/**
 * 网盘资源搜索系统 - 公共样式
 * 冷色调配色方案 (Requirements 15.1-15.10)
 */

/* ========================================
   CSS Variables - 颜色系统
   ======================================== */
:root {
    /* 主色调 - 蓝色系 */
    --primary-color: #1890ff;
    --primary-hover: #40a9ff;
    --primary-active: #096dd9;
    --primary-light: #e6f7ff;
    
    /* 辅助色 - 青色系 */
    --secondary-color: #13c2c2;
    --secondary-hover: #36cfc9;
    --secondary-active: #08979c;
    
    /* 成功/警告/错误色 */
    --success-color: #52c41a;
    --warning-color: #faad14;
    --error-color: #ff4d4f;
    --info-color: #1890ff;
    
    /* 中性灰色 */
    --gray-1: #ffffff;
    --gray-2: #fafafa;
    --gray-3: #f5f5f5;
    --gray-4: #f0f2f5;
    --gray-5: #d9d9d9;
    --gray-6: #bfbfbf;
    --gray-7: #8c8c8c;
    --gray-8: #595959;
    --gray-9: #434343;
    --gray-10: #262626;
    --gray-11: #1f1f1f;
    --gray-12: #141414;
    
    /* 背景色 */
    --bg-base: #ffffff;
    --bg-light: #f0f2f5;
    --bg-dark: #001529;
    
    /* 文字颜色 */
    --text-primary: #262626;
    --text-secondary: #8c8c8c;
    --text-disabled: #bfbfbf;
    --text-inverse: #ffffff;
    
    /* 边框颜色 */
    --border-color: #d9d9d9;
    --border-light: #f0f0f0;
    
    /* 阴影 */
    --shadow-sm: 0 1px 2px 0 rgba(0, 0, 0, 0.03), 0 1px 6px -1px rgba(0, 0, 0, 0.02), 0 2px 4px 0 rgba(0, 0, 0, 0.02);
    --shadow-md: 0 3px 6px -4px rgba(0, 0, 0, 0.12), 0 6px 16px 0 rgba(0, 0, 0, 0.08), 0 9px 28px 8px rgba(0, 0, 0, 0.05);
    --shadow-lg: 0 6px 16px -8px rgba(0, 0, 0, 0.08), 0 9px 28px 0 rgba(0, 0, 0, 0.05), 0 12px 48px 16px rgba(0, 0, 0, 0.03);
    
    /* 圆角 */
    --radius-sm: 4px;
    --radius-md: 8px;
    --radius-lg: 12px;
    --radius-full: 9999px;
    
    /* 间距 */
    --spacing-xs: 4px;
    --spacing-sm: 8px;
    --spacing-md: 16px;
    --spacing-lg: 24px;
    --spacing-xl: 32px;
    --spacing-xxl: 48px;
    
    /* 字体 */
    --font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, 'Helvetica Neue', Arial, 'Noto Sans', sans-serif, 'Apple Color Emoji', 'Segoe UI Emoji';
    --font-family-mono: 'SFMono-Regular', Consolas, 'Liberation Mono', Menlo, Courier, monospace;
    
    /* 字号 */
    --font-size-xs: 12px;
    --font-size-sm: 14px;
    --font-size-base: 16px;
    --font-size-lg: 18px;
    --font-size-xl: 20px;
    --font-size-xxl: 24px;
    --font-size-xxxl: 30px;
    
    /* 行高 */
    --line-height-tight: 1.25;
    --line-height-normal: 1.5;
    --line-height-relaxed: 1.75;
    
    /* 过渡 */
    --transition-fast: 0.1s ease;
    --transition-normal: 0.2s ease;
    --transition-slow: 0.3s ease;
    
    /* 层级 */
    --z-dropdown: 1000;
    --z-sticky: 1020;
    --z-fixed: 1030;
    --z-modal-backdrop: 1040;
    --z-modal: 1050;
    --z-popover: 1060;
    --z-tooltip: 1070;
    --z-toast: 1080;
}

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

html {
    font-size: 16px;
    -webkit-text-size-adjust: 100%;
    -webkit-tap-highlight-color: transparent;
}


body {
    font-family: var(--font-family);
    font-size: var(--font-size-sm);
    line-height: var(--line-height-normal);
    color: var(--text-primary);
    background-color: var(--bg-light);
    -webkit-font-smoothing: antialiased;
    -moz-osx-font-smoothing: grayscale;
}

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

a:hover {
    color: var(--primary-hover);
}

img {
    max-width: 100%;
    height: auto;
    vertical-align: middle;
}

ul, ol {
    list-style: none;
}

button, input, select, textarea {
    font-family: inherit;
    font-size: inherit;
    line-height: inherit;
}

/* ========================================
   Typography - 排版
   ======================================== */
h1, h2, h3, h4, h5, h6 {
    margin-bottom: var(--spacing-sm);
    font-weight: 600;
    line-height: var(--line-height-tight);
    color: var(--text-primary);
}

h1 { font-size: var(--font-size-xxxl); }
h2 { font-size: var(--font-size-xxl); }
h3 { font-size: var(--font-size-xl); }
h4 { font-size: var(--font-size-lg); }
h5 { font-size: var(--font-size-base); }
h6 { font-size: var(--font-size-sm); }

p {
    margin-bottom: var(--spacing-md);
}

.text-primary { color: var(--primary-color); }
.text-secondary { color: var(--text-secondary); }
.text-success { color: var(--success-color); }
.text-warning { color: var(--warning-color); }
.text-error { color: var(--error-color); }
.text-muted { color: var(--text-disabled); }

.text-center { text-align: center; }
.text-left { text-align: left; }
.text-right { text-align: right; }

/* ========================================
   Layout - 布局容器
   ======================================== */
.container {
    width: 100%;
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 var(--spacing-md);
}

.container-fluid {
    width: 100%;
    padding: 0 var(--spacing-md);
}

.container-sm { max-width: 640px; }
.container-md { max-width: 768px; }
.container-lg { max-width: 1024px; }
.container-xl { max-width: 1280px; }

/* Flexbox utilities */
.flex { display: flex; }
.flex-inline { display: inline-flex; }
.flex-col { flex-direction: column; }
.flex-row { flex-direction: row; }
.flex-wrap { flex-wrap: wrap; }
.flex-nowrap { flex-wrap: nowrap; }

.items-start { align-items: flex-start; }
.items-center { align-items: center; }
.items-end { align-items: flex-end; }
.items-stretch { align-items: stretch; }

.justify-start { justify-content: flex-start; }
.justify-center { justify-content: center; }
.justify-end { justify-content: flex-end; }
.justify-between { justify-content: space-between; }
.justify-around { justify-content: space-around; }

.flex-1 { flex: 1; }
.flex-auto { flex: auto; }
.flex-none { flex: none; }

.gap-xs { gap: var(--spacing-xs); }
.gap-sm { gap: var(--spacing-sm); }
.gap-md { gap: var(--spacing-md); }
.gap-lg { gap: var(--spacing-lg); }
.gap-xl { gap: var(--spacing-xl); }

/* Grid utilities */
.grid { display: grid; }
.grid-cols-1 { grid-template-columns: repeat(1, minmax(0, 1fr)); }
.grid-cols-2 { grid-template-columns: repeat(2, minmax(0, 1fr)); }
.grid-cols-3 { grid-template-columns: repeat(3, minmax(0, 1fr)); }
.grid-cols-4 { grid-template-columns: repeat(4, minmax(0, 1fr)); }

/* ========================================
   Spacing utilities
   ======================================== */
.m-0 { margin: 0; }
.m-xs { margin: var(--spacing-xs); }
.m-sm { margin: var(--spacing-sm); }
.m-md { margin: var(--spacing-md); }
.m-lg { margin: var(--spacing-lg); }
.m-xl { margin: var(--spacing-xl); }

.mt-0 { margin-top: 0; }
.mt-xs { margin-top: var(--spacing-xs); }
.mt-sm { margin-top: var(--spacing-sm); }
.mt-md { margin-top: var(--spacing-md); }
.mt-lg { margin-top: var(--spacing-lg); }
.mt-xl { margin-top: var(--spacing-xl); }

.mb-0 { margin-bottom: 0; }
.mb-xs { margin-bottom: var(--spacing-xs); }
.mb-sm { margin-bottom: var(--spacing-sm); }
.mb-md { margin-bottom: var(--spacing-md); }
.mb-lg { margin-bottom: var(--spacing-lg); }
.mb-xl { margin-bottom: var(--spacing-xl); }

.ml-0 { margin-left: 0; }
.ml-xs { margin-left: var(--spacing-xs); }
.ml-sm { margin-left: var(--spacing-sm); }
.ml-md { margin-left: var(--spacing-md); }
.ml-lg { margin-left: var(--spacing-lg); }
.ml-auto { margin-left: auto; }

.mr-0 { margin-right: 0; }
.mr-xs { margin-right: var(--spacing-xs); }
.mr-sm { margin-right: var(--spacing-sm); }
.mr-md { margin-right: var(--spacing-md); }
.mr-lg { margin-right: var(--spacing-lg); }
.mr-auto { margin-right: auto; }

.mx-auto { margin-left: auto; margin-right: auto; }

.p-0 { padding: 0; }
.p-xs { padding: var(--spacing-xs); }
.p-sm { padding: var(--spacing-sm); }
.p-md { padding: var(--spacing-md); }
.p-lg { padding: var(--spacing-lg); }
.p-xl { padding: var(--spacing-xl); }

.pt-0 { padding-top: 0; }
.pt-sm { padding-top: var(--spacing-sm); }
.pt-md { padding-top: var(--spacing-md); }
.pt-lg { padding-top: var(--spacing-lg); }

.pb-0 { padding-bottom: 0; }
.pb-sm { padding-bottom: var(--spacing-sm); }
.pb-md { padding-bottom: var(--spacing-md); }
.pb-lg { padding-bottom: var(--spacing-lg); }

.px-sm { padding-left: var(--spacing-sm); padding-right: var(--spacing-sm); }
.px-md { padding-left: var(--spacing-md); padding-right: var(--spacing-md); }
.px-lg { padding-left: var(--spacing-lg); padding-right: var(--spacing-lg); }

.py-sm { padding-top: var(--spacing-sm); padding-bottom: var(--spacing-sm); }
.py-md { padding-top: var(--spacing-md); padding-bottom: var(--spacing-md); }
.py-lg { padding-top: var(--spacing-lg); padding-bottom: var(--spacing-lg); }


/* ========================================
   Buttons - 按钮组件
   ======================================== */
.btn {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    gap: var(--spacing-xs);
    padding: 8px 16px;
    font-size: var(--font-size-sm);
    font-weight: 500;
    line-height: 1.5;
    text-align: center;
    white-space: nowrap;
    vertical-align: middle;
    cursor: pointer;
    user-select: none;
    border: 1px solid transparent;
    border-radius: var(--radius-md);
    transition: all var(--transition-normal);
}

.btn:disabled {
    opacity: 0.65;
    cursor: not-allowed;
}

.btn-primary {
    color: var(--text-inverse);
    background-color: var(--primary-color);
    border-color: var(--primary-color);
}

.btn-primary:hover:not(:disabled) {
    background-color: var(--primary-hover);
    border-color: var(--primary-hover);
}

.btn-primary:active:not(:disabled) {
    background-color: var(--primary-active);
    border-color: var(--primary-active);
}

.btn-secondary {
    color: var(--text-primary);
    background-color: var(--gray-1);
    border-color: var(--border-color);
}

.btn-secondary:hover:not(:disabled) {
    color: var(--primary-color);
    border-color: var(--primary-color);
}

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

.btn-success:hover:not(:disabled) {
    background-color: #73d13d;
    border-color: #73d13d;
}

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

.btn-warning:hover:not(:disabled) {
    background-color: #ffc53d;
    border-color: #ffc53d;
}

.btn-danger {
    color: var(--text-inverse);
    background-color: var(--error-color);
    border-color: var(--error-color);
}

.btn-danger:hover:not(:disabled) {
    background-color: #ff7875;
    border-color: #ff7875;
}

.btn-link {
    color: var(--primary-color);
    background-color: transparent;
    border-color: transparent;
}

.btn-link:hover:not(:disabled) {
    color: var(--primary-hover);
}

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

.btn-text:hover:not(:disabled) {
    background-color: var(--gray-4);
}

/* Button sizes */
.btn-sm {
    padding: 4px 8px;
    font-size: var(--font-size-xs);
}

.btn-lg {
    padding: 12px 24px;
    font-size: var(--font-size-base);
}

.btn-block {
    display: flex;
    width: 100%;
}

/* Button group */
.btn-group {
    display: inline-flex;
}

.btn-group .btn:not(:first-child) {
    border-top-left-radius: 0;
    border-bottom-left-radius: 0;
    margin-left: -1px;
}

.btn-group .btn:not(:last-child) {
    border-top-right-radius: 0;
    border-bottom-right-radius: 0;
}

/* ========================================
   Form Controls - 表单组件
   ======================================== */
.form-group {
    margin-bottom: var(--spacing-md);
}

.form-label {
    display: block;
    margin-bottom: var(--spacing-xs);
    font-size: var(--font-size-sm);
    font-weight: 500;
    color: var(--text-primary);
}

.form-label.required::after {
    content: '*';
    color: var(--error-color);
    margin-left: 4px;
}

.form-control {
    display: block;
    width: 100%;
    padding: 8px 12px;
    font-size: var(--font-size-sm);
    line-height: 1.5;
    color: var(--text-primary);
    background-color: var(--gray-1);
    background-clip: padding-box;
    border: 1px solid var(--border-color);
    border-radius: var(--radius-md);
    transition: border-color var(--transition-fast), box-shadow var(--transition-fast);
}

.form-control:focus {
    border-color: var(--primary-color);
    outline: 0;
    box-shadow: 0 0 0 2px rgba(24, 144, 255, 0.2);
}

.form-control:disabled,
.form-control[readonly] {
    background-color: var(--gray-3);
    opacity: 1;
    cursor: not-allowed;
}

.form-control::placeholder {
    color: var(--text-disabled);
    opacity: 1;
}

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

.form-control.is-invalid:focus {
    box-shadow: 0 0 0 2px rgba(255, 77, 79, 0.2);
}

.form-control-sm {
    padding: 4px 8px;
    font-size: var(--font-size-xs);
}

.form-control-lg {
    padding: 12px 16px;
    font-size: var(--font-size-base);
}

/* Textarea */
textarea.form-control {
    min-height: 100px;
    resize: vertical;
}

/* Select */
select.form-control {
    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 5l6 6 6-6'/%3e%3c/svg%3e");
    background-repeat: no-repeat;
    background-position: right 12px center;
    background-size: 12px;
    padding-right: 36px;
}

/* Checkbox & Radio */
.form-check {
    display: flex;
    align-items: center;
    gap: var(--spacing-sm);
    margin-bottom: var(--spacing-sm);
}

.form-check-input {
    width: 16px;
    height: 16px;
    margin: 0;
    cursor: pointer;
    accent-color: var(--primary-color);
}

.form-check-label {
    font-size: var(--font-size-sm);
    color: var(--text-primary);
    cursor: pointer;
}

/* Form text & feedback */
.form-text {
    display: block;
    margin-top: var(--spacing-xs);
    font-size: var(--font-size-xs);
    color: var(--text-secondary);
}

.invalid-feedback {
    display: none;
    margin-top: var(--spacing-xs);
    font-size: var(--font-size-xs);
    color: var(--error-color);
}

.form-control.is-invalid ~ .invalid-feedback {
    display: block;
}

/* Input group */
.input-group {
    display: flex;
    align-items: stretch;
}

.input-group .form-control {
    flex: 1;
    min-width: 0;
}

.input-group .form-control:not(:first-child) {
    border-top-left-radius: 0;
    border-bottom-left-radius: 0;
}

.input-group .form-control:not(:last-child) {
    border-top-right-radius: 0;
    border-bottom-right-radius: 0;
}

.input-group-text {
    display: flex;
    align-items: center;
    padding: 8px 12px;
    font-size: var(--font-size-sm);
    color: var(--text-secondary);
    background-color: var(--gray-3);
    border: 1px solid var(--border-color);
}

.input-group-text:first-child {
    border-right: 0;
    border-radius: var(--radius-md) 0 0 var(--radius-md);
}

.input-group-text:last-child {
    border-left: 0;
    border-radius: 0 var(--radius-md) var(--radius-md) 0;
}

.input-group .btn:first-child {
    border-top-right-radius: 0;
    border-bottom-right-radius: 0;
}

.input-group .btn:last-child {
    border-top-left-radius: 0;
    border-bottom-left-radius: 0;
}


/* ========================================
   Cards - 卡片组件
   ======================================== */
.card {
    position: relative;
    display: flex;
    flex-direction: column;
    background-color: var(--gray-1);
    border: 1px solid var(--border-light);
    border-radius: var(--radius-lg);
    box-shadow: var(--shadow-sm);
}

.card-header {
    padding: var(--spacing-md);
    border-bottom: 1px solid var(--border-light);
    background-color: var(--gray-2);
    border-radius: var(--radius-lg) var(--radius-lg) 0 0;
}

.card-header:first-child {
    border-radius: calc(var(--radius-lg) - 1px) calc(var(--radius-lg) - 1px) 0 0;
}

.card-title {
    margin-bottom: 0;
    font-size: var(--font-size-base);
    font-weight: 600;
}

.card-body {
    flex: 1 1 auto;
    padding: var(--spacing-md);
}

.card-footer {
    padding: var(--spacing-md);
    border-top: 1px solid var(--border-light);
    background-color: var(--gray-2);
    border-radius: 0 0 var(--radius-lg) var(--radius-lg);
}

.card-img-top {
    border-radius: var(--radius-lg) var(--radius-lg) 0 0;
}

.card-hover:hover {
    box-shadow: var(--shadow-md);
    transform: translateY(-2px);
    transition: all var(--transition-normal);
}

/* ========================================
   Tables - 表格组件
   ======================================== */
.table {
    width: 100%;
    margin-bottom: var(--spacing-md);
    border-collapse: collapse;
    background-color: var(--gray-1);
}

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

.table th {
    font-weight: 600;
    color: var(--text-primary);
    background-color: var(--gray-2);
}

.table tbody tr:hover {
    background-color: var(--gray-2);
}

.table-striped tbody tr:nth-of-type(odd) {
    background-color: var(--gray-2);
}

.table-bordered {
    border: 1px solid var(--border-light);
}

.table-bordered th,
.table-bordered td {
    border: 1px solid var(--border-light);
}

.table-sm th,
.table-sm td {
    padding: 8px 12px;
}

/* Table wrapper for responsive */
.table-responsive {
    display: block;
    width: 100%;
    overflow-x: auto;
    -webkit-overflow-scrolling: touch;
}

/* ========================================
   Badges & Tags - 徽章和标签
   ======================================== */
.badge {
    display: inline-flex;
    align-items: center;
    padding: 2px 8px;
    font-size: var(--font-size-xs);
    font-weight: 500;
    line-height: 1.5;
    border-radius: var(--radius-sm);
}

.badge-primary {
    color: var(--primary-color);
    background-color: var(--primary-light);
}

.badge-success {
    color: var(--success-color);
    background-color: #f6ffed;
}

.badge-warning {
    color: #d48806;
    background-color: #fffbe6;
}

.badge-danger {
    color: var(--error-color);
    background-color: #fff2f0;
}

.badge-secondary {
    color: var(--text-secondary);
    background-color: var(--gray-4);
}

.tag {
    display: inline-flex;
    align-items: center;
    gap: 4px;
    padding: 4px 8px;
    font-size: var(--font-size-xs);
    line-height: 1;
    border: 1px solid var(--border-color);
    border-radius: var(--radius-sm);
    background-color: var(--gray-2);
}

.tag-closable {
    cursor: pointer;
}

.tag-close {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    width: 14px;
    height: 14px;
    font-size: 10px;
    color: var(--text-secondary);
    cursor: pointer;
    border-radius: 50%;
}

.tag-close:hover {
    color: var(--error-color);
    background-color: rgba(255, 77, 79, 0.1);
}

/* ========================================
   Alerts - 提示框
   ======================================== */
.alert {
    position: relative;
    padding: 12px 16px;
    margin-bottom: var(--spacing-md);
    border: 1px solid transparent;
    border-radius: var(--radius-md);
}

.alert-success {
    color: #135200;
    background-color: #f6ffed;
    border-color: #b7eb8f;
}

.alert-info {
    color: #003a8c;
    background-color: #e6f7ff;
    border-color: #91d5ff;
}

.alert-warning {
    color: #ad6800;
    background-color: #fffbe6;
    border-color: #ffe58f;
}

.alert-danger {
    color: #a8071a;
    background-color: #fff2f0;
    border-color: #ffccc7;
}

.alert-dismissible {
    padding-right: 40px;
}

.alert-close {
    position: absolute;
    top: 12px;
    right: 16px;
    padding: 0;
    background: transparent;
    border: 0;
    cursor: pointer;
    opacity: 0.5;
}

.alert-close:hover {
    opacity: 1;
}

/* ========================================
   Modal - 模态框
   ======================================== */
.modal-backdrop {
    position: fixed;
    top: 0;
    left: 0;
    z-index: var(--z-modal-backdrop);
    width: 100vw;
    height: 100vh;
    background-color: rgba(0, 0, 0, 0.45);
    opacity: 0;
    transition: opacity var(--transition-normal);
}

.modal-backdrop.show {
    opacity: 1;
}

.modal {
    position: fixed;
    top: 0;
    left: 0;
    z-index: var(--z-modal);
    display: none;
    width: 100%;
    height: 100%;
    overflow-x: hidden;
    overflow-y: auto;
    outline: 0;
}

.modal.show {
    display: block;
}

.modal-dialog {
    position: relative;
    width: auto;
    max-width: 500px;
    margin: 100px auto;
    pointer-events: none;
    transform: translateY(-20px);
    opacity: 0;
    transition: transform var(--transition-normal), opacity var(--transition-normal);
}

.modal.show .modal-dialog {
    transform: translateY(0);
    opacity: 1;
}

.modal-content {
    position: relative;
    display: flex;
    flex-direction: column;
    width: 100%;
    pointer-events: auto;
    background-color: var(--gray-1);
    border-radius: var(--radius-lg);
    box-shadow: var(--shadow-lg);
}

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

.modal-title {
    margin: 0;
    font-size: var(--font-size-lg);
    font-weight: 600;
}

.modal-close {
    padding: 0;
    background: transparent;
    border: 0;
    font-size: 20px;
    cursor: pointer;
    opacity: 0.5;
}

.modal-close:hover {
    opacity: 1;
}

.modal-body {
    position: relative;
    flex: 1 1 auto;
    padding: var(--spacing-lg);
}

.modal-footer {
    display: flex;
    align-items: center;
    justify-content: flex-end;
    gap: var(--spacing-sm);
    padding: var(--spacing-md);
    border-top: 1px solid var(--border-light);
}

.modal-sm { max-width: 300px; }
.modal-lg { max-width: 800px; }
.modal-xl { max-width: 1140px; }


/* ========================================
   Pagination - 分页组件
   ======================================== */
.pagination {
    display: flex;
    align-items: center;
    gap: var(--spacing-xs);
    list-style: none;
    padding: 0;
    margin: 0;
}

.page-item {
    display: inline-flex;
}

.page-link {
    display: flex;
    align-items: center;
    justify-content: center;
    min-width: 32px;
    height: 32px;
    padding: 0 8px;
    font-size: var(--font-size-sm);
    color: var(--text-primary);
    background-color: var(--gray-1);
    border: 1px solid var(--border-color);
    border-radius: var(--radius-sm);
    cursor: pointer;
    transition: all var(--transition-fast);
}

.page-link:hover {
    color: var(--primary-color);
    border-color: var(--primary-color);
}

.page-item.active .page-link {
    color: var(--text-inverse);
    background-color: var(--primary-color);
    border-color: var(--primary-color);
}

.page-item.disabled .page-link {
    color: var(--text-disabled);
    pointer-events: none;
    background-color: var(--gray-3);
}

/* ========================================
   Loading & Spinner - 加载状态
   ======================================== */
.spinner {
    display: inline-block;
    width: 20px;
    height: 20px;
    border: 2px solid var(--gray-4);
    border-top-color: var(--primary-color);
    border-radius: 50%;
    animation: spin 0.8s linear infinite;
}

.spinner-sm {
    width: 14px;
    height: 14px;
    border-width: 2px;
}

.spinner-lg {
    width: 32px;
    height: 32px;
    border-width: 3px;
}

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

.loading-overlay {
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    display: flex;
    align-items: center;
    justify-content: center;
    background-color: rgba(255, 255, 255, 0.8);
    z-index: 10;
}

.skeleton {
    background: linear-gradient(90deg, var(--gray-3) 25%, var(--gray-4) 50%, var(--gray-3) 75%);
    background-size: 200% 100%;
    animation: skeleton-loading 1.5s infinite;
    border-radius: var(--radius-sm);
}

@keyframes skeleton-loading {
    0% { background-position: 200% 0; }
    100% { background-position: -200% 0; }
}

/* ========================================
   Toast / Notification - 消息提示
   ======================================== */
.toast-container {
    position: fixed;
    top: 24px;
    right: 24px;
    z-index: var(--z-toast);
    display: flex;
    flex-direction: column;
    gap: var(--spacing-sm);
}

.toast {
    display: flex;
    align-items: flex-start;
    gap: var(--spacing-sm);
    min-width: 300px;
    max-width: 400px;
    padding: var(--spacing-md);
    background-color: var(--gray-1);
    border-radius: var(--radius-md);
    box-shadow: var(--shadow-lg);
    animation: toast-in 0.3s ease;
}

@keyframes toast-in {
    from {
        opacity: 0;
        transform: translateX(100%);
    }
    to {
        opacity: 1;
        transform: translateX(0);
    }
}

.toast-icon {
    flex-shrink: 0;
    width: 20px;
    height: 20px;
}

.toast-content {
    flex: 1;
    min-width: 0;
}

.toast-title {
    font-weight: 600;
    margin-bottom: 4px;
}

.toast-message {
    font-size: var(--font-size-sm);
    color: var(--text-secondary);
}

.toast-close {
    flex-shrink: 0;
    padding: 0;
    background: transparent;
    border: 0;
    cursor: pointer;
    opacity: 0.5;
}

.toast-close:hover {
    opacity: 1;
}

.toast-success .toast-icon { color: var(--success-color); }
.toast-error .toast-icon { color: var(--error-color); }
.toast-warning .toast-icon { color: var(--warning-color); }
.toast-info .toast-icon { color: var(--info-color); }

/* ========================================
   Dropdown - 下拉菜单
   ======================================== */
.dropdown {
    position: relative;
    display: inline-block;
}

.dropdown-toggle::after {
    display: inline-block;
    margin-left: 6px;
    vertical-align: middle;
    content: '';
    border-top: 4px solid;
    border-right: 4px solid transparent;
    border-bottom: 0;
    border-left: 4px solid transparent;
}

.dropdown-menu {
    position: absolute;
    top: 100%;
    left: 0;
    z-index: var(--z-dropdown);
    display: none;
    min-width: 160px;
    padding: var(--spacing-xs) 0;
    margin-top: var(--spacing-xs);
    background-color: var(--gray-1);
    border: 1px solid var(--border-light);
    border-radius: var(--radius-md);
    box-shadow: var(--shadow-md);
}

.dropdown-menu.show {
    display: block;
}

.dropdown-menu-right {
    right: 0;
    left: auto;
}

.dropdown-item {
    display: flex;
    align-items: center;
    gap: var(--spacing-sm);
    width: 100%;
    padding: 8px 16px;
    font-size: var(--font-size-sm);
    color: var(--text-primary);
    background-color: transparent;
    border: 0;
    cursor: pointer;
    text-align: left;
}

.dropdown-item:hover {
    background-color: var(--gray-3);
}

.dropdown-item.active {
    color: var(--primary-color);
    background-color: var(--primary-light);
}

.dropdown-divider {
    height: 0;
    margin: var(--spacing-xs) 0;
    overflow: hidden;
    border-top: 1px solid var(--border-light);
}

/* ========================================
   Empty State - 空状态
   ======================================== */
.empty-state {
    display: flex;
    flex-direction: column;
    align-items: center;
    justify-content: center;
    padding: var(--spacing-xxl);
    text-align: center;
}

.empty-state-icon {
    width: 80px;
    height: 80px;
    margin-bottom: var(--spacing-md);
    color: var(--gray-5);
}

.empty-state-title {
    font-size: var(--font-size-lg);
    font-weight: 600;
    color: var(--text-primary);
    margin-bottom: var(--spacing-sm);
}

.empty-state-description {
    font-size: var(--font-size-sm);
    color: var(--text-secondary);
    margin-bottom: var(--spacing-lg);
    max-width: 400px;
}

/* ========================================
   Utility Classes - 工具类
   ======================================== */
.hidden { display: none !important; }
.visible { visibility: visible !important; }
.invisible { visibility: hidden !important; }

.overflow-hidden { overflow: hidden; }
.overflow-auto { overflow: auto; }
.overflow-scroll { overflow: scroll; }

.w-full { width: 100%; }
.h-full { height: 100%; }
.min-h-screen { min-height: 100vh; }

.rounded { border-radius: var(--radius-md); }
.rounded-sm { border-radius: var(--radius-sm); }
.rounded-lg { border-radius: var(--radius-lg); }
.rounded-full { border-radius: var(--radius-full); }

.shadow { box-shadow: var(--shadow-sm); }
.shadow-md { box-shadow: var(--shadow-md); }
.shadow-lg { box-shadow: var(--shadow-lg); }
.shadow-none { box-shadow: none; }

.border { border: 1px solid var(--border-color); }
.border-0 { border: 0; }
.border-top { border-top: 1px solid var(--border-color); }
.border-bottom { border-bottom: 1px solid var(--border-color); }

.bg-white { background-color: var(--gray-1); }
.bg-light { background-color: var(--bg-light); }
.bg-primary { background-color: var(--primary-color); }

.cursor-pointer { cursor: pointer; }
.cursor-not-allowed { cursor: not-allowed; }

.select-none { user-select: none; }
.select-all { user-select: all; }

.truncate {
    overflow: hidden;
    text-overflow: ellipsis;
    white-space: nowrap;
}

.line-clamp-2 {
    display: -webkit-box;
    -webkit-line-clamp: 2;
    -webkit-box-orient: vertical;
    overflow: hidden;
}

.line-clamp-3 {
    display: -webkit-box;
    -webkit-line-clamp: 3;
    -webkit-box-orient: vertical;
    overflow: hidden;
}

/* ========================================
   Responsive Breakpoints - 响应式断点
   ======================================== */
/* Mobile first approach */
/* sm: 640px, md: 768px, lg: 1024px, xl: 1280px */

@media (max-width: 639px) {
    .hidden-mobile { display: none !important; }
    
    .container {
        padding: 0 var(--spacing-sm);
    }
    
    .modal-dialog {
        margin: var(--spacing-md);
        max-width: calc(100% - var(--spacing-lg));
    }
    
    .toast-container {
        left: var(--spacing-md);
        right: var(--spacing-md);
    }
    
    .toast {
        min-width: auto;
        max-width: none;
    }
}

@media (min-width: 640px) {
    .hidden-sm { display: none !important; }
    .grid-cols-sm-2 { grid-template-columns: repeat(2, minmax(0, 1fr)); }
}

@media (min-width: 768px) {
    .hidden-md { display: none !important; }
    .grid-cols-md-2 { grid-template-columns: repeat(2, minmax(0, 1fr)); }
    .grid-cols-md-3 { grid-template-columns: repeat(3, minmax(0, 1fr)); }
}

@media (min-width: 1024px) {
    .hidden-lg { display: none !important; }
    .grid-cols-lg-3 { grid-template-columns: repeat(3, minmax(0, 1fr)); }
    .grid-cols-lg-4 { grid-template-columns: repeat(4, minmax(0, 1fr)); }
}

@media (min-width: 1280px) {
    .hidden-xl { display: none !important; }
    .grid-cols-xl-4 { grid-template-columns: repeat(4, minmax(0, 1fr)); }
    .grid-cols-xl-5 { grid-template-columns: repeat(5, minmax(0, 1fr)); }
}

/* ========================================
   Accessibility - 无障碍
   ======================================== */
.sr-only {
    position: absolute;
    width: 1px;
    height: 1px;
    padding: 0;
    margin: -1px;
    overflow: hidden;
    clip: rect(0, 0, 0, 0);
    white-space: nowrap;
    border: 0;
}

:focus-visible {
    outline: 2px solid var(--primary-color);
    outline-offset: 2px;
}

/* Reduced motion */
@media (prefers-reduced-motion: reduce) {
    *,
    *::before,
    *::after {
        animation-duration: 0.01ms !important;
        animation-iteration-count: 1 !important;
        transition-duration: 0.01ms !important;
    }
}