/* ============================================
   老师端样式
   ============================================ */

/* ============================================
   登录页
   ============================================ */

.login-container {
    max-width: var(--max-width);
    margin: 0 auto;
    padding: 60px 16px 16px;
    min-height: 100vh;
}

.login-logo {
    text-align: center;
    margin-bottom: 32px;
}

.login-logo h1 {
    font-size: 24px;
    color: var(--dark);
}

.login-logo p {
    color: var(--gray-text);
    font-size: 14px;
    margin-top: 4px;
}

.login-card {
    background: #fff;
    border-radius: var(--radius);
    padding: 24px 20px;
    box-shadow: var(--shadow);
}

.login-card .form-group {
    margin-bottom: 16px;
}

.login-card .btn {
    margin-top: 8px;
}

/* ============================================
   管理后台框架
   ============================================ */

.admin-layout {
    display: flex;
    min-height: 100vh;
}

/* 侧边栏 */
.sidebar {
    width: 220px;
    background: #1e293b;
    color: #cbd5e1;
    display: flex;
    flex-direction: column;
    flex-shrink: 0;
    position: fixed;
    top: 0;
    left: 0;
    bottom: 0;
    z-index: 100;
    overflow-y: auto;
}

.sidebar-header {
    padding: 20px;
    border-bottom: 1px solid #334155;
}

.sidebar-header h2 {
    font-size: 16px;
    color: #fff;
}

.sidebar-header p {
    font-size: 12px;
    color: #64748b;
    margin-top: 2px;
}

.sidebar-nav {
    flex: 1;
    padding: 8px 0;
}

.sidebar-nav a {
    display: flex;
    align-items: center;
    gap: 10px;
    padding: 12px 20px;
    color: #cbd5e1;
    font-size: 14px;
    transition: background 0.2s, color 0.2s;
    border-left: 3px solid transparent;
}

.sidebar-nav a:hover {
    background: #334155;
    color: #fff;
}

.sidebar-nav a.active {
    background: #334155;
    color: #fff;
    border-left-color: var(--primary);
}

.sidebar-nav .nav-icon {
    font-size: 18px;
    width: 22px;
    text-align: center;
}

.sidebar-footer {
    padding: 16px 20px;
    border-top: 1px solid #334155;
    font-size: 12px;
}

.sidebar-footer .teacher-info {
    display: flex;
    align-items: center;
    gap: 8px;
    margin-bottom: 8px;
}

.sidebar-footer .teacher-avatar {
    width: 32px;
    height: 32px;
    border-radius: 50%;
    background: var(--primary);
    color: #fff;
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 14px;
    font-weight: 600;
}

.sidebar-footer .teacher-name {
    color: #e2e8f0;
    font-size: 13px;
}

.sidebar-footer .logout-btn {
    color: #f87171;
    font-size: 13px;
    cursor: pointer;
    display: inline-block;
}

/* 主内容区 */
.admin-main {
    flex: 1;
    margin-left: 220px;
    padding: 24px;
    background: var(--gray-bg);
    min-height: 100vh;
}

.page-header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    margin-bottom: 20px;
}

.page-header h1 {
    font-size: 22px;
    color: var(--dark);
}

.page-header .actions {
    display: flex;
    gap: 8px;
    flex-wrap: wrap;
}

/* ============================================
   仪表盘统计卡片
   ============================================ */

.stat-cards {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(180px, 1fr));
    gap: 16px;
    margin-bottom: 24px;
}

.stat-card {
    background: #fff;
    border-radius: var(--radius);
    padding: 20px;
    box-shadow: var(--shadow);
    display: flex;
    align-items: center;
    gap: 16px;
}

.stat-icon {
    width: 48px;
    height: 48px;
    border-radius: 12px;
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 24px;
    flex-shrink: 0;
}

.stat-icon.blue { background: var(--primary-light); }
.stat-icon.green { background: var(--success-bg); }
.stat-icon.orange { background: var(--warning-bg); }
.stat-icon.red { background: var(--danger-bg); }
.stat-icon.gray { background: #f0f0f0; }

.stat-info {
    flex: 1;
}

.stat-value {
    font-size: 28px;
    font-weight: 700;
    line-height: 1.2;
}

.stat-label {
    font-size: 13px;
    color: var(--gray-text);
    margin-top: 2px;
}

/* ============================================
   环形图
   ============================================ */

.donut-chart-container {
    display: flex;
    align-items: center;
    gap: 24px;
    flex-wrap: wrap;
}

.donut-chart {
    flex-shrink: 0;
}

.donut-legend {
    display: flex;
    flex-direction: column;
    gap: 8px;
}

.legend-item {
    display: flex;
    align-items: center;
    gap: 8px;
    font-size: 14px;
}

.legend-dot {
    width: 12px;
    height: 12px;
    border-radius: 3px;
    flex-shrink: 0;
}

/* ============================================
   面板/区块
   ============================================ */

.panel {
    background: #fff;
    border-radius: var(--radius);
    padding: 20px;
    box-shadow: var(--shadow);
    margin-bottom: 20px;
}

.panel-title {
    font-size: 16px;
    font-weight: 600;
    margin-bottom: 16px;
    display: flex;
    align-items: center;
    justify-content: space-between;
}

.panel-row {
    display: flex;
    gap: 20px;
    flex-wrap: wrap;
}

.panel-col {
    flex: 1;
    min-width: 240px;
}

/* ============================================
   名单表格
   ============================================ */

.table-container {
    background: #fff;
    border-radius: var(--radius);
    box-shadow: var(--shadow);
    overflow: hidden;
    margin-bottom: 20px;
}

.table-toolbar {
    padding: 16px 20px;
    display: flex;
    gap: 12px;
    align-items: center;
    flex-wrap: wrap;
    border-bottom: 1px solid var(--gray-border);
}

.table-toolbar .search-box {
    flex: 1;
    min-width: 200px;
    padding: 8px 12px;
    border: 1px solid var(--gray-border);
    border-radius: var(--radius-sm);
    font-size: 14px;
}

.filter-tabs {
    display: flex;
    gap: 4px;
    background: var(--gray-bg);
    padding: 4px;
    border-radius: var(--radius-sm);
}

.filter-tab {
    padding: 6px 14px;
    border-radius: 6px;
    font-size: 13px;
    cursor: pointer;
    color: var(--gray-text);
    transition: all 0.2s;
}

.filter-tab.active {
    background: #fff;
    color: var(--primary);
    font-weight: 600;
    box-shadow: 0 1px 3px rgba(0,0,0,0.1);
}

.table-scroll {
    overflow-x: auto;
}

.table-scroll .data-table {
    min-width: 600px;
}

.selection-tag {
    display: inline-block;
    padding: 2px 10px;
    border-radius: 20px;
    font-size: 12px;
    font-weight: 500;
}

.selection-tag.double { background: var(--primary-light); color: var(--primary); }
.selection-tag.single { background: var(--warning-bg); color: var(--warning); }
.selection-tag.none { background: #f0f0f0; color: var(--gray-text); }
.selection-tag.pending { background: var(--danger-bg); color: var(--danger); }

/* ============================================
   代改弹窗
   ============================================ */

.edit-modal .option-row {
    display: flex;
    align-items: center;
    gap: 10px;
    padding: 12px;
    border: 2px solid var(--gray-border);
    border-radius: var(--radius-sm);
    margin-bottom: 8px;
    cursor: pointer;
    transition: border-color 0.2s;
}

.edit-modal .option-row:hover {
    border-color: var(--primary);
}

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

.edit-modal .radio-dot {
    width: 18px;
    height: 18px;
    border: 2px solid var(--gray-border);
    border-radius: 50%;
    flex-shrink: 0;
    transition: border-color 0.2s;
}

.edit-modal .option-row.selected .radio-dot {
    border-color: var(--primary);
    background: var(--primary);
    box-shadow: inset 0 0 0 3px #fff;
}

/* ============================================
   邀请码卡片
   ============================================ */

.code-card {
    display: flex;
    align-items: center;
    justify-content: space-between;
    padding: 12px 16px;
    background: var(--gray-bg);
    border-radius: var(--radius-sm);
    margin-bottom: 8px;
}

.code-card .code-value {
    font-size: 20px;
    font-weight: 700;
    letter-spacing: 4px;
    color: var(--primary);
    font-family: 'Courier New', monospace;
}

.code-card .code-actions {
    display: flex;
    gap: 8px;
}

/* ============================================
   通知文案区
   ============================================ */

.notification-section {
    margin-bottom: 20px;
}

.notification-card {
    background: #fff;
    border-radius: var(--radius);
    padding: 20px;
    box-shadow: var(--shadow);
    margin-bottom: 16px;
}

.notification-card h3 {
    font-size: 16px;
    margin-bottom: 12px;
    display: flex;
    align-items: center;
    gap: 8px;
}

.notification-card .notification-meta {
    font-size: 12px;
    color: var(--gray-text);
    margin-bottom: 8px;
}

.notification-body {
    background: var(--gray-bg);
    border-radius: var(--radius-sm);
    padding: 14px;
    font-size: 14px;
    line-height: 1.8;
    white-space: pre-wrap;
    max-height: 300px;
    overflow-y: auto;
}

/* ============================================
   学期选择器
   ============================================ */

.semester-selector {
    display: flex;
    align-items: center;
    gap: 12px;
    padding: 12px 16px;
    background: #fff;
    border-radius: var(--radius-sm);
    box-shadow: var(--shadow);
    margin-bottom: 16px;
}

.semester-selector select {
    padding: 6px 12px;
    border: 1px solid var(--gray-border);
    border-radius: 6px;
    font-size: 14px;
    cursor: pointer;
}

.period-selector {
    display: flex;
    gap: 8px;
    flex-wrap: wrap;
    margin-bottom: 16px;
}

.period-chip {
    padding: 6px 14px;
    border-radius: 20px;
    font-size: 13px;
    cursor: pointer;
    border: 1px solid var(--gray-border);
    background: #fff;
    color: var(--gray-text);
    transition: all 0.2s;
}

.period-chip.active {
    background: var(--primary);
    color: #fff;
    border-color: var(--primary);
}

.period-chip.closed {
    opacity: 0.6;
}

/* ============================================
   文件上传
   ============================================ */

.upload-area {
    border: 2px dashed var(--gray-border);
    border-radius: var(--radius);
    padding: 32px 20px;
    text-align: center;
    cursor: pointer;
    transition: border-color 0.2s;
}

.upload-area:hover {
    border-color: var(--primary);
}

.upload-area.dragover {
    border-color: var(--primary);
    background: var(--primary-light);
}

.upload-icon {
    font-size: 40px;
    margin-bottom: 8px;
}

.upload-area p {
    color: var(--gray-text);
    font-size: 14px;
}

.upload-area .upload-link {
    color: var(--primary);
    font-weight: 500;
}

/* ============================================
   空状态
   ============================================ */

.empty-state {
    text-align: center;
    padding: 40px 20px;
    color: var(--gray-text);
}

.empty-state .empty-icon {
    font-size: 48px;
    margin-bottom: 12px;
}

.empty-state p {
    font-size: 15px;
}

/* ============================================
   响应式：小屏侧边栏收起
   ============================================ */

@media (max-width: 768px) {
    .sidebar {
        transform: translateX(-100%);
        transition: transform 0.3s;
    }

    .sidebar.open {
        transform: translateX(0);
    }

    .admin-main {
        margin-left: 0;
        padding: 16px;
    }

    .mobile-menu-btn {
        display: flex !important;
    }

    .stat-cards {
        grid-template-columns: 1fr 1fr;
    }

    .page-header {
        flex-direction: column;
        align-items: flex-start;
        gap: 8px;
    }
}

.mobile-menu-btn {
    display: none;
    position: fixed;
    top: 16px;
    right: 16px;
    z-index: 101;
    width: 40px;
    height: 40px;
    background: var(--primary);
    color: #fff;
    border-radius: 8px;
    align-items: center;
    justify-content: center;
    font-size: 20px;
    cursor: pointer;
    box-shadow: var(--shadow);
}

.sidebar-overlay {
    display: none;
    position: fixed;
    inset: 0;
    background: rgba(0,0,0,0.4);
    z-index: 99;
}

.sidebar-overlay.show {
    display: block;
}