/* ===== Variables ===== */
:root {
    --bg-primary: #0f1419;
    --bg-secondary: #1a1f2e;
    --bg-tertiary: #242b3d;
    --bg-hover: #2a3247;
    --bg-active: #2d3650;
    --text-primary: #e8ecf1;
    --text-secondary: #9ca3af;
    --text-muted: #6b7280;
    --border-color: #2d3648;
    --accent-primary: #3b82f6;
    --accent-primary-hover: #2563eb;
    --accent-success: #10b981;
    --accent-success-hover: #059669;
    --accent-danger: #ef4444;
    --accent-danger-hover: #dc2626;
    --accent-warning: #f59e0b;
    --sidebar-width: 260px;
    --sidebar-collapsed: 64px;
    --header-height: 60px;
    --transition: all 0.3s ease;
}

/* ===== Reset & Base ===== */
* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}

body {
    font-family: 'Microsoft YaHei', 'PingFang SC', 'Helvetica Neue', Arial, sans-serif;
    background: var(--bg-primary);
    color: var(--text-primary);
    font-size: 14px;
    line-height: 1.5;
    overflow: hidden;
}

a {
    text-decoration: none;
    color: inherit;
}

ul {
    list-style: none;
}

/* ===== Layout ===== */
.app {
    display: flex;
    height: 100vh;
    width: 100vw;
}

/* ===== Sidebar ===== */
.sidebar {
    width: var(--sidebar-width);
    background: var(--bg-secondary);
    border-right: 1px solid var(--border-color);
    display: flex;
    flex-direction: column;
    transition: var(--transition);
    flex-shrink: 0;
}

.sidebar.collapsed {
    width: var(--sidebar-collapsed);
}

.sidebar-header {
    height: var(--header-height);
    display: flex;
    align-items: center;
    justify-content: space-between;
    padding: 0 16px;
    border-bottom: 1px solid var(--border-color);
}

.logo {
    display: flex;
    align-items: center;
    gap: 10px;
    font-size: 16px;
    font-weight: 600;
    color: var(--text-primary);
    white-space: nowrap;
}

.logo i {
    font-size: 22px;
    color: var(--accent-primary);
}

.sidebar.collapsed .logo span {
    display: none;
}

.sidebar-toggle {
    background: none;
    border: none;
    color: var(--text-secondary);
    font-size: 18px;
    cursor: pointer;
    padding: 4px;
    border-radius: 4px;
    transition: var(--transition);
}

.sidebar-toggle:hover {
    color: var(--text-primary);
    background: var(--bg-hover);
}

.sidebar.collapsed .sidebar-toggle {
    display: none;
}

/* Sidebar Navigation */
.sidebar-nav {
    flex: 1;
    overflow-y: auto;
    padding: 8px 0;
}

.sidebar-nav::-webkit-scrollbar {
    width: 4px;
}

.sidebar-nav::-webkit-scrollbar-thumb {
    background: var(--bg-tertiary);
    border-radius: 2px;
}

.nav-item {
    position: relative;
}

.nav-link {
    display: flex;
    align-items: center;
    padding: 12px 16px;
    color: var(--text-secondary);
    transition: var(--transition);
    cursor: pointer;
    gap: 10px;
}

.nav-link > i:first-child {
    font-size: 18px;
    min-width: 22px;
    text-align: center;
}

.nav-link span {
    flex: 1;
    white-space: nowrap;
}

.nav-link .arrow {
    font-size: 16px;
    transition: var(--transition);
}

.nav-item.open .arrow {
    transform: rotate(180deg);
}

.nav-link:hover {
    color: var(--text-primary);
    background: var(--bg-hover);
}

.nav-item.active > .nav-link {
    color: var(--accent-primary);
    background: var(--bg-active);
    border-left: 3px solid var(--accent-primary);
}

.sidebar.collapsed .nav-link span,
.sidebar.collapsed .nav-link .arrow {
    display: none;
}

/* Submenu */
.submenu {
    max-height: 0;
    overflow: hidden;
    transition: max-height 0.3s ease;
    background: rgba(0,0,0,0.15);
}

.nav-item.open .submenu {
    max-height: 500px;
}

.submenu-link {
    display: flex;
    align-items: center;
    padding: 10px 16px 10px 48px;
    color: var(--text-secondary);
    font-size: 13px;
    transition: var(--transition);
    gap: 8px;
}

.submenu-link i {
    font-size: 15px;
}

.submenu-link:hover {
    color: var(--text-primary);
    background: var(--bg-hover);
}

.submenu-link.active {
    color: var(--accent-primary);
    background: var(--bg-active);
}

.sidebar.collapsed .submenu {
    display: none;
}

/* ===== Main Wrapper ===== */
.main-wrapper {
    flex: 1;
    display: flex;
    flex-direction: column;
    overflow: hidden;
}

/* ===== Header ===== */
.header {
    height: var(--header-height);
    background: var(--bg-secondary);
    border-bottom: 1px solid var(--border-color);
    display: flex;
    align-items: center;
    justify-content: space-between;
    padding: 0 20px;
    flex-shrink: 0;
}

.header-left {
    display: flex;
    align-items: center;
    gap: 16px;
}

.menu-btn {
    display: none;
    background: none;
    border: none;
    color: var(--text-secondary);
    font-size: 20px;
    cursor: pointer;
    padding: 4px;
}

.page-title {
    font-size: 18px;
    font-weight: 500;
    color: var(--text-primary);
}

.header-right {
    display: flex;
    align-items: center;
    gap: 16px;
}

.user-info {
    display: flex;
    align-items: center;
    gap: 8px;
    padding: 6px 12px;
    border-radius: 6px;
    background: var(--bg-tertiary);
}

.user-avatar {
    width: 28px;
    height: 28px;
    border-radius: 50%;
    background: var(--accent-primary);
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 16px;
}

.user-name {
    font-weight: 500;
}

.logout-btn {
    display: flex;
    align-items: center;
    gap: 6px;
    padding: 6px 14px;
    background: var(--accent-danger);
    color: #fff;
    border: none;
    border-radius: 6px;
    cursor: pointer;
    font-size: 13px;
    transition: var(--transition);
}

.logout-btn:hover {
    background: var(--accent-danger-hover);
}

/* ===== Main Content ===== */
.main-content {
    flex: 1;
    overflow-y: auto;
    padding: 20px;
    background: var(--bg-primary);
}

.page {
    display: none;
}

.page.active {
    display: block;
    animation: fadeIn 0.3s ease;
}

@keyframes fadeIn {
    from { opacity: 0; transform: translateY(10px); }
    to { opacity: 1; transform: translateY(0); }
}

/* ===== Card ===== */
.card {
    background: var(--bg-secondary);
    border: 1px solid var(--border-color);
    border-radius: 8px;
    padding: 20px;
}

.empty-card {
    display: flex;
    flex-direction: column;
    align-items: center;
    justify-content: center;
    min-height: 300px;
    gap: 16px;
    color: var(--text-muted);
}

.empty-card i {
    font-size: 48px;
}

.empty-card p {
    font-size: 16px;
}

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

.search-box {
    position: relative;
    flex: 1;
    max-width: 320px;
}

.search-box i {
    position: absolute;
    left: 12px;
    top: 50%;
    transform: translateY(-50%);
    color: var(--text-muted);
    font-size: 16px;
}

.search-box input {
    width: 100%;
    padding: 10px 12px 10px 38px;
    background: var(--bg-tertiary);
    border: 1px solid var(--border-color);
    border-radius: 6px;
    color: var(--text-primary);
    font-size: 14px;
    outline: none;
    transition: var(--transition);
}

.search-box input:focus {
    border-color: var(--accent-primary);
}

.search-box input::placeholder {
    color: var(--text-muted);
}

/* ===== Buttons ===== */
.btn {
    display: inline-flex;
    align-items: center;
    gap: 6px;
    padding: 10px 18px;
    border: none;
    border-radius: 6px;
    font-size: 14px;
    cursor: pointer;
    transition: var(--transition);
    white-space: nowrap;
}

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

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

.btn-secondary {
    background: var(--bg-tertiary);
    color: var(--text-primary);
    border: 1px solid var(--border-color);
}

.btn-secondary:hover {
    background: var(--bg-hover);
}

.btn-sm {
    padding: 5px 12px;
    font-size: 12px;
    border-radius: 4px;
}

.btn-edit {
    background: var(--accent-primary);
    color: #fff;
    margin-right: 6px;
}

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

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

.btn-delete:hover {
    background: var(--accent-danger-hover);
}

/* ===== Table ===== */
.table-responsive {
    overflow-x: auto;
}

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

.data-table th,
.data-table td {
    padding: 14px 16px;
    text-align: left;
    border-bottom: 1px solid var(--border-color);
}

.data-table th {
    font-weight: 500;
    color: var(--text-secondary);
    font-size: 13px;
    text-transform: uppercase;
    letter-spacing: 0.5px;
    background: rgba(0,0,0,0.1);
}

.data-table tbody tr {
    transition: var(--transition);
}

.data-table tbody tr:hover {
    background: var(--bg-hover);
}

.data-table tbody tr:last-child td {
    border-bottom: none;
}

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

.badge-admin {
    background: rgba(59, 130, 246, 0.15);
    color: var(--accent-primary);
}

.badge-user {
    background: rgba(16, 185, 129, 0.15);
    color: var(--accent-success);
}

.badge-success {
    background: rgba(16, 185, 129, 0.15);
    color: var(--accent-success);
}

.badge-danger {
    background: rgba(239, 68, 68, 0.15);
    color: var(--accent-danger);
}

/* ===== Permission Matrix ===== */
.permission-matrix {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(220px, 1fr));
    gap: 16px;
}

.perm-module {
    background: var(--bg-tertiary);
    border: 1px solid var(--border-color);
    border-radius: 8px;
    padding: 16px;
}

.perm-module-title {
    font-weight: 600;
    margin-bottom: 12px;
    display: flex;
    align-items: center;
    gap: 8px;
    color: var(--text-primary);
}

.perm-module-title i {
    color: var(--accent-primary);
}

.perm-grid {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 8px;
}

.perm-check {
    display: flex;
    align-items: center;
    gap: 6px;
    font-size: 13px;
    color: var(--text-secondary);
    cursor: pointer;
    padding: 4px 8px;
    border-radius: 4px;
    transition: var(--transition);
}

.perm-check:hover {
    background: var(--bg-hover);
    color: var(--text-primary);
}

.perm-check input[type="checkbox"] {
    accent-color: var(--accent-primary);
    width: 16px;
    height: 16px;
    cursor: pointer;
}

/* ===== Card Header ===== */
.card-header {
    padding: 16px 20px;
    border-bottom: 1px solid var(--border-color);
}

.card-title {
    font-size: 15px;
    font-weight: 600;
    color: var(--text-primary);
}

/* ===== Modal ===== */
.modal {
    display: none;
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    z-index: 1000;
    align-items: center;
    justify-content: center;
}

.modal.active {
    display: flex;
}

.modal-overlay {
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    background: rgba(0,0,0,0.6);
    backdrop-filter: blur(4px);
}

.modal-content {
    position: relative;
    background: var(--bg-secondary);
    border: 1px solid var(--border-color);
    border-radius: 12px;
    width: 100%;
    max-width: 480px;
    margin: 20px;
    animation: modalIn 0.3s ease;
}

@keyframes modalIn {
    from { opacity: 0; transform: scale(0.95); }
    to { opacity: 1; transform: scale(1); }
}

.modal-header {
    display: flex;
    align-items: center;
    justify-content: space-between;
    padding: 20px 24px;
    border-bottom: 1px solid var(--border-color);
}

.modal-header h3 {
    font-size: 18px;
    font-weight: 500;
}

.modal-close {
    background: none;
    border: none;
    color: var(--text-muted);
    font-size: 20px;
    cursor: pointer;
    padding: 4px;
    transition: var(--transition);
}

.modal-close:hover {
    color: var(--text-primary);
}

.modal-body {
    padding: 24px;
}

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

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

.form-group input,
.form-group select {
    width: 100%;
    padding: 10px 14px;
    background: var(--bg-tertiary);
    border: 1px solid var(--border-color);
    border-radius: 6px;
    color: var(--text-primary);
    font-size: 14px;
    outline: none;
    transition: var(--transition);
}

.form-group input:focus,
.form-group select:focus {
    border-color: var(--accent-primary);
}

.modal-footer {
    display: flex;
    justify-content: flex-end;
    gap: 12px;
    padding: 16px 24px 24px;
}

/* ===== Responsive ===== */
@media (max-width: 768px) {
    .sidebar {
        position: fixed;
        left: -260px;
        top: 0;
        height: 100vh;
        z-index: 999;
    }

    .sidebar.open {
        left: 0;
    }

    .menu-btn {
        display: block;
    }

    .main-wrapper {
        width: 100%;
    }

    .page-toolbar {
        flex-direction: column;
        align-items: stretch;
    }

    .search-box {
        max-width: 100%;
    }
}