:root {
    --primary: #2563eb;
    --primary-dark: #1d4ed8;
    --secondary: #64748b;
    --success: #10b981;
    --warning: #f59e0b;
    --danger: #ef4444;
    --dark: #1e293b;
    --light: #f1f5f9;
    --white: #ffffff;
    --border: #e2e8f0;
    --shadow: 0 1px 3px rgba(0,0,0,0.1);
    --radius: 8px;
}

* { box-sizing: border-box; }

body {
    margin: 0;
    font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, "Helvetica Neue", Arial, sans-serif;
    background: var(--light);
    color: var(--dark);
    font-size: 14px;
}

/* 登录页 */
.login-body {
    background: linear-gradient(135deg, var(--primary) 0%, #1e3a8a 100%);
    min-height: 100vh;
    display: flex;
    align-items: center;
    justify-content: center;
    padding: 20px;
}

.login-box {
    background: var(--white);
    border-radius: var(--radius);
    box-shadow: 0 20px 60px rgba(0,0,0,0.3);
    width: 100%;
    max-width: 420px;
    padding: 40px;
}

.login-box h1 {
    margin: 0 0 8px;
    font-size: 24px;
    color: var(--dark);
    text-align: center;
}

.login-box .subtitle {
    text-align: center;
    color: var(--secondary);
    margin-bottom: 30px;
}

.form-group {
    margin-bottom: 20px;
}

.form-group label {
    display: block;
    margin-bottom: 6px;
    font-weight: 500;
}

.form-control {
    width: 100%;
    padding: 12px 14px;
    border: 1px solid var(--border);
    border-radius: var(--radius);
    font-size: 14px;
    transition: border-color .2s;
}

.form-control:focus {
    outline: none;
    border-color: var(--primary);
}

.btn {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    gap: 6px;
    padding: 10px 18px;
    border: none;
    border-radius: var(--radius);
    font-size: 14px;
    cursor: pointer;
    transition: all .2s;
    text-decoration: none;
}

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

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

.btn-success { background: var(--success); color: var(--white); }
.btn-danger { background: var(--danger); color: var(--white); }
.btn-secondary { background: var(--secondary); color: var(--white); }

.btn-sm { padding: 6px 12px; font-size: 13px; }

.btn-block { width: 100%; }

.alert {
    padding: 12px 16px;
    border-radius: var(--radius);
    margin-bottom: 20px;
}

.alert-danger { background: #fee2e2; color: #991b1b; }
.alert-success { background: #d1fae5; color: #065f46; }

/* 布局 */
.layout {
    display: flex;
    min-height: 100vh;
}

.sidebar {
    width: 240px;
    background: var(--dark);
    color: var(--white);
    display: flex;
    flex-direction: column;
    position: fixed;
    left: 0;
    top: 0;
    bottom: 0;
    z-index: 100;
    transition: transform .3s;
}

.brand {
    padding: 20px;
    font-size: 18px;
    font-weight: 700;
    border-bottom: 1px solid rgba(255,255,255,0.1);
    display: flex;
    align-items: center;
    gap: 10px;
}

.nav { flex: 1; padding: 12px 0; }

.nav a {
    display: flex;
    align-items: center;
    gap: 12px;
    padding: 14px 20px;
    color: rgba(255,255,255,0.8);
    text-decoration: none;
    transition: all .2s;
}

.nav a:hover,
.nav a.active {
    background: rgba(255,255,255,0.1);
    color: var(--white);
}

.logout {
    padding: 12px 0;
    border-top: 1px solid rgba(255,255,255,0.1);
}

.logout a {
    display: flex;
    align-items: center;
    gap: 12px;
    padding: 14px 20px;
    color: rgba(255,255,255,0.7);
    text-decoration: none;
}

.main {
    flex: 1;
    margin-left: 240px;
    display: flex;
    flex-direction: column;
}

.topbar {
    height: 60px;
    background: var(--white);
    border-bottom: 1px solid var(--border);
    display: flex;
    align-items: center;
    padding: 0 24px;
    gap: 16px;
    position: sticky;
    top: 0;
}

.menu-toggle {
    display: none;
    background: none;
    border: none;
    font-size: 20px;
    cursor: pointer;
    color: var(--dark);
}

.topbar-title {
    flex: 1;
    font-size: 18px;
    font-weight: 600;
}

.topbar-user {
    display: flex;
    align-items: center;
    gap: 6px;
    color: var(--secondary);
}

.content {
    padding: 24px;
    flex: 1;
}

/* 卡片 */
.card {
    background: var(--white);
    border-radius: var(--radius);
    box-shadow: var(--shadow);
    margin-bottom: 20px;
}

.card-header {
    padding: 16px 20px;
    border-bottom: 1px solid var(--border);
    display: flex;
    align-items: center;
    justify-content: space-between;
    flex-wrap: wrap;
    gap: 10px;
}

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

.card-body { padding: 20px; }

/* 统计 */
.stats-grid {
    display: grid;
    grid-template-columns: repeat(4, 1fr);
    gap: 20px;
    margin-bottom: 24px;
}

.stat-card {
    background: var(--white);
    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: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 20px;
    color: var(--white);
}

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

.stat-info h3 {
    margin: 0;
    font-size: 24px;
    font-weight: 700;
}

.stat-info p {
    margin: 4px 0 0;
    color: var(--secondary);
}

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

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

th, td {
    padding: 12px 16px;
    text-align: left;
    border-bottom: 1px solid var(--border);
}

th {
    background: var(--light);
    font-weight: 600;
    color: var(--secondary);
    font-size: 13px;
    text-transform: uppercase;
}

tr:hover { background: #f8fafc; }

.badge {
    display: inline-block;
    padding: 4px 10px;
    border-radius: 20px;
    font-size: 12px;
    font-weight: 500;
}

.badge-success { background: #d1fae5; color: #065f46; }
.badge-danger { background: #fee2e2; color: #991b1b; }
.badge-warning { background: #fef3c7; color: #92400e; }
.badge-secondary { background: #e2e8f0; color: #475569; }

/* 进度条 */
.progress-bar-wrap { margin-bottom: 10px; }
.progress-bar {
    height: 28px;
    border-radius: var(--radius);
    overflow: hidden;
    display: flex;
    background: #e2e8f0;
    margin-bottom: 12px;
}
.progress-paid { background: var(--success); height: 100%; }
.progress-unpaid { background: var(--warning); height: 100%; }
.progress-cancel { background: var(--danger); height: 100%; }
.progress-legend { display: flex; gap: 20px; flex-wrap: wrap; font-size: 13px; }
.progress-legend .dot {
    display: inline-block;
    width: 10px; height: 10px;
    border-radius: 50%;
    margin-right: 4px;
}
.progress-legend .dot.green { background: var(--success); }
.progress-legend .dot.orange { background: var(--warning); }
.progress-legend .dot.red { background: var(--danger); }

/* 分页 */
.pagination {
    display: flex;
    gap: 6px;
    margin-top: 20px;
    justify-content: center;
    flex-wrap: wrap;
}

.pagination a, .pagination span {
    padding: 6px 12px;
    border-radius: var(--radius);
    border: 1px solid var(--border);
    text-decoration: none;
    color: var(--dark);
}

.pagination a:hover { background: var(--light); }
.pagination .current { background: var(--primary); color: var(--white); border-color: var(--primary); }

/* 响应式 */
@media (max-width: 992px) {
    .stats-grid { grid-template-columns: repeat(2, 1fr); }
}

@media (max-width: 768px) {
    .sidebar {
        transform: translateX(-100%);
    }
    .sidebar.open { transform: translateX(0); }
    .main { margin-left: 0; }
    .menu-toggle { display: block; }
    .stats-grid { grid-template-columns: 1fr; }
    .card-header { flex-direction: column; align-items: flex-start; }
    .topbar { padding: 0 16px; }
    .content { padding: 16px; }
    .login-box { padding: 28px; }
}