/**
 * 图书借阅管理系统 - 自定义样式
 * 遵循UI设计规范
 */

/* ==================== CSS变量定义 ==================== */
:root {
    /* 主色调 */
    --primary-color: #2c3e50;
    --secondary-color: #3498db;
    --success-color: #27ae60;
    --warning-color: #f39c12;
    --danger-color: #e74c3c;
    --info-color: #3498db;
    
    /* 背景色 */
    --bg-color: #f5f7fa;
    --bg-light: #ffffff;
    --bg-dark: #2c3e50;
    
    /* 文字色 */
    --text-primary: #2c3e50;
    --text-secondary: #7f8c8d;
    --text-muted: #95a5a6;
    --text-light: #ffffff;
    
    /* 边框色 */
    --border-color: #dcdfe6;
    --border-light: #ebeef5;
    
    /* 阴影 */
    --shadow-sm: 0 2px 4px rgba(0,0,0,0.08);
    --shadow-md: 0 4px 12px rgba(0,0,0,0.1);
    --shadow-lg: 0 8px 24px rgba(0,0,0,0.12);
    
    /* 圆角 */
    --radius-sm: 4px;
    --radius-md: 6px;
    --radius-lg: 8px;
    --radius-xl: 12px;
    
    /* 布局尺寸 */
    --sidebar-width: 240px;
    --header-height: 60px;
    --footer-height: 40px;
    
    /* 过渡动画 */
    --transition-fast: 0.15s ease;
    --transition-normal: 0.25s ease;
    --transition-slow: 0.35s ease;
}

/* ==================== 基础重置 ==================== */
* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}

body {
    font-family: 'Microsoft YaHei', 'PingFang SC', -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, sans-serif;
    font-size: 14px;
    line-height: 1.5;
    color: var(--text-primary);
    background-color: var(--bg-color);
    overflow-x: hidden;
}

a {
    color: var(--secondary-color);
    text-decoration: none;
    transition: color var(--transition-fast);
}

a:hover {
    color: #217dbb;
}

/* ==================== 主框架布局 ==================== */
.app-container {
    display: flex;
    flex-direction: column;
    min-height: 100vh;
}

.app-header {
    position: fixed;
    top: 0;
    left: 0;
    right: 0;
    height: var(--header-height);
    background: linear-gradient(135deg, var(--primary-color) 0%, #1a252f 100%);
    box-shadow: var(--shadow-md);
    z-index: 1000;
    display: flex;
    align-items: center;
    justify-content: space-between;
    padding: 0 20px;
}

.app-body {
    display: flex;
    margin-top: var(--header-height);
    min-height: calc(100vh - var(--header-height) - var(--footer-height));
}

.app-sidebar {
    position: fixed;
    top: var(--header-height);
    left: 0;
    width: var(--sidebar-width);
    height: calc(100vh - var(--header-height));
    background: var(--bg-light);
    box-shadow: var(--shadow-sm);
    overflow-y: auto;
    transition: width var(--transition-normal);
    z-index: 999;
}

.app-main {
    margin-left: var(--sidebar-width);
    flex: 1;
    padding: 20px;
    min-height: calc(100vh - var(--header-height) - var(--footer-height));
    transition: margin-left var(--transition-normal);
}

.app-footer {
    background: var(--bg-light);
    border-top: 1px solid var(--border-light);
    padding: 10px 20px;
    text-align: center;
    color: var(--text-secondary);
    font-size: 13px;
}

/* ==================== 顶部导航栏 ==================== */
.header-logo {
    display: flex;
    align-items: center;
    color: var(--text-light);
}

.header-logo img {
    height: 36px;
    margin-right: 12px;
}

.header-logo h1 {
    font-size: 18px;
    font-weight: 600;
    margin: 0;
}

.header-nav {
    display: flex;
    align-items: center;
    gap: 20px;
}

.header-nav-item {
    color: rgba(255,255,255,0.8);
    display: flex;
    align-items: center;
    gap: 6px;
    cursor: pointer;
    padding: 8px 12px;
    border-radius: var(--radius-md);
    transition: all var(--transition-fast);
}

.header-nav-item:hover {
    color: var(--text-light);
    background: rgba(255,255,255,0.1);
}

.header-user {
    display: flex;
    align-items: center;
    gap: 10px;
    color: var(--text-light);
    cursor: pointer;
    padding: 6px 12px;
    border-radius: var(--radius-md);
    transition: background var(--transition-fast);
}

.header-user:hover {
    background: rgba(255,255,255,0.1);
}

.header-user-avatar {
    width: 36px;
    height: 36px;
    border-radius: 50%;
    background: var(--secondary-color);
    display: flex;
    align-items: center;
    justify-content: center;
}

.header-user-name {
    font-size: 14px;
}

/* ==================== 侧边栏菜单 ==================== */
.sidebar-menu {
    padding: 10px 0;
}

.menu-item {
    display: block;
    padding: 0;
    margin: 4px 8px;
    border-radius: var(--radius-md);
    overflow: hidden;
}

.menu-link {
    display: flex;
    align-items: center;
    padding: 12px 16px;
    color: var(--text-primary);
    transition: all var(--transition-fast);
    cursor: pointer;
}

.menu-link:hover {
    background: var(--bg-color);
    color: var(--secondary-color);
}

.menu-link.active {
    background: linear-gradient(135deg, var(--secondary-color) 0%, #2980b9 100%);
    color: var(--text-light);
}

.menu-icon {
    width: 20px;
    margin-right: 12px;
    text-align: center;
    font-size: 16px;
}

.menu-text {
    flex: 1;
    font-size: 14px;
}

.menu-arrow {
    font-size: 12px;
    transition: transform var(--transition-fast);
}

.menu-item.open .menu-arrow {
    transform: rotate(90deg);
}

.submenu {
    display: none;
    background: var(--bg-color);
    border-radius: 0 0 var(--radius-md) var(--radius-md);
}

.menu-item.open .submenu {
    display: block;
}

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

.submenu-link:hover {
    color: var(--secondary-color);
    background: rgba(52,152,219,0.08);
}

.submenu-link.active {
    color: var(--secondary-color);
    font-weight: 500;
}

/* ==================== 卡片组件 ==================== */
.card {
    background: var(--bg-light);
    border-radius: var(--radius-lg);
    box-shadow: var(--shadow-sm);
    margin-bottom: 20px;
    transition: box-shadow var(--transition-fast);
}

.card:hover {
    box-shadow: var(--shadow-md);
}

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

.card-title {
    font-size: 16px;
    font-weight: 600;
    color: var(--text-primary);
    margin: 0;
}

.card-body {
    padding: 20px;
}

.card-footer {
    padding: 16px 20px;
    border-top: 1px solid var(--border-light);
    background: var(--bg-color);
    border-radius: 0 0 var(--radius-lg) var(--radius-lg);
}

/* ==================== 统计卡片 ==================== */
.stat-cards {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(240px, 1fr));
    gap: 20px;
    margin-bottom: 24px;
}

.stat-card {
    background: var(--bg-light);
    border-radius: var(--radius-lg);
    padding: 24px;
    display: flex;
    align-items: center;
    gap: 20px;
    box-shadow: var(--shadow-sm);
    transition: all var(--transition-normal);
    position: relative;
    overflow: hidden;
}

.stat-card::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    width: 4px;
    height: 100%;
}

.stat-card.primary::before { background: var(--secondary-color); }
.stat-card.success::before { background: var(--success-color); }
.stat-card.warning::before { background: var(--warning-color); }
.stat-card.danger::before { background: var(--danger-color); }

.stat-card:hover {
    transform: translateY(-4px);
    box-shadow: var(--shadow-md);
}

.stat-icon {
    width: 60px;
    height: 60px;
    border-radius: var(--radius-lg);
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 28px;
    color: var(--text-light);
}

.stat-card.primary .stat-icon { background: linear-gradient(135deg, var(--secondary-color) 0%, #2980b9 100%); }
.stat-card.success .stat-icon { background: linear-gradient(135deg, var(--success-color) 0%, #1e8449 100%); }
.stat-card.warning .stat-icon { background: linear-gradient(135deg, var(--warning-color) 0%, #d68910 100%); }
.stat-card.danger .stat-icon { background: linear-gradient(135deg, var(--danger-color) 0%, #c0392b 100%); }

.stat-content {
    flex: 1;
}

.stat-value {
    font-size: 28px;
    font-weight: 700;
    color: var(--text-primary);
    line-height: 1.2;
}

.stat-label {
    font-size: 14px;
    color: var(--text-secondary);
    margin-top: 4px;
}

/* ==================== 按钮组件 ==================== */
.btn {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    gap: 6px;
    padding: 0 16px;
    height: 36px;
    font-size: 14px;
    font-weight: 500;
    border-radius: var(--radius-md);
    border: none;
    cursor: pointer;
    transition: all var(--transition-fast);
    text-decoration: none;
}

.btn-lg { height: 42px; padding: 0 20px; font-size: 15px; }
.btn-sm { height: 30px; padding: 0 12px; font-size: 13px; }

.btn-primary {
    background: linear-gradient(135deg, var(--primary-color) 0%, #1a252f 100%);
    color: var(--text-light);
}

.btn-primary:hover {
    background: linear-gradient(135deg, #34495e 0%, #2c3e50 100%);
    transform: translateY(-1px);
    box-shadow: var(--shadow-sm);
}

.btn-secondary {
    background: var(--secondary-color);
    color: var(--text-light);
}

.btn-secondary:hover {
    background: #2980b9;
}

.btn-success {
    background: var(--success-color);
    color: var(--text-light);
}

.btn-success:hover {
    background: #1e8449;
}

.btn-warning {
    background: var(--warning-color);
    color: var(--text-light);
}

.btn-warning:hover {
    background: #d68910;
}

.btn-danger {
    background: var(--danger-color);
    color: var(--text-light);
}

.btn-danger:hover {
    background: #c0392b;
}

.btn-outline {
    background: transparent;
    border: 1px solid var(--border-color);
    color: var(--text-primary);
}

.btn-outline:hover {
    border-color: var(--secondary-color);
    color: var(--secondary-color);
}

/* ==================== 表单组件 ==================== */
.form-group {
    margin-bottom: 20px;
}

.form-label {
    display: block;
    margin-bottom: 8px;
    font-size: 14px;
    font-weight: 500;
    color: var(--text-primary);
}

.form-label .required {
    color: var(--danger-color);
    margin-left: 4px;
}

.form-control {
    width: 100%;
    height: 38px;
    padding: 0 12px;
    font-size: 14px;
    color: var(--text-primary);
    background: var(--bg-light);
    border: 1px solid var(--border-color);
    border-radius: var(--radius-sm);
    transition: all var(--transition-fast);
}

.form-control:focus {
    outline: none;
    border-color: var(--secondary-color);
    box-shadow: 0 0 0 3px rgba(52,152,219,0.15);
}

.form-control.error {
    border-color: var(--danger-color);
}

.form-error {
    font-size: 12px;
    color: var(--danger-color);
    margin-top: 4px;
}

textarea.form-control {
    height: auto;
    padding: 10px 12px;
    min-height: 100px;
    resize: vertical;
}

.form-select {
    appearance: none;
    background-image: url("data:image/svg+xml,%3csvg xmlns='http://www.w3.org/2000/svg' viewBox='0 0 16 16'%3e%3cpath fill='none' stroke='%23343a40' stroke-linecap='round' stroke-linejoin='round' stroke-width='2' d='m2 5 6 6 6-6'/%3e%3c/svg%3e");
    background-repeat: no-repeat;
    background-position: right 12px center;
    background-size: 12px;
    padding-right: 36px;
}

/* ==================== 表格组件 ==================== */
.table-wrapper {
    overflow-x: auto;
    background: var(--bg-light);
    border-radius: var(--radius-lg);
}

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

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

.table th {
    font-weight: 600;
    color: var(--text-primary);
    background: var(--bg-color);
    white-space: nowrap;
}

.table tbody tr:hover {
    background: rgba(52,152,219,0.04);
}

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

/* ==================== 状态标签 ==================== */
.badge {
    display: inline-flex;
    align-items: center;
    padding: 4px 10px;
    font-size: 12px;
    font-weight: 500;
    border-radius: 20px;
}

.badge-primary { background: rgba(52,152,219,0.1); color: var(--secondary-color); }
.badge-success { background: rgba(39,174,96,0.1); color: var(--success-color); }
.badge-warning { background: rgba(243,156,18,0.1); color: var(--warning-color); }
.badge-danger { background: rgba(231,76,60,0.1); color: var(--danger-color); }
.badge-secondary { background: rgba(127,140,141,0.1); color: var(--text-secondary); }

/* ==================== 分页组件 ==================== */
.pagination {
    display: flex;
    align-items: center;
    justify-content: center;
    gap: 8px;
    padding: 20px 0;
}

.pagination-item {
    min-width: 36px;
    height: 36px;
    display: flex;
    align-items: center;
    justify-content: center;
    padding: 0 10px;
    border-radius: var(--radius-sm);
    color: var(--text-primary);
    cursor: pointer;
    transition: all var(--transition-fast);
}

.pagination-item:hover {
    background: var(--bg-color);
    color: var(--secondary-color);
}

.pagination-item.active {
    background: var(--secondary-color);
    color: var(--text-light);
}

.pagination-item.disabled {
    color: var(--text-muted);
    cursor: not-allowed;
}

/* ==================== 面包屑导航 ==================== */
.breadcrumb {
    display: flex;
    align-items: center;
    gap: 8px;
    margin-bottom: 20px;
    font-size: 14px;
}

.breadcrumb-item {
    color: var(--text-secondary);
}

.breadcrumb-item a {
    color: var(--text-secondary);
}

.breadcrumb-item a:hover {
    color: var(--secondary-color);
}

.breadcrumb-item.active {
    color: var(--text-primary);
    font-weight: 500;
}

.breadcrumb-separator {
    color: var(--text-muted);
}

/* ==================== 搜索栏 ==================== */
.search-bar {
    display: flex;
    align-items: center;
    gap: 12px;
    padding: 16px 20px;
    background: var(--bg-light);
    border-radius: var(--radius-lg);
    margin-bottom: 20px;
    flex-wrap: wrap;
}

.search-input {
    flex: 1;
    min-width: 200px;
}

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

.toolbar-left,
.toolbar-right {
    display: flex;
    align-items: center;
    gap: 10px;
}

/* ==================== 加载动画 ==================== */
.loading {
    display: flex;
    align-items: center;
    justify-content: center;
    padding: 40px;
}

.loading-spinner {
    width: 40px;
    height: 40px;
    border: 3px solid var(--border-light);
    border-top-color: var(--secondary-color);
    border-radius: 50%;
    animation: spin 0.8s linear infinite;
}

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

/* ==================== 空状态 ==================== */
.empty-state {
    display: flex;
    flex-direction: column;
    align-items: center;
    justify-content: center;
    padding: 60px 20px;
    color: var(--text-secondary);
}

.empty-state-icon {
    font-size: 64px;
    color: var(--border-color);
    margin-bottom: 16px;
}

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

/* ==================== iframe内容区 ==================== */
.iframe-container {
    width: 100%;
    height: calc(100vh - var(--header-height) - 40px);
    border: none;
}

/* ==================== 响应式 ==================== */
@media (max-width: 768px) {
    .app-sidebar {
        width: 0;
        transform: translateX(-100%);
    }
    
    .app-sidebar.open {
        width: var(--sidebar-width);
        transform: translateX(0);
    }
    
    .app-main {
        margin-left: 0;
    }
    
    .stat-cards {
        grid-template-columns: 1fr;
    }
    
    .header-logo h1 {
        display: none;
    }
    
    .menu-toggle {
        display: flex;
    }
}

.menu-toggle {
    display: none;
    width: 40px;
    height: 40px;
    align-items: center;
    justify-content: center;
    color: var(--text-light);
    cursor: pointer;
    font-size: 20px;
}

/* ==================== 滚动条美化 ==================== */
::-webkit-scrollbar {
    width: 6px;
    height: 6px;
}

::-webkit-scrollbar-track {
    background: var(--bg-color);
}

::-webkit-scrollbar-thumb {
    background: var(--border-color);
    border-radius: 3px;
}

::-webkit-scrollbar-thumb:hover {
    background: var(--text-muted);
}

/* ==================== 工具类 ==================== */
.text-primary { color: var(--primary-color) !important; }
.text-secondary { color: var(--text-secondary) !important; }
.text-success { color: var(--success-color) !important; }
.text-warning { color: var(--warning-color) !important; }
.text-danger { color: var(--danger-color) !important; }

.bg-primary { background-color: var(--primary-color) !important; }
.bg-secondary { background-color: var(--secondary-color) !important; }
.bg-success { background-color: var(--success-color) !important; }
.bg-warning { background-color: var(--warning-color) !important; }
.bg-danger { background-color: var(--danger-color) !important; }

.mt-0 { margin-top: 0 !important; }
.mt-1 { margin-top: 8px !important; }
.mt-2 { margin-top: 16px !important; }
.mt-3 { margin-top: 24px !important; }
.mb-0 { margin-bottom: 0 !important; }
.mb-1 { margin-bottom: 8px !important; }
.mb-2 { margin-bottom: 16px !important; }
.mb-3 { margin-bottom: 24px !important; }

.d-flex { display: flex !important; }
.align-center { align-items: center !important; }
.justify-between { justify-content: space-between !important; }
.gap-1 { gap: 8px !important; }
.gap-2 { gap: 16px !important; }