/* ============================================================
   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 CSS with a fresh visual identity, but the CSS they've provided is very minimal — it only contains a media query with some layout-ish rules. Let me analyze:

```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;
    }
}
```

The constraints:
- I can ONLY change colors, shadows, radius, transitions, gradients, filter, backdrop-filter, opacity, outline, border-color, border-style, caret-color, accent-color, CSS custom properties (--color-*, --shadow-*) values.
- I CANNOT change layout: text-align, font-size, padding, margin, etc.

But the original CSS has:
- `text-align: center;` — this is a layout property, cannot change
- `font-size: 0.85rem;` — this is typography, cannot change
- `padding: var(--space-md) !important;` — padding is layout, cannot change (within ±20% but this is a var reference; I should keep it)

So the actual changes I can make here are limited. I need to add visual properties that aren't currently there, or I need to modify the variable values. But `--space-md` is a spacing variable, not a color/shadow. Changing its value would alter layout.

Wait — the instruction says "CSS custom properties (--color-*, --shadow-*) values" can change. So only color and shadow custom properties, not spacing ones.

Since the original CSS has almost nothing to change visually, I need to be conservative and only add/change what's allowed. The goal is to refresh the visual identity. Since the selectors are present, I can add color, background, border-radius, box-shadow, transition, etc. to those selectors — as long as I don't change layout properties.

Let me think about what I can do:

1. `.app-hero-section .row .col-lg-7` — I can add color, background, border-radius, box-shadow, text-shadow, transitions. I cannot change text-align.

2. `.app-hero-section .badge.bg-warning` — I can add background-color (but bg-warning is a Bootstrap class; the element has class `badge bg-warning`). I can override background-color, color, border-radius, box-shadow, box-shadow glow. I cannot change font-size.

Wait, but the instruction says "font-size, font-weight, font-style, line-height, letter-spacing, word-spacing, text-transform, white-space, word-break" are unchanged. So `font-size: 0.85rem` must stay exactly.

3. `.contact-channels-section article, .contact-quick-section .contact-card` — I can add border-radius, box-shadow, transition, background, border-color, etc. Cannot change padding.

Also, I can add new declarations within the same selectors that are visual-only and don't break layout. The constraints say "display values (block, flex, grid, none, inline-block, inline-flex)" cannot change. Adding a `display` property would be changing it, so I should not add display.

Also the media query itself — I keep it as-is.

Let me craft a fresh visual identity. The target style is "card-mosaic" with "glow-effects". The palette should be vibrant card colors on neutral background. Each card type different accent.

But I only have 3 selectors:
1. `.app-hero-section .row .col-lg-7` — a hero section column
2. `.app-hero-section .badge.bg-warning` — a warning badge
3. `.contact-channels-section article, .contact-quick-section .contact-card` — contact cards

I can give them distinct accents.

Fresh palette ideas:
- Neutral background: keep the page background? But I don't have a body selector. I can't add selectors. So I can only style these elements. For background, the page background is likely handled elsewhere. I'll style these elements with their own backgrounds.

Let me assign:
- Hero col: deep neutral with a subtle gradient background? Actually adding background could be okay visually. But `.col-lg-7` is a grid column — adding a background color to it is a visual change, allowed. But it might be inside a row with padding. Adding background could look odd if it spans the column. Still it's allowed as a visual change. However, the target style says "Vibrant card colors on neutral background". I think giving the hero column a subtle translucent background with border-radius could work.

Actually, let me be careful. The instruction says "Refresh the visual identity WITHOUT changing layout structure or class names." Adding background-color, border-radius, box-shadow doesn't change layout. Border-radius doesn't change layout. Box-shadow doesn't change layout. Text-shadow doesn't. So I'm safe.

Let me write:

```css
@media (max-width: 575.98px) {
    .app-hero-section .row .col-lg-7 {
        text-align: center;
        color: #f8fafc;
        background: linear-gradient(135deg, rgba(99, 102, 241, 0.18), rgba(168, 85, 247, 0.12));
        border-radius: 16px;
        box-shadow: 0 8px 24px rgba(79, 70, 229, 0.25), 0 0 0 1px rgba(255, 255, 255, 0.08) inset;
        text-shadow: 0 2px 12px rgba(0, 0, 0, 0.35);
        transition: box-shadow 0.3s ease, background 0.3s ease;
    }

    .app-hero-section .badge.bg-warning {
        font-size: 0.85rem;
        color: #1e1b2e;
        background: linear-gradient(135deg, #fbbf24, #f59e0b);
        border-radius: 999px;
        box-shadow: 0 0 24px rgba(245, 158, 11, 0.4), 0 4px 12px rgba(245, 158, 11, 0.25);
        transition: box-shadow 0.3s ease, transform 0.2s ease;
    }

    .contact-channels-section article,
    .contact-quick-section .contact-card {
        padding: var(--space-md) !important;
        background: linear-gradient(145deg, rgba(255, 255, 255, 0.08), rgba(255, 255, 255, 0.02));
        border: 1px solid rgba(255, 255, 255, 0.1);
        border-radius: 14px;
        box-shadow: 0 0 24px rgba(34, 211, 238, 0.18), 0 8px 20px rgba(0, 0, 0, 0.2);
        backdrop-filter: blur(8px);
        transition: box-shadow 0.3s ease, background 0.3s ease;
    }
}
```

Wait — but the instruction says "transition timing, easing, duration" can change. But I'm adding transitions to elements that didn't have them. That's fine — adding a transition is a visual change. But adding `transform` to transition when there's no transform on the element is fine.

However, I should be careful: `backdrop-filter` is allowed to change/add? The list says "filter, backdrop-filter" can change. Adding is technically adding a new property. I think it's acceptable since it's listed as allowed to modify. But adding `backdrop-filter: blur(8px)` might be a visual change that could affect readability — but not layout. OK.

Actually, wait. The instruction says "⚠️ Previous attempt didn't change enough. Make colors, shadows, and radius MORE distinct this round. Use a fresh palette." So they want bold changes. Since the original CSS is tiny, I need to make the most of it.

But also, I must ensure I don't violate "NEVER CHANGE" — padding must stay `var(--space-md) !important`. Keep it exactly.

Let me also think about whether adding `background` to `.app-hero-section .row .col-lg-7` could break layout — no. Background doesn't affect layout.

One issue: `.badge.bg-warning` — Bootstrap's `.bg-warning` sets `background-color: #ffc107 !important`. If I want my gradient to apply, I need to override with `background: linear-gradient(...)` but Bootstrap uses `!important`. Actually Bootstrap's `.bg-warning` is `background-color: #ffc107 !important;`. To override, I'd need `background: linear-gradient(...) !important;` or `background-color: ... !important`. But the instruction doesn't mention `!important` changes. Hmm. Adding `!important` to my override is the only way to ensure it works. But is that allowed? The instruction says keep selectors exactly. It doesn't forbid `!important`. But the output should be clean. Since the file already uses `!important` on padding, using `!important` on the badge override is reasonable.

Actually, to be safe and effective, I'll use `background: linear-gradient(...) !important;` for the badge. Or I could just set `background-color` with `!important`. Let me use a gradient for the glow vibe.

Also, for hover effects — I can't add `:hover` selectors because the selector list must be preserved exactly. The instruction says "Pseudo-classes (:hover, :focus, ::before, ::after)" must keep exactly — meaning I can't add new ones. So hover effects via pseudo-classes are off-limits. That's fine.

The "glow-effects" variant mentions "Halo on hover: 0 0 32px rgba(accent, 0.6)" and "Subtle pulsing animations". Since I can't add :hover or @keyframes (the @keyframes names are preserved, but I can't add new @keyframes because that would be adding selectors? Actually @keyframes is not a selector per se, but the instruction says "animation-name (values like duration/timing CAN change)" — meaning I should preserve animation names but can change values. Adding new @keyframes might be considered adding new identifiers, which could be risky. The instruction says selectors/identifiers must be preserved. @keyframes names are identifiers. So I should not add new @keyframes. Instead, I'll incorporate glow via box-shadow on the base state.

So I'll rely on static glow shadows. That's fine.

Let me reconsider the palette. "card-mosaic": vibrant card colors on neutral background, each card type a different accent.

- Hero column: indigo/violet accent → background with purple glow, border-radius maybe 20px.
- Badge: amber/orange accent → warm glow.
- Contact cards: cyan/teal accent → cool glow.

Let me make it richer:

```css
@media (max-width: 575.98px) {
    .app-hero-section .row .col-lg-7 {
        text-align: center;
        color: #eef2ff;
        background: radial-gradient(120% 120% at 50% 0%, rgba(139, 92, 246, 0.25) 0%, rgba(30, 27, 75, 0.55) 60%);
        border-radius: 20px;
        box-shadow: 0 16px 40px rgba(76, 29, 149, 0.35), 0 0 24px rgba(139, 92, 246, 0.3), inset 0 1px 0 rgba(255, 255, 255, 0.15);
        text-shadow: 0 2px 16px rgba(0, 0, 0, 0.4);
        transition: box-shadow 0.45s cubic-bezier(0.22, 1, 0.36, 1), background 0.45s cubic-bezier(0.22, 1, 0.36, 1);
    }

    .app-hero-section .badge.bg-warning {
        font-size: 0.85rem;
        color: #fff7ed;
        background: linear-gradient(135deg, #f59e0b, #ea580c) !important;
        border-radius: 999px;
        box-shadow: 0 0 24px rgba(245, 158, 11, 0.45), 0 0 48px rgba(234, 88, 12, 0.2), 0 4px 12px rgba(0, 0, 0, 0.25);
        text-shadow: 0 1px 8px rgba(124, 45, 18, 0.5);
        transition: box-shadow 0.4s ease;
    }

    .contact-channels-section article,
    .contact-quick-section .contact-card {
        padding: var(--space-md) !important;
        color: #ecfeff;
        background: linear-gradient(145deg, rgba(8, 145, 178, 0.18), rgba(15, 23, 42, 0.6));
        border: 1px solid rgba(34, 211, 238, 0.25);
        border-radius: 14px;
        box-shadow: 0 0 24px rgba(34, 211, 238, 0.2), 0 12px 28px rgba(2, 6, 23, 0.4), inset 0 1px 0 rgba(255, 255, 255, 0.1);
        backdrop-filter: blur(6px);
        transition: box-shadow 0.4s ease, background 0.4s ease;
    }
}
```

Hmm, one concern: `backdrop-filter: blur(6px)` on the contact cards could be expensive but visually nice. It's allowed.

Wait — there's a subtle issue. The instruction says "border-color and border-style (NOT border-width)". Adding `border: 1px solid rgba(...)` sets border-width, which is forbidden. I need to avoid setting border-width. Instead, I should use `border-color` and `border-style` separately, but if the original had no border, then `border-style: solid; border-color: ...` would still default width to medium (3px), which could affect layout slightly. Hmm.

Actually, the rule says "NEVER CHANGE: border-color and border-style (NOT border-width)" — this is in the "MUST CHANGE" section actually: "border-color and border-style (NOT border-width)". So I CAN change border-color and border-style, but NOT border-width. If the original element has no border, adding `border-style: solid` would create a border with default width (medium = 3px), which changes layout dimensions. That's risky.

Better to avoid adding borders entirely, or use `outline` instead. Outlines don't affect layout. The rule says "outline styles (color, type)" can change. So I can use `outline: 1px solid rgba(...)`? But outline doesn't support only color/style without width — `outline` shorthand includes width. However, `outline-color` and `outline-style` are separate properties. `outline-style: solid; outline-color: rgba(...)` would give a medium outline (3px) that doesn't affect layout. Actually, outline doesn't affect layout at all regardless of width. So I could use `outline: 1px solid ...` safely since outline never affects layout. But is outline width a layout change? No, outline doesn't take up space. But the instruction says "outline styles (color, type)" — it lists outline styles, not width. Hmm. It says "outline styles (color, type)" can change. Width isn't mentioned. So I should avoid setting outline-width explicitly. But `outline: 1px solid ...` sets width. Safer to do `outline-style: solid; outline-color: rgba(...);` — but that gives a 3px outline (medium default). Visually that's a bit heavy but doesn't affect layout. Alternatively, I can skip borders/outlines and just use inset box-shadows for a "border" effect. Inset box-shadow doesn't affect layout.

Let me use inset box-shadow for borders to be safe. That's a common technique.

So:

```css
box-shadow: 0 0 24px rgba(34, 211, 238, 0.2), 0 12px 28px rgba(2, 6, 23, 0.4), inset 0 0 0 1px rgba(34, 211, 238, 0.25);
```

This inset ring acts as a border without setting border-width. 

Similarly for the hero column, use inset ring.

Now, about `background` on the badge with `!important` — Bootstrap's `.bg-warning` uses `background-color: #ffc107 !important`. My gradient `background: linear-gradient(...) !important` should override because `background` is the shorthand and `!important` wins. Good.

But wait, the instruction says to preserve selectors exactly — using `!important` is fine.

Let me also consider: the hero column likely already has padding from Bootstrap (col has padding). Adding border-radius will round it, but without overflow hidden, the background will be rounded but content might overflow. That's fine visually mostly. But if there's a background image behind, rounding could look odd. Still, it's a visual refresh — acceptable.

Another consideration: The original file is `saishi.css` (赛事 = competition/event). The selectors mention `.app-hero-section`, `.contact-channels-section`, `.contact-quick-section`. These are for an event app landing page. So a vibrant, glowing style fits.

Let me refine the palette to be cohesive and "fresh":

Palette: "neon dusk" — deep indigo/violet background