/* ============================================================
   THEME.CSS v3.0 - 主题主样式
   ============================================================
   匹配 Section 模板的 class 名称
   - CSS Variables 设计令牌
   - 所有 Section 主样式 (布局/背景/排版)
   ============================================================ */

/* ============================================
   1. CSS Variables
   ============================================ */
:root {
    /* 品牌色 */
    --color-primary: #3b82f6;
    --color-primary-dark: #1e3a8a;
    --color-primary-darker: #1e293b;
    --color-accent: #fbbf24;
    --color-accent-dark: #f59e0b;
    --color-success: #16a34a;
    --color-danger: #dc2626;

    /* 中性色 */
    --color-text: #334155;
    --color-text-muted: #64748b;
    --color-text-light: #94a3b8;
    --color-bg: #ffffff;
    --color-bg-soft: #f8fafc;
    --color-bg-muted: #f1f5f9;
    --color-border: #e5e7eb;
    --color-border-soft: #f1f5f9;

    /* 渐变 (Section 背景) */
    --gradient-hero: linear-gradient(135deg, #1e3a8a 0%, #3b82f6 100%);
    --gradient-deep: linear-gradient(135deg, #0f172a 0%, #1e3a8a 100%);
    --gradient-dept: linear-gradient(135deg, #312e81 0%, #4f46e5 100%);
    --gradient-security: linear-gradient(135deg, #1e293b, #0f172a);
    --gradient-mission: linear-gradient(135deg, #1e3a8a, #312e81);
    --gradient-trust: linear-gradient(135deg, #0f172a, #1e3a8a);
    --gradient-cta: linear-gradient(135deg, #1e3a8a 0%, #3b82f6 100%);
    --gradient-accent: linear-gradient(135deg, #fbbf24, #f59e0b);
    --gradient-icon: linear-gradient(135deg, #3b82f6, #1e3a8a);

    /* 玻璃效果 */
    --glass-bg: rgba(255, 255, 255, 0.08);
    --glass-border: rgba(255, 255, 255, 0.15);
    --glass-blur: blur(10px);

    /* 阴影 */
    --shadow-sm: 0 4px 12px rgba(0, 0, 0, 0.05);
    --shadow-md: 0 8px 20px rgba(0, 0, 0, 0.08);
    --shadow-lg: 0 12px 30px rgba(0, 0, 0, 0.1);
    --shadow-xl: 0 15px 35px rgba(0, 0, 0, 0.12);
    --shadow-primary: 0 12px 30px rgba(59, 130, 246, 0.15);
    --shadow-accent: 0 10px 25px rgba(251, 191, 36, 0.15);

    /* 圆角 */
    --radius-sm: 6px;
    --radius-md: 12px;
    --radius-lg: 16px;
    --radius-pill: 30px;

    /* 间距 */
    --space-xs: 0.5rem;
    --space-sm: 1rem;
    --space-md: 1.5rem;
    --space-lg: 2rem;
    --space-xl: 3rem;
    --space-2xl: 5rem;

    /* 过渡 */
    --transition-fast: 0.2s ease;
    --transition-base: 0.3s ease;
    --transition-slow: 0.5s ease;
}

/* ============================================
   2. Base
   ============================================ */
:where(body) {
    color: var(--color-text);
    background: var(--color-bg);
    line-height: 1.6;
    -webkit-font-smoothing: antialiased;
}

:where(img) {
    max-width: 100%;
    height: auto;
}

/* ============================================
   3. 通用工具
   ============================================ */
.bg-glass {
    background: var(--glass-bg);
    backdrop-filter: var(--glass-blur);
    -webkit-backdrop-filter: var(--glass-blur);
    border: 1px solid var(--glass-border);
}

.icon-circle {
    width: 60px;
    height: 60px;
    background: var(--gradient-icon);
    border-radius: 50%;
    display: inline-flex;
    align-items: center;
    justify-content: center;
    color: #fff;
    font-size: 1.5rem;
    flex-shrink: 0;
}

/* ============================================
   4. Header (HeaderSection)
   ============================================ */
.header {
    background: #fff;
    z-index: 1030;
}

.header .navbar-brand img {
    transition: transform var(--transition-fast);
}

.header .navbar-brand:hover img {
    transform: scale(1.05);
}

.header .nav-link {
    font-weight: 500;
    color: var(--color-text);
    transition: color var(--transition-fast);
}

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

/* ============================================
   5. Hero (HeroSection)
   ============================================ */
.hero-section {
    min-height: 480px;
    background: var(--gradient-hero);
    color: #fff;
    padding-block: var(--space-2xl);
    position: relative;
    overflow: hidden;
}

.hero-section::before {
    content: '';
    position: absolute;
    inset: 0;
    background: rgba(0, 0, 0, 0.15);
    z-index: 0;
    pointer-events: none;
}

.hero-section > .container {
    position: relative;
    z-index: 1;
}

.hero-section h1 {
    font-size: clamp(2rem, 4vw, 2.8rem);
    font-weight: 700;
    margin-bottom: var(--space-sm);
    line-height: 1.2;
}

.hero-section h2 {
    font-size: clamp(1.1rem, 2vw, 1.4rem);
    opacity: 0.9;
    margin-bottom: var(--space-md);

    font-weight: 500;
}

.hero-section .lead {
    font-size: 1.1rem;
    max-width: 700px;
    margin-inline: auto;
    opacity: 0.95;
}

.hero-buttons {
    display: flex;
    gap: var(--space-sm);
    justify-content: center;
    flex-wrap: wrap;
    margin-block-start: var(--space-md);
}

/* ============================================
   6. Notice Bar (NoticeBarSection)
   ============================================ */
.notice-bar {
    animation: noticeSlideIn 0.5s ease-out;
}

.notice-bar a {
    transition: opacity var(--transition-fast);
}

.notice-bar a:hover {
    opacity: 0.85;
}

@keyframes noticeSlideIn {
    from { transform: translateY(-100%); opacity: 0; }
    to   { transform: translateY(0); opacity: 1; }
}

/* ============================================
   7. Breadcrumb (BreadcrumbSection)
   ============================================ */
.breadcrumb-nav {
    background: var(--color-bg-muted);
}

.breadcrumb-nav .breadcrumb-item a {
    transition: color var(--transition-fast);
}

.breadcrumb-nav .breadcrumb-item a:hover {
    color: var(--color-primary-dark) !important;
}

/* ============================================
   8. Why Us (WhyUsSection)
   ============================================ */
.why-us-section {
    background: var(--color-bg-soft);
}

.whyus-card {
    background: #fff;
    border: 1px solid var(--color-border-soft);
    border-radius: var(--radius-lg);
    padding: var(--space-md);
    transition: all var(--transition-base);
    height: 100%;
}

.whyus-card:hover {
    transform: translateY(-5px);
    box-shadow: var(--shadow-primary);
}

/* ============================================
   9. About (AboutSection)
   ============================================ */
.about-section {
    background: var(--gradient-deep);
    color: #fff;
}

.about-img-wrap {
    overflow: hidden;
    border-radius: var(--radius-lg);
}

.about-img-wrap img {
    transition: transform var(--transition-slow);
}

.about-img-wrap:hover img {
    transform: scale(1.05);
}

.about-card {
    transition: all var(--transition-base);
}

.about-card:hover {
    transform: translateY(-3px);
    background: rgba(255, 255, 255, 0.12);
}

.text-white-75 {
    color: rgba(255, 255, 255, 0.75) !important;
}

/* ============================================
   10. Departments (DepartmentsSection)
   ============================================ */
.departments-section {
    background: var(--gradient-dept);
    color: #fff;
}

.departments-title {
    font-size: clamp(1.6rem, 3vw, 2.2rem);
    font-weight: 700;
    margin-bottom: var(--space-sm);
}

.departments-subtitle {
    font-size: 1.05rem;
    max-width: 800px;
    margin-inline: auto;
    color: rgba(255, 255, 255, 0.85);
}

.departments-grid {
    display: grid;
    grid-template-columns: 1fr;
    gap: var(--space-lg);
    margin-block-start: var(--space-lg);
}

@media (min-width: 768px) {
    .departments-grid {
        grid-template-columns: 1fr 1fr;
    }
}

.d-item {
    background: var(--glass-bg);
    backdrop-filter: var(--glass-blur);
    -webkit-backdrop-filter: var(--glass-blur);
    padding: var(--space-md);
    border-radius: var(--radius-md);
    margin-bottom: var(--space-sm);
}

.d-num {
    font-size: 1.5rem;
    font-weight: 700;
    color: var(--color-accent);
    margin-bottom: var(--space-xs);
}

.d-num span {
    color: #fff;
    font-size: 1.1rem;
    margin-inline-start: var(--space-xs);
}

.d-image {
    margin-bottom: var(--space-sm);
}

.d-image img {
    width: 100%;
    border-radius: var(--radius-md);
}

/* ============================================
   11. Security Network (SecuritySection)
   ============================================ */
.security-section {
    background: var(--gradient-security);
    color: #fff;
}

.security-network {
    position: relative;
    max-width: 800px;
    margin: var(--space-xl) auto;
    min-height: 400px;
    display: grid;
    grid-template-columns: 1fr;
    gap: var(--space-md);
}

@media (min-width: 768px) {
    .security-network {
        grid-template-columns: repeat(3, 1fr);
        grid-template-rows: repeat(3, auto);
    }

    .core-node        { grid-column: 2; grid-row: 2; }
    .node-top-left    { grid-column: 1; grid-row: 1; }
    .node-top-right   { grid-column: 3; grid-row: 1; }
    .node-bottom-left { grid-column: 1; grid-row: 3; }
    .node-bottom-right{ grid-column: 3; grid-row: 3; }
}

.core-node {
    background: var(--gradient-accent);
    border-radius: 50%;
    width: 140px;
    height: 140px;
    display: flex;
    flex-direction: column;
    align-items: center;
    justify-content: center;
    margin-inline: auto;
    color: var(--color-primary-darker);
    font-weight: 700;
    box-shadow: 0 0 30px rgba(251, 191, 36, 0.4);
}

.node {
    background: var(--glass-bg);
    backdrop-filter: var(--glass-blur);
    -webkit-backdrop-filter: var(--glass-blur);
    border-radius: var(--radius-md);
    padding: var(--space-sm);
    text-align: center;
    color: #fff;
    transition: all var(--transition-base);
}

.node:hover {
    transform: scale(1.05);
    background: rgba(255, 255, 255, 0.12);
}

.node-title {
    font-weight: 600;
    color: var(--color-accent);
    margin-block: var(--space-xs);
}

@media (max-width: 767.98px) {
    .core-node { width: 120px; height: 120px; }
}

/* ============================================
   12. Honor (HonorSection)
   ============================================ */
.honor-section {
    background: var(--color-bg-soft);
}

.honor-row {
    padding-block: var(--space-sm);
}

.honor-text-card {
    padding: var(--space-md);
    background: #fff;
    border-radius: var(--radius-md);
    border-inline-start: 4px solid var(--color-primary);
    transition: all var(--transition-base);
}

.honor-text-card:hover {
    transform: translateY(-3px);
    box-shadow: var(--shadow-md);
}

/* ============================================
   13. Mission (MissionSection)
   ============================================ */
.mission-section {
    background: var(--gradient-mission);
    padding-block: var(--space-2xl);
    color: #fff;
}

.mission-list li {
    margin-bottom: var(--space-sm);
    color: #e2e8f0;
}

/* ============================================
   14. Stats (StatsSection)
   ============================================ */
.stats-section {
    background: #fff;
}

.stats-card {
    transition: all var(--transition-base);
    background: var(--color-bg-soft);
}

.stats-card:hover {
    transform: translateY(-5px);
    box-shadow: var(--shadow-md);
    background: linear-gradient(135deg, #fff 0%, #f0f7ff 100%);
}

.stats-card h3 {
    font-variant-numeric: tabular-nums;
    color: var(--color-primary-darker);
}

/* ============================================
   15. News (NewsSection)
   ============================================ */
.news-section {
    background: var(--color-bg-soft);
}

.news-card {
    transition: all var(--transition-base);
    border: 1px solid var(--color-border-soft);
}

.news-card:hover {
    transform: translateY(-5px);
    box-shadow: var(--shadow-lg);
}

.news-img-wrap {
    height: 200px;
    overflow: hidden;
    position: relative;
}

.news-img-wrap img {
    width: 100%;
    height: 100%;
    object-fit: cover;
    transition: transform var(--transition-slow);
}

.news-card:hover .news-img-wrap img {
    transform: scale(1.08);
}

/* ============================================
   16. Matches (MatchesSection)
   ============================================ */
.matches-section {
    background: var(--color-bg-soft);
}

.match-card {
    transition: all var(--transition-base);
    border: 1px solid var(--color-border-soft);
}

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

.match-card .team {
    min-width: 0;
}

.match-card .team .small {
    overflow: hidden;
    text-overflow: ellipsis;
    white-space: nowrap;
}

.match-card .score {
    font-variant-numeric: tabular-nums;
    color: var(--color-primary-darker);
}

/* ============================================
   17. Trust (TrustSection)
   ============================================ */
.trust-section {
    background: var(--gradient-trust);
    color: #fff;
}

.trust-card {
    background: var(--glass-bg);
    backdrop-filter: var(--glass-blur);
    -webkit-backdrop-filter: var(--glass-blur);
    border-radius: var(--radius-md);
    padding: var(--space-lg) var(--space-sm);
    height: 100%;
    transition: all var(--transition-base);
}

.trust-card:hover {
    transform: translateY(-3px);
    background: rgba(255, 255, 255, 0.12);
}

/* ============================================
   18. Partners (PartnersSection)
   ============================================ */
.partners-section {
    background: var(--color-bg-soft);
}

.partner-card {
    transition: all var(--transition-base);
}

.partner-card:hover {
    transform: translateY(-5px);
    box-shadow: var(--shadow-primary);
}

/* ============================================
   19. Testimonials (TestimonialsSection)
   ============================================ */
.testimonials-section {
    background: #fff;
}

.testimonial-card {
    transition: all var(--transition-base);
    border-block-start: 4px solid transparent;
}

.testimonial-card:hover {
    border-block-start-color: var(--color-accent);
    transform: translateY(-5px);
    box-shadow: var(--shadow-md);
}

/* ============================================
   20. C
TA Banner (CtaBannerSection)
   ============================================ */
.cta-banner-section {
    background: var(--gradient-cta);
    color: #fff;
    position: relative;
    overflow: hidden;
}

.cta-banner-section::before {
    content: '';
    position: absolute;
    inset: 0;
    background: rgba(0, 0, 0, 0.2);
    z-index: 0;
}

.cta-banner-section > .container {
    position: relative;
    z-index: 1;
}

.cta-banner-section .btn-warning {
    box-shadow: var(--shadow-accent);
}

.text-white-75 {
    color: rgba(255, 255, 255, 0.85) !important;
}

/* ============================================
   21. Footer (FooterSection)
   ============================================ */
.footer {
    font-size: 0.9rem;
    color: #cbd5e1;
}

The user wants me to rewrite a CSS file with a conservative mode - only visual changes, no layout changes. The target style is "editorial-magazine" with a "tight-rhythm" variant.

Target style:
- Editorial neutrals: cream/beige backgrounds (#f5f1e8), ink black text (#1a1a1a)
- Single accent color (deep red #c44536 or olive #6b705c)

Tight-rhythm variant:
- Compact spacing (padding 8-16px, gap 8-12px)
- Small border-radius (2-6px)
- Subtle shadows or none
- Information-dense feel

However, I need to be careful - the layout-related properties like gap, padding, margin should stay within ±20%. Since the original uses gap: 1.5rem, I should keep it similar. The tight-rhythm says gap 8-12px but I can't change gap significantly. Let me keep gaps similar.

Let me go through the CSS:

1. `.footer a` - transition
2. `.footer a:hover` - color
3. `.footer-copyright` - font-size (unchanged)
4. `.footer-beian` - font-size, line-height, opacity
5. `.footer-beian a:hover` - color, text-decoration
6. `.footer-beian img` - margin-inline-end, transition
7. `.footer-beian a:hover img` - transform
8. `.footer-beian li` - white-space
9. Media query - flex-direction, gap, etc.
10. Form controls - border-color, box-shadow
11. `.btn-primary` - background-color, border-color
12. `.btn-primary:hover` - background-color, border-color
13. `.input-group-text` - background-color, border-color
14. Reduced motion - unchanged
15. Grid layout defaults - selectors with grid-template-columns (must stay same)
16. Responsive - same selectors

Since the original CSS doesn't define CSS custom properties (like --color-primary), they must exist elsewhere. But I can only rewrite this file. So I'll need to use the actual color values.

Let me think about what to change:

**Colors:**
- `--color-accent` is referenced. In editorial style, accent = deep red #c44536 or olive #6b705c. Let me pick deep red #c44536 as the accent.
- `--color-primary` is referenced for buttons and form focus. I'll use the deep red as primary too, or maybe a darker ink color. Actually for editorial, primary could be the deep red.
- `--color-bg-muted` should be a cream/beige tone
- `--color-border` should be a warm gray/beige border

Since the CSS uses CSS variables, I can redefine the variables at the top of the file? Wait, that would change the CSS structure but not HTML. The instructions say I can change "CSS custom properties (--color-*, --shadow-*) values". But this file doesn't define them - it references them. I could add a `:root` block to define/override them, but the instruction says "Preserving ALL selectors and layout exactly." Adding a `:root` block would add a selector... Hmm.

Actually, the instructions say "Only colors, shadows, and decorative properties may change." and "CSS custom properties (--color-*, --shadow-*) values" are in the "must change" list. But this file only references them. I think the safest approach is to replace the variable references with concrete color values, or redefine the variables inline.

Wait, but if I replace `var(--color-primary)` with a hex value, that changes the value but not the selector. That should be fine.

Let me consider: the original CSS references:
- `var(--color-accent)`
- `var(--transition-fast)`
- `var(--color-primary)`
- `var(--color-bg-muted)`
- `var(--color-border)`
- `var(--space-xs)`

I'll replace these with concrete editorial values:
- `--color-accent` → `#c44536` (deep red)
- `--transition-fast` → `0.25s ease` (or similar transition)
- `--color-primary` → `#c44536` (deep red) or maybe `#1a1a1a` ink for primary buttons. Editorial style often uses black buttons. Let me use ink black #1a1a1a for primary buttons, and deep red as accent. But the form focus uses primary. Hmm.

Actually let me think about the palette:
- Background: cream #f5f1e8
- Ink: #1a1a1a
- Accent: deep red #c44536

For `.btn-primary`, an editorial magazine look would use ink black or deep red. Let me go with deep red #c44536 as primary since it's the single accent. Or ink black for buttons. I'll use ink black `#1a1a1a` for `.btn-primary` - that's very editorial (like a "Buy" button in a magazine). Hover could be deep red.

Actually, keeping it simple:
- `--color-primary` → `#c44536` (deep red)
- `--color-bg-muted` → `#e8e1d3` (darker cream)
- `--color-border` → `#d8cfbc` (warm beige border)
- `--color-accent` → `#c44536`

For `.btn-primary:hover`, original uses `#2563eb` (blue). I'll change to a darker red `#a3362a` or ink.

**Other changes:**

- `.footer-beian` opacity: 0.85 → could keep or change slightly. It's opacity, in the "must change" list. Let me change to 0.8 or 0.9. I'll do 0.8.
- `.footer-beian img` transition: change timing
- `.footer-beian a:hover img` transform scale(1.2) - transform values can change? The instruction says "transform" isn't explicitly listed but it's a decorative property. The "NEVER CHANGE" list doesn't include transform. Actually it does not mention transform at all. But "transform: scale(1.2)" is a hover effect, not layout. I'll keep it or change to 1.15. Let me change slightly to 1.15 for tight-rhythm.

- Form focus shadow: `0 0 0 0.2rem rgba(59, 130, 246, 0.15)` → change color to a warm shadow. Editorial: `0 0 0 0.2rem rgba(196, 69, 54, 0.12)` or use a beige. I'll use `0 0 0 3px rgba(196, 69, 54, 0.12)`.

- Border-radius: The original doesn't have border-radius on many things. I can add border-radius to form controls? The target variant suggests small border-radius 2-6px. I can add border-radius: 4px to `.form-control`, `.form-select`, `.btn-primary`, `.input-group-text`. But wait - adding border-radius could be considered a visual change, which is allowed. However, I need to be careful not to add selectors. Adding properties inside existing selectors is fine.

Actually, the instruction says "Only colors, shadows, and decorative properties may change" - border-radius is explicitly allowed ("border-radius (visual rounding only)").

Let me also think about the transition values:
- `var(--transition-fast)` - I'll replace with `0.2s ease-in-out` or similar.

Let me now write the full output:

```css
.footer a {
    transition: color 0.25s ease;
}

.footer a:hover {
    color: #c44536 !important;
}

.footer-copyright {
    font-size: 0.85rem;
}

/* Beian */
.footer-beian {
    font-size: 0.8rem;
    line-height: 1.8;
    opacity: 0.8;
}

.footer-beian a:hover {
    color: #c44536 !important;
    text-decoration: underline !important;
}

.footer-beian img {
    margin-inline-end: 4px;
    transition: transform 0.25s ease;
}

.footer-beian a:hover img {
    transform: scale(1.15);
}

.footer-beian li {
    white-space: nowrap;
}

@media (max-width: 575.98px) {
    .footer-beian ul {
        flex-direction: column;
        gap: var(--space-xs) !important;
    }

    .footer-beian li {
        white-space: normal;
        text-align: center;
    }
}

/* ============================================
   22. Form (Login/Signup/Contact)
   ============================================ */
.form-control:focus,
.form-select:focus {
    border-color: #c44536;
    box-shadow: 0 0 0 3px rgba(196, 69, 54, 0.12);
    border-radius: 4px;
}

.btn-primary {
    background-color: #1a1a1a;
    border-color: #1a1a1a;
    border-radius: 4px;
}

.btn-primary:hover,
.btn-primary:focus {
    background-color: #c44536;
    border-color: #c44536;
}

.input-group-text {
    background-color: #e8e1d3;
    border-color: #d8cfbc;
    border-radius: 4px;
}

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

/* ============================================================
   Grid Layout Defaults (CSS-Variant-Ready)
   CSSVariantEngine sẽ override các rules này
   ============================================================ */

/* 新闻网格 (默认 3 列) */
.news-grid {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: 1.5rem;
}

/* 功能特性列表 (默认 3 列) */
.feature-list {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: 1.5rem;
}

/* 用户评价 (默认 3 列) */
.testimonial-list {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: 1.5rem;
}

/* 合作伙伴 (默认 4 列) */
.partner-grid {
    display: grid;
    grid-template-columns: repeat(4, 1fr);
    gap: 1.5rem;
    align-items: center;
}

/* 数据统计 (默认 4 列) */
.stats-grid {
    display: grid;
    grid-template-columns: repeat(4, 1fr);
    gap: 1.5rem;
    text-align: center;
}

/* FAQ 列表 (默认单列居中) */
.faq-list {
    max-width: 820px;
    margin: 0 auto;
}

/* Hero 内容 (默认居中) */
.hero-content {
    text-align: center;
    max-width: 800px;
    margin: 0 auto;
}

/* Hero 分割布局 (左文右图) */
.hero-split {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 2rem;
    align-items: center;
}
.hero-split-text { }
.hero-split-img { text-align: center; }

/* CTA 内容 (默认居中) */
.cta-inner {
    text-align: center;
    max-width: 800px;
    margin: 0 auto;
}

/* 作者团队 (默认 4 列) */
.authors-grid {
    display: grid;
    grid-template-columns: repeat(4, 1fr);
    gap: 1.5rem;
}

/* 联系渠道 (默认 3 列) */
.channels-grid {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: 1.5rem;
}

/* 文章列表 (默认 2 列) */
.post-list-grid {
    display: grid;
    grid-template-columns: repeat(2, 1fr);
    gap: 1.5rem;
}

/* 相关文章 (默认 3 列) */
.related-grid {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: 1rem;
}

/* 赛事列表 (默认 3 列) */
.matches-grid {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: 1rem;
}

/* 步 骤网格 (默认 4 列) */
.steps-grid {
    display: grid;
    grid-template-columns: repeat(4, 1fr);
    gap: 1.5rem;
}

/* 二维码网格 (默认 3 列) */
.qr-grid {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: 1.5rem;
    justify-items: center;
}

/* 荣誉列表 (默认 2 列交替) */
.honor-list {
    display: flex;
    flex-direction: column;
    gap: 3rem;
}
.honor-row {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 2rem;
    align-items: center;
}
.honor-row-reverse {
    direction: rtl;
}
.honor-row-reverse > * {
    direction: ltr;
}

/* ============================================================
   Responsive Defaults
   ============================================================ */
@media (max-width: 1024px) {
    .news-grid,
    .feature-list,
    .channels-grid,
    .testimonial-list { grid-template-columns: repeat(2, 1fr); }

    .partner-grid,
    .stats-grid,
    .authors-grid { grid-template-columns: repeat(2, 1fr); }

    .matches-grid { grid-template-columns: repeat(2, 1fr); }
    .steps-grid { grid-template-columns: repeat(2, 1fr); }

    .hero-split { grid-template-columns: 1fr; }
    .honor-row { grid-template-columns: 1fr; }
    .honor-row-reverse { direction: ltr; }
}

@media (max-width: 640px) {
    .news-grid,
    .feature-list,
    .testimonial-list,
    .channels-grid,
    .post-list-grid,
    .related-grid,
    .authors-grid,
    .matches-grid { grid-template-columns: 1fr; }

    .partner-grid,
    .stats-grid { grid-template-columns: repeat(2, 1fr); }

    .steps-grid { grid-template-columns: 1fr; }
    .qr-grid { grid-template-columns: 1fr; max-width: 300px; margin: 0 auto; }

    .faq-list { max-width: 100%; }
}
```

Wait, I need to double-check: the original `.footer-beian` has `opacity: 0.85`. I changed to 0.8. That's fine.

The original has `transition: color var(--transition-fast)`. I replaced with `transition: color 0.25s ease`. Good.

Should I change the grid gaps? The target style is "tight-rhythm" with gap 8-12px, but the "never change" list says "gap, row-gap, column-gap (keep similar)". The original gaps are 1.5rem = 24px, 2rem = 32px, 3rem = 48px, 1rem = 16px. The instruction allows ±20% on padding/margin but for gap it says "keep similar". Since 1.5rem → 24px, changing to 12px would be a 50% reduction, which might break the "keep similar" rule. I'll keep the gaps as-is.

Actually, the "tight-rhythm" is an "effect variant" that says "Compact spacing (Aggressive: padding 8-16px, gap 8-12px)". But the conservative mode says never change gap significantly. I'll prioritize the conservative constraints. Keep gaps.

Also, should I change `--space-xs` in the media query? It references a variable that I don't know the value of. I'll keep it as `var(--space-xs)` since changing it would require knowledge of the variable. Actually, I could replace it with a concrete value like `8px`, but that might break consistency if the variable is used elsewhere. However, replacing with a concrete value in the same range is safer for this file's independence. But if the variable is defined elsewhere with a different value, replacing it could change layout. Since it's `gap: var(--space-xs)`, and the target is tight-rhythm, I could set it to `8px`. But conservative mode says keep gap similar. The original `--space-xs` is likely 8px or 0.5rem in a Bootstrap-like system. I'll keep `var(--space-xs)` to be safe - it preserves the original reference exactly.

Hmm, but the task says "CSS custom properties (--color-*, --shadow-*) values" must change. `--space-xs` is not a color or shadow, so I can leave it.

Now, about adding border-radius to `.form-control:focus`, `.btn-primary`, `.input-group-text`: 
- Original `.btn-primary` doesn't have border-radius. Bootstrap `.btn` typically has border-radius from base styles. Adding `border-radius: 4px` is a visual change, allowed.
- `.form-control:focus` - same. Adding border-radius 4px. Actually, Bootstrap forms already have border-radius from base `.form-control`. But to be safe, adding it is fine since it's decorative.

Wait, but if I add border-radius to `.form-control:focus`, it only applies on focus,