/**
 * Components Styles - 组件样式库
 * 元思维交互式编程学习平台
 */

/* ===== 按钮基础 ===== */
.btn {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    gap: var(--spacing-sm);
    padding: 0.5rem 1rem;
    border-radius: var(--radius-lg);
    font-size: var(--text-sm);
    font-weight: 500;
    font-family: inherit;
    cursor: pointer;
    border: none;
    transition: var(--transition-bounce);
    text-decoration: none;
    white-space: nowrap;
}

.btn:disabled {
    opacity: 0.5;
    cursor: not-allowed;
}

.btn-sm {
    padding: 0.375rem 0.75rem;
    font-size: var(--text-xs);
}

.btn-lg {
    padding: 0.75rem 1.5rem;
    font-size: var(--text-base);
}

.btn-xl {
    padding: 1rem 2rem;
    font-size: var(--text-lg);
    border-radius: var(--radius-xl);
}

/* ===== 按钮变体 ===== */
.btn-primary {
    background: linear-gradient(135deg, var(--primary) 0%, var(--primary-dark) 100%);
    color: white;
    box-shadow: var(--shadow-primary);
}

.btn-primary:hover:not(:disabled) {
    transform: translateY(-2px);
    box-shadow: 0 8px 30px rgba(var(--primary-rgb), 0.6);
}

.btn-secondary {
    background: rgba(255, 255, 255, 0.05);
    color: var(--text-primary);
    border: 1px solid var(--border-default);
}

.btn-secondary:hover:not(:disabled) {
    background: rgba(255, 255, 255, 0.1);
    border-color: rgba(255, 255, 255, 0.2);
}

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

.btn-ghost:hover:not(:disabled) {
    background: rgba(255, 255, 255, 0.05);
    color: var(--text-primary);
}

.btn-success {
    background: linear-gradient(135deg, var(--success) 0%, #059669 100%);
    color: white;
}

.btn-success:hover:not(:disabled) {
    transform: translateY(-2px);
}

.btn-danger {
    background: linear-gradient(135deg, var(--error) 0%, #dc2626 100%);
    color: white;
}

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

.btn-outline-primary:hover:not(:disabled) {
    background: rgba(var(--primary-rgb), 0.1);
}

/* ===== 统一品牌标识 ===== */
/* 完整横版 Logo（图标+文字） */
.brand-logo-full {
    height: 38px;
    /* 进一步缩小，追求更精致、均衡的布局感 */
    width: auto;
    max-width: 180px;
    object-fit: contain;
    transition: all var(--transition-fast);
    image-rendering: -webkit-optimize-contrast;
    display: block;
    /* 极致细腻的阴影 */
    filter: drop-shadow(0 1px 2px rgba(0, 0, 0, 0.1));
}

.brand-logo-full:hover {
    transform: scale(1.02);
}

.brand-logo-full--sm {
    height: 36px;
    /* 移动端/窄版从 28px 提升 */
    max-width: 160px;
}

.brand-logo-full--lg {
    height: 56px;
    max-width: 240px;
}

/* 方形图标 Logo（仅图标部分，用于小空间） */
.brand-logo {
    width: 40px;
    height: 40px;
    border-radius: var(--radius-lg);
    background: linear-gradient(135deg, var(--primary) 0%, var(--secondary) 100%);
    display: flex;
    align-items: center;
    justify-content: center;
    color: white;
    flex-shrink: 0;
    transition: transform var(--transition-fast);
}

.brand-logo:hover {
    transform: scale(1.05);
}

.brand-logo svg {
    width: 24px;
    height: 24px;
}

.brand-logo--sm {
    width: 32px;
    height: 32px;
}

.brand-logo--sm svg {
    width: 18px;
    height: 18px;
}

.brand-logo--lg {
    width: 56px;
    height: 56px;
}

.brand-logo--lg svg {
    width: 32px;
    height: 32px;
}

.brand-name {
    font-size: var(--text-xl);
    font-weight: 700;
    background: linear-gradient(135deg, var(--primary) 0%, var(--secondary) 50%, var(--accent) 100%);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
}

.brand-name--sm {
    font-size: var(--text-lg);
}

.brand-subtitle {
    font-size: var(--text-xs);
    color: var(--text-muted);
    line-height: 1;
}

.brand-group {
    display: flex;
    align-items: center;
    gap: var(--spacing-sm);
    text-decoration: none;
}

.brand-group:hover .brand-logo {
    transform: scale(1.05);
}

.brand-group:hover .brand-logo-full {
    transform: scale(1.02);
}

.brand-info {
    display: flex;
    flex-direction: column;
    gap: 2px;
}

/* ===== 导航栏 ===== */
.nav {
    position: sticky;
    top: 0;
    z-index: var(--z-sticky);
    background: rgba(10, 15, 26, 0.9);
    backdrop-filter: blur(20px);
    -webkit-backdrop-filter: blur(20px);
    border-bottom: 1px solid var(--border-light);
}

.nav--fixed {
    position: fixed;
    left: 0;
    right: 0;
}

.nav-container {
    max-width: 1200px;
    margin: 0 auto;
    padding: var(--spacing-sm) var(--spacing-lg);
    /* 缩小 padding，让大 Logo 撑满视觉 */
    display: flex;
    align-items: center;
    justify-content: space-between;
}

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

.nav-brand {
    display: flex;
    align-items: center;
    gap: var(--spacing-sm);
}

.nav-logo {
    width: 40px;
    height: 40px;
    border-radius: var(--radius-lg);
    background: linear-gradient(135deg, var(--primary) 0%, var(--secondary) 100%);
    display: flex;
    align-items: center;
    justify-content: center;
    color: white;
}

.nav-title {
    font-size: var(--text-xl);
    font-weight: 700;
}

.nav-links {
    display: flex;
    align-items: center;
    gap: var(--spacing-xl);
}

.nav-link {
    color: var(--text-secondary);
    font-size: var(--text-sm);
    transition: var(--transition-fast);
}

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

.nav-link.active {
    color: var(--primary);
}

.nav-actions {
    display: flex;
    align-items: center;
    gap: var(--spacing-sm);
}

/* 下拉菜单 */
.nav-dropdown {
    position: relative;
}

.nav-dropdown-menu {
    position: absolute;
    top: 100%;
    left: 0;
    margin-top: var(--spacing-sm);
    min-width: 160px;
    background: var(--bg-tertiary);
    border-radius: var(--radius-lg);
    box-shadow: var(--shadow-xl);
    border: 1px solid var(--border-default);
    opacity: 0;
    visibility: hidden;
    transform: translateY(-10px);
    transition: var(--transition-fast);
    z-index: var(--z-dropdown);
}

.nav-dropdown:hover .nav-dropdown-menu {
    opacity: 1;
    visibility: visible;
    transform: translateY(0);
}

.nav-dropdown-item {
    display: flex;
    align-items: center;
    gap: var(--spacing-sm);
    padding: var(--spacing-sm) var(--spacing-md);
    color: var(--text-secondary);
    font-size: var(--text-sm);
    transition: var(--transition-fast);
}

.nav-dropdown-item:first-child {
    border-radius: var(--radius-lg) var(--radius-lg) 0 0;
}

.nav-dropdown-item:last-child {
    border-radius: 0 0 var(--radius-lg) var(--radius-lg);
}

.nav-dropdown-item:hover {
    background: rgba(255, 255, 255, 0.05);
    color: var(--text-primary);
}

/* 导航栏分隔线 */
.nav-divider {
    width: 1px;
    height: 20px;
    background: var(--border-default);
    margin: 0 var(--spacing-sm);
}

/* 导航栏返回按钮 */
.nav-back {
    display: flex;
    align-items: center;
    gap: var(--spacing-xs);
    color: var(--text-secondary);
    font-size: var(--text-sm);
    transition: var(--transition-fast);
}

.nav-back:hover {
    color: var(--text-primary);
}

.nav-back svg {
    width: 20px;
    height: 20px;
}

/* 导航栏页面标题 */
.nav-page-title {
    font-size: var(--text-sm);
    font-weight: 500;
    color: var(--text-primary);
    max-width: 200px;
    overflow: hidden;
    text-overflow: ellipsis;
    white-space: nowrap;
}

/* 移动端菜单 */
.nav-mobile-toggle {
    display: none;
    padding: var(--spacing-sm);
    background: none;
    border: none;
    color: var(--text-primary);
    cursor: pointer;
    border-radius: var(--radius-md);
    transition: var(--transition-fast);
}

.nav-mobile-toggle:hover {
    background: rgba(255, 255, 255, 0.05);
}

.nav-mobile-toggle svg {
    width: 24px;
    height: 24px;
}

/* 移动端菜单 - 覆盖层 */
.nav-mobile-overlay {
    display: none;
    position: fixed;
    inset: 0;
    background: rgba(0, 0, 0, 0.5);
    z-index: calc(var(--z-sticky) - 1);
    opacity: 0;
    transition: opacity var(--transition-normal);
}

.nav-mobile-overlay.open {
    display: block;
    opacity: 1;
}

/* 移动端菜单 - 侧边栏 */
.nav-mobile-menu {
    display: none;
    position: fixed;
    top: 0;
    right: -280px;
    width: 280px;
    height: 100vh;
    background: var(--bg-secondary);
    z-index: var(--z-sticky);
    padding: var(--spacing-lg);
    transition: right var(--transition-normal);
    overflow-y: auto;
}

.nav-mobile-menu.open {
    display: block;
    right: 0;
}

.nav-mobile-menu-header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    margin-bottom: var(--spacing-xl);
    padding-bottom: var(--spacing-md);
    border-bottom: 1px solid var(--border-default);
}

.nav-mobile-menu-close {
    width: 32px;
    height: 32px;
    display: flex;
    align-items: center;
    justify-content: center;
    background: none;
    border: none;
    color: var(--text-secondary);
    cursor: pointer;
    border-radius: var(--radius-md);
}

.nav-mobile-menu-close:hover {
    background: rgba(255, 255, 255, 0.05);
    color: var(--text-primary);
}

.nav-mobile-link {
    display: flex;
    align-items: center;
    gap: var(--spacing-sm);
    padding: var(--spacing-md);
    color: var(--text-secondary);
    font-size: var(--text-base);
    border-radius: var(--radius-md);
    transition: var(--transition-fast);
    margin-bottom: var(--spacing-xs);
}

.nav-mobile-link:hover,
.nav-mobile-link.active {
    background: rgba(var(--primary-rgb), 0.1);
    color: var(--primary);
}

.nav-mobile-link svg {
    width: 20px;
    height: 20px;
}

@media (max-width: 768px) {
    .nav-links {
        display: none;
    }

    .nav-mobile-toggle {
        display: flex;
    }

    .nav-actions .hidden-mobile {
        display: none;
    }

    .nav-container {
        padding: var(--spacing-sm) var(--spacing-md);
    }

    .brand-name {
        font-size: var(--text-lg);
    }

    .brand-subtitle {
        display: none;
    }
}

/* ===== 卡片 ===== */
.card {
    background: var(--bg-glass);
    backdrop-filter: blur(10px);
    -webkit-backdrop-filter: blur(10px);
    border: 1px solid var(--border-default);
    border-radius: var(--radius-2xl);
    padding: var(--spacing-lg);
    transition: var(--transition-bounce);
}

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

.card-interactive {
    cursor: pointer;
}

.card-interactive:hover {
    border-color: rgba(var(--primary-rgb), 0.3);
    background: rgba(255, 255, 255, 0.06);
}

/* 特性卡片 */
.feature-card {
    background: rgba(255, 255, 255, 0.03);
    border: 1px solid var(--border-light);
    backdrop-filter: blur(10px);
    border-radius: var(--radius-2xl);
    padding: var(--spacing-lg);
    transition: var(--transition-bounce);
}

.feature-card:hover {
    background: rgba(255, 255, 255, 0.06);
    border-color: rgba(var(--primary-rgb), 0.3);
    transform: translateY(-8px);
    box-shadow: var(--shadow-lg);
}

.feature-icon {
    width: 56px;
    height: 56px;
    border-radius: var(--radius-xl);
    background: linear-gradient(135deg, rgba(var(--primary-rgb), 0.2) 0%, rgba(var(--secondary-rgb), 0.2) 100%);
    border: 1px solid rgba(var(--primary-rgb), 0.3);
    display: flex;
    align-items: center;
    justify-content: center;
    margin-bottom: var(--spacing-lg);
}

/* 课程卡片 */
.course-card {
    background: linear-gradient(135deg, rgba(var(--primary-rgb), 0.1) 0%, rgba(var(--secondary-rgb), 0.1) 100%);
    border: 1px solid rgba(var(--primary-rgb), 0.2);
    border-radius: var(--radius-2xl);
    padding: var(--spacing-xl);
    transition: var(--transition-normal);
}

.course-card:hover {
    border-color: rgba(var(--primary-rgb), 0.5);
    transform: scale(1.02);
    box-shadow: 0 10px 30px rgba(var(--primary-rgb), 0.2);
}

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

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

.form-label .required {
    color: var(--error);
}

.form-input {
    width: 100%;
    padding: 0.75rem 1rem;
    border-radius: var(--radius-md);
    background: rgba(30, 41, 59, 0.5);
    border: 1px solid rgba(71, 85, 105, 0.5);
    color: var(--text-primary);
    font-size: var(--text-sm);
    font-family: inherit;
    transition: var(--transition-fast);
}

.form-input:focus {
    outline: none;
    border-color: var(--primary);
    box-shadow: 0 0 0 3px rgba(var(--primary-rgb), 0.2);
}

.form-input::placeholder {
    color: rgba(148, 163, 184, 0.6);
}

.form-input:disabled {
    opacity: 0.5;
    cursor: not-allowed;
}

.form-error {
    color: var(--error);
    font-size: var(--text-sm);
    margin-top: var(--spacing-xs);
}

.form-hint {
    color: var(--text-muted);
    font-size: var(--text-xs);
    margin-top: var(--spacing-xs);
}

/* ===== 模态框 ===== */
.modal-overlay {
    position: fixed;
    inset: 0;
    background: var(--bg-overlay);
    backdrop-filter: blur(4px);
    -webkit-backdrop-filter: blur(4px);
    z-index: var(--z-modal);
    display: flex;
    align-items: center;
    justify-content: center;
    padding: var(--spacing-md);
    opacity: 0;
    visibility: hidden;
    transition: var(--transition-normal);
}

.modal-overlay.open {
    opacity: 1;
    visibility: visible;
}

.modal {
    background: var(--bg-glass);
    backdrop-filter: blur(20px);
    -webkit-backdrop-filter: blur(20px);
    border: 1px solid var(--border-default);
    border-radius: var(--radius-2xl);
    padding: var(--spacing-xl);
    width: 100%;
    max-width: 28rem;
    max-height: 90vh;
    overflow-y: auto;
    transform: scale(0.95);
    transition: var(--transition-normal);
}

.modal-overlay.open .modal {
    transform: scale(1);
}

.modal-header {
    display: flex;
    align-items: center;
    justify-content: space-between;
    margin-bottom: var(--spacing-lg);
}

.modal-title {
    font-size: var(--text-2xl);
    font-weight: 700;
}

.modal-close {
    width: 32px;
    height: 32px;
    display: flex;
    align-items: center;
    justify-content: center;
    background: none;
    border: none;
    color: var(--text-secondary);
    cursor: pointer;
    border-radius: var(--radius-md);
    transition: var(--transition-fast);
    font-size: 1.5rem;
}

.modal-close:hover {
    background: rgba(255, 255, 255, 0.1);
    color: var(--text-primary);
}

/* ===== 徽章 ===== */
.badge {
    display: inline-flex;
    align-items: center;
    padding: 0.25rem 0.75rem;
    border-radius: var(--radius-full);
    font-size: var(--text-xs);
    font-weight: 500;
}

.badge-primary {
    background: rgba(var(--primary-rgb), 0.2);
    color: var(--primary-light);
}

.badge-secondary {
    background: rgba(var(--secondary-rgb), 0.2);
    color: var(--secondary-light);
}

.badge-success {
    background: rgba(16, 185, 129, 0.2);
    color: #6ee7b7;
}

.badge-warning {
    background: rgba(245, 158, 11, 0.2);
    color: #fcd34d;
}

.badge-error {
    background: rgba(239, 68, 68, 0.2);
    color: #fca5a5;
}

.badge-neutral {
    background: rgba(100, 116, 139, 0.2);
    color: #94a3b8;
}

/* ===== 进度环 ===== */
.progress-ring {
    transform: rotate(-90deg);
}

.progress-ring-circle {
    transition: stroke-dashoffset 0.5s ease;
}

/* ===== Toast 提示 ===== */
.toast-container {
    position: fixed;
    top: 80px;
    right: 20px;
    z-index: var(--z-toast);
    display: flex;
    flex-direction: column;
    gap: var(--spacing-sm);
}

.toast {
    display: flex;
    align-items: center;
    gap: var(--spacing-sm);
    padding: var(--spacing-sm) var(--spacing-md);
    background: var(--bg-tertiary);
    border: 1px solid var(--border-default);
    border-radius: var(--radius-lg);
    box-shadow: var(--shadow-lg);
    animation: toastSlideIn 0.3s ease;
    max-width: 360px;
}

.toast.toast-success {
    border-color: var(--success);
    background: rgba(16, 185, 129, 0.1);
}

.toast.toast-error {
    border-color: var(--error);
    background: rgba(239, 68, 68, 0.1);
}

.toast.toast-warning {
    border-color: var(--warning);
    background: rgba(245, 158, 11, 0.1);
}

.toast.toast-info {
    border-color: var(--info);
    background: rgba(59, 130, 246, 0.1);
}

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

.toast-message {
    flex: 1;
    font-size: var(--text-sm);
}

.toast-close {
    flex-shrink: 0;
    background: none;
    border: none;
    color: var(--text-muted);
    cursor: pointer;
    padding: 4px;
}

.toast.hiding {
    animation: toastSlideOut 0.3s ease forwards;
}

@keyframes toastSlideIn {
    from {
        opacity: 0;
        transform: translateX(100%);
    }

    to {
        opacity: 1;
        transform: translateX(0);
    }
}

@keyframes toastSlideOut {
    from {
        opacity: 1;
        transform: translateX(0);
    }

    to {
        opacity: 0;
        transform: translateX(100%);
    }
}

/* ===== 骨架屏 ===== */
.skeleton {
    background: linear-gradient(90deg,
            rgba(255, 255, 255, 0.05) 0%,
            rgba(255, 255, 255, 0.1) 50%,
            rgba(255, 255, 255, 0.05) 100%);
    background-size: 200% 100%;
    animation: skeletonShimmer 1.5s ease-in-out infinite;
    border-radius: var(--radius-md);
}

@keyframes skeletonShimmer {
    0% {
        background-position: 200% 0;
    }

    100% {
        background-position: -200% 0;
    }
}

.skeleton-text {
    height: 1em;
    margin-bottom: 0.5em;
}

.skeleton-text:last-child {
    width: 60%;
}

.skeleton-avatar {
    width: 48px;
    height: 48px;
    border-radius: var(--radius-lg);
}

.skeleton-card {
    height: 200px;
    border-radius: var(--radius-2xl);
}

/* ===== 品牌标语 ===== */
.brand-slogan {
    background: linear-gradient(90deg,
            rgba(var(--primary-rgb), 0.1) 0%,
            rgba(var(--secondary-rgb), 0.1) 50%,
            rgba(var(--accent-rgb), 0.1) 100%);
    border-left: 4px solid var(--primary);
    padding: var(--spacing-sm) var(--spacing-lg);
    border-radius: 0 var(--radius-lg) var(--radius-lg) 0;
}

/* ===== 统计数字 ===== */
.stat-number {
    background: linear-gradient(135deg, var(--primary) 0%, var(--secondary) 100%);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
    font-weight: 700;
}

/* ===== Footer ===== */
.footer {
    background: linear-gradient(180deg, transparent 0%, rgba(10, 15, 26, 0.95) 100%);
    padding: var(--spacing-2xl) var(--spacing-lg);
}

.footer-container {
    max-width: 1200px;
    margin: 0 auto;
    display: flex;
    flex-direction: column;
    align-items: center;
    gap: var(--spacing-lg);
}

@media (min-width: 768px) {
    .footer-container {
        flex-direction: row;
        justify-content: space-between;
    }
}

/* ===== 微交互效果 ===== */
.hover-lift {
    transition: transform var(--transition-bounce), box-shadow var(--transition-bounce);
}

.hover-lift:hover {
    transform: translateY(-4px);
    box-shadow: var(--shadow-lg);
}

.hover-scale {
    transition: transform var(--transition-fast);
}

.hover-scale:hover {
    transform: scale(1.02);
}

.hover-glow {
    transition: box-shadow var(--transition-normal);
}

.hover-glow:hover {
    box-shadow: 0 0 20px rgba(var(--primary-rgb), 0.3);
}

/* 点击反馈 */
.click-feedback {
    transition: transform var(--transition-fast);
}

.click-feedback:active {
    transform: scale(0.97);
}

/* 焦点环 */
.focus-ring:focus {
    outline: none;
    box-shadow: 0 0 0 3px rgba(var(--primary-rgb), 0.3);
}

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

/* ===== 加载状态 ===== */
.loading-spinner {
    width: 40px;
    height: 40px;
    border: 3px solid var(--border-default);
    border-top-color: var(--primary);
    border-radius: 50%;
    animation: spin 0.8s linear infinite;
}

.loading-spinner--sm {
    width: 20px;
    height: 20px;
    border-width: 2px;
}

.loading-spinner--lg {
    width: 56px;
    height: 56px;
    border-width: 4px;
}

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

/* 按钮加载状态 */
.btn--loading {
    position: relative;
    color: transparent !important;
    pointer-events: none;
}

.btn--loading::after {
    content: '';
    position: absolute;
    top: 50%;
    left: 50%;
    width: 20px;
    height: 20px;
    margin: -10px 0 0 -10px;
    border: 2px solid rgba(255, 255, 255, 0.3);
    border-top-color: white;
    border-radius: 50%;
    animation: spin 0.8s linear infinite;
}

/* 页面加载骨架 */
.page-loading {
    display: flex;
    flex-direction: column;
    align-items: center;
    justify-content: center;
    min-height: 60vh;
    gap: var(--spacing-md);
}

.page-loading-text {
    color: var(--text-secondary);
    font-size: var(--text-sm);
}

/* 内容加载占位 */
.content-placeholder {
    background: var(--bg-glass);
    border: 1px solid var(--border-default);
    border-radius: var(--radius-2xl);
    padding: var(--spacing-lg);
    animation: pulse 2s ease-in-out infinite;
}

@keyframes pulse {

    0%,
    100% {
        opacity: 1;
    }

    50% {
        opacity: 0.6;
    }
}

/* ===== 编程链接按钮组 ===== */
.code-links {
    display: flex;
    align-items: center;
    gap: var(--spacing-sm);
}

.code-link {
    display: flex;
    align-items: center;
    gap: 6px;
    padding: 6px 12px;
    font-size: var(--text-sm);
    border-radius: var(--radius-md);
    border: 1px solid var(--border-default);
    background: rgba(255, 255, 255, 0.02);
    color: var(--text-secondary);
    transition: var(--transition-fast);
}

.code-link:hover {
    border-color: var(--primary);
    background: rgba(var(--primary-rgb), 0.1);
    color: var(--primary);
}

.code-link--cpp {
    border-color: rgba(16, 185, 129, 0.3);
}

.code-link--cpp:hover {
    border-color: var(--primary);
    background: rgba(var(--primary-rgb), 0.1);
}

.code-link--python {
    border-color: rgba(59, 130, 246, 0.3);
}

.code-link--python:hover {
    border-color: var(--secondary);
    background: rgba(var(--secondary-rgb), 0.1);
}

.code-link svg {
    width: 16px;
    height: 16px;
}

/* ===== 优化的模态框 ===== */
.modal-overlay {
    position: fixed;
    inset: 0;
    background: rgba(0, 0, 0, 0.7);
    backdrop-filter: blur(8px);
    -webkit-backdrop-filter: blur(8px);
    z-index: var(--z-modal);
    display: flex;
    align-items: center;
    justify-content: center;
    padding: var(--spacing-md);
    opacity: 0;
    visibility: hidden;
    transition: opacity var(--transition-normal), visibility var(--transition-normal);
}

.modal-overlay.open {
    opacity: 1;
    visibility: visible;
}

.modal {
    background: var(--bg-secondary);
    border: 1px solid var(--border-default);
    border-radius: var(--radius-2xl);
    padding: var(--spacing-xl);
    width: 100%;
    max-width: 440px;
    max-height: 90vh;
    overflow-y: auto;
    transform: translateY(20px) scale(0.95);
    opacity: 0;
    transition: transform var(--transition-normal), opacity var(--transition-normal);
}

.modal-overlay.open .modal {
    transform: translateY(0) scale(1);
    opacity: 1;
}

.modal-header {
    display: flex;
    align-items: center;
    justify-content: space-between;
    margin-bottom: var(--spacing-lg);
}

.modal-title {
    font-size: var(--text-2xl);
    font-weight: 700;
    color: var(--text-primary);
}

.modal-close {
    width: 36px;
    height: 36px;
    display: flex;
    align-items: center;
    justify-content: center;
    background: rgba(255, 255, 255, 0.05);
    border: none;
    color: var(--text-secondary);
    cursor: pointer;
    border-radius: var(--radius-md);
    transition: var(--transition-fast);
    font-size: 1.25rem;
}

.modal-close:hover {
    background: rgba(255, 255, 255, 0.1);
    color: var(--text-primary);
}

/* 模态框内的标签切换 */
.modal-tabs {
    display: flex;
    gap: var(--spacing-xs);
    margin-bottom: var(--spacing-lg);
    padding: 4px;
    background: rgba(255, 255, 255, 0.03);
    border-radius: var(--radius-lg);
}

.modal-tab {
    flex: 1;
    padding: var(--spacing-sm) var(--spacing-md);
    background: transparent;
    border: none;
    border-radius: var(--radius-md);
    color: var(--text-secondary);
    font-size: var(--text-sm);
    font-weight: 500;
    cursor: pointer;
    transition: var(--transition-fast);
}

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

.modal-tab.active {
    background: rgba(var(--primary-rgb), 0.15);
    color: var(--primary);
}

/* ===== 响应式容器 ===== */
.section {
    padding: var(--section-padding-y) var(--container-padding-x);
}

@media (max-width: 768px) {
    .section {
        padding: var(--section-padding-y-mobile) var(--container-padding-x-mobile);
    }
}

.section-header {
    text-align: center;
    margin-bottom: var(--spacing-12);
}

.section-title {
    font-size: var(--text-3xl);
    font-weight: 700;
    margin-bottom: var(--spacing-sm);
}

.section-subtitle {
    font-size: var(--text-base);
    color: var(--text-secondary);
    max-width: 600px;
    margin: 0 auto;
}

@media (max-width: 768px) {
    .section-title {
        font-size: var(--text-2xl);
    }

    .section-subtitle {
        font-size: var(--text-sm);
    }
}

/* ===== 移动端响应式改进 ===== */
@media (max-width: 640px) {
    .card {
        padding: var(--spacing-md);
    }

    .feature-card {
        padding: var(--spacing-md);
    }

    .course-card {
        padding: var(--spacing-lg);
    }

    .modal {
        padding: var(--spacing-lg);
        max-width: 100%;
        margin: var(--spacing-md);
        border-radius: var(--radius-xl);
    }

    .btn-xl {
        padding: 0.875rem 1.5rem;
        font-size: var(--text-base);
    }
}
/* =========================================
   现代登录/注册弹窗重构 (Modern Auth Redesign)
   ========================================= */

/* 1. 容器玻璃拟态升级 */
body .auth-modal {
    background: rgba(15, 23, 42, 0.65) !important;
    backdrop-filter: blur(24px) saturate(180%);
    -webkit-backdrop-filter: blur(24px) saturate(180%);
    border: 1px solid rgba(255, 255, 255, 0.08); /* 极细边框 */
    box-shadow: 
        0 25px 50px -12px rgba(0, 0, 0, 0.5), /* 深度投影 */
        0 0 100px -20px rgba(59, 130, 246, 0.1) inset; /* 内部幽蓝微光 */
    border-radius: 24px;
    overflow: hidden;
    max-width: 900px;
}

/* 2. 双栏布局优化 (PC端) */
body .auth-modal__layout {
    grid-template-columns: 280px 1fr; /* 左侧更窄，留白更多给内容 */
}

body .auth-modal__aside {
    background: linear-gradient(135deg, rgba(59, 130, 246, 0.1) 0%, rgba(15, 23, 42, 0.4) 100%) !important;
    border-right: 1px solid rgba(255, 255, 255, 0.05);
    position: relative;
    overflow: hidden;
}

/* 增加左侧背景的动态光效 */
body .auth-modal__aside::before {
    content: '';
    position: absolute;
    top: -50%;
    left: -50%;
    width: 200%;
    height: 200%;
    background: radial-gradient(circle, rgba(59, 130, 246, 0.15) 0%, transparent 60%);
    animation: rotate-glow 15s linear infinite;
    pointer-events: none;
}

@keyframes rotate-glow {
    0% { transform: rotate(0deg); }
    100% { transform: rotate(360deg); }
}

/* 3. 移动端彻底重构 */
@media (max-width: 768px) {
    body .auth-modal {
        max-width: 100vw !important;
        margin: 0;
        border-radius: 24px 24px 0 0; /* 底部抽屉圆角 */
        position: fixed;
        bottom: 0;
        left: 0;
        right: 0;
        top: auto;
        transform: translateY(100%); /* 默认隐藏，由JS控制显示 */
        border: none;
        border-top: 1px solid rgba(255, 255, 255, 0.15);
        box-shadow: 0 -10px 40px rgba(0,0,0,0.6);
        max-height: 85vh;
        overflow-y: auto;
    }

    body .modal-overlay.open .auth-modal {
        transform: translateY(0); /* 滑出动画 */
        border-radius: 24px 24px 0 0 !important;
    }

    /* 隐藏左侧营销区 */
    body .auth-modal__aside {
        display: none !important;
    }

    body .auth-modal__layout {
        display: block !important; /* 单栏 */
    }

    body .auth-modal__content {
        padding: 32px 24px !important;
    }

    /* 在表单顶部显示Logo (本来在PC只在左侧显示) */
    body .auth-header {
        text-align: center;
        margin-bottom: 24px;
        position: relative;
    }
    
    body .auth-header::before {
        content: '';
        display: block;
        width: 48px;
        height: 48px;
        background-image: url('/static/logo-icon.png?v=3');
        background-size: contain;
        background-repeat: no-repeat;
        margin: 0 auto 16px auto;
        filter: drop-shadow(0 0 10px rgba(59, 130, 246, 0.5));
    }
}

/* 4. 输入框极感升级 */
body .input-group input {
    background: rgba(2, 6, 23, 0.4) !important; /* 深空黑填充 */
    border: 1px solid rgba(255, 255, 255, 0.08) !important;
    border-radius: 12px !important;
    color: #f8fafc !important;
    padding: 14px 16px !important;
    font-size: 15px;
    transition: all 0.3s cubic-bezier(0.4, 0, 0.2, 1);
}

body .input-group input:hover {
    background: rgba(2, 6, 23, 0.6) !important;
    border-color: rgba(255, 255, 255, 0.2) !important;
}

body .input-group input:focus {
    background: rgba(2, 6, 23, 0.8) !important;
    border-color: #3b82f6 !important;
    box-shadow: 
        0 0 0 4px rgba(59, 130, 246, 0.15),
        0 0 20px rgba(59, 130, 246, 0.1) inset !important;
    outline: none;
}

/* 5. 验证码暗黑模式修复 */
div#captcha-container {
    background: transparent !important;
    border: 1px solid rgba(255, 255, 255, 0.1);
    border-radius: 12px;
    overflow: hidden;
    /* 核心魔法：反转颜色+色相旋转，使白底变黑底，又不破坏彩色线条 */
    filter: invert(0.92) hue-rotate(180deg) brightness(1.2) contrast(1.2);
    box-shadow: inset 0 0 10px rgba(0,0,0,0.5);
    height: 48px; /* 与输入框等高 */
}

div#captcha-container svg {
    transform: scale(1.1); /* 稍微放大填满 */
}

/* 6. Tab 胶囊切换风格 */
body .auth-tabs {
    background: rgba(0, 0, 0, 0.2) !important;
    padding: 4px !important;
    border-radius: 50px !important; /* 胶囊圆角 */
    border: 1px solid rgba(255, 255, 255, 0.05);
    display: inline-flex;
    width: 100%;
}

body .auth-tab {
    flex: 1;
    border-radius: 40px !important;
    padding: 10px 0 !important;
    color: #94a3b8 !important;
    transition: all 0.3s ease;
    border-bottom: none !important; /* 移除之前的下划线风格 */
    position: relative;
    z-index: 1;
}

body .auth-tab.active {
    background: linear-gradient(135deg, rgba(59, 130, 246, 0.2), rgba(59, 130, 246, 0.1));
    color: #fff !important;
    box-shadow: 0 4px 12px rgba(0, 0, 0, 0.1);
    text-shadow: 0 0 10px rgba(59, 130, 246, 0.5);
    font-weight: 600;
}

/* 7. 主按钮流光质感 */
body .btn-auth-submit {
    background: linear-gradient(135deg, #3b82f6 0%, #2563eb 50%, #1d4ed8 100%) !important;
    border-radius: 12px !important;
    padding: 14px !important;
    font-size: 16px;
    font-weight: 600;
    letter-spacing: 0.5px;
    box-shadow: 
        0 4px 6px -1px rgba(0, 0, 0, 0.2),
        0 0 0 1px rgba(255, 255, 255, 0.1) inset !important; /* 内部高光 */
    transition: transform 0.2s, box-shadow 0.2s;
    position: relative;
    overflow: hidden;
}

/* 按钮微光扫过动画 */
body .btn-auth-submit::after {
    content: '';
    position: absolute;
    top: 0;
    left: -100%;
    width: 100%;
    height: 100%;
    background: linear-gradient(
        90deg,
        transparent,
        rgba(255, 255, 255, 0.2),
        transparent
    );
    transition: 0.5s;
}

body .btn-auth-submit:hover {
    transform: translateY(-2px);
    box-shadow: 
        0 10px 15px -3px rgba(37, 99, 235, 0.4),
        0 4px 6px -2px rgba(37, 99, 235, 0.2) !important;
}

body .btn-auth-submit:hover::after {
    left: 100%;
}

/* 8. 标题与文字优化 */
body .auth-title {
    font-size: 24px !important;
    font-weight: 700;
    letter-spacing: -0.5px;
    margin-bottom: 24px;
    background: linear-gradient(to right, #fff, #94a3b8);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    -webkit-text-fill-color: initial !important; /* 修复某些浏览器不兼容 */
    color: #fff;
}