:root {
    --bg-primary: #0a0a1a;
    --bg-secondary: #1a1a2e;
    --bg-card: #16213e;
    --text-primary: #e0e0e0;
    --text-secondary: #a0a0a0;
    --accent: #667eea;
    --accent-gradient: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    --border: #2a2a3e;
    --success: #4ade80;
    --warning: #fbbf24;
    --danger: #f87171;
}

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

body {
    font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, sans-serif;
    background: var(--bg-primary);
    color: var(--text-primary);
    min-height: 100vh;
}

#app { display: flex; min-height: 100vh; }

/* 侧边栏 */
.sidebar {
    width: 200px;
    background: var(--bg-secondary);
    border-right: 1px solid var(--border);
    padding: 20px 0;
    position: fixed;
    height: 100vh;
    overflow-y: auto;
    z-index: 100;
}

.logo {
    padding: 0 20px 20px;
    font-size: 18px;
    font-weight: bold;
    border-bottom: 1px solid var(--border);
    margin-bottom: 10px;
}

.version-badge {
    background: var(--accent-gradient);
    color: white;
    padding: 4px 12px;
    border-radius: 12px;
    font-size: 12px;
    font-weight: 600;
    margin-right: 10px;
}

.filter-bar {
    display: flex;
    gap: 15px;
    align-items: flex-end;
    padding: 15px 20px;
    background: var(--bg-card);
    border-radius: 8px;
    margin-bottom: 20px;
}

.filter-bar .form-group.inline {
    display: flex;
    flex-direction: column;
    gap: 5px;
}

.filter-bar .form-group.inline label {
    font-size: 12px;
    color: var(--text-secondary);
}

.filter-bar .form-group.inline input {
    padding: 8px 12px;
    border: 1px solid var(--border);
    border-radius: 6px;
    background: var(--bg-secondary);
    color: var(--text-primary);
    font-size: 14px;
}

.filter-bar .btn-primary {
    padding: 8px 20px;
    height: fit-content;
}

.menu { list-style: none; }
.menu li {
    padding: 12px 20px;
    cursor: pointer;
    transition: all 0.3s;
    border-left: 3px solid transparent;
    font-size: 14px;
}
.menu li:hover { background: rgba(102, 126, 234, 0.1); }
.menu li.active {
    background: rgba(102, 126, 234, 0.15);
    border-left-color: var(--accent);
    color: var(--accent);
}

/* 主内容区 */
.main-content {
    flex: 1;
    margin-left: 200px;
    padding: 20px;
    min-height: 100vh;
}

.top-bar {
    display: flex;
    justify-content: space-between;
    align-items: center;
    margin-bottom: 20px;
    padding-bottom: 15px;
    border-bottom: 1px solid var(--border);
}

.btn-primary {
    background: var(--accent-gradient);
    color: white;
    border: none;
    padding: 10px 20px;
    border-radius: 8px;
    cursor: pointer;
    font-size: 14px;
}
.btn-primary:hover { opacity: 0.9; }

.btn-secondary {
    background: var(--bg-card);
    color: var(--text-primary);
    border: 1px solid var(--border);
    padding: 8px 16px;
    border-radius: 8px;
    cursor: pointer;
}

.btn-danger {
    background: var(--danger);
    color: white;
    border: none;
    padding: 8px 16px;
    border-radius: 8px;
    cursor: pointer;
}

/* 卡片 */
.card {
    background: var(--bg-card);
    border-radius: 12px;
    padding: 20px;
    margin-bottom: 15px;
    border: 1px solid var(--border);
}

.card-header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    margin-bottom: 15px;
}

.card-title { font-size: 16px; font-weight: 600; }

/* 课程计划卡片网格 */
.course-plans-grid {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(350px, 1fr));
    gap: 20px;
    padding: 20px 0;
}

.course-plan-card {
    background: var(--bg-card);
    border-radius: 12px;
    padding: 20px;
    border: 1px solid var(--border);
    transition: transform 0.2s, box-shadow 0.2s;
    cursor: pointer;
}

.course-plan-card:hover {
    transform: translateY(-2px);
    box-shadow: 0 8px 25px rgba(102, 126, 234, 0.15);
}

.course-plan-card-header {
    display: flex;
    justify-content: space-between;
    align-items: flex-start;
    margin-bottom: 15px;
}

.course-plan-card-title {
    font-size: 18px;
    font-weight: 600;
    color: var(--text-primary);
    margin-bottom: 5px;
}

.course-plan-archived-badge {
    font-size: 12px;
    font-weight: 500;
    color: #f59e0b;
    background: rgba(245, 158, 11, 0.12);
    padding: 2px 8px;
    border-radius: 4px;
    margin-left: 8px;
    vertical-align: middle;
}

.course-plan-card-student {
    font-size: 14px;
    color: var(--text-secondary);
}

.course-plan-card-type {
    padding: 4px 12px;
    border-radius: 20px;
    font-size: 12px;
    font-weight: 500;
}

.course-plan-card-type.holiday {
    background: rgba(102, 126, 234, 0.2);
    color: #667eea;
}

.course-plan-card-type.short_term {
    background: rgba(74, 222, 128, 0.2);
    color: #4ade80;
}

.course-plan-card-type.semester {
    background: rgba(251, 191, 36, 0.2);
    color: #fbbf24;
}

.course-plan-card-body {
    margin-bottom: 15px;
}

.course-plan-card-info {
    display: flex;
    flex-wrap: wrap;
    gap: 10px;
    margin-bottom: 15px;
}

.course-plan-card-info-item {
    display: flex;
    align-items: center;
    gap: 5px;
    font-size: 13px;
    color: var(--text-secondary);
}

.course-plan-card-info-item i {
    font-size: 14px;
}

.course-plan-card-progress {
    margin-bottom: 10px;
}

.course-plan-card-progress-label {
    display: flex;
    justify-content: space-between;
    font-size: 12px;
    color: var(--text-secondary);
    margin-bottom: 5px;
}

.course-plan-card-progress-bar {
    height: 6px;
    background: var(--bg-secondary);
    border-radius: 3px;
    overflow: hidden;
}

.course-plan-card-progress-fill {
    height: 100%;
    background: var(--accent-gradient);
    border-radius: 3px;
    transition: width 0.3s;
}

.course-plan-card-footer {
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding-top: 15px;
    border-top: 1px solid var(--border);
}

.course-plan-card-status {
    padding: 4px 10px;
    border-radius: 20px;
    font-size: 12px;
    font-weight: 500;
}

.course-plan-card-status.active {
    background: rgba(74, 222, 128, 0.2);
    color: #4ade80;
}

.course-plan-card-status.paused {
    background: rgba(251, 191, 36, 0.2);
    color: #fbbf24;
}

.course-plan-card-status.completed {
    background: rgba(102, 126, 234, 0.2);
    color: #667eea;
}

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

/* 统计卡片 */
.stats-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(200px, 1fr));
    gap: 15px;
    margin-bottom: 20px;
}

.stat-card {
    background: var(--bg-card);
    border-radius: 12px;
    padding: 20px;
    border: 1px solid var(--border);
}

.stat-value {
    font-size: 32px;
    font-weight: bold;
    color: var(--accent);
    margin: 10px 0;
}

.stat-label { color: var(--text-secondary); font-size: 14px; }

/* 表格 */
.table-container { overflow-x: auto; }

.table {
    width: 100%;
    border-collapse: collapse;
}

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

.table th { color: var(--text-secondary); font-weight: 500; font-size: 14px; }
.table td { font-size: 14px; }
.table tr:hover { background: rgba(102, 126, 234, 0.05); }

/* 表单 */
.form-group { margin-bottom: 15px; }
.form-group label {
    display: block;
    margin-bottom: 5px;
    color: var(--text-secondary);
    font-size: 14px;
}
.form-group input,
.form-group textarea,
input, textarea, select {
    width: 100%;
    padding: 10px 12px;
    border: 1px solid var(--border);
    border-radius: 6px;
    background: var(--bg-secondary);
    color: var(--text-primary);
    font-size: 14px;
}

select[multiple] {
    height: auto;
    min-height: 80px;
}

select option {
    padding: 6px;
}

.form-group small {
    color: var(--text-secondary);
    font-size: 12px;
    margin-top: 4px;
    display: block;
}
.form-group input:focus,
.form-group textarea:focus {
    outline: none;
    border-color: var(--accent);
}

/* 模态框 */
.modal {
    display: none;
    position: fixed;
    top: 0; left: 0;
    width: 100%; height: 100%;
    background: rgba(0,0,0,0.7);
    justify-content: center;
    align-items: center;
    z-index: 1000;
}
.modal.active { display: flex; }

.modal-content {
    background: var(--bg-card);
    border-radius: 12px;
    width: 90%;
    max-width: 500px;
    max-height: 90vh;
    overflow-y: auto;
    border: 1px solid var(--border);
}

.modal-header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: 20px;
    border-bottom: 1px solid var(--border);
}

.modal-close {
    background: none;
    border: none;
    color: var(--text-secondary);
    font-size: 24px;
    cursor: pointer;
}

.modal-body { padding: 20px; }

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

/* 空状态 */
.empty-state {
    text-align: center;
    padding: 60px 20px;
    color: var(--text-secondary);
}
.empty-state-icon { font-size: 48px; margin-bottom: 15px; }

/* 学生卡片网格 */
.student-grid {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(320px, 1fr));
    gap: 20px;
    padding: 20px;
}

.student-card {
    background: var(--bg-card);
    border-radius: 12px;
    padding: 20px;
    border: 1px solid var(--border);
    cursor: pointer;
    transition: transform 0.2s, box-shadow 0.2s;
}

.student-card:hover {
    transform: translateY(-2px);
    box-shadow: 0 8px 24px rgba(102, 126, 234, 0.15);
}

.student-card-header {
    display: flex;
    align-items: center;
    gap: 12px;
    margin-bottom: 16px;
}

.student-avatar {
    width: 48px;
    height: 48px;
    border-radius: 50%;
    background: var(--accent-gradient);
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 24px;
    flex-shrink: 0;
}

.student-avatar.avatar-male {
    background: linear-gradient(135deg, #4a90e2 0%, #357abd 100%);
}

.student-avatar.avatar-female {
    background: linear-gradient(135deg, #e74c8c 0%, #c0397c 100%);
}

.student-avatar.avatar-default {
    background: linear-gradient(135deg, #95a5a6 0%, #7f8c8d 100%);
}

.gender-tag {
    display: inline-block;
    padding: 2px 8px;
    border-radius: 10px;
    font-size: 11px;
    font-weight: 600;
    margin-left: 6px;
    vertical-align: middle;
}

.gender-tag.male {
    background: rgba(74, 144, 226, 0.2);
    color: #4a90e2;
}

.gender-tag.female {
    background: rgba(231, 76, 140, 0.2);
    color: #e74c8c;
}
.student-info h3 {
    font-size: 16px;
    margin-bottom: 4px;
}

.student-grade {
    font-size: 12px;
    color: var(--text-secondary);
}

.student-subjects {
    margin-left: auto;
    display: flex;
    gap: 6px;
    flex-wrap: wrap;
}

.subject-tag {
    padding: 2px 8px;
    border-radius: 12px;
    font-size: 11px;
    background: rgba(102, 126, 234, 0.2);
    color: var(--accent);
}

/* 课时信息区域 */
.student-hours-section {
    background: rgba(102, 126, 234, 0.05);
    border-radius: 8px;
    padding: 12px;
    margin-bottom: 12px;
}

.hours-stats {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: 12px;
    margin-bottom: 12px;
}

.hours-stat {
    text-align: center;
}

.hours-label {
    font-size: 11px;
    color: var(--text-secondary);
    margin-bottom: 4px;
}

.hours-value {
    font-size: 24px;
    font-weight: bold;
    color: var(--text-primary);
}

.hours-value.hours-low {
    color: var(--danger);
}

.hours-value.hours-negative {
    color: #ff4444;
    font-weight: bold;
}

.hours-warning {
    font-size: 11px;
    color: #ff4444;
    margin-top: 4px;
    font-weight: bold;
}

.hours-price {
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: 8px 0;
    border-top: 1px solid var(--border);
    font-size: 13px;
}

.price-value {
    color: var(--accent);
    font-weight: bold;
}

.hours-progress {
    margin-top: 8px;
}

.progress-bar {
    height: 6px;
    background: var(--bg-secondary);
    border-radius: 3px;
    overflow: hidden;
    margin-bottom: 4px;
}

.progress-fill {
    height: 100%;
    background: var(--accent-gradient);
    border-radius: 3px;
    transition: width 0.3s;
}

.progress-text {
    font-size: 11px;
    color: var(--text-secondary);
}

.student-card-footer {
    display: flex;
    gap: 8px;
    justify-content: flex-end;
}

.btn-sm {
    padding: 6px 12px;
    font-size: 12px;
}

/* 学生详情 */
.student-detail {
    max-height: 60vh;
    overflow-y: auto;
}

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

.detail-section h4 {
    font-size: 14px;
    margin-bottom: 12px;
    color: var(--accent);
}

.detail-grid {
    display: grid;
    grid-template-columns: repeat(2, 1fr);
    gap: 8px;
    font-size: 13px;
}

.detail-grid label {
    color: var(--text-secondary);
    margin-right: 4px;
}

.hour-account {
    display: grid;
    grid-template-columns: repeat(4, 1fr);
    gap: 12px;
}

.account-card {
    background: var(--bg-secondary);
    border-radius: 8px;
    padding: 12px;
    text-align: center;
}

.account-label {
    font-size: 11px;
    color: var(--text-secondary);
    margin-bottom: 4px;
}

.account-value {
    font-size: 20px;
    font-weight: bold;
}

.text-success { color: var(--success); }
.text-danger { color: var(--danger); }

/* 家长链接 */
.parent-link-box {
    display: flex;
    gap: 8px;
    align-items: center;
}

.parent-link-input {
    flex: 1;
    background: var(--bg-secondary);
    border: 1px solid var(--border);
    border-radius: 6px;
    padding: 8px 12px;
    color: var(--text-primary);
    font-size: 13px;
    font-family: monospace;
}

.link-hint {
    font-size: 12px;
    color: var(--text-secondary);
    margin-top: 8px;
}

.transaction-list {
    max-height: 200px;
    overflow-y: auto;
}

.transaction-item {
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: 8px 12px;
    border-radius: 6px;
    margin-bottom: 6px;
    background: var(--bg-secondary);
    font-size: 13px;
}

.transaction-item.purchase {
    border-left: 3px solid var(--success);
}

.transaction-item.consume {
    border-left: 3px solid var(--warning);
}

.transaction-type {
    font-weight: bold;
    margin-right: 8px;
}

.transaction-date {
    color: var(--text-secondary);
    font-size: 11px;
}

.hours.purchase { color: var(--success); }
.hours.consume { color: var(--warning); }

.balance {
    color: var(--text-secondary);
    font-size: 11px;
    margin-left: 8px;
}

.transaction-notes {
    font-size: 11px;
    color: var(--text-secondary);
    margin-top: 4px;
    width: 100%;
}

.hour-preview {
    background: var(--bg-secondary);
    border-radius: 8px;
    padding: 12px;
    margin-top: 12px;
}

.preview-item {
    display: flex;
    justify-content: space-between;
    margin-bottom: 8px;
}

/* 学生详情 - 上课记录列表 */
.student-lessons-list {
    max-height: 300px;
    overflow-y: auto;
}

.lesson-list {
    display: flex;
    flex-direction: column;
    gap: 8px;
}

.lesson-item {
    display: flex;
    gap: 12px;
    padding: 10px 12px;
    border-radius: 8px;
    background: var(--bg-secondary);
    border-left: 3px solid var(--border);
    font-size: 13px;
    align-items: flex-start;
}

.lesson-item.completed {
    border-left-color: var(--success);
}

.lesson-item.cancelled {
    border-left-color: var(--warning);
}

.lesson-item.absent {
    border-left-color: var(--danger);
}

.lesson-date {
    display: flex;
    flex-direction: column;
    min-width: 60px;
    text-align: center;
    flex-shrink: 0;
}

.date-day {
    font-weight: bold;
    color: var(--text-primary);
    font-size: 14px;
}

.date-time {
    color: var(--text-secondary);
    font-size: 11px;
    margin-top: 2px;
}

.lesson-info {
    display: flex;
    flex-direction: column;
    gap: 4px;
    flex: 1;
}

.lesson-status {
    font-size: 12px;
    font-weight: 500;
    padding: 2px 8px;
    border-radius: 4px;
    display: inline-block;
    width: fit-content;
}

.lesson-status.status-completed {
    background: rgba(74, 222, 128, 0.15);
    color: var(--success);
}

.lesson-status.status-cancelled {
    background: rgba(251, 191, 36, 0.15);
    color: var(--warning);
}

.lesson-status.status-absent {
    background: rgba(248, 113, 113, 0.15);
    color: var(--danger);
}

.lesson-duration {
    color: var(--text-secondary);
    font-size: 12px;
}

.lesson-content {
    color: var(--text-primary);
    line-height: 1.4;
    word-break: break-word;
}

.empty-text {
    color: var(--text-secondary);
    font-size: 13px;
    text-align: center;
    padding: 16px;
}

/* 响应式 */
@media (max-width: 768px) {
    .sidebar { width: 60px; }
    .sidebar .logo { font-size: 0; text-align: center; }
    .sidebar .logo::before { content: "📚"; font-size: 20px; }
    .menu li { padding: 12px; font-size: 0; text-align: center; }
    .menu li::before { font-size: 18px; }
    .main-content { margin-left: 60px; padding: 10px; }
    .stats-grid { grid-template-columns: repeat(2, 1fr); }
    .student-grid { grid-template-columns: 1fr; }
    .hour-account { grid-template-columns: repeat(2, 1fr); }
}

/* 工具栏 */
.toolbar {
    display: flex;
    justify-content: space-between;
    align-items: center;
    margin-bottom: 20px;
    gap: 16px;
}

.toolbar-left {
    flex: 1;
}

.toolbar-right {
    display: flex;
    gap: 10px;
}

/* 状态筛选按钮 */
.status-filter {
    display: flex;
    gap: 8px;
    margin-top: 10px;
    flex-wrap: wrap;
}

.status-filter-btn {
    padding: 6px 14px;
    border: 1px solid var(--border);
    border-radius: 20px;
    background: var(--bg-secondary);
    color: var(--text-secondary);
    font-size: 13px;
    cursor: pointer;
    transition: all 0.2s;
}

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

.status-filter-btn.active {
    background: var(--primary);
    color: white;
    border-color: var(--primary);
}

/* 已归档标记 */
.archived-badge {
    padding: 4px 10px;
    border-radius: 12px;
    background: rgba(251, 191, 36, 0.2);
    color: #fbbf24;
    font-size: 12px;
    font-weight: 500;
}

/* 搜索框 */
.search-box input {
    width: 100%;
    max-width: 300px;
    padding: 10px 16px;
    border: 1px solid var(--border);
    border-radius: 8px;
    background: var(--bg-secondary);
    color: var(--text-primary);
    font-size: 14px;
}

.search-box input:focus {
    outline: none;
    border-color: var(--accent);
}

/* 表单行 */
.form-row {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 16px;
}

/* 详情区块 */
.detail-section {
    margin-bottom: 24px;
    padding-bottom: 16px;
    border-bottom: 1px solid var(--border);
}

.detail-section:last-child {
    border-bottom: none;
}

.detail-section h4 {
    margin-bottom: 12px;
    color: var(--accent);
}

.detail-section p {
    margin-bottom: 8px;
    line-height: 1.6;
}

/* 小按钮 */
.btn-sm {
    padding: 6px 12px;
    font-size: 12px;
    border-radius: 6px;
    border: none;
    cursor: pointer;
    margin-right: 4px;
}

.btn-sm:last-child {
    margin-right: 0;
}