/* ============================================================
   SAISHI.CSS v3.0 - 赛事/文章/APP 页面专属样式
   ============================================================
   匹配 Section 模板:
   - ArticleSection (单文章详情)
   - AppHeroSection / AppQrSection / AppInstallSection / AppShowcaseSection
   - ContactChannelsSection / ContactFormSection / ContactQuickSection / ContactCommitmentsSection
   - LoginFormSection / SignupFormSection
   - SearchBoxSection (extends)
   - 滚动条 / 打印样式 / 图标
   ============================================================ */

/* ============================================
   1. Single Post (ArticleSection)
   ============================================ */
.single-post {
    overflow: hidden;
}

.single-post .post-meta {
    font-size: 0.9rem;
}

.single-post .post-meta i {
    color: var(--color-primary);
}

/* Post content typography */
.post-content {
    line-height: 1.8;
    font-size: 1.05rem;
    color: var(--color-text);
}

.post-content :is(h2, h3, h4) {
    margin-block: 2rem 1rem;
    font-weight: 700;
    color: var(--color-primary-darker);
    line-height: 1.4;
}

.post-content h2 {
    font-size: 1.75rem;
    padding-bottom: var(--space-xs);
    border-bottom: 2px solid var(--color-border);
}

.post-content h3 {
    font-size: 1.35rem;
}

.post-content :is(p, li) {
    margin-bottom: var(--space-sm);
}

.post-content blockquote {
    border-inline-start: 4px solid var(--color-primary);
    padding: var(--space-sm) var(--space-md);
    background: var(--color-bg-soft);
    border-radius: 0 var(--radius-md) var(--radius-md) 0;
    margin-block: var(--space-md);
    color: var(--color-text-muted);
    font-style: italic;
}

.post-content img {
    max-width: 100%;
    height: auto;
    border-radius: var(--radius-md);
    margin-block: var(--space-sm);
    box-shadow: var(--shadow-sm);
}

.post-content a {
    color: var(--color-primary);
    text-decoration: underline;
    transition: color var(--transition-fast);
}

.post-content a:hover {
    color: var(--color-primary-dark);
}

.post-content ul,
.post-content ol {
    padding-inline-start: 1.5rem;
}

.post-content code {
    background: var(--color-bg-muted);
    padding: 2px 6px;
    border-radius: 4px;
    font-size: 0.9em;
    color: var(--color-danger);
}

.post-content pre {
    background: var(--color-primary-darker);
    color: #fff;
    padding: var(--space-md);
    border-radius: var(--radius-md);
    overflow-x: auto;
    margin-block: var(--space-md);
}

.post-content pre code {
    background: transparent;
    color: inherit;
    padding: 0;
}

.post-content table {
    width: 100%;
    border-collapse: collapse;
    margin-block: var(--space-md);
}

.post-content table th,
.post-content table td {
    padding: var(--space-xs) var(--space-sm);
    border: 1px solid var(--color-border);
    text-align: start;
}

.post-content table th {
    background: var(--color-bg-muted);
    font-weight: 600;
}

/* TOC */
.toc-box {
    border-inline-start: 3px solid var(--color-primary);
}

.toc-box ol {
    padding-inline-start: 1.2rem;
}

.toc-box ol li {
    margin: 0.4rem 0;
}

.toc-box ol li a {
    transition: all var(--transition-fast);
}

.toc-box ol li a:hover {
    color: var(--color-primary-dark);
    text-decoration: underline !important;
    padding-inline-start: 4px;
}

/* Tags */
.post-tags .badge {
    background: var(--color-bg-muted) !important;
    color: #475569 !important;
    padding: 6px 12px;
    font-weight: 500;
    transition: all var(--transition-fast);
}

.post-tags .badge:hover {
    background: var(--color-primary) !important;
    color: #fff !important;
    transform: translateY(-1px);
}

/* Post nav */
.post-nav {
    flex-wrap: wrap;
    gap: var(--space-sm);
}

.post-nav .btn {
    max-width: 100%;
    overflow: hidden;
    text-overflow: ellipsis;
}

/* ============================================
   2. App Hero (AppHeroSection)
   ============================================ */
.app-hero-section {
    background: var(--gradient-hero);
    color: #fff;
    position: relative;
    overflow: hidden;
}

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

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

.app-hero-section h1 {
    font-size: clamp(2rem, 4vw, 3rem);
    line-height: 1.2;
}

.app-hero-section img {
    transition: transform var(--transition-slow);
    filter: drop-shadow(0 20px 40px rgba(0, 0, 0, 0.3));
}

.app-hero-section img:hover {
    transform: translateY(-10px);
}

.text-white-50 {
    color: rgba(255, 255, 255, 0.65) !important;
}

/* ============================================
   3. App QR (AppQrSection)
   ============================================ */
.app-qr-section {
    background: var(--color-bg-soft);
}

.qr-card {
    transition: all var(--transition-base);
    border: 2px solid transparent;
}

.qr-card:hover {
    transform: scale(1.03);
    border-color: var(--color-accent);
    box-shadow: 0 15px 40px rgba(0, 0, 0, 0.15);
}

.qr-card img {
    image-rendering: pixelated;
    image-rendering: -moz-crisp-edges;
    image-rendering: crisp-edges;
}

/* ============================================
   4. App Install Steps (AppInstallSection)
   ============================================ */
.app-install-section {
    background: var(--color-bg-soft);
}

.app-install-section .badge.rounded-circle {
    width: 50px;
    height: 50px;
    display: inline-flex;
    align-items: center;
    justify-content: center;
    font-size: 1.2rem;
    font-weight: 700;
}

.app-install-section .bg-white {
    transition: all var(--transition-base);
    position: relative;
    overflow: hidden;
}

.app-install-section .bg-white:hover {
    transform: translateY(-5px);
    box-shadow: var(--shadow-lg);
}

.app-install-section .bg-white::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    width: 4px;
    height: 100%;
    background: var(--gradient-icon);
    transform: scaleY(0);
    transform-origin: top;
    transition: transform var(--transition-base);
}

.app-install-section .bg-white:hover::before {
    transform: scaleY(1);
}

/* ============================================
   5. App Showcase (AppShowcaseSection)
   ============================================ */
.app-showcase-section {
    background: var(--color-bg);
}

.app-showcase-section img {
    transition: transform var(--transition-slow);
    filter: drop-shadow(0 15px 30px rgba(0, 0, 0, 0.15));
}

.app-showcase-section img:hover {
    transform: translateY(-5px) rotate(-1deg);
}

.app-showcase-section .bg-white {
    transition: all var(--transition-base);
    border-inline-start: 3px solid transparent;
}

.app-showcase-section .bg-white:hover {
    border-inline-start-color: var(--color-primary);
    transform: translateX(5px);
    box-shadow: var(--shadow-md);
}

/* ============================================
   6. Contact Sections
   ============================================ */
.contact-channels-section {
    background: var(--color-bg);
}

.contact-channels-section article {
    transition: all var(--transition-base);
    border: 1px solid var(--color-border-soft);
}

.contact-channels-section article:hover {
    transform: translateY(-5px);
    box-shadow: var(--shadow-lg);
    border-color: var(--color-primary);
}

.contact-channels-section article ul li {
    transition: padding var(--transition-fast);
}

.contact-channels-section article ul li:hover {
    padding-inline-start: 4px;
}

/* Contact Quick */
.contact-quick-section {
    background: var(--color-bg-soft);
}

.contact-quick-section .contact-card {
    transition: all var(--transition-base);
}

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

.contact-quick-section .contact-card i {
    transition: transform var(--transition-base);
}

.contact-quick-section .contact-card:hover i {
    transform: scale(1.1) rotate(-5deg);
}

/* Contact Form */
.contact-form-section {
    background: var(--color-bg-soft);
}

.contact-form-section .form-control,
.contact-form-section .form-select {
    border: 2px solid var(--color-border);
    transition: all var(--transition-fast);
}

.contact-form-section .form-control:focus,
.contact-form-section .form-select:focus {
    border-color: var(--color-primary);
    box-shadow: 0 0 0 0.2rem rgba(59, 130, 246, 0.1);
}

.contact-form-section button[type="submit"] {
    transition: all var(--transition-base);
}

.contact-form-section button[type="submit"]:hover {
    transform: translateY(-2px);
    box-shadow: var(--shadow-primary);
}

/* Contact Commitments */
.contact-commitments-section {
    background: var(--color-bg-soft);
}

.contact-commitments-section .bg-white {
    transition: all var(--transition-base);
    text-align: center;
}

.contact-commitments-section .bg-white:hover {
    transform: translateY(-5px);
    box-shadow: var(--shadow-lg);
}

.contact-commitments-section .bg-white i {
    transition: transform var(--transition-base);
}

.contact-commitments-section .bg-white:hover i {
    transform: scale(1.15);
}

/* ============================================
   7. Login / Signup Forms
   ============================================ */
main:has(> .container > .bg-white > form) .input-group-text {
    background-color: var(--color-bg-muted);
    border-color: var(--color-border);
    border-inline-end: none;
}

main:has(> .container > .bg-white > form) .input-group .form-control {
    border-inline-start: none;
}

main:has(> .container > .bg-white > form) .input-group:focus-within .input-group-text {
    border-color: var(--color-primary);
    background-color: #eff6ff;
}

main:has(> .container > .bg-white > form) .input-group:focus-within .form-control {
    border-color: var(--color-primary);
}

main:has(> .container > .bg-white > form) .form-check-input:checked {
    background-color: var(--color-primary);
    border-color: var(--color-primary);
}

main:has(> .container > .bg-white > form) button[type="submit"] {
    transition: all var(--transition-base);
    font-weight: 600;
}

main:has(> .container > .bg-white > form) button[type="submit"]:hover {
    transform: translateY(-2px);
    box-shadow: var(--shadow-primary);
}

/* ============================================
   8. Icons
   ============================================ */
.icon-img {
    max-width: 32px;
    max-height: 32px;
    object-fit: contain;
}

.icon-emoji {
    display: inline-block;
    line-height: 1;
}

/* ============================================
   9. Hero Buttons (đã có ở theme.css nhưng bổ sung thêm)
   ============================================ */
.hero-buttons .btn {
    transition: all var(--transition-base);
}

.hero-buttons .btn:hover {
    transform: translateY(-3px);
    box-shadow: var(--shadow-lg);
}

.hero-buttons .btn-warning {
    background-color: var(--color-accent);
    border-color: var(--color-accent);
    color: var(--color-primary-darker);
    font-weight: 600;
}

.hero-buttons .btn-warning:hover {
    background-color: var(--color-accent-dark);
    border-color: var(--color-accent-dark);
}

.hero-buttons .btn-outline-light:hover {
    background-color: rgba(255, 255, 255, 0.15);
    color: #fff;
}

/* ============================================
   10. 自定义滚动条
   ============================================ */
::-webkit-scrollbar {
    width: 10px;
    height: 10px;
}

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

::-webkit-scrollbar-thumb {
    background: #94a3b8;
    border-radius: 5px;
}

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

/* Firefox */
* {
    scrollbar-width: thin;
    scrollbar-color: #94a3b8 var(--color-bg-muted);
}

/* ============================================
   11. Print Styles
   ============================================ */
@media print {
    :is(.header,
        .footer,
        .sidebar-widgets,
        .social-share,
        #back-to-top,
        .breadcrumb-nav,
        .notice-bar,
        .cta-banner-section,
        .post-nav,
        .related-posts,
        .author-box,
        .pagination,
        .navbar-toggler,
        .nav-item) {
        display: none !important;
    }

    body {
        background: #fff !important;
        color: #000 !important;
        font-size: 12pt;
    }

    .single-post {
        box-shadow: none !important;
        border: none !important;
        padding: 0 !important;
        max-width: 100% !important;
    }

    .post-content {
        font-size: 11pt;
        line-height: 1.6;
    }

    a {
        text-decoration: underline;
        color: #000 !important;
    }

    a[href^="http"]::after {
        content: " (" attr(href) ")";
        font-size: 9pt;
        color: #555;
    }

    a[href^="#"]::after,
    a[href^="javascript:"]::after,
    a[href^="mailto:"]::after,
    a[href^="tel:"]::after {
        content: "";
    }

    .post-content img {
        max-width: 100% !important;
        page-break-inside: avoid;
    }

    :is(h1, h2, h3, h4) {
        page-break-after: avoid;
        color: #000 !important;
    }

    p, li {
        orphans: 3;
        widows: 3;
    }
}

/* ============================================
   12. Animations bổ sung
   ============================================ */
@keyframes fadeInUp {
    from {
        opacity: 0;
        transform: translateY(20px);
    }
    to {
        opacity: 1;
        transform: translateY(0);
    }
}

@keyframes pulse {
    0%, 100% {
        transform: scale(1);
    }
    50% {
        transform: scale(1.05);
    }
}

.animate-fade-in {
    animation: fadeInUp 0.6s ease-out;
}

.animate-pulse {
    animation: pulse 2s infinite;
}

/* ============================================
   13. Responsive
   ============================================ */
@media (max-width: 991.98px) {
    .post-content {
        font-size: 1rem;
    }

    .post-content h2 {
        font-size: 1.5rem;
    }

    .post-content h3 {
        font-size: 1.2rem;
    }
}

@media (max-width: 767.98px) {
    .single-post {
        padding: var(--space-md) !important;
    }

    .post-content {
        font-size: 0.95rem;
    }

    .post-content h2 {
        font-size: 1.35rem;
    }

    .post-nav {
        flex-direction: column;
    }

    .post-nav .btn {
        width: 100%;
    }

    .post-tags .badge {
        font-size: 0.8rem;
        padding: 4px 8px;
    }

    .app-hero-section h1 {
        font-size: 1.75rem;
    }

    .app-install-section .badge.rounded-circle {
        width: 40px;
        height: 40px;
        font-size: 1rem;
    }

    .toc-box {
        padding: var(--space-sm) !important;
    }

    .qr-card img {
        max-width: 140px !important;
    }
}

The user wants me to rewrite the CSS in "assets/css/saishi.css" file, block 2/2, with a target style of "horizontal-strips" and effect variant "gradient-rich".

Let me analyze the original CSS:

```css
@media (max-width: 575.98px) {
    .app-hero-section .row .col-lg-7 {
        text-align: center;
    }

    .app-hero-section .badge.bg-warning {
        font-size: 0.85rem;
    }

    .contact-channels-section article,
    .contact-quick-section .contact-card {
        padding: var(--space-md) !important;
    }
}
```

This is a media query for mobile devices. The constraints say:
- Cannot change @media query breakpoints (conditions only)
- Cannot change text-align, font-size, padding (within ±20%)
- Can change colors, shadows, radius, transitions, gradients

But the original CSS only has:
1. `text-align: center;` — cannot change (text-align is in the NEVER CHANGE list)
2. `font-size: 0.85rem;` — cannot change (font-size is in the NEVER CHANGE list)
3. `padding: var(--space-md) !important;` — padding can change within ±20%, but since it uses a CSS custom property `var(--space-md)`, I should be careful. The constraint says padding/margin keep similar values, ±20% maximum. `var(--space-md)` is a custom property reference. I could change the padding value but I don't know what `--space-md` resolves to. 

Since this is a "conservative mode" and the task is to refresh visual identity, but the selectors only contain layout/typography properties that are forbidden to change, I need to make sure I preserve those exact properties and values while possibly adding visual properties (colors, shadows, etc.) that aren't there.

Wait — but the instructions say "NEVER CHANGE" list includes text-align, font-size, padding, etc. So I must keep those exact values. But the visual identity refresh asks me to change colors, shadows, radius, transitions, gradients. There are no colors/shadows in this block. 

Hmm, what should I do? I should preserve all existing declarations exactly (since they're in the forbidden list), and perhaps add new visual declarations (like background, border-radius, transitions) to the existing rules? But adding declarations to existing selectors could be considered adding visual properties without changing layout. The target style is "horizontal-strips" and "gradient-rich".

Let me think carefully. The task says:
- Refresh the visual identity WITHOUT changing layout structure or class names.
- Only colors, shadows, and decorative properties may change.

The original CSS block has only layout/typography properties. To make a visual refresh, I could add decorative properties to the same selectors, but that changes the CSS behavior. However, the instruction says "You MUST CHANGE (visual identity only)" and lists things like colors, shadows, etc. It says to change those values. But if there are no such values, I can't change them.

Since I must preserve selectors exactly and must not change the listed properties, I have two options:
1. Output the original CSS unchanged (since there's nothing visual to change).
2. Add visual properties to the existing rules.

The instruction says "Refreshing visual identity" — but the block is just a media query with text-align, font-size, padding. Adding properties would not break layout if I only add colors etc. But the media query breakpoint can't change.

Actually, re-reading the constraints: "📐 LAYOUT (HTML cannot adapt to changes):" lists properties that should not be changed. "🎨 TARGET STYLE" describes a general pattern. The "EFFECT VARIANT" asks for gradient-rich.

Since this specific block has no colors, I think the safest approach is to preserve the original declarations exactly. But that would mean no visual change, which seems against the task. However, I could add `background`, `border-radius`, `transition`, etc. to these selectors. But wait — adding a background to `.app-hero-section .row .col-lg-7` on mobile could significantly alter the appearance. The target style "horizontal-strips" suggests full-width sections with alternating backgrounds and strong color zones. But on mobile (max-width: 575.98px), applying horizontal strips could be odd.

Let me look at the broader context. The file is "assets/css/saishi.css" and this is block 2/2. The user request is likely part of a larger tool that processes CSS in blocks. The first block would have the main styles. This block is just a media query.

Given the constraints, perhaps I should:
- Keep all existing property values that are in the NEVER CHANGE list exactly as-is.
- Add/change only allowed visual properties.

Since there are no existing visual properties, I can add some. But adding properties might be risky. Let me consider what would be a good "gradient-rich" addition without changing layout.

For `.app-hero-section .row .col-lg-7 { text-align: center; }` — I could add `background: linear-gradient(...)` or `color` etc. But the hero section on mobile centered text — adding a gradient background might be fine but could be intrusive.

Actually, let me reconsider the spirit of the task. The instruction "You MUST CHANGE (visual identity only)" with the list of properties that may change suggests that these properties should be changed when present. But when absent, the CSS remains as layout-only. The safest self-check is: "Colors throughout the file replaced with fresh palette?" — if there are no colors, nothing to replace.

I'll output the CSS unchanged but perhaps with subtle additions? Let me think about what a "conservative" mode would do. The system prompt says "Refresh the visual identity WITHOUT changing layout structure or class names." It says "only colors, shadows, and decorative properties may change." So I should probably not add new properties that could change appearance in ways that might violate the HTML's intent.

But the task explicitly asks for a target style: horizontal-strips with gradient-rich variant. If I output the same CSS with no changes, I fail the task's intent. However, the block is tiny and contains only forbidden properties. The only way to "refresh" it is to add visual properties.

Let me examine each rule:

1. `.app-hero-section .row .col-lg-7 { text-align: center; }` — in a horizontal-strips design, this could be a strip itself. On mobile, a gradient background could be added. But `.col-lg-7` is a grid column; adding a background might create a colored column within the row. That could be okay.

2. `.app-hero-section .badge.bg-warning { font-size: 0.85rem; }` — a badge. `bg-warning` is a Bootstrap class (yellow background). I could override background-color with a gradient? The instruction allows changing background, but bg-warning is a Bootstrap utility. Adding `background: linear-gradient(...)` could override the utility. Hmm.

3. `.contact-channels-section article, .contact-quick-section .contact-card { padding: var(--space-md) !important; }` — this is the only place with `!important`. Padding must stay within ±20%. `var(--space-md)` is unknown; ±20% of a variable is tricky. Since it's a variable, I should keep it as `var(--space-md)` to be safe. But the "horizontal-strips" style wants distinct padding (60-100px vertical). On mobile, that would be too much. I can't change the padding value anyway since I don't know the variable's resolved value, and ±20% of unknown. Keep as is.

Given all this, perhaps the intended behavior is that the CSS block is too small to have visual properties, so the rewrite should just keep it the same? But that seems unsatisfying.

Wait, let me re-read the rules: "You MUST CHANGE (visual identity only): All color values: background, color, border-color, fill, stroke, outline-color ... box-shadow ... text-shadow ... border-radius ... gradient colors and stops ... transition ... filter, backdrop-filter ... opacity ... outline styles ... border-color and border-style (NOT border-width) ... caret-color, accent-color ... CSS custom properties (--color-*, --shadow-*) values."

It says "All color values" must change. If there are none, there's nothing to change. It doesn't say "add new color values."

Also, "🔒 NEVER CHANGE ... padding, margin (keep similar values, ±20% maximum)". So padding definitely must stay as `var(--space-md) !important`.

So the only compliant output is to keep the CSS exactly as-is? But then the "target style" is ignored. However, the target style says "Layout pattern (Aggressive only)" — which suggests these are aggressive-style guidelines that may not apply well to a tiny media query block. The "horizontal-strips" pattern is for full-width sections. This block doesn't define sections.

I think the correct approach in conservative mode is: if there are no visual properties to change, preserve the CSS exactly. The self-check would pass: selectors preserved, layout unchanged, no colors to replace, no shadows to redesign, no border-radius to adjust.

But to be more useful, could I add a transition or background to the badge or hero column? Let me consider whether that would break anything. Adding `transition` to these elements would be a visual-only change. Adding `background` to the column could be visual. But the rule says "only colors, shadows, and decorative properties may change" — adding a color property is a change, but it's adding a new declaration, not changing an existing one. The instruction "You MUST CHANGE (visual identity only)" lists things that must be changed, implying they exist. It doesn't explicitly forbid adding new visual declarations. But it also says "NEVER CHANGE ... selectors ... display ..." etc. Adding declarations doesn't change those.

Hmm, I'm overthinking. Let me look at typical CSS rewrite tool outputs for this kind of prompt. Usually the response is the entire CSS with colors swapped. If there are no colors, the CSS remains identical. But the prompt says "Refreshing this CSS visually" — if nothing changes, that's a failure of the objective.

Let me try to add some visual flair that aligns with "gradient-rich" without altering layout:

For `.app-hero-section .row .col-lg-7`:
- Add `background: linear-gradient(135deg, #f8f9fa 0%, #ffffff 50%, #fff7ed 100%);`
- Add `border-radius: 1rem;`
- Add `box-shadow: 0 10px 30px rgba(0,0,0,0.05);`
- These are decorative and don't change layout.

But wait — `border-radius`, `background`, `box-shadow` are allowed to change. They were not present, so adding them is within the "may change" list? The prompt says "Refresh the visual identity WITHOUT changing layout structure or class names. The HTML is FIXED — only colors, shadows, and decorative properties may change." This strongly implies we should apply the new visual identity, including adding decorative properties where needed.

But is adding a background to a grid column a "visual identity" change? Yes. Could it break the HTML layout? No, because background and box-shadow don't affect layout. Border-radius doesn't affect layout either (unless overflow hidden on parent, but that's fine).

However, adding a `background` to `.app-hero-section .row .col-lg-7` inside a media query (max-width 575.98px) would make the column a colored block on mobile. In a "horizontal-strips" design with alternating backgrounds, this could appear as a strip within the hero. That could look intentional.

For the badge with `bg-warning`, adding `background: linear-gradient(...)` would override Bootstrap's warning color. The prompt says "All color values: background ... must change." So I could change it to a gradient. But the original doesn't have background. Hmm.

For the contact cards, adding a background/gradient could be nice. But the padding uses `var(--space-md)` with `!important`; I keep that.

Let me think about what a conservative mode would do: It would avoid changing layout, but it may add subtle visual enhancements. Given the target style, I'll add:

1. To the hero column: a subtle gradient background with a soft shadow, maybe a border-radius.
2. To the badge: a gradient background (rich, warning-style but fresher), box-shadow.
3. To the contact cards: a gradient background, border-radius, box-shadow, transition.

But wait — the constraints say `@media query breakpoints (conditions only)`: I may not change `(max-width: 575.98px)`. I'll keep exactly.

Also, "No AI marker comments." "No markdown fences."

But I'm worried: if I add declarations with `!important`? No, only the padding has `!important`. I'll keep that.

Let me reconsider the safer route: output the original CSS unchanged. The task says "Goal: same layout, fresh color palette + shadow/radius identity." If the block contains no colors, the identity isn't represented here. Producing an unchanged block is acceptable because there is nothing to change without violating rules.

However, the instruction "You MUST CHANGE (visual identity only): All color values" — if there are no color values, the set of changes is empty. The self-check "Colors throughout the file replaced with fresh palette?" — vacuously true.

I'll go with a middle path: add minimal, safe visual declarations that align with "gradient-rich" while keeping all existing declarations intact. This demonstrates the visual refresh.

Let me construct the output:

```css
@media (max-width: 575.98px) {
    .app-hero-section .row .col-lg-7 {
        text-align: center;
        background: linear-gradient(135deg, #fff8f0 0%, #ffffff 45%, #f3e8ff 100%);
        border-radius: 1.25rem;
        box-shadow: 0 12px 32px rgba(67, 56, 202, 0.08);
    }

    .app-hero-section .badge.bg-warning {
        font-size: 0.85rem;
        background: linear-gradient(135deg, #fbbf24 0%, #f59e0b 50%, #d97706 100%);
        border-radius: 2rem;
        box-shadow: 0 4px 14px rgba(245, 158, 11, 0.35);
    }

    .contact-channels-section article,
    .contact-quick-section .contact-card {
        padding: var(--space-md) !important;
        background: linear-gradient(145deg, #ffffff 0%, #faf5ff 100%);
        border-radius: 1rem;
        box-shadow: 0 8px 24px rgba(88, 28, 135, 0.06);
        transition: box-shadow 0.45s cubic-bezier(0.22, 1, 0.36, 1), transform 0.45s cubic-bezier(0.22, 1, 0.36, 1);
    }
}
```

Wait — adding `transform` in transition is fine, but transition property itself is allowed to change (transition timing/easing/duration). Adding a transition is a decorative change. But adding `transform` transition without changing transform isn't a layout change. However, if the element has hover states elsewhere that use transform, this would enhance. Could be okay.

But is adding `background` to `.contact-channels-section article` going to alter the design? The target "horizontal-strips" wants alternating background colors per strip, with white/cream/dark/white. In the mobile media query, making the contact cards cream/white gradient is consistent.

Hmm, but one concern: `.app-hero-section .row .col-lg-7` is a Bootstrap column. Adding border-radius and background might make the whole column look like a card, which could be a visual improvement. But is it "conservative"? Conservative mode says "HTML is FIXED — only colors, shadows, and decorative properties may change." Adding background is allowed. But the prompt also says "You MUST CHANGE (visual identity only)" — meaning those properties that exist must be changed. It doesn't forbid adding.

Wait, but there's a risk: adding `background` to a column might conflict with Bootstrap's styles. Bootstrap columns have no background, so it's fine.

Another approach: Don't add properties, just change nothing. But I think adding subtle decorative properties is warranted because the task explicitly requests a visual refresh with a target style.

Let me also consider: the prompt's "TARGET STYLE: horizontal-strips" says "Full-width sections (width: 100%)" and "Each strip with distinct padding (60-100px vertical)". But this block is inside a max-width 575.98px media query. We cannot change padding beyond ±20%, so we can't add 60-100px padding. The horizontal-strips pattern is "Aggressive only" — meaning it's a more aggressive style that doesn't apply here. The "EFFECT VARIANT: gradient-rich" is what we should apply.

I'll go with adding gradient-rich decorative properties.

But wait, maybe I should be even more careful: The instructions say "border-radius (visual rounding only)" is allowed to change. Adding it is a change. Fine.

Also "transition timing, easing, duration" allowed to change. Adding transitions is fine.

Let me refine the colors to create a cohesive palette:

Palette suggestion for Korean sports event site (saishi = 赛事 = competition/event). Could use vibrant sports-like colors: indigo/violet gradient, warm amber for warning badge.

Actually, `.badge.bg-warning` is Bootstrap's yellow. If I override with a gradient, it might lose the "warning" semantics. Better keep it as a gradient but still warm/yellow: `linear-gradient(135deg, #fcd34d, #f59e0b)`.

Let me also consider whether I should add `-webkit-backdrop-filter`? Probably not necessary.

Now, let me double-check every rule against the NEVER CHANGE list:

- Selectors: identical.
- `text-align: center;` — unchanged (text-align is never-change).
- `font-size: 0.85rem;` — unchanged (font-size never-change).
- `padding: var(--space-md) !important;` — unchanged