),
        0 0 0 1px rgba(79, 70, 229, 0.18);
}
.fb-tabs .fb-tab:focus-visible {
    box-shadow:
        0 0 0 2px #fff,
        0 0 0 4px rgba(79, 70, 229, 0.45);
}

/* ============================================================
   申论主观题作答区
   ============================================================ */
.subjective-area {
    margin-top: 20px;
    display: flex;
    flex-direction: column;
    gap: 10px;
}

.subjective-tip {
    background: rgba(79, 70, 229, 0.06);
    border-left: 3px solid var(--color-primary);
    border-radius: 0 8px 8px 0;
    padding: 10px 14px;
    font-size: 13px;
    color: var(--color-text-secondary, #64748b);
    line-height: 1.6;
}

.subjective-input {
    width: 100%;
    min-height: 220px;
    max-height: 520px;
    padding: 14px 16px;
    border: 1.5px solid var(--color-border);
    border-radius: 10px;
    font-size: 15px;
    line-height: 1.75;
    color: var(--color-text);
    background: var(--color-bg-card, #fff);
    resize: vertical;
    transition: border-color .18s ease, box-shadow .18s ease;
    box-sizing: border-box;
    font-family: inherit;
}
.subjective-input:focus {
    outline: none;
    border-color: var(--color-primary);
    box-shadow: 0 0 0 3px rgba(79, 70, 229, 0.12);
}

.subjective-bottom {
    display: flex;
    align-items: center;
    gap: 10px;
}

.subjective-upload-btn {
    cursor: pointer;
    user-select: none;
}

.subjective-images {
    display: flex;
    flex-wrap: wrap;
    gap: 10px;
    min-height: 24px;
}
.subjective-images[data-empty="true"] {
    align-items: center;
}

.subjective-img-item {
    position: relative;
    width: 100px;
    height: 100px;
    border-radius: 8px;
    overflow: hidden;
    border: 1.5px solid var(--color-border);
    background: var(--color-bg-secondary, #f8fafc);
    flex-shrink: 0;
}
.subjective-img-item img {
    width: 100%;
    height: 100%;
    object-fit: cover;
    display: block;
}
.subjective-img-item.is-uploading {
    display: flex;
    align-items: center;
    justify-content: center;
}
.subjective-img-uploading {
    font-size: 12px;
    color: var(--color-text-secondary, #64748b);
    text-align: center;
    padding: 8px;
}
.subjective-img-remove {
    position: absolute;
    top: 4px;
    right: 4px;
    width: 20px;
    height: 20px;
    border-radius: 50%;
    background: rgba(0,0,0,.55);
    color: #fff;
    border: none;
    cursor: pointer;
    font-size: 14px;
    line-height: 1;
    display: flex;
    align-items: center;
    justify-content: center;
    padding: 0;
    transition: background .15s;
}
.subjective-img-remove:hover {
    background: rgba(220, 38, 38, .85);
}

/* 解析弹窗里"我的作答"区域 */
.my-subj-answer {
    background: var(--color-bg-secondary, #f8fafc);
    border: 1px solid var(--color-border);
    border-radius: 8px;
    padding: 14px 16px;
    white-space: pre-wrap;
    word-break: break-word;
    font-size: 14px;
    line-height: 1.75;
    margin-bottom: 16px;
    max-height: 320px;
    overflow-y: auto;
}
.my-subj-images {
    display: flex;
    flex-wrap: wrap;
    gap: 10px;
    margin-bottom: 16px;
}
.my-subj-images a {
    display: block;
    width: 90px;
    height: 90px;
    border-radius: 8px;
    overflow: hidden;
    border: 1.5px solid var(--color-border);
    flex-shrink: 0;
}
.my-subj-images img {
    width: 100%;
    height: 100%;
    object-fit: cover;
    display: block;
}

/* ============ AI 评分卡片（仅申论） ============ */
.analysis-modal-body .ai-score-header {
    display: flex;
    gap: 16px;
    align-items: stretch;
    margin-bottom: 8px;
}
.analysis-modal-body .ai-score-card {
    flex: 0 0 160px;
    background: linear-gradient(135deg, #4f8cff 0%, #2a5edb 100%);
    color: #fff;
    border-radius: 10px;
    padding: 18px 16px;
    display: flex;
    align-items: baseline;
    justify-content: center;
    flex-wrap: wrap;
    line-height: 1;
    box-shadow: 0 2px 8px rgba(42, 94, 219, 0.18);
}
.analysis-modal-body .ai-score-num {
    font-size: 44px;
    font-weight: 800;
    letter-spacing: -1px;
}
.analysis-modal-body .ai-score-divider {
    font-size: 22px;
    margin: 0 4px;
    opacity: 0.85;
}
.analysis-modal-body .ai-score-full {
    font-size: 22px;
    font-weight: 600;
    opacity: 0.92;
}
.analysis-modal-body .ai-score-unit {
    font-size: 14px;
    margin-left: 4px;
    opacity: 0.85;
}
.analysis-modal-body .ai-score-summary {
    flex: 1 1 auto;
    min-width: 0;
}

.analysis-modal-body .ai-score-dims {
    display: flex;
    flex-direction: column;
    gap: 8px;
    margin: 6px 0 6px;
}
.analysis-modal-body .ai-score-dim {
    display: flex;
    align-items: center;
    gap: 10px;
}
.analysis-modal-body .ai-score-dim-label {
    flex: 0 0 88px;
    color: var(--color-text);
    font-size: 13px;
}
.analysis-modal-body .ai-score-dim-bar {
    flex: 1 1 auto;
    height: 8px;
    background: #eef2f7;
    border-radius: 4px;
    overflow: hidden;
}
.analysis-modal-body .ai-score-dim-fill {
    height: 100%;
    background: linear-gradient(90deg, #4f8cff, #1e6cf5);
    border-radius: 4px;
    transition: width .25s ease;
}
.analysis-modal-body .ai-score-dim-value {
    flex: 0 0 38px;
    text-align: right;
    font-size: 13px;
    color: var(--color-text-secondary);
    font-variant-numeric: tabular-nums;
}

.analysis-modal-body .ai-score-list {
    margin: 4px 0 8px;
    padding-left: 22px;
    line-height: 1.7;
}
.analysis-modal-body .ai-score-list li {
    margin: 2px 0;
}
.analysis-modal-body .ai-score-list.is-good li::marker { color: #2ca15a; }
.analysis-modal-body .ai-score-list.is-bad li::marker { color: #d9534f; }
.analysis-modal-body .ai-score-list.is-tip li::marker { color: #f5a623; }
.analysis-modal-body .ai-score-list.is-hit li::marker { color: #2ca15a; }
.analysis-modal-body .ai-score-list.is-miss li::marker { color: #d9534f; }

.analysis-modal-body .ai-score-points {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 14px;
}
.analysis-modal-body .ai-score-points-title {
    font-weight: 600;
    font-size: 13px;
    color: var(--color-text-secondary);
    margin-bottom: 4px;
}
.analysis-modal-body .ai-score-outdated {
    margin: 12px 0 4px;
    padding: 10px 12px;
    background: #fff8e6;
    border-left: 3px solid #f5a623;
    border-radius: 4px;
}

/* 评分卡顶部工具条：左侧题型徽标，右侧「重新批改」按钮 */
.analysis-modal-body .ai-score-toolbar {
    display: flex;
    justify-content: space-between;
    align-items: center;
    gap: 8px;
    margin: 0 0 8px 0;
}
.analysis-modal-body .ai-score-toolbar:has(> :only-child),
.analysis-modal-body .ai-score-toolbar:empty {
    justify-content: flex-end;
}
.analysis-modal-body .ai-score-kind {
    display: inline-block;
    padding: 3px 10px;
    border-radius: 12px;
    font-size: 12px;
    line-height: 1.4;
    border: 1px solid transparent;
    user-select: none;
}
.analysis-modal-body .ai-score-kind-obj {
    background: #eaf6ff;
    color: #0d63b8;
    border-color: #b9dcf7;
}
.analysis-modal-body .ai-score-kind-essay {
    background: #fff1ea;
    color: #b14a0a;
    border-color: #f5cfb6;
}
.analysis-modal-body .ai-score-rescore-btn {
    border: 1px solid #d6e0ee;
    background: #fff;
    color: #2e6dd9;
    padding: 4px 12px;
    border-radius: 16px;
    font-size: 12px;
    cursor: pointer;
    transition: all .15s ease;
}
.analysis-modal-body .ai-score-rescore-btn:hover:not(:disabled) {
    background: #eef4ff;
    border-color: #2e6dd9;
}
.analysis-modal-body .ai-score-rescore-btn:disabled {
    opacity: .55;
    cursor: not-allowed;
}

@media (max-width: 640px) {
    .analysis-modal-body .ai-score-header { flex-direction: column; }
    .analysis-modal-body .ai-score-card { flex: 0 0 auto; width: 100%; }
    .analysis-modal-body .ai-score-points { grid-template-columns: 1fr; }
}

/* ============== 顶部用户下拉菜单 ============== */
.user-menu {
    position: relative;
}
.user-menu-trigger {
    display: inline-flex;
    align-items: center;
    gap: 8px;
    background: transparent;
    border: 1px solid transparent;
    border-radius: 999px;
    padding: 4px 10px 4px 4px;
    cursor: pointer;
    transition: background var(--duration), border-color var(--duration);
}
.user-menu-trigger:hover {
    background: #f3f4f6;
    border-color: var(--color-border);
}
.user-menu-caret {
    color: var(--color-text-muted);
    font-size: 10px;
    margin-left: 2px;
}
.user-menu-dropdown {
    position: absolute;
    right: 0;
    top: calc(100% + 6px);
    min-width: 160px;
    background: #fff;
    border: 1px solid var(--color-border);
    border-radius: var(--radius);
    box-shadow: var(--shadow);
    padding: 6px;
    z-index: 100;
}
.user-menu-dropdown[hidden] {
    display: none;
}
.user-menu-item {
    display: block;
    width: 100%;
    text-align: left;
    background: transparent;
    border: 0;
    padding: 8px 12px;
    font-size: 14px;
    color: var(--color-text);
    border-radius: 6px;
    cursor: pointer;
    text-decoration: none;
}
.user-menu-item:hover {
    background: #f3f4f6;
    color: var(--color-text);
}
.user-menu-item.active {
    background: var(--color-primary-soft);
    color: var(--color-primary);
}

/* ============== 个人设置页 ============== */
.settings-layout {
    display: grid;
    grid-template-columns: 200px 1fr;
    gap: 20px;
    align-items: flex-start;
}
.settings-sidebar {
    background: #fff;
    border: 1px solid var(--color-border);
    border-radius: var(--radius-lg);
    padding: 12px 8px;
    position: sticky;
    top: 84px;
}
.settings-tab {
    display: block;
    padding: 10px 14px;
    border-radius: var(--radius);
    color: var(--color-text-secondary);
    font-size: 14px;
    text-decoration: none;
    margin-bottom: 4px;
    transition: all var(--duration);
}
.settings-tab:hover {
    background: #f3f4f6;
    color: var(--color-text);
}
.settings-tab.active {
    background: var(--color-primary-soft);
    color: var(--color-primary);
    font-weight: 600;
}
.settings-content {
    padding: 28px 32px;
}
.settings-section-title {
    margin: 0 0 24px;
    font-size: 18px;
    font-weight: 600;
    padding-bottom: 12px;
    border-bottom: 1px solid var(--color-border);
}
.form-row {
    display: grid;
    grid-template-columns: 100px 1fr;
    gap: 16px;
    align-items: flex-start;
    padding: 14px 0;
}
.form-row + .form-row {
    border-top: 1px solid var(--color-border);
}
.form-row-label {
    color: var(--color-text-secondary);
    font-size: 14px;
    padding-top: 8px;
}
.form-row-body {
    min-width: 0;
}
.form-row-body .form-input {
    max-width: 360px;
}
.form-static {
    padding: 8px 0;
    color: var(--color-text);
    font-size: 14px;
}
.avatar-edit {
    display: flex;
    align-items: flex-start;
    gap: 20px;
}
.avatar-preview {
    width: 96px;
    height: 96px;
    border-radius: 50%;
    overflow: hidden;
    background: linear-gradient(135deg, #818cf8, #6366f1);
    color: #fff;
    display: inline-flex;
    align-items: center;
    justify-content: center;
    font-size: 36px;
    font-weight: 700;
    flex: 0 0 auto;
}
.avatar-preview img {
    width: 100%;
    height: 100%;
    object-fit: cover;
    display: block;
}
.avatar-fallback {
    line-height: 1;
}
.avatar-actions {
    flex: 1;
    min-width: 0;
    padding-top: 6px;
}
@media (max-width: 768px) {
    .settings-layout { grid-template-columns: 1fr; }
    .settings-sidebar { position: static; display: flex; flex-wrap: wrap; gap: 4px; }
    .settings-tab { flex: 1 0 auto; text-align: center; }
    .form-row { grid-template-columns: 1fr; gap: 6px; }
    .form-row-label { padding-top: 0; }
}