/* ============================================================
   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;
    }
}

We need to rewrite the CSS with the new visual identity while preserving layout, selectors, etc. The original CSS is a media query block with three rule sets. We can only change visual properties. The original has:

- text-align: center; (layout/typography, but text-align is in never change? They said text-align is in "never change" under typography? Actually they listed text-align in layout? Let's check: "text-align, vertical-align" are in layout/never change. So keep.
- font-size: 0.85rem; (font-size, typography, keep)
- padding: var(--space-md) !important; (padding, keep similar, but we can adjust ±20%? However it's a var. Probably keep as is. But we can change? The instruction says "padding, margin (keep similar values, ±20% maximum)". However here it's var(--space-md). We could change the value? But it's a CSS custom property reference. They said "CSS custom properties (--color-*, --shadow-*) values" can change, but --space-md is spacing. Better keep same. But we can still keep.

But the main task says "Refresh this CSS visually. Keep ALL selectors and layout exactly as-is. Only change colors, shadows, radius, transitions, gradients." Here there are no colors, shadows, radius, transitions, gradients. So perhaps we need to add new visual properties? Wait, the original CSS is tiny. The task is to refresh this CSS file. But the original file only contains media query rules. We need to produce a rewritten CSS that preserves selectors and layout, but changes visual identity. Since there are no visual properties, maybe we should add some? But the instruction says "Only change colors, shadows, radius, transitions, gradients." It doesn't say add new properties. But we can add properties as long as we don't change layout. However, adding color, border-radius, box-shadow, etc. to these elements could be acceptable. But careful: We cannot change display, position, etc. But we can add decorative properties.

But also the "Target style" suggests a sidebar-classic with sharp edges. That seems unrelated to this snippet. Possibly the original full file is larger, but only this block is provided? Actually the user provided a chunk "块2/2" (block 2/2). The file "assets/css/saishi.css" has only this block? They want to rewrite this specific chunk. The original CSS in the code block is just the media query. So we need to output the same selectors with some visual refreshes. But we must be careful: The media query and the selectors are "layout" and "text" so we cannot change them. But we can add new declarations to each selector.

Let's analyze each rule:

1. `.app-hero-section .row .col-lg-7 { text-align: center; }`
This is a layout rule, but text-align is forbidden to change. We could add color? But the element is a column container. Adding color would inherit to text children. We could add maybe background gradient? But that would be visual. However, adding background to col-lg-7 might alter appearance. That's allowed as long as it doesn't affect layout. But we need to think about the context: It's an app hero section. Adding a background gradient to a column may not be desired. But the task says refresh visual identity without changing layout structure. We can add visual properties. But we should preserve the original declarations exactly? Actually "Keep ALL selectors and layout exactly as-is" and "Only change colors, shadows, radius, transitions, gradients." That means we can change values of existing visual properties, and we could add visual properties? Usually in CSS refactoring, adding properties is allowed if it doesn't break layout. But the instruction says "Only change colors, shadows, radius, transitions, gradients." It doesn't explicitly say "add", but "refresh" implies we can add visual effects. However, to be safe, we can add new declarations that are purely visual, e.g., color, background, border-radius, box-shadow, transition.

But we must not change padding, margin, etc. For the second rule, `font-size` is typography, cannot change. It already has a font-size. We can leave it. But to "refresh" we may want to change color or something. But the selector `.app-hero-section .badge.bg-warning` targets a badge. It already has font-size. We could add background-color, color, border-radius, box-shadow, transition. But note the badge already has Bootstrap classes bg-warning, so changing background-color might override. That's fine. But we need to ensure we don't break the layout. We can change color values. For example, set `color: #1a1a1a; background-color: #f0b429;` etc. But we need to follow the target palette.

The third rule: `.contact-channels-section article, .contact-quick-section .contact-card { padding: var(--space-md) !important; }` We cannot change padding (or keep similar). We can add background, border, box-shadow, transition. But careful: The selector is a list, so adding properties will apply to both.

Given the "side-classic" style with sharp edges, we can add border-radius: 0, border: 2px solid, box-shadow: 4px 4px 0px some color, transition: 0.15s. But we must not change padding. That would be a visual refresh.

But wait: The instruction says "Only change colors, shadows, radius, transitions, gradients." That suggests we should only alter these types. We can add new declarations if they are of these types. That is likely acceptable. But we must preserve all original declarations? Actually "Keep ALL selectors and layout exactly as-is" means the layout declarations must remain. We can add new declarations after the original ones. The original declarations are text-align, font-size, padding. Those are not visual in the allowed list. But we can't remove them. We must keep them. So the output should include the same declarations plus possibly new visual ones.

But the task says "Refresh this CSS visually. Keep ALL selectors and layout exactly as-is. Only change colors, shadows, radius, transitions, gradients." This could be interpreted as: Within the existing CSS, you may only modify values of color, shadow, radius, transition, gradient properties; all other declarations must remain unchanged. Since the original CSS has no such properties, the refreshed CSS would be identical? But that can't be the intention. Maybe there is a larger CSS file, but the provided chunk is the only one. However, the file fingerprint and "块2/2" suggests this is part of a larger file. The user wants us to rewrite the entire file? But the input only shows this block. Actually the prompt says "File: assets/css/saishi.css#块2/2" meaning this is block 2/2, perhaps split into two chunks. The original CSS in the code block is only that media query. We need to output only that chunk rewritten.

Given that the original chunk is layout-focused, perhaps the correct approach is to preserve it as-is, because there are no visual properties to change. But the task specifically wants a refresh. We can add visual properties to these selectors to fulfill the request, without changing layout. However, we must not change the selectors. Adding visual properties is acceptable.

Let's design the new visual identity based on sidebar-classic and sharp-edges.

For `.app-hero-section .row .col-lg-7`: This is a column in a hero section. Usually contains text. We could add `color: #1f2a37;` (dark) but that might change text color. Since text-align is center, perhaps the text is centered in the col. Adding color is fine. But we don't know the parent background. To keep safe, maybe add a subtle background? That would be a visual change. But adding a background to a column could create a colored box. That might be okay, but it changes the look significantly. However, the target style is "sidebar-classic" with darker sidebar and lighter main. The hero section likely is a main content area, so maybe lighter. But we shouldn't overdo.

Better to add a `transition` and maybe `color`? But if the element doesn't have a border etc., adding a box-shadow might be odd.

Let's inspect the selectors:

- `.app-hero-section .row .col-lg-7` is a Bootstrap column. It likely contains hero content. It's not a card. Adding box-shadow to a column might be weird.

- `.app-hero-section .badge.bg-warning` is a badge. We can change its background-color, color, border, border-radius, box-shadow, transition. This is a card-like element, so sharp edges works.

- `.contact-channels-section article` and `.contact-quick-section .contact-card` are card-like elements. They have padding. We can add background, border, box-shadow, border-radius, transition. These are ideal.

We need to use a color palette: sidebar darker (#252e3a), main lighter. Functional accent. For sharp edges, use 2-3px solid borders, 4px 4px 0px offset shadows, small/zero radius, snappy transitions 0.15s.

Let's define some CSS variables? We can add custom properties on :root? But the original chunk doesn't include :root, and adding a :root rule would be outside the media query? Actually we need to output only the CSS for the given chunk. We can add a comment? No comments. If we add a `:root` rule, it would be new selector, but the selector list must be preserved? The instruction: "Keep ALL selectors" means we can't add new selectors. So we cannot add :root. We can use existing variables from the original stylesheet? The original uses `var(--space-md)`, so there are custom properties defined elsewhere. We can reference variables like `var(--color-sidebar)` if we assume they exist. But to be safe, we should use direct color values.

We must keep all original declarations exactly. So:

Original:
```
@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;
    }
}
```

Rewritten: We keep the media query, same selector blocks, but add visual declarations. We can also change the existing `padding`? No, keep the same value. We can change `text-align`? No. Change `font-size`? No.

We could add `color`, `background-color`, `border`, `border-radius`, `box-shadow`, `transition`.

But note: For the column, adding a background might make the col a block. That's visual. However, the col already has width/height from Bootstrap grid. Adding a background is fine. But we need to avoid affecting layout (no padding/margin changes). We can add `background` but that might create a colored rectangle. The target style "sidebar-classic" maybe the hero section is light. Let's choose a light background? But if we add background with padding? No padding change. Existing padding is from Bootstrap. A background might extend to the entire col, but within the grid. That could look like a banner. But the original hero section likely already has a background. Adding another background might conflict. Hmm.

Maybe for the column, just add `color` and `transition`. That's minimal. But to satisfy "sharp edges", we could add a `border-left`? But that's a border color/style change. We can add `border-left: 4px solid accent;`? That would be a visual change but no layout change. However, it might look like a highlighted column. Could be okay. But the selector is `.col-lg-7`, inside a row. Adding a left border might shift the content? No, border is within width by default (box-sizing: border-box in Bootstrap, so width includes border). But border-width changes are not allowed? Actually "border-color and border-style (NOT border-width)" are allowed to change. The instruction says we can change border-color and border-style, but not border-width. It doesn't say we cannot add border-width? Wait: "🔒 NEVER CHANGE: ... border-color and border-style (NOT border-width)" is under allowed? Let's read the list:

Under "✅ YOU MUST CHANGE (visual identity only)" includes:
- All color values: background, color, border-color, fill, stroke, outline-color
- box-shadow...
- text-shadow
- border-radius...
- gradient colors...
- transition...
- filter...
- opacity
- outline styles (color, type)
- border-color and border-style (NOT border-width)
- caret-color, accent-color
- CSS custom properties (--color-*, --shadow-*) values

So border-color and border-style are allowed; border-width is not allowed. We cannot change border-width, but we can set border-color/style if a border already exists. We cannot add a `border` shorthand with width 2px? Because that would set border-width, which is forbidden. But we can set `border-style: solid; border-color: ...;` without setting width? The default border-width is medium, but if there was no border before, adding `border-style: solid` with no width would make a 0-width? Actually default border-width is medium (3px?) if style not none. But border-style setting with no border-width in shorthand will result in medium width. That would be adding a border, which changes layout? If box-sizing is border-box, the width stays same, but content box shrinks by border width. That could affect layout. Since border-width is not allowed, we should avoid setting border-width. We can set `outline` instead, because outline doesn't affect layout. The allowed list includes outline-color and outline-style. So we can add an outline with a width? The instruction says "outline styles (color, type)" allowed, but not outline-width? Actually it says "outline styles (color, type)" - that means we can change outline color and type, not width. But we can use `outline` shorthand? Usually outline-width is part of style. To be safe, we can use `outline: 2px solid #...`? That changes outline-width, which may be forbidden. However, the never-change list doesn't mention outline-width. Wait, the never-change list mostly layout properties. Outline-width doesn't affect layout (outline is drawn outside the element, does not affect layout). So it's safe. The instruction says "outline styles (color, type)" under must change, meaning we can set outline color and style, but likely also width? Actually they say "outline styles (color, type)" not "outline-width". But since outline doesn't affect layout, changing width is okay as a visual property. Still, we should minimize risk. We can use `box-shadow` for borders, because box-shadow doesn't affect layout. That's the "sharp offset shadow" effect. We can achieve the sharp border look with box-shadow: inset 0 0 0 2px color, plus offset 4px 4px 0px color. That gives a strong border look without actual border. This is allowed because box-shadow is allowed.

So for cards, we can use:
```
background-color: #ffffff;
border-radius: 0;
box-shadow: 2px 2px 0 0 #252e3a, inset 0 0 0 2px #252e3a;
transition: box-shadow 0.15s ease, transform 0.15s ease;
```
But transform is not allowed? It might affect layout? Transform doesn't affect layout, but it's not in allowed list. We can omit.

For the badge, we can use:
```
background-color: #f0b429;
color: #252e3a;
border-radius: 0;
box-shadow: 2px 2px 0 0 #252e3a;
transition: background-color 0.15s ease;
```
But note the badge is `.badge.bg-warning` — Bootstrap bg-warning will set background-color to warning color. If we override it, that's fine. We should set `background-color` to accent. Also, in a media query, this applies only on small screens. That's okay.

For the hero column, maybe:
```
color: #2b2f36;
transition: color 0.15s ease;
```
Maybe no box-shadow. But to make it "refreshed", we can add a subtle `text-shadow`? Since text is centered, a text-shadow could be okay. But the target style "sharp edges" doesn't imply text-shadow. We could add `border-left`? No.

Maybe we can add `background` gradient to the column? Since it's a hero section, a subtle gradient might be nice. But adding a background to a column could interfere. However, it's allowed. To avoid layout changes, we can use background gradient on the column itself. But then the text sits on it. If the col is full width, it might look like a banner. That could be part of the refresh.

Let's think about the whole design. The "sidebar-classic" target style: two-column structure with sidebar darker (#252e3a), main lighter. But this chunk doesn't contain sidebar. So the palette can be applied to the page's other sections. The sidebar is dark; main is light. Accent color for actions. We'll use accent maybe #f0b429 (golden yellow) or #e85d4a? Let's choose a functional accent. Classic sidebar often uses a blue accent: #3b82f6. But "classic" maybe a muted red/orange. Let's use a blue-gray palette: main light #f8fafc, accent #3b82f6, dark #252e3a.

But we don't know the existing colors. The original has no colors, so we can define a fresh look.

Given this is a media query for small screens, we probably only need to apply a few tweaks. In responsive design, we often adjust padding and text alignment. To refresh visually, we can add background-color, box-shadow, etc.

However, the instruction says "Output the rewritten CSS now". The output should be the entire chunk, not just the added properties. So we need to preserve the existing properties and add new ones.

Let's produce