The user wants me to rewrite the CSS with a new visual identity. Let me analyze:

Target style: sidebar-classic
Layout pattern: Two-column structure "grid-template-columns: 280px 1fr" or "1fr 320px", clear primary/secondary hierarchy, moderate gap (24-32px)

But wait, the original CSS has specific layout patterns like `.news-grid { grid-template-columns: 2fr 1fr; }` and `.faq-wrapper { grid-template-columns: 2fr 1fr; }`. These are layout properties which I CANNOT change. The target style mentions a two-column structure but that's an "Aggressive only" mode. In conservative mode, I must preserve the exact grid-template-columns. However, the original already has two-column structures in `.news-grid` and `.faq-wrapper`. So I just keep those.

Color palette target:
- Sidebar darker (#252e3a), main lighter
- Functional accent for actions

Effect variant: glow-effects
- Glow shadows in accent color: 0 0 24px rgba(accent, 0.4)
- Halo on hover: 0 0 32px rgba(accent, 0.6)
- Medium radius (8-16px)
- Subtle pulsing animations

So I need to:
1. Change all colors to a sidebar-classic palette with a darker sidebar color (#252e3a-ish), lighter main, functional accent.
2. Add glow shadows.
3. Medium border-radius (8-16px).
4. Subtle pulsing animations (I can add @keyframes, the keyframe names can be new, but the instruction says @keyframes names must be preserved? No—it says "@keyframes names (values inside CAN change)". Since the original has no @keyframes, I can add new ones? The instruction says to preserve selectors exactly. Adding new @keyframes might be okay, but since HTML is fixed and CSS selectors must be preserved, I think I can add new @keyframes rules since they don't change layout. The instruction says "animation-name (values like duration/timing CAN change)". Adding keyframes for a pulse animation would be a visual change. I'll add a subtle pulse to the glow.

Let me design a new palette:

Sidebar-classic:
- Sidebar darker: #252e3a (a slate dark blue-gray)
- Main lighter: #f4f6f8 or #eef1f4
- Accent: maybe a warm amber/gold or a teal for actions. The "glow-effects" variant wants accent-color glows. Let me pick a nice accent that contrasts with the dark slate. Amber/orange works well: #f59e0b or #e67e22. Or a bright teal: #14b8a6.

Let me think. The original was ocean blues (#0077b6, #00b4d8, #caf0f8). I need a FRESH palette that's distinct. So no more ocean blues. Let's go with a "classic editorial" feel: deep slate sidebar, warm ivory main, and a golden amber accent.

New palette:
- --color-primary: #2d3436 (dark slate) — but primary is used for text links and cta background. Let me define:
  - --color-primary: #1f2937 (gray-800) — for links/buttons
  - --color-primary-dark: #111827 (gray-900)
  - --color-accent: #d97706 (amber-600) — for glows and highlights
  - --color-surface: #f8fafc (light slate)
  - --color-text: #1e293b (slate-800)
  - --rgb-primary: 31,41,55 → 31,41,55
  - --rgb-accent: 217,119,6

Actually, let me make it more classic with a dark slate sidebar. Since only visual values change, I'll update the CSS variables to reflect a new theme.

Let me reconsider: "Sidebar darker (#252e3a), main lighter". So maybe:
- --color-primary: #252e3a (dark slate) — used for CTA background and links? That could work.
- --color-accent: #e8a33d or #f0a500 (golden) — for glows.
- --color-surface: #f5f0e8 (warm ivory) or #eef2f6 light gray
- --color-text: #2c3e50 or #34495e

Let me pick a refined classic palette:
- Primary: #2c3e50 (dark slate blue)
- Primary dark: #1a252f
- Accent: #e67e22 (orange/amber)
- Surface: #f8f5f0 (warm off-white)
- Text: #2d3748

Actually let me use the exact requested sidebar color #252e3a as the primary.
- --color-primary: #252e3a (dark slate)
- --color-primary-dark: #1a1f26 (darker)
- --color-accent: #e0963b (warm amber) or #d9822b
- --color-surface: #f7f4ee (warm ivory)
- --color-text: #2b3440 (slate)
- --rgb-primary: 37,46,58
- --rgb-accent: 224,150,59

Radius: medium (8-16px). Original was 2/4/8/12. I'll bump to:
- --radius-sm: 6px
- --radius-md: 10px
- --radius-lg: 14px
- --radius-xl: 18px

Shadows with glow:
- --shadow-sm: 0 1px 3px rgba(37,46,58,0.08), 0 0 12px rgba(224,150,59,0.12)
- --shadow-md: 0 4px 12px rgba(37,46,58,0.10), 0 0 24px rgba(224,150,59,0.18)
- --shadow-lg: 0 8px 24px rgba(37,46,58,0.14), 0 0 32px rgba(224,150,59,0.28)

Transitions: keep quick but slightly different easing, maybe 0.25s cubic-bezier(0.4, 0, 0.2, 1).

Spacing: keep within ±20% of original. Original:
- --space-section: 3rem → keep 3rem (or 2.75rem? 3rem is fine, within ±20% if I keep same)
- --space-card: 1.25rem → keep
- --space-gap: 1rem → keep

The target layout pattern says gap 24-32px for two-column, but the original HTML has gaps set via CSS variables (1rem = 16px). The rule says gap must keep similar values (±20% max). So 1rem → 1.25rem (20% increase) would be allowed? 1.25/1 = +25%, exceeds 20%. Actually 1.2rem = +20%. But changing gap might break layout subtly. Better to keep gaps as-is. The "moderate gap 24-32px" is for aggressive mode only. I'll keep gaps.

Now the media query at 640px changes --space-section to 2rem and --space-card to 1rem. I'll keep those.

Now I need to preserve ALL selectors exactly. Let me go through the original and rewrite only visual properties.

Also I can add @keyframes for subtle pulsing. Since the original has no animation, adding a pulse animation to cards' box-shadow would create the glow effect. But the instruction says "animation-name (values like duration/timing CAN change)" — implies existing animations can change values. Adding new animation properties is a visual change and wouldn't break layout. However, it adds new rules — the "preserve selectors" means I shouldn't remove or rename selectors, but adding new ones like @keyframes pulse should be acceptable. Many CSS refresh tasks allow adding keyframes. I'll add a subtle pulse for glow on cards. But should I add animation to `.card`? That would be a persistent pulse that might be distracting but matches "subtle pulsing animations". I'll keep it very subtle.

Actually, to be safe and conservative, I could add the keyframes and apply them to the existing `.card` selector. Since `.card, [class*="card"]` already exists, I can add `animation` property there. Adding a property to an existing selector is fine. But adding `animation` to cards might cause performance issues; I'll keep it gentle.

Let me also update the `:hover` shadow to a stronger glow.

Let me also update the `.cta-section` background — it currently uses `background: var(--color-primary); color: #fff;`. With the new primary (dark slate), that fits well. I can change to a gradient: `background: linear-gradient(135deg, var(--color-primary), var(--color-primary-dark));` But the original is `background: var(--color-primary)`. Changing to gradient is a visual change allowed (gradient colors/stops can change). It keeps the same selector and property, just different value. Fine.

Also `.card { border: 1px solid rgba(var(--rgb-primary), .08); }` — I can change the rgba alpha or the rgb values (since --rgb-primary changes, it's automatic). I could set `border: 1px solid rgba(var(--rgb-primary), 0.1)` or add a glow border. I'll keep border-width the same (1px) but change color/alpha and maybe border-style from solid to something else? The rule says "border-color and border-style (NOT border-width)" may change. So I could do `border: 1px solid rgba(var(--rgb-accent), 0.18)` — that changes color. I'll use accent-tinted border for a warmer look.

Also the media query at 1024px has `.news-grid { grid-template-columns: repeat(2, 1fr) !important; }` — grid-template-columns is LAYOUT: cannot change. Keep as-is.

Note: responsive rules like `.feature-list { grid-template-columns: repeat(2, 1fr) !important; }` remain unchanged because they're layout.

Let me now write the full rewritten CSS.

Original structure:

```css
/* CSSVariantEngine v3.0 — map-map-yaxin.com */
/* Palette: ocean | Radius: subtle | Shadow: none */
/* Spacing: balanced | Transition: quick */
/* Section layouts: {...} */

:root {
    --color-primary: #0077b6;
    ...
}

body { ... }
h1, h2, h3, h4 { ... }
section, .section { ... }
.card, [class*="card"] { ... }
.btn, button[class*="btn"], a[class*="btn"] { ... }
a:not([class]) { ... }

/* ========== Section Layout Variants ========== */

/* news: featured-left */
/* 左大右小 (1大+2小) */
                .news-grid { display: grid; grid-template-columns: 2fr 1fr; grid-template-rows: auto auto; gap: var(--space-gap); }
                .news-grid > *:first-child { grid-row: span 2; }

/* features: centered */
/* 居中大卡片 */
                .feature-list { display: flex; flex-direction: column; align-items: center; gap: calc(var(--space-gap) * 2); max-width: 720px; margin: 0 auto; }

/* hero: left-aligned */
.hero-content { text-align: left; max-width: 600px; }

/* testimonials: grid-3 */
.testimonial-list { display: grid; grid-template-columns: repeat(3, 1fr); gap: var(--space-gap); }

/* partners: grid-6 */
.partner-grid { display: grid; grid-template-columns: repeat(6, 1fr); gap: var(--space-gap); align-items: center; }

/* faq: with-sidebar */
/* FAQ 左 + 联系信息右 */
                .faq-wrapper { display: grid; grid-template-columns: 2fr 1fr; gap: 2rem; }

/* stats: inline */
/* 水平排列 */
                .stats-grid { display: flex; justify-content: center; gap: 3rem; }

/* cta: full-bg */
.cta-section { background: var(--color-primary); color: #fff; padding: 4rem 2rem; }

/* Page Layout: full-width */
/* 无侧边栏, 全宽 */
            .page-main { max-width: 1200px; margin: 0 auto; }

/* 条件性装饰 */
.card:hover, [class*="card"]:hover { transform: translateY(-4px); box-shadow: var(--shadow-lg); }
.card { border: 1px solid rgba(var(--rgb-primary), .08); }
header, .header, .navbar { background: transparent; }

/* Responsive */
@media (max-width: 1024px) {
    .news-grid { grid-template-columns: repeat(2, 1fr) !important; }
    .feature-list { grid-template-columns: repeat(2, 1fr) !important; }
    .partner-grid { grid-template-columns: repeat(3, 1fr) !important; }
    .stats-grid { grid-template-columns: repeat(2, 1fr) !important; }
    .hero-inner { grid-template-columns: 1fr !important; }
}
@media (max-width: 640px) {
    :root { --space-section: 2rem; --space-card: 1rem; --space-gap: 0.75rem; }
    .news-grid { grid-template-columns: 1fr !important; }
    .feature-list { grid-template-columns: 1fr !important; }
    .faq-list { grid-template-columns: 1fr !important; }
    .testimonial-list { column-count: 1 !important; }
    .partner-grid { grid-template-columns: repeat(2, 1fr) !important; }
    .stats-grid { grid-template-columns: repeat(2, 1fr) !important; }
    .cta-inner { grid-template-columns: 1fr !important; }
}
```

Wait, `.faq-list { grid-template-columns: 1fr !important; }` — grid-template-columns on a list? That's a selector in the media query. I must keep it.

Now rewriting with new palette and effects. I'll keep the comment headers (they describe layout, not visual), that's fine. Comments aren't selectors. But the instruction says "No  comments" — I should not add AI marker comments. I can keep or update the original comments. The original comments include "Palette: ocean" etc. I should update those comments to reflect the new palette, but comments are safe. Actually since the first characters must be CSS, starting with `/*` is fine as it's a CSS comment.

Let me be careful: the top comment says "/* CSSVariantEngine v3.0 — map-map-yaxin.com */" — I'll keep it, but update the palette/radius/shadow comments to match new design. That's fine.

Now, let me craft the new values.

Palette:
- --color-primary: #252e3a (dark slate sidebar tone)
- --color-primary-dark: #181e26 (near black slate)
- --color-accent: #e0953d (warm amber) — hmm, or a more vibrant gold #e8a33d. Let me use #e09f3e.
- --color-surface: #f5f1e8 (warm paper)
- --color-text: #2d3a4a (deep slate, softer than pure black)
- --rgb-primary: 37,46,58
- --rgb-accent: 224,159,62

Radius:
- --radius-sm: 6px
- --radius-md: 10px
- --radius-lg: 14px
- --radius-xl: 20px

Shadows (multi-layer glow):
- --shadow-sm: 0 1px 2px rgba(37,46,58,0.10), 0 0 12px rgba(224,159,62,0.10)
- --shadow-md: 0 4px 12px rgba(37,46,58,0.12), 0 0 24px rgba(224,159,62,0.20)
- --shadow-lg: 0 10px 28px rgba(37,46,58,0.18), 0 0 32px rgba(224,159,62,0.30)

Transition:
- --transition: 0.25s cubic-bezier(0.25, 0.46, 0.45, 0.94)

Spacing: keep same values (3rem, 1.25rem, 1rem). Heading weight and body line-height: keep same? These are typography-ish. The rule says font-weight and line-height cannot change. So keep 600 and 1.7.

Now, body: `body { color: var(--color-text); line-height: var(--body-line-height); }` — keep. Should I set background? The original doesn't set body background. The "main lighter" could be achieved via a background on body. Adding `background: var(--color-surface);` to body is a color change, allowed, and won't break layout. But the original body selector has only color and line-height. Adding a background property is fine — selectors preserved, just adding a visual property. I'll add `background-color: var(--color-surface);` or just `background: var(--color-surface);`. It's a visual enhancement.

Header: `header, .header, .navbar { background: transparent; }` — with sidebar-classic, maybe the header should have the dark sidebar color? The target says "Sidebar darker, main lighter". But in this layout, there's no actual sidebar