/******************************************************************************
 * @file    adu-components.css
 * @brief   Adu Network Studio — 统一组件库
 *
 * @details 本文件提供所有可复用的 UI 组件，合并自：
 *          - theme.css (按钮/卡片/表单/徽章/警告/信息网格/空状态)
 *          - apple-glass.css (玻璃面板/毛玻璃卡片)
 *          - public-content.css (内容卡片/Pill/搜索框/功能面板)
 *          - learning/*.php 内联样式 (学习中心特有组件)
 *
 *          命名约定：所有新增统一组件使用 .btn-adu-* / .card-adu-* 等前缀
 *          以区分于旧版 .btn-theme-* / .glass-card-* 等类名。
 *
 * @version  1.0.0
 ******************************************************************************/

/* ============================================================
   1. Buttons — 统一按钮系统
   ============================================================ */

/* Base button */
.btn-adu {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    gap: 0.5rem;
    padding: 0.625rem 1.25rem;
    border-radius: var(--radius-sm);
    font-weight: 600;
    font-size: 0.875rem;
    line-height: 1.5;
    text-decoration: none;
    border: 1px solid transparent;
    cursor: pointer;
    transition: all 0.25s var(--ease-out-expo);
    white-space: nowrap;
    user-select: none;
}

.btn-adu:hover {
    transform: translateY(-1px);
}

.btn-adu:active {
    transform: scale(0.97);
    transition: transform 0.12s ease;
}

/* Primary */
.btn-adu-primary {
    background: var(--btn-primary-bg);
    color: var(--btn-primary-text);
    border-color: transparent;
}

.btn-adu-primary:hover {
    background: var(--btn-primary-hover);
    color: var(--btn-primary-text);
    box-shadow: var(--shadow-glow);
}

/* Secondary */
.btn-adu-secondary {
    background: var(--btn-secondary-bg);
    color: var(--btn-secondary-text);
    border-color: var(--border-default);
}

.btn-adu-secondary:hover {
    background: var(--btn-secondary-hover);
    color: var(--text-primary);
    border-color: var(--border-strong);
}

/* Gradient / CTA */
.btn-adu-gradient {
    background: var(--brand-gradient);
    color: #ffffff;
    border-color: transparent;
    box-shadow: 0 4px 20px rgba(37, 99, 235, 0.25);
    padding: 0.75rem 1.5rem;
}

.btn-adu-gradient:hover {
    opacity: 0.92;
    color: #ffffff;
    box-shadow: 0 8px 32px rgba(37, 99, 235, 0.4);
    transform: translateY(-2px);
}

/* Ghost — minimal border */
.btn-adu-ghost {
    background: transparent;
    color: var(--text-secondary);
    border-color: var(--border-default);
}

.btn-adu-ghost:hover {
    background: var(--bg-muted);
    color: var(--text-primary);
    border-color: var(--border-strong);
}

/* View action (green) */
.btn-adu-view {
    background: var(--accent-success);
    color: #ffffff;
    border-color: transparent;
}

.btn-adu-view:hover {
    background: var(--accent-success-hover);
    color: #ffffff;
}

/* Download action (blue) */
.btn-adu-download {
    background: var(--accent-primary);
    color: #ffffff;
    border-color: transparent;
}

.btn-adu-download:hover {
    background: var(--accent-hover);
    color: #ffffff;
}

/* Size variants */
.btn-adu-sm {
    padding: 0.4rem 0.85rem;
    font-size: 0.8125rem;
    border-radius: var(--radius-xs);
}

.btn-adu-lg {
    padding: 0.85rem 1.75rem;
    font-size: 1rem;
    border-radius: var(--radius-lg);
}

/* Pill / round variant */
.btn-adu-pill {
    border-radius: var(--radius-full);
    padding: 0.7rem 1.35rem;
}

/* Ripple effect */
.btn-adu-ripple {
    position: relative;
    overflow: hidden;
}

.btn-adu-ripple::after {
    content: "";
    position: absolute;
    inset: 0;
    background: radial-gradient(circle at center, rgba(255,255,255,0.3) 0%, transparent 70%);
    opacity: 0;
    transition: opacity 0.4s ease;
}

.btn-adu-ripple:hover::after {
    opacity: 1;
}

/* Block (full-width) */
.btn-adu-block {
    width: 100%;
}


/* ============================================================
   2. Cards — 统一卡片系统
   ============================================================ */

/* Base card */
.card-adu {
    background: var(--card-bg);
    border: 1px solid var(--card-border);
    border-radius: var(--radius-xl);
    box-shadow: var(--card-shadow);
    transition: all 0.3s var(--ease-out-expo);
}

.card-adu:hover {
    box-shadow: var(--card-hover-shadow);
    border-color: var(--border-strong);
}

/* Glass card */
.card-adu-glass {
    background: var(--glass-bg);
    border: 1px solid var(--glass-border);
    backdrop-filter: var(--glass-blur);
    -webkit-backdrop-filter: var(--glass-blur);
    box-shadow: var(--glass-shadow);
    border-radius: var(--radius-xl);
}

.card-adu-glass-heavy {
    background: var(--glass-bg);
    border: 1px solid var(--glass-border);
    backdrop-filter: var(--glass-blur-heavy);
    -webkit-backdrop-filter: var(--glass-blur-heavy);
    box-shadow: 0 12px 40px rgba(15, 23, 42, 0.1);
    border-radius: var(--radius-2xl);
}

/* Hover card — lift on hover */
.card-adu-hover {
    transition: transform 0.35s var(--ease-out-expo),
                box-shadow 0.35s var(--ease-out-expo),
                border-color 0.35s ease;
}

.card-adu-hover:hover {
    transform: translateY(-6px);
    box-shadow: 0 20px 48px rgba(37, 99, 235, 0.12);
    border-color: rgba(37, 99, 235, 0.35);
}

.card-adu-hover:active {
    transform: scale(0.98);
    transition: transform 0.12s ease;
}

/* Glow card — mouse tracking glow */
.card-adu-glow {
    position: relative;
    overflow: hidden;
}

.card-adu-glow::after {
    content: "";
    position: absolute;
    inset: 0;
    border-radius: inherit;
    background: radial-gradient(
        600px circle at var(--mouse-x, 50%) var(--mouse-y, 50%),
        rgba(37, 99, 235, 0.12),
        transparent 40%
    );
    opacity: 0;
    transition: opacity 0.4s ease;
    pointer-events: none;
    z-index: 1;
}

.card-adu-glow:hover::after {
    opacity: 1;
}

/* Resource card — with cover image area */
.card-adu-resource {
    background: var(--card-bg);
    border: 1px solid var(--card-border);
    border-radius: var(--radius-xl);
    overflow: hidden;
    box-shadow: var(--card-shadow);
    transition: all 0.3s var(--ease-out-expo);
    position: relative;
    height: 100%;
    display: flex;
    flex-direction: column;
}

.card-adu-resource:hover {
    box-shadow: var(--card-hover-shadow);
    border-color: var(--accent-primary);
    transform: translateY(-3px);
}

.card-adu-resource-cover {
    background: var(--accent-muted);
    height: 160px;
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 3rem;
    color: var(--accent-primary);
    position: relative;
    overflow: hidden;
}

.card-adu-resource-cover::after {
    content: '';
    position: absolute;
    top: -50%;
    right: -50%;
    width: 100%;
    height: 100%;
    background: var(--accent-primary);
    opacity: 0.05;
    border-radius: 50%;
}

.card-adu-resource-body {
    padding: 1.25rem;
    flex: 1;
    display: flex;
    flex-direction: column;
}

.card-adu-resource-title {
    color: var(--text-primary);
    font-weight: 600;
    font-size: 1rem;
    margin-bottom: 0.5rem;
    line-height: 1.4;
}

.card-adu-resource-meta {
    color: var(--text-muted);
    font-size: 0.8125rem;
    margin-top: auto;
}

/* Content card — for blog posts */
.card-adu-content {
    background: var(--card-bg);
    border: 1px solid var(--card-border);
    border-radius: var(--radius-xl);
    padding: 1.5rem;
    transition: all 0.3s var(--ease-out-expo);
    display: flex;
    flex-direction: column;
    gap: 0.75rem;
}

.card-adu-content:hover {
    box-shadow: var(--card-hover-shadow);
    border-color: var(--accent-primary);
    transform: translateY(-2px);
}

.card-adu-content-kicker {
    display: inline-flex;
    align-items: center;
    gap: 0.35rem;
    font-size: 0.75rem;
    font-weight: 600;
    color: var(--accent-primary);
    text-transform: uppercase;
    letter-spacing: 0.05em;
}

.card-adu-content-title {
    color: var(--text-primary);
    font-weight: 600;
    font-size: 1.15rem;
    line-height: 1.4;
}

.card-adu-content-excerpt {
    color: var(--text-secondary);
    font-size: 0.9rem;
    line-height: 1.7;
}

.card-adu-content-meta {
    display: flex;
    align-items: center;
    gap: 1rem;
    font-size: 0.8125rem;
    color: var(--text-muted);
}


/* ============================================================
   3. Badges & Pills
   ============================================================ */

/* Base badge */
.badge-adu {
    display: inline-flex;
    align-items: center;
    gap: 0.35rem;
    padding: 0.25rem 0.65rem;
    border-radius: var(--radius-xs);
    font-size: 0.6875rem;
    font-weight: 600;
    text-transform: uppercase;
    letter-spacing: 0.025em;
    white-space: nowrap;
}

/* File type badges */
.badge-adu-pdf  { background: rgba(220, 38, 38, 0.1);  color: var(--accent-error); }
.badge-adu-doc  { background: rgba(37, 99, 235, 0.1);   color: var(--accent-primary); }
.badge-adu-video { background: rgba(147, 51, 234, 0.1); color: var(--accent-purple); }
.badge-adu-zip  { background: rgba(234, 179, 8, 0.1);   color: var(--accent-warning); }
.badge-adu-image { background: rgba(34, 197, 94, 0.1);  color: var(--accent-success); }
.badge-adu-code  { background: rgba(14, 165, 233, 0.1);  color: var(--accent-info); }

/* Glass badge */
.badge-adu-glass {
    display: inline-flex;
    align-items: center;
    gap: 0.4rem;
    padding: 0.4rem 0.85rem;
    border-radius: var(--radius-full);
    background: var(--glass-bg);
    border: 1px solid var(--glass-border);
    backdrop-filter: blur(12px);
    -webkit-backdrop-filter: blur(12px);
    font-size: 0.78rem;
    font-weight: 600;
    color: var(--text-secondary);
    transition: border-color 0.25s ease, background-color 0.25s ease;
}

.badge-adu-glass:hover {
    border-color: var(--accent-primary);
}

/* Featured badge */
.badge-adu-featured {
    background: linear-gradient(135deg, rgba(234, 179, 8, 0.15), rgba(234, 179, 8, 0.08));
    color: var(--accent-warning);
    border: 1px solid rgba(234, 179, 8, 0.2);
}


/* ============================================================
   4. Category Pills
   ============================================================ */

.pill-adu {
    display: inline-flex;
    align-items: center;
    gap: 0.375rem;
    padding: 0.5rem 1rem;
    border-radius: var(--radius-full);
    background: var(--bg-subtle);
    border: 1px solid var(--border-default);
    color: var(--text-secondary);
    font-weight: 500;
    font-size: 0.875rem;
    text-decoration: none;
    transition: all 0.2s ease;
    cursor: pointer;
}

.pill-adu:hover {
    border-color: var(--accent-primary);
    color: var(--accent-primary);
    background: var(--accent-subtle);
}

.pill-adu.active {
    background: var(--accent-primary);
    border-color: var(--accent-primary);
    color: white;
}

/* Channel pill — with icon */
.pill-adu-channel {
    background: var(--bg-muted);
    border-color: transparent;
}

.pill-adu-channel:hover {
    background: var(--accent-subtle);
    border-color: var(--accent-muted);
}


/* ============================================================
   5. Forms — 统一表单控件
   ============================================================ */

.form-control-adu {
    background: var(--input-bg);
    border: 1px solid var(--input-border);
    color: var(--text-primary);
    border-radius: var(--radius-sm);
    padding: 0.625rem 0.875rem;
    font-size: 0.875rem;
    transition: all 0.2s ease;
    width: 100%;
}

.form-control-adu::placeholder {
    color: var(--input-placeholder);
}

.form-control-adu:focus {
    background: var(--input-bg);
    border-color: var(--input-focus-border);
    color: var(--text-primary);
    box-shadow: 0 0 0 3px rgba(59, 130, 246, 0.1);
    outline: none;
}


/* ============================================================
   6. Search Box
   ============================================================ */

.search-box-adu {
    display: flex;
    align-items: center;
    gap: 0.5rem;
    background: var(--card-bg);
    border: 1px solid var(--border-default);
    border-radius: var(--radius-lg);
    padding: 0.375rem;
    box-shadow: var(--shadow-lg);
}

.search-box-adu .form-control {
    background: transparent;
    border: none;
    color: var(--text-primary);
    padding: 0.75rem 1rem;
    font-size: 0.9375rem;
    flex: 1;
}

.search-box-adu .form-control::placeholder {
    color: var(--text-muted);
}

.search-box-adu .form-control:focus {
    box-shadow: none;
    outline: none;
}

.search-box-adu .btn {
    background: var(--accent-primary);
    color: white;
    border: none;
    border-radius: var(--radius-sm);
    padding: 0.75rem 1.5rem;
    font-weight: 600;
}

.search-box-adu .btn:hover {
    background: var(--accent-hover);
    color: white;
}


/* ============================================================
   7. Alerts — 统一警告提示
   ============================================================ */

.alert-adu {
    padding: 1rem 1.25rem;
    border-radius: var(--radius-sm);
    font-size: 0.9rem;
    display: flex;
    align-items: flex-start;
    gap: 0.6rem;
}

.alert-adu-success {
    background: rgba(34, 197, 94, 0.1);
    border: 1px solid rgba(34, 197, 94, 0.2);
    color: var(--accent-success);
}

.alert-adu-warning {
    background: rgba(234, 179, 8, 0.1);
    border: 1px solid rgba(234, 179, 8, 0.2);
    color: var(--accent-warning);
}

.alert-adu-error {
    background: rgba(220, 38, 38, 0.1);
    border: 1px solid rgba(220, 38, 38, 0.2);
    color: var(--accent-error);
}

.alert-adu-info {
    background: rgba(14, 165, 233, 0.1);
    border: 1px solid rgba(14, 165, 233, 0.2);
    color: var(--accent-info);
}


/* ============================================================
   8. Empty State
   ============================================================ */

.empty-state-adu {
    text-align: center;
    padding: 4rem 2rem;
}

.empty-state-adu-icon {
    width: 80px;
    height: 80px;
    margin: 0 auto 1.5rem;
    display: flex;
    align-items: center;
    justify-content: center;
    background: var(--bg-muted);
    border-radius: 50%;
    color: var(--text-muted);
    font-size: 2rem;
}

.empty-state-adu-title {
    font-size: 1.25rem;
    font-weight: 600;
    color: var(--text-primary);
    margin-bottom: 0.5rem;
}

.empty-state-adu-text {
    color: var(--text-muted);
    max-width: 400px;
    margin: 0 auto;
}


/* ============================================================
   9. Info Grid — 信息展示网格
   ============================================================ */

.info-grid-adu {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(200px, 1fr));
    gap: 1rem;
}

.info-item-adu {
    display: flex;
    align-items: center;
    gap: 0.75rem;
    padding: 1rem;
    background: var(--bg-subtle);
    border-radius: var(--radius-sm);
    border: 1px solid var(--border-default);
}

.info-item-adu-icon {
    width: 40px;
    height: 40px;
    display: flex;
    align-items: center;
    justify-content: center;
    background: var(--accent-muted);
    border-radius: var(--radius-sm);
    color: var(--accent-primary);
    flex-shrink: 0;
}

.info-item-adu-content {
    flex: 1;
    min-width: 0;
}

.info-item-adu-label {
    font-size: 0.75rem;
    color: var(--text-muted);
    text-transform: uppercase;
    letter-spacing: 0.05em;
    margin-bottom: 0.125rem;
}

.info-item-adu-value {
    font-size: 0.875rem;
    font-weight: 600;
    color: var(--text-primary);
    word-break: break-all;
}


/* ============================================================
   10. Pagination
   ============================================================ */

.pagination-adu {
    display: flex;
    justify-content: center;
    gap: 0.35rem;
    list-style: none;
    padding: 0;
    margin: 1.5rem 0 0;
}

.pagination-adu .page-link {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    min-width: 2.5rem;
    min-height: 2.5rem;
    padding: 0.5rem 0.85rem;
    border-radius: var(--radius-sm);
    background: var(--card-bg);
    border: 1px solid var(--border-default);
    color: var(--text-secondary);
    font-weight: 500;
    font-size: 0.9rem;
    text-decoration: none;
    transition: all 0.2s ease;
}

.pagination-adu .page-link:hover {
    border-color: var(--accent-primary);
    color: var(--accent-primary);
    background: var(--accent-subtle);
}

.pagination-adu .page-item.active .page-link {
    background: var(--accent-primary);
    border-color: var(--accent-primary);
    color: white;
}

.pagination-adu .page-item.disabled .page-link {
    opacity: 0.4;
    pointer-events: none;
}


/* ============================================================
   11. Section Title
   ============================================================ */

.section-title-adu {
    font-size: 1.5rem;
    font-weight: 700;
    color: var(--text-primary);
    margin-bottom: 1.5rem;
    position: relative;
    padding-bottom: 0.75rem;
}

.section-title-adu::after {
    content: '';
    position: absolute;
    bottom: 0;
    left: 0;
    width: 48px;
    height: 3px;
    background: var(--accent-primary);
    border-radius: 2px;
}

/* Section header with subtitle watermark */
.section-header-adu {
    margin-bottom: 2.4rem;
    position: relative;
}

.section-header-adu h2 {
    margin: 0;
    font-size: clamp(1.6rem, 3.5vw, 2.6rem);
    line-height: 1.05;
    letter-spacing: -0.03em;
    position: relative;
    z-index: 1;
}

.section-header-adu .subtitle-watermark {
    position: absolute;
    top: -1rem;
    left: 0;
    z-index: 0;
    color: rgba(37, 99, 235, 0.08);
    font-size: clamp(2rem, 6vw, 4.5rem);
    font-weight: 800;
    letter-spacing: 0.1em;
    text-transform: uppercase;
    pointer-events: none;
}


/* ============================================================
   12. Loading Spinner
   ============================================================ */

.spinner-adu {
    width: 40px;
    height: 40px;
    border-radius: 50%;
    border: 3px solid var(--border-default);
    border-top-color: var(--accent-primary);
    animation: spinner-rotate 0.8s linear infinite;
}

.spinner-adu-sm { width: 24px; height: 24px; border-width: 2px; }
.spinner-adu-lg { width: 56px; height: 56px; border-width: 4px; }

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


/* ============================================================
   13. Image Hover Zoom
   ============================================================ */

.img-hover-zoom {
    overflow: hidden;
    border-radius: inherit;
}

.img-hover-zoom img {
    transition: transform 0.6s var(--ease-out-expo);
    width: 100%;
    height: 100%;
    object-fit: cover;
}

.img-hover-zoom:hover img {
    transform: scale(1.06);
}


/* ============================================================
   14. Utility Classes
   ============================================================ */

.bg-base    { background-color: var(--bg-base) !important; }
.bg-subtle  { background-color: var(--bg-subtle) !important; }
.bg-muted   { background-color: var(--bg-muted) !important; }
.bg-surface { background-color: var(--bg-surface0) !important; }
.bg-card    { background-color: var(--card-bg) !important; }

.text-accent          { color: var(--accent-primary) !important; }
.text-secondary-theme { color: var(--text-secondary) !important; }
.text-muted-theme     { color: var(--text-muted) !important; }

.border-accent   { border-color: var(--accent-primary) !important; }
.border-default  { border-color: var(--border-default) !important; }

.text-balance { text-wrap: balance; }
.text-pretty  { text-wrap: pretty; }


/* ============================================================
   15. Responsive Adjustments
   ============================================================ */

@media (max-width: 768px) {
    .card-adu-resource-cover {
        height: 120px;
        font-size: 2.5rem;
    }

    .section-title-adu {
        font-size: 1.25rem;
    }

    .info-grid-adu {
        grid-template-columns: 1fr;
    }

    .search-box-adu .btn {
        padding: 0.65rem 1rem;
    }
}
.site-shell {
    min-height: 100vh;
    background:
        radial-gradient(circle at top right, rgba(37, 99, 235, 0.12), transparent 28%),
        radial-gradient(circle at left center, rgba(56, 189, 248, 0.09), transparent 22%),
        linear-gradient(180deg, var(--bg-subtle) 0%, var(--bg-base) 18%, var(--bg-base) 100%);
}

.site-shell main {
    position: relative;
}

.navbar-theme.navbar-elevated {
    background: rgba(255, 255, 255, 0.82);
    border-bottom: 1px solid var(--border-default);
    box-shadow: var(--shadow-sm);
    backdrop-filter: blur(18px);
    -webkit-backdrop-filter: blur(18px);
}

[data-theme="dark"] .navbar-theme.navbar-elevated {
    background: rgba(9, 9, 11, 0.84);
}

.navbar-theme .navbar-brand {
    display: inline-flex;
    align-items: center;
    gap: 0.75rem;
}

.brand-mark {
    width: 2.25rem;
    height: 2.25rem;
    display: inline-flex;
    align-items: center;
    justify-content: center;
    border-radius: 0.9rem;
    background: linear-gradient(135deg, rgba(37, 99, 235, 0.14), rgba(14, 165, 233, 0.24));
    color: var(--accent-primary);
    box-shadow: inset 0 1px 0 rgba(255, 255, 255, 0.35);
}

.navbar-theme .navbar-toggler {
    border: 1px solid var(--border-default);
    background: var(--bg-surface0);
    border-radius: 0.9rem;
    box-shadow: none;
}

.navbar-theme .navbar-toggler-icon {
    background-image: url("data:image/svg+xml,%3csvg xmlns='http://www.w3.org/2000/svg' viewBox='0 0 30 30'%3e%3cpath stroke='rgba(39,39,42,0.84)' stroke-linecap='round' stroke-miterlimit='10' stroke-width='2' d='M4 7h22M4 15h22M4 23h22'/%3e%3c/svg%3e");
}

[data-theme='dark'] .navbar-theme .navbar-toggler-icon {
    background-image: url("data:image/svg+xml,%3csvg xmlns='http://www.w3.org/2000/svg' viewBox='0 0 30 30'%3e%3cpath stroke='rgba(244,244,245,0.88)' stroke-linecap='round' stroke-miterlimit='10' stroke-width='2' d='M4 7h22M4 15h22M4 23h22'/%3e%3c/svg%3e");
}

.navbar-theme .navbar-toggler:focus-visible {
    box-shadow: 0 0 0 4px rgba(37, 99, 235, 0.14);
}

/* 导航链接 + 主题切换按钮（补齐新链缺口 · 自 theme.css 移植，统一模板与所有新链页面一致） */
.navbar-theme .navbar-brand {
    color: var(--navbar-text);
    font-weight: 700;
}

.navbar-theme .nav-link {
    color: var(--navbar-text-muted) !important;
    font-weight: 500;
    padding: 0.5rem 1rem !important;
    border-radius: var(--radius-sm);
    transition: color var(--theme-transition), background-color var(--theme-transition);
}

.navbar-theme .nav-link:hover {
    color: var(--navbar-text) !important;
    background: var(--bg-muted);
}

.navbar-theme .nav-link.active {
    color: var(--accent-primary) !important;
}

.theme-toggle {
    background: var(--bg-muted);
    border: 1px solid var(--border-default);
    border-radius: var(--radius-sm);
    width: 40px;
    height: 40px;
    display: inline-flex;
    align-items: center;
    justify-content: center;
    cursor: pointer;
    transition: all 0.2s ease;
    color: var(--text-secondary);
    font-size: 1rem;
}

.theme-toggle:hover {
    background: var(--bg-emphasis);
    border-color: var(--border-strong);
    color: var(--text-primary);
}

.theme-toggle:focus-visible {
    outline: 3px solid rgba(37, 99, 235, 0.4);
    outline-offset: 3px;
}

.content-hero {
    position: relative;
    padding: 4.75rem 0 3rem;
    overflow: hidden;
}

.content-hero::before {
    content: "";
    position: absolute;
    inset: 0;
    background:
        linear-gradient(90deg, rgba(228, 228, 231, 0.45) 1px, transparent 1px),
        linear-gradient(rgba(228, 228, 231, 0.45) 1px, transparent 1px);
    background-size: 56px 56px;
    opacity: 0.35;
    pointer-events: none;
}

[data-theme="dark"] .content-hero::before {
    opacity: 0.12;
}

.content-hero::after {
    content: "";
    position: absolute;
    top: -7rem;
    right: -8rem;
    width: 28rem;
    height: 28rem;
    background: radial-gradient(circle, rgba(37, 99, 235, 0.16), transparent 70%);
    pointer-events: none;
}

.hero-grid {
    position: relative;
    z-index: 1;
    display: grid;
    grid-template-columns: minmax(0, 1.3fr) minmax(280px, 0.7fr);
    gap: 1.25rem;
    align-items: stretch;
}

.hero-panel,
.hero-side-panel,
.surface-panel,
.sidebar-panel,
.metric-card,
.footer-card {
    border: 1px solid rgba(255, 255, 255, 0.4);
    background: rgba(255, 255, 255, 0.78);
    box-shadow: var(--shadow-lg);
    backdrop-filter: blur(18px);
    -webkit-backdrop-filter: blur(18px);
}

[data-theme="dark"] .hero-panel,
[data-theme="dark"] .hero-side-panel,
[data-theme="dark"] .surface-panel,
[data-theme="dark"] .sidebar-panel,
[data-theme="dark"] .metric-card,
[data-theme="dark"] .footer-card {
    border-color: rgba(63, 63, 70, 0.8);
    background: rgba(24, 24, 27, 0.82);
}

.hero-panel,
.hero-side-panel,
.surface-panel,
.sidebar-panel,
.footer-card {
    border-radius: 1.6rem;
}

.hero-panel {
    padding: 2rem;
}

.hero-side-panel {
    padding: 1.25rem;
}

.hero-badge {
    display: inline-flex;
    align-items: center;
    gap: 0.5rem;
    padding: 0.45rem 0.85rem;
    border-radius: 999px;
    background: var(--accent-subtle);
    color: var(--accent-primary);
    font-size: 0.78rem;
    font-weight: 700;
    text-transform: uppercase;
    letter-spacing: 0.08em;
    margin-bottom: 1rem;
}

.hero-title {
    font-size: clamp(2.4rem, 5vw, 4.6rem);
    line-height: 0.98;
    letter-spacing: -0.04em;
    margin-bottom: 1rem;
}

.hero-lead {
    max-width: 42rem;
    font-size: 1.05rem;
    line-height: 1.85;
    color: var(--text-secondary);
    margin-bottom: 1.4rem;
}

.hero-actions {
    display: flex;
    flex-wrap: wrap;
    gap: 0.85rem;
}

.btn-primary-soft,
.btn-secondary-soft {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    gap: 0.55rem;
    min-height: 2.9rem;
    padding: 0.75rem 1.2rem;
    border-radius: 0.95rem;
    font-weight: 600;
    text-decoration: none;
    border: 1px solid transparent;
    transition: transform 0.2s ease, box-shadow 0.2s ease, background-color 0.2s ease, color 0.2s ease, border-color 0.2s ease;
}

.btn-primary-soft {
    background: var(--brand-gradient);
    color: #fff;
    box-shadow: var(--shadow-glow);
}

.btn-primary-soft:hover {
    color: #fff;
    transform: translateY(-1px);
}

.btn-secondary-soft {
    background: var(--bg-surface0);
    color: var(--text-primary);
    border-color: var(--border-default);
}

.btn-secondary-soft:hover {
    color: var(--accent-primary);
    border-color: var(--accent-primary);
    transform: translateY(-1px);
}

.hero-side-title,
.sidebar-title {
    display: flex;
    align-items: center;
    gap: 0.6rem;
    margin: 0 0 1rem;
    font-size: 1rem;
    font-weight: 700;
    color: var(--text-primary);
}

.metric-list {
    display: grid;
    gap: 0.8rem;
}

.metric-card {
    border-radius: 1.15rem;
    padding: 1rem 1.1rem;
}

.metric-card strong {
    display: block;
    font-size: 1.7rem;
    line-height: 1;
    color: var(--text-primary);
    margin-bottom: 0.35rem;
    font-variant-numeric: tabular-nums;
}

.metric-card span {
    color: var(--text-muted);
    font-size: 0.92rem;
}

.content-main {
    padding: 0 0 4rem;
}

.page-grid {
    display: grid;
    grid-template-columns: minmax(0, 1.65fr) minmax(290px, 0.7fr);
    gap: 1.5rem;
}

.main-stack,
.sidebar-stack,
.feed-stack {
    display: grid;
    gap: 1.25rem;
}

.surface-panel {
    padding: 1.5rem;
    transition: transform 0.22s ease, box-shadow 0.22s ease, border-color 0.22s ease;
}

.content-card {
    position: relative;
    overflow: hidden;
}

.content-card:hover {
    transform: translateY(-2px);
}

.card-kicker {
    display: flex;
    flex-wrap: wrap;
    align-items: center;
    gap: 0.7rem;
    margin-bottom: 0.9rem;
}

.channel-pill,
.muted-pill,
.featured-pill {
    display: inline-flex;
    align-items: center;
    gap: 0.35rem;
    padding: 0.35rem 0.75rem;
    border-radius: 999px;
    font-size: 0.76rem;
    font-weight: 700;
}

.channel-pill {
    background: var(--accent-subtle);
    color: var(--accent-primary);
}

.muted-pill {
    background: var(--bg-muted);
    color: var(--text-secondary);
}

.featured-pill {
    background: linear-gradient(135deg, #0f172a, #2563eb);
    color: #fff;
}

.content-title,
.content-title a {
    color: var(--text-primary);
    text-decoration: none;
}

.content-title {
    font-size: clamp(1.35rem, 2vw, 1.7rem);
    line-height: 1.15;
    letter-spacing: -0.03em;
    margin-bottom: 0.9rem;
}

.content-title a:hover {
    color: var(--accent-primary);
}

.meta-row {
    display: flex;
    flex-wrap: wrap;
    gap: 0.9rem 1rem;
    color: var(--text-muted);
    font-size: 0.9rem;
    margin-bottom: 1rem;
}

.meta-row span,
.meta-row a {
    display: inline-flex;
    align-items: center;
    gap: 0.4rem;
    color: inherit;
    text-decoration: none;
}

.meta-row a:hover {
    color: var(--accent-primary);
}

.content-excerpt {
    color: var(--text-secondary);
    line-height: 1.8;
    margin-bottom: 1.15rem;
}

.content-actions {
    display: flex;
    flex-wrap: wrap;
    justify-content: space-between;
    gap: 0.75rem;
    align-items: center;
}

.sidebar-panel {
    padding: 1.2rem 1.2rem 1.3rem;
}

.search-shell label {
    display: block;
    margin-bottom: 0.65rem;
    font-size: 0.85rem;
    font-weight: 600;
    color: var(--text-secondary);
}

.search-shell .input-group {
    border-radius: 1rem;
    overflow: hidden;
    border: 1px solid var(--border-default);
    background: var(--bg-surface0);
}

.search-shell .form-control,
.search-shell .btn {
    border: none;
    min-height: 3rem;
}

.search-shell .form-control {
    background: transparent;
    color: var(--text-primary);
}

.search-shell .form-control::placeholder {
    color: var(--text-muted);
}

.search-shell .btn {
    background: var(--brand-gradient-subtle);
    color: #fff;
    padding-inline: 1rem;
}

.chip-cloud {
    display: flex;
    flex-wrap: wrap;
    gap: 0.65rem;
}

.chip-cloud a,
.count-link {
    display: inline-flex;
    align-items: center;
    justify-content: space-between;
    gap: 0.65rem;
    padding: 0.55rem 0.85rem;
    border-radius: 0.95rem;
    background: var(--bg-subtle);
    color: var(--text-secondary);
    text-decoration: none;
    border: 1px solid var(--border-default);
    transition: border-color 0.2s ease, color 0.2s ease, transform 0.2s ease, background-color 0.2s ease;
}

.chip-cloud a:hover,
.count-link:hover,
.count-link.active {
    color: var(--accent-primary);
    border-color: var(--accent-primary);
    background: var(--accent-subtle);
    transform: translateY(-1px);
}

.rank-list {
    display: grid;
    gap: 0.9rem;
}

.rank-item {
    display: grid;
    grid-template-columns: auto 1fr;
    gap: 0.9rem;
    align-items: start;
}

.rank-index {
    width: 2rem;
    height: 2rem;
    border-radius: 0.8rem;
    display: inline-flex;
    align-items: center;
    justify-content: center;
    background: var(--accent-subtle);
    color: var(--accent-primary);
    font-weight: 700;
    font-variant-numeric: tabular-nums;
}

.rank-item a {
    color: var(--text-primary);
    text-decoration: none;
}

.rank-item a:hover {
    color: var(--accent-primary);
}

.rank-meta {
    color: var(--text-muted);
    font-size: 0.82rem;
    margin-top: 0.25rem;
}

.article-prose {
    color: var(--text-secondary);
    line-height: 1.95;
    font-size: 1rem;
}

.article-prose img {
    max-width: 100%;
    height: auto;
    border-radius: 1rem;
    margin: 1.5rem 0;
}

.article-prose pre {
    overflow-x: auto;
    border-radius: 1rem;
    padding: 1.15rem 1.25rem;
    background: #0f172a;
    color: #e2e8f0;
}

.article-prose code {
    padding: 0.15rem 0.4rem;
    border-radius: 0.45rem;
    background: var(--bg-muted);
    color: var(--accent-active);
}

.article-prose pre code {
    padding: 0;
    background: transparent;
    color: inherit;
}

.empty-state {
    padding: 3rem 1.5rem;
    text-align: center;
}

.empty-state i {
    font-size: 2.6rem;
    color: var(--accent-primary);
    margin-bottom: 1rem;
}

.site-footer {
    margin-top: 4rem;
}

.site-footer__wrap {
    padding: 1.4rem 1.5rem;
}

.site-footer__text {
    color: var(--text-secondary);
    line-height: 1.8;
}

.site-footer__links,
.site-footer__record {
    display: flex;
    flex-wrap: wrap;
    gap: 0.75rem 1rem;
    align-items: center;
}

.site-footer__record.border-top {
    border-color: var(--border-default) !important;
}

.site-footer__links a,
.site-footer__record a {
    color: var(--text-muted);
    text-decoration: none;
}

.site-footer__links a:hover,
.site-footer__record a:hover {
    color: var(--accent-primary);
}

.site-footer__record img {
    height: 18px;
    width: auto;
}

.pagination .page-link {
    border-radius: 0.85rem !important;
    border-color: var(--border-default);
    color: var(--text-secondary);
    margin-inline: 0.18rem;
    min-width: 2.6rem;
    text-align: center;
}

.pagination .page-link:hover,
.pagination .page-item.active .page-link {
    background: var(--accent-primary);
    border-color: var(--accent-primary);
    color: #fff;
}

@media (max-width: 991.98px) {
    .hero-grid,
    .page-grid {
        grid-template-columns: 1fr;
    }

    .content-hero {
        padding-top: 4rem;
    }
}

@media (max-width: 767.98px) {
    .hero-panel,
    .surface-panel,
    .sidebar-panel,
    .site-footer__wrap {
        padding: 1.1rem;
        border-radius: 1.25rem;
    }

    .hero-title {
        font-size: 2.3rem;
    }

    .content-actions {
        flex-direction: column;
        align-items: stretch;
    }
}

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

/* ============================================================
   旧类 -> 新类 映射参考（标记逐页迁移用，既有定义保留以零破坏）
   .btn-primary-soft   -> .btn-adu-primary
   .btn-secondary-soft -> .btn-adu-secondary
   .channel-pill       -> .pill-adu-channel
   .featured-pill      -> .badge-adu-featured
   .content-card       -> .card-adu-content
   ============================================================ */

/* ============================================================
   代码块（spec 5 · 学习站核心）
   ============================================================ */
.code-block { position: relative; border: 1px solid var(--border-default); border-radius: var(--radius-md); overflow: hidden; margin: var(--space-lg) 0; }
.code-block__bar { display: flex; justify-content: space-between; align-items: center; padding: var(--space-sm) var(--space-md); background: var(--bg-muted); font-size: var(--text-xs); color: var(--text-muted); font-family: var(--font-mono); }
.code-block__copy { cursor: pointer; border: 0; background: transparent; color: var(--accent-primary); font: inherit; display: inline-flex; align-items: center; gap: 4px; min-height: 28px; padding: 0 6px; }
.code-block__copy:focus-visible { outline: 3px solid rgba(37,99,235,.5); }
.code-block pre { margin: 0; padding: var(--space-md); overflow-x: auto; background: var(--bg-subtle); }
.code-block code { font-family: var(--font-mono); font-size: 13px; line-height: var(--leading-relaxed); color: var(--text-secondary); }

/* ============================================================
   表单字段态（spec 5）
   ============================================================ */
.form-field { margin-bottom: var(--space-lg); }
.form-label { display: block; margin-bottom: var(--space-xs); font-size: var(--text-sm); font-weight: 500; color: var(--text-secondary); }
.form-label .req { color: var(--accent-error); margin-left: 2px; }
.form-control-adu:focus-visible { outline: none; border-color: var(--accent-primary); box-shadow: 0 0 0 3px rgba(37, 99, 235, .18); }
.form-control-adu[aria-invalid="true"] { border-color: var(--accent-error); }
.form-help { margin-top: var(--space-xs); font-size: var(--text-xs); color: var(--text-muted); }
.form-error { margin-top: var(--space-xs); font-size: var(--text-xs); color: var(--accent-error); }

/* ============================================================
   禁用态 + 面包屑（spec 5）
   ============================================================ */
.btn-adu:disabled, .btn-adu[aria-disabled="true"] { opacity: .5; cursor: not-allowed; pointer-events: none; }
.breadcrumb-adu { display: flex; flex-wrap: wrap; gap: var(--space-xs); align-items: center; list-style: none; padding: 0; margin: 0 0 var(--space-lg); font-size: var(--text-sm); color: var(--text-muted); }
.breadcrumb-adu a { color: var(--text-secondary); text-decoration: none; }
.breadcrumb-adu a:hover { color: var(--accent-primary); }
.breadcrumb-adu li:not(:last-child)::after { content: "/"; margin-left: var(--space-xs); color: var(--text-subtle); }