/*
 * SkillsJars Helper — Landing Page Stylesheet
 * ----------------------------------------------------------------------------
 * 模块作用 (why this file exists):
 *   按 .claude/skills/landing-page-guide-v2 的 "Design First" 原则, 把整页面
 *   的设计系统 (字体 / 颜色 / 间距 / 动效) 集中沉淀为 CSS Custom Properties,
 *   再用 vanilla CSS 实现全部 11 essential elements 的视觉, 不依赖任何前端
 *   构建链, 直接由 nginx 静态托管.
 *
 * Aesthetic direction: Editorial-Tech (Dark Editorial + Retro-Futuristic)
 *   - 受众是 JetBrains 开发者, 深色基底贴近 IDE 主题
 *   - 字体: Inter (display + body, 同家族多重) + JetBrains Mono (code).
 *     注: skill 黑名单包含 Inter, 初版按 skill 推荐选了 Unbounded + Manrope,
 *     但用户反馈 "字体看着别扭, 改大众点" — 用户偏好优先, 改回 Inter.
 *     中文 fallback 走 PingFang SC / Microsoft YaHei / Hiragino Sans GB.
 *   - 主色取 IntelliJ 风格暖橙 #FF7A1A, accent 用 cyan #5EEAD4
 *     (避开 skill 警告的 "purple gradient on white" AI 套路)
 *   - 9 个 Agent 用 bento-grid 而不是死板 3 列, 体现 "目录枢纽" 感
 *
 * 关键约束 (key constraints):
 *   - 0 网络依赖 (除字体 CDN), 单文件 nginx 即可发布
 *   - 所有动效尊重 prefers-reduced-motion
 *   - 颜色对比度满足 WCAG AA (text vs background ≥ 4.5:1)
 */

/* ============================================================
 * 1. Design tokens (CSS variables)
 * ============================================================ */
:root {
  /* Typography — Inter 同字体多重 (大众优先), 中文回退到 PingFang / 雅黑 */
  --font-display: 'Inter', 'PingFang SC', 'Microsoft YaHei', 'Hiragino Sans GB', system-ui, sans-serif;
  --font-body: 'Inter', 'PingFang SC', 'Microsoft YaHei', 'Hiragino Sans GB', system-ui, sans-serif;
  --font-mono: 'JetBrains Mono', ui-monospace, 'SF Mono', Menlo, monospace;

  /* Color palette — 暖色调暗色基底, 避免冰冷紫渐变 */
  --color-bg: #0A0A0B;
  --color-bg-soft: #101015;
  --color-surface: #14141A;
  --color-surface-hover: #1C1C24;
  --color-elevated: #22222C;

  --color-text: #F5F5F4;
  --color-text-soft: #C4C4C0;
  --color-text-muted: #8E8E92;
  --color-text-faint: #5C5C63;

  --color-accent: #FF7A1A;          /* IntelliJ-flavored 暖橙 — primary CTA */
  --color-accent-glow: rgba(255, 122, 26, 0.35);
  --color-cool: #5EEAD4;            /* Cyan — links / hover */
  --color-magenta: #FB7185;         /* 强调点缀 (rare) */

  --color-border: rgba(255, 255, 255, 0.08);
  --color-border-strong: rgba(255, 255, 255, 0.18);

  /* Radii */
  --radius-sm: 6px;
  --radius-md: 12px;
  --radius-lg: 20px;
  --radius-pill: 999px;

  /* Spacing scale */
  --space-1: 0.25rem;
  --space-2: 0.5rem;
  --space-3: 0.75rem;
  --space-4: 1rem;
  --space-6: 1.5rem;
  --space-8: 2rem;
  --space-12: 3rem;
  --space-16: 4rem;
  --space-24: 6rem;
  --space-32: 8rem;

  /* Motion */
  --ease: cubic-bezier(0.4, 0, 0.2, 1);
  --ease-out: cubic-bezier(0.16, 1, 0.3, 1);
  --dur-fast: 160ms;
  --dur: 280ms;
  --dur-slow: 520ms;

  /* Layout */
  --max-w: 1240px;
  --max-w-narrow: 880px;
}

/* ============================================================
 * 2. Reset & base
 * ============================================================ */
*,
*::before,
*::after {
  box-sizing: border-box;
}

html {
  -webkit-text-size-adjust: 100%;
  scroll-behavior: smooth;
}

body {
  margin: 0;
  background: var(--color-bg);
  color: var(--color-text);
  font-family: var(--font-body);
  font-size: 17px;
  line-height: 1.65;
  font-weight: 400;
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
  /* 全局 grain noise overlay — 让暗色基底有质感, 避免廉价感
   * 用 SVG turbulence 内联, 0 网络成本 */
  background-image:
    radial-gradient(1200px 800px at 80% -10%, rgba(255, 122, 26, 0.08), transparent 60%),
    radial-gradient(900px 600px at -10% 30%, rgba(94, 234, 212, 0.05), transparent 65%),
    url("data:image/svg+xml;utf8,<svg xmlns='http://www.w3.org/2000/svg' width='160' height='160'><filter id='n'><feTurbulence type='fractalNoise' baseFrequency='0.9' numOctaves='2'/><feColorMatrix values='0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0.05 0'/></filter><rect width='100%25' height='100%25' filter='url(%23n)'/></svg>");
  background-attachment: fixed, fixed, fixed;
}

h1, h2, h3, h4, h5, h6 {
  font-family: var(--font-display);
  font-weight: 600;
  letter-spacing: -0.02em;
  line-height: 1.08;
  margin: 0;
  color: var(--color-text);
}

/* ============================================================
 * 中文版字距 / 行距修正
 * ----------------------------------------------------------------------------
 * Inter 在英文上用 -0.035em ~ -0.02em 的负 letter-spacing 做 ligature 收紧;
 * fallback 到 PingFang/雅黑 后, 同样的负字距对中文方块字几乎无视觉收紧效果,
 * 反而 line-height: 1 在中文上看起来过紧 (方块字垂直填满 em-box). 这里给中文
 * 单独放宽 line-height、把 letter-spacing 调到接近 0, 让中文版主标题 / 章节
 * 标题 / FAQ 标题不再 "看着挤".
 * 用 :lang(zh-Hans) + :lang(zh) 双重选择器, 确保覆盖到声明 lang="zh-Hans"
 * 与 lang="zh" 两种写法; 不影响英文版 (<html lang="en">) 渲染.
 * ============================================================ */
:lang(zh-Hans) .hero-title,
:lang(zh) .hero-title {
  letter-spacing: -0.005em;
  line-height: 1.2;
}

:lang(zh-Hans) .section-title,
:lang(zh) .section-title {
  letter-spacing: -0.005em;
  line-height: 1.3;
}

:lang(zh-Hans) .faq-item summary,
:lang(zh) .faq-item summary {
  letter-spacing: 0;
  line-height: 1.55;
}

:lang(zh-Hans) h3,
:lang(zh) h3 {
  letter-spacing: -0.005em;
  line-height: 1.35;
}

p {
  margin: 0;
}

a {
  color: var(--color-cool);
  text-decoration: none;
  transition: color var(--dur-fast) var(--ease);
}

a:hover {
  color: var(--color-accent);
}

img {
  max-width: 100%;
  display: block;
}

code, pre, kbd, samp {
  font-family: var(--font-mono);
  font-size: 0.9em;
}

::selection {
  background: var(--color-accent);
  color: var(--color-bg);
}

.container {
  width: 100%;
  max-width: var(--max-w);
  margin: 0 auto;
  padding: 0 var(--space-6);
}

/* ============================================================
 * 3. Buttons & badges
 * ============================================================ */
.btn {
  display: inline-flex;
  align-items: center;
  gap: var(--space-2);
  padding: 0.95rem 1.5rem;
  font-family: var(--font-display);
  font-size: 0.95rem;
  font-weight: 500;
  letter-spacing: -0.01em;
  border-radius: var(--radius-pill);
  border: 1px solid transparent;
  cursor: pointer;
  text-decoration: none;
  transition:
    transform var(--dur-fast) var(--ease),
    box-shadow var(--dur) var(--ease),
    background-color var(--dur-fast) var(--ease),
    border-color var(--dur-fast) var(--ease);
  white-space: nowrap;
}

.btn-primary {
  background: var(--color-accent);
  color: #1A0E04;
  box-shadow: 0 8px 28px -6px var(--color-accent-glow);
}

.btn-primary:hover {
  transform: translateY(-2px);
  box-shadow: 0 14px 40px -8px var(--color-accent-glow);
  color: #1A0E04;
}

.btn-ghost {
  background: transparent;
  color: var(--color-text);
  border-color: var(--color-border-strong);
}

.btn-ghost:hover {
  background: var(--color-surface);
  border-color: var(--color-cool);
  color: var(--color-cool);
  transform: translateY(-2px);
}

.btn-lg {
  padding: 1.15rem 1.9rem;
  font-size: 1.05rem;
}

.badge {
  display: inline-flex;
  align-items: center;
  gap: var(--space-2);
  padding: 0.4rem 0.9rem;
  font-family: var(--font-mono);
  font-size: 0.78rem;
  font-weight: 500;
  letter-spacing: 0;
  color: var(--color-text-soft);
  background: var(--color-surface);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-pill);
}

.badge-dot {
  width: 6px;
  height: 6px;
  border-radius: 50%;
  background: var(--color-accent);
  box-shadow: 0 0 12px var(--color-accent);
  animation: pulse 2.4s var(--ease) infinite;
}

@keyframes pulse {
  0%, 100% { opacity: 1; transform: scale(1); }
  50% { opacity: 0.55; transform: scale(0.85); }
}

/* ============================================================
 * 4. Element 2: Header / Navigation
 * ============================================================ */
.site-header {
  position: sticky;
  top: 0;
  z-index: 50;
  backdrop-filter: saturate(180%) blur(14px);
  -webkit-backdrop-filter: saturate(180%) blur(14px);
  background: rgba(10, 10, 11, 0.65);
  border-bottom: 1px solid transparent;
  transition: border-color var(--dur) var(--ease), background-color var(--dur) var(--ease);
}

.site-header[data-scrolled='true'] {
  background: rgba(10, 10, 11, 0.85);
  border-bottom-color: var(--color-border);
}

.nav {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: var(--space-4) 0;
}

.brand {
  display: inline-flex;
  align-items: center;
  gap: var(--space-3);
  font-family: var(--font-display);
  font-weight: 600;
  font-size: 1.05rem;
  color: var(--color-text);
  letter-spacing: -0.02em;
}

.brand:hover { color: var(--color-text); }

.brand-mark {
  width: 36px;
  height: 36px;
  border-radius: var(--radius-sm);
  display: grid;
  place-items: center;
  flex-shrink: 0;
  /* 用真实插件图标 SVG (含玻璃罐 + 三色液体) 取代文字 mark, 让品牌延续 IDE 内的视觉
   * 阴影沿用暖橙发光, 让深色基底上图标有浮起感 */
  box-shadow: 0 6px 20px -8px var(--color-accent-glow);
  background: rgba(255, 255, 255, 0.04);
  border: 1px solid var(--color-border);
}

.brand-mark img,
.brand-mark svg {
  width: 100%;
  height: 100%;
  display: block;
}

.brand-name {
  display: flex;
  flex-direction: column;
  line-height: 1.05;
}

.brand-name-sub {
  font-family: var(--font-mono);
  font-size: 0.65rem;
  color: var(--color-text-muted);
  letter-spacing: 0.08em;
  text-transform: uppercase;
}

.nav-links {
  display: none;
  gap: var(--space-8);
  list-style: none;
  margin: 0;
  padding: 0;
}

.nav-links a {
  color: var(--color-text-soft);
  font-size: 0.92rem;
}

.nav-links a:hover { color: var(--color-text); }

.nav-actions {
  display: inline-flex;
  align-items: center;
  gap: var(--space-3);
}

.nav-cta {
  display: inline-flex;
  align-items: center;
  gap: var(--space-2);
  padding: 0.55rem 1.05rem;
  font-size: 0.85rem;
  font-family: var(--font-display);
  font-weight: 500;
  border-radius: var(--radius-pill);
  border: 1px solid var(--color-border-strong);
  color: var(--color-text);
  transition: border-color var(--dur-fast) var(--ease), color var(--dur-fast) var(--ease);
}

.nav-cta:hover {
  border-color: var(--color-accent);
  color: var(--color-accent);
}

/* 语言切换 — 极简两段式 toggle, 当前语言高亮 */
.lang-switch {
  display: inline-flex;
  align-items: center;
  padding: 3px;
  background: var(--color-surface);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-pill);
  font-family: var(--font-mono);
  font-size: 0.72rem;
  letter-spacing: 0.04em;
}

.lang-switch a {
  display: inline-block;
  padding: 0.28rem 0.7rem;
  border-radius: var(--radius-pill);
  color: var(--color-text-muted);
  text-decoration: none;
  transition: color var(--dur-fast) var(--ease), background-color var(--dur-fast) var(--ease);
}

.lang-switch a:hover {
  color: var(--color-text);
}

.lang-switch a[aria-current='true'] {
  background: var(--color-accent);
  color: #1A0E04;
}

.lang-switch a[aria-current='true']:hover {
  color: #1A0E04;
}

@media (min-width: 880px) {
  .nav-links { display: flex; }
}

/* ============================================================
 * 5. Element 3-6: Hero (title, subtitle, CTA, social proof, media)
 * ============================================================ */
.hero {
  position: relative;
  padding: var(--space-24) 0 var(--space-16);
  overflow: hidden;
}

.hero-grid {
  display: grid;
  grid-template-columns: 1fr;
  gap: var(--space-12);
  align-items: center;
}

@media (min-width: 1024px) {
  .hero-grid {
    grid-template-columns: minmax(0, 1.3fr) minmax(0, 1fr);
    gap: var(--space-16);
  }
}

.hero-eyebrow {
  margin-bottom: var(--space-6);
}

.hero-title {
  font-size: clamp(2.4rem, 6.2vw, 5.4rem);
  font-weight: 600;
  letter-spacing: -0.035em;
  line-height: 1.05;
  /* 让浏览器在多行间均衡分布字符, 避免中文出现 "个 JAR." 这种孤字成行 */
  text-wrap: balance;
}

.hero-title .word {
  display: inline-block;
  opacity: 0;
  transform: translateY(28px);
  animation: word-in 720ms var(--ease-out) forwards;
}

.hero-title em {
  font-style: normal;
  background: linear-gradient(120deg, var(--color-accent) 0%, #FFB070 50%, var(--color-cool) 100%);
  background-clip: text;
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  position: relative;
}

.hero-title em::after {
  content: '';
  position: absolute;
  left: 0;
  right: 0;
  bottom: 0.05em;
  height: 0.08em;
  background: var(--color-accent);
  opacity: 0.25;
  border-radius: 2px;
}

@keyframes word-in {
  to { opacity: 1; transform: translateY(0); }
}

.hero-sub {
  margin-top: var(--space-6);
  max-width: 36em;
  font-size: clamp(1.05rem, 1.5vw, 1.2rem);
  line-height: 1.6;
  color: var(--color-text-soft);
}

.hero-cta {
  margin-top: var(--space-8);
  display: flex;
  flex-wrap: wrap;
  gap: var(--space-4);
}

.hero-proof {
  margin-top: var(--space-12);
  display: grid;
  grid-template-columns: repeat(3, minmax(0, 1fr));
  gap: var(--space-6);
  max-width: 540px;
}

.proof-stat {
  display: flex;
  flex-direction: column;
  gap: var(--space-1);
}

.proof-num {
  font-family: var(--font-display);
  font-size: clamp(1.6rem, 3vw, 2.2rem);
  font-weight: 600;
  letter-spacing: -0.04em;
  color: var(--color-text);
  line-height: 1;
}

.proof-num em {
  font-style: normal;
  color: var(--color-accent);
}

.proof-label {
  font-family: var(--font-mono);
  font-size: 0.72rem;
  color: var(--color-text-muted);
  letter-spacing: 0.06em;
  text-transform: uppercase;
}

/* Hero IDE mockup — 替代占位截图, 用 HTML/CSS 模拟 IntelliJ Tool Window */
.ide-mock {
  background: var(--color-surface);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-lg);
  overflow: hidden;
  box-shadow:
    0 1px 0 rgba(255, 255, 255, 0.05) inset,
    0 30px 80px -20px rgba(0, 0, 0, 0.6),
    0 0 0 1px rgba(255, 122, 26, 0.05);
  transform: perspective(1400px) rotateY(-3deg) rotateX(2deg);
  transition: transform var(--dur-slow) var(--ease-out);
}

.ide-mock:hover {
  transform: perspective(1400px) rotateY(-1deg) rotateX(0.5deg) translateY(-4px);
}

.ide-mock-titlebar {
  display: flex;
  align-items: center;
  gap: var(--space-2);
  padding: var(--space-3) var(--space-4);
  background: var(--color-bg-soft);
  border-bottom: 1px solid var(--color-border);
}

.ide-mock-titlebar .dot {
  width: 11px;
  height: 11px;
  border-radius: 50%;
  background: #3a3a40;
}

.ide-mock-titlebar .dot:first-child { background: #FF5F57; }
.ide-mock-titlebar .dot:nth-child(2) { background: #FEBC2E; }
.ide-mock-titlebar .dot:nth-child(3) { background: #28C840; }

.ide-mock-titlebar .tab {
  margin-left: var(--space-4);
  padding: 0.2rem 0.7rem;
  font-family: var(--font-mono);
  font-size: 0.72rem;
  color: var(--color-text-muted);
  background: var(--color-surface);
  border-radius: 4px;
}

.ide-mock-body {
  display: grid;
  grid-template-columns: 36px 1fr;
  min-height: 360px;
}

.ide-mock-rail {
  background: var(--color-bg-soft);
  border-right: 1px solid var(--color-border);
  padding-top: var(--space-4);
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: var(--space-3);
  font-family: var(--font-mono);
  font-size: 0.62rem;
  color: var(--color-text-faint);
}

.ide-mock-rail .rail-item {
  writing-mode: vertical-rl;
  text-orientation: mixed;
  padding: var(--space-2) 0;
  letter-spacing: 0.08em;
  text-transform: uppercase;
}

.ide-mock-rail .rail-item.active {
  color: var(--color-accent);
}

.ide-mock-tree {
  padding: var(--space-3) 0;
  font-family: var(--font-mono);
  font-size: 0.78rem;
  color: var(--color-text-soft);
}

.tree-row {
  display: flex;
  align-items: center;
  gap: var(--space-2);
  padding: 0.28rem var(--space-4);
  cursor: default;
  transition: background-color var(--dur-fast) var(--ease);
  white-space: nowrap;
}

.tree-row:hover {
  background: var(--color-surface-hover);
}

.tree-row.tree-skill {
  padding-left: 2.6rem;
  color: var(--color-text);
}

.tree-row.tree-artifact {
  font-weight: 500;
  color: var(--color-text);
}

.tree-row.tree-skill .tree-coord {
  color: var(--color-text-muted);
  margin-left: auto;
  font-size: 0.7rem;
}

.tree-icon {
  font-size: 0.7rem;
  color: var(--color-text-faint);
  width: 1em;
  text-align: center;
}

.tree-skill-icon {
  width: 14px;
  height: 14px;
  border-radius: 3px;
  background: linear-gradient(135deg, var(--color-accent), #B8421A);
  display: grid;
  place-items: center;
  color: #1A0E04;
  font-family: var(--font-display);
  font-size: 0.55rem;
  font-weight: 700;
  letter-spacing: -0.05em;
}

.tree-badges {
  display: inline-flex;
  gap: 4px;
  margin-left: auto;
  align-items: center;
}

.tree-badge {
  width: 14px;
  height: 14px;
  border-radius: 3px;
  background: var(--color-elevated);
  display: grid;
  place-items: center;
  border: 1px solid var(--color-border);
}

.tree-badge img {
  width: 11px;
  height: 11px;
  object-fit: contain;
  filter: brightness(1.1);
}

/* ============================================================
 * 6. Section primitives
 * ============================================================ */
section {
  padding: var(--space-24) 0;
  position: relative;
}

.section-eyebrow {
  font-family: var(--font-mono);
  font-size: 0.78rem;
  letter-spacing: 0.16em;
  text-transform: uppercase;
  color: var(--color-accent);
  margin-bottom: var(--space-4);
  display: inline-flex;
  align-items: center;
  gap: var(--space-3);
}

.section-eyebrow::before {
  content: '';
  width: 24px;
  height: 1px;
  background: var(--color-accent);
}

.section-title {
  font-size: clamp(2rem, 4vw, 3.4rem);
  letter-spacing: -0.03em;
  line-height: 1.15;
  max-width: 18em;
  text-wrap: balance;
}

.section-lead {
  margin-top: var(--space-4);
  font-size: clamp(1rem, 1.4vw, 1.15rem);
  color: var(--color-text-soft);
  max-width: 38em;
}

.section-head {
  margin-bottom: var(--space-16);
}

/* Reveal-on-scroll animation — driven by IntersectionObserver in main.js */
.reveal {
  opacity: 0;
  transform: translateY(28px);
  transition:
    opacity var(--dur-slow) var(--ease-out),
    transform var(--dur-slow) var(--ease-out);
}

.reveal.is-in {
  opacity: 1;
  transform: translateY(0);
}

.reveal-stagger > * {
  opacity: 0;
  transform: translateY(28px);
  transition:
    opacity 600ms var(--ease-out),
    transform 600ms var(--ease-out);
}

.reveal-stagger.is-in > * {
  opacity: 1;
  transform: translateY(0);
}

.reveal-stagger.is-in > *:nth-child(1) { transition-delay: 0ms; }
.reveal-stagger.is-in > *:nth-child(2) { transition-delay: 70ms; }
.reveal-stagger.is-in > *:nth-child(3) { transition-delay: 140ms; }
.reveal-stagger.is-in > *:nth-child(4) { transition-delay: 210ms; }
.reveal-stagger.is-in > *:nth-child(5) { transition-delay: 280ms; }
.reveal-stagger.is-in > *:nth-child(6) { transition-delay: 350ms; }
.reveal-stagger.is-in > *:nth-child(7) { transition-delay: 420ms; }
.reveal-stagger.is-in > *:nth-child(8) { transition-delay: 490ms; }
.reveal-stagger.is-in > *:nth-child(9) { transition-delay: 560ms; }

/* ============================================================
 * 7. Element 7: Benefits (bento grid, asymmetric)
 * ============================================================ */
.benefits-grid {
  display: grid;
  grid-template-columns: repeat(6, 1fr);
  gap: var(--space-4);
}

.benefit {
  grid-column: span 6;
  background: var(--color-surface);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-lg);
  padding: var(--space-8);
  position: relative;
  overflow: hidden;
  transition:
    transform var(--dur) var(--ease),
    border-color var(--dur) var(--ease),
    background-color var(--dur) var(--ease);
}

.benefit:hover {
  transform: translateY(-4px);
  border-color: var(--color-border-strong);
  background: var(--color-surface-hover);
}

.benefit::before {
  content: '';
  position: absolute;
  inset: 0;
  background: radial-gradient(800px 220px at var(--mx, 30%) -20%, rgba(255, 122, 26, 0.08), transparent 60%);
  opacity: 0;
  transition: opacity var(--dur) var(--ease);
  pointer-events: none;
}

.benefit:hover::before { opacity: 1; }

.benefit-num {
  font-family: var(--font-mono);
  font-size: 0.72rem;
  letter-spacing: 0.12em;
  color: var(--color-text-faint);
  text-transform: uppercase;
}

.benefit-title {
  font-size: 1.6rem;
  letter-spacing: -0.02em;
  margin-top: var(--space-3);
}

.benefit-desc {
  margin-top: var(--space-4);
  color: var(--color-text-soft);
  line-height: 1.6;
}

.benefit-icon {
  width: 44px;
  height: 44px;
  border-radius: var(--radius-sm);
  background: linear-gradient(135deg, rgba(255, 122, 26, 0.18), rgba(255, 122, 26, 0.02));
  border: 1px solid rgba(255, 122, 26, 0.25);
  display: grid;
  place-items: center;
  color: var(--color-accent);
  margin-bottom: var(--space-6);
}

.benefit-icon svg { width: 22px; height: 22px; }

/* 卡片底部内联链接 — 用于 benefit 05 跳到第三方插件集成指南
 * 控制视觉权重, 不喧宾夺主于 benefit-title */
.benefit-link {
  display: inline-flex;
  align-items: center;
  gap: var(--space-2);
  margin-top: var(--space-6);
  font-family: var(--font-mono);
  font-size: 0.78rem;
  letter-spacing: 0.04em;
  color: var(--color-cool);
  border-bottom: 1px dashed rgba(94, 234, 212, 0.4);
  padding-bottom: 2px;
  transition: color var(--dur-fast) var(--ease), border-color var(--dur-fast) var(--ease);
}

.benefit-link:hover {
  color: var(--color-accent);
  border-bottom-color: var(--color-accent);
}

.benefit-link span {
  transition: transform var(--dur-fast) var(--ease);
}

.benefit-link:hover span {
  transform: translateX(3px);
}

/* Asymmetric bento on desktop */
@media (min-width: 880px) {
  .benefit-1 { grid-column: span 4; }
  .benefit-2 { grid-column: span 2; }
  .benefit-3 { grid-column: span 2; }
  .benefit-4 { grid-column: span 4; }
  .benefit-5 { grid-column: span 3; }
  .benefit-6 { grid-column: span 3; }
}

/* Element 8 alt: Agents matrix (3x3) */
.agents-section {
  background: linear-gradient(180deg, transparent, rgba(20, 20, 26, 0.6) 50%, transparent);
}

.agents-grid {
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: var(--space-3);
}

@media (min-width: 720px) { .agents-grid { grid-template-columns: repeat(3, 1fr); } }

.agent-card {
  background: var(--color-surface);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-md);
  padding: var(--space-6);
  display: flex;
  flex-direction: column;
  gap: var(--space-3);
  transition:
    transform var(--dur) var(--ease),
    border-color var(--dur) var(--ease),
    background-color var(--dur) var(--ease),
    box-shadow var(--dur) var(--ease);
}

.agent-card:hover {
  transform: translateY(-4px);
  border-color: var(--color-accent);
  box-shadow: 0 16px 40px -16px var(--color-accent-glow);
}

.agent-card img {
  width: 28px;
  height: 28px;
  object-fit: contain;
  image-rendering: -webkit-optimize-contrast;
}

.agent-name {
  font-family: var(--font-display);
  font-size: 1.1rem;
  font-weight: 600;
  letter-spacing: -0.02em;
}

.agent-path {
  font-family: var(--font-mono);
  font-size: 0.78rem;
  color: var(--color-text-muted);
}

/* ============================================================
 * 8. Element 8: Use cases ("Who it's for") — replaces fake testimonials
 * ============================================================ */
.usecases-grid {
  display: grid;
  grid-template-columns: 1fr;
  gap: var(--space-4);
}

@media (min-width: 880px) { .usecases-grid { grid-template-columns: repeat(2, 1fr); } }

.usecase {
  background: linear-gradient(180deg, var(--color-surface), var(--color-bg-soft));
  border: 1px solid var(--color-border);
  border-radius: var(--radius-lg);
  padding: var(--space-8);
  transition: transform var(--dur) var(--ease), border-color var(--dur) var(--ease);
}

.usecase:hover {
  transform: translateY(-2px);
  border-color: var(--color-cool);
}

.usecase-tag {
  display: inline-block;
  font-family: var(--font-mono);
  font-size: 0.72rem;
  letter-spacing: 0.1em;
  text-transform: uppercase;
  color: var(--color-cool);
  padding: 0.3rem 0.7rem;
  background: rgba(94, 234, 212, 0.08);
  border: 1px solid rgba(94, 234, 212, 0.25);
  border-radius: var(--radius-pill);
  margin-bottom: var(--space-4);
}

.usecase-title {
  font-size: 1.5rem;
  letter-spacing: -0.02em;
  margin-bottom: var(--space-3);
}

.usecase-body {
  color: var(--color-text-soft);
  line-height: 1.65;
}

.usecase-body strong {
  color: var(--color-text);
  font-weight: 600;
}

/* ============================================================
 * 9. Element 9: FAQ (accordion)
 * ============================================================ */
.faq-list {
  display: flex;
  flex-direction: column;
  gap: var(--space-2);
  max-width: 880px;
  margin-left: auto;
  margin-right: auto;
}

/* FAQ 区域整体居中 — 包括标题与列表
 * 其它 section 维持左对齐, 这里是按用户反馈单独修正
 *
 * 历史: 这里原本有一个 .section-title (EN: "Honest answers to obvious questions."
 * ZH: "对显而易见的问题, 给一个老实的答案."), 用户反馈过于自夸/别扭, 已删除.
 * 现在 section-head 只剩 eyebrow, 所以单独把 #faq 的 eyebrow 视觉重量调高,
 * 让它独立承担 "这是 FAQ 区" 的视觉提示. */
#faq .section-head {
  text-align: center;
  max-width: 880px;
  margin-left: auto;
  margin-right: auto;
  margin-bottom: var(--space-12);
}

#faq .section-eyebrow {
  justify-content: center;
  font-size: 0.95rem;
  letter-spacing: 0.22em;
  margin-bottom: 0;
}

#faq .section-eyebrow::before,
#faq .section-eyebrow::after {
  content: '';
  width: 36px;
  height: 1px;
  background: var(--color-accent);
}

#faq .section-eyebrow::after {
  margin-left: var(--space-3);
}

.faq-item {
  background: var(--color-surface);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-md);
  transition: border-color var(--dur) var(--ease), background-color var(--dur) var(--ease);
}

.faq-item[open] {
  border-color: var(--color-accent);
  background: var(--color-surface-hover);
}

/* summary 故意 NOT 用 flex.
 *   原 flex + space-between 会把 summary 的子节点 (text / <code> / text / ::after)
 *   均匀撑开, 导致 "跟手动复制粘贴 SKILL.md 比有什么不同?" 中间出现大段空白.
 *   改成 block + position:relative + ::after 绝对定位, question 文本就回到
 *   inline-flow, <code> 与文字自然连续, 视觉一致. */
.faq-item summary {
  list-style: none;
  cursor: pointer;
  position: relative;
  padding: var(--space-6) var(--space-8);
  /* 给右侧 + 号留出 1.6rem (图标) + ~1rem (gap) 的位置 */
  padding-right: calc(var(--space-8) + 2.4rem);
  font-family: var(--font-display);
  font-size: 1.1rem;
  font-weight: 500;
  letter-spacing: -0.01em;
  line-height: 1.45;
  color: var(--color-text);
}

.faq-item summary::-webkit-details-marker { display: none; }

.faq-item summary::after {
  content: '+';
  position: absolute;
  /* 居中对齐到 summary 第一行的视觉中线 (与 padding-top 对齐) */
  top: var(--space-6);
  right: var(--space-8);
  font-family: var(--font-mono);
  font-weight: 400;
  font-size: 1.6rem;
  color: var(--color-accent);
  line-height: 1;
  transition: transform var(--dur) var(--ease);
}

.faq-item[open] summary::after { transform: rotate(45deg); }

.faq-body {
  padding: 0 var(--space-8) var(--space-6);
  color: var(--color-text-soft);
  line-height: 1.7;
}

.faq-body code {
  background: var(--color-bg-soft);
  border: 1px solid var(--color-border);
  padding: 0.1rem 0.4rem;
  border-radius: 4px;
  color: var(--color-cool);
}

/* ============================================================
 * 10. Element 10: Final CTA
 * ============================================================ */
.final-cta {
  margin: var(--space-16) 0 var(--space-24);
}

.final-cta-card {
  position: relative;
  background:
    radial-gradient(1000px 400px at 80% -20%, rgba(255, 122, 26, 0.45), transparent 60%),
    radial-gradient(800px 400px at 0% 110%, rgba(94, 234, 212, 0.18), transparent 65%),
    linear-gradient(180deg, #1B0E05, #0A0A0B);
  border: 1px solid rgba(255, 122, 26, 0.3);
  border-radius: var(--radius-lg);
  padding: clamp(var(--space-12), 6vw, var(--space-24));
  text-align: center;
  overflow: hidden;
  isolation: isolate;
}

.final-cta-card::before {
  content: '';
  position: absolute;
  inset: -2px;
  background: linear-gradient(120deg, transparent 30%, rgba(255, 122, 26, 0.5), transparent 70%);
  z-index: -1;
  filter: blur(20px);
  opacity: 0.4;
}

.final-cta-title {
  font-size: clamp(2rem, 5vw, 3.8rem);
  letter-spacing: -0.035em;
  margin-bottom: var(--space-4);
}

.final-cta-sub {
  font-size: clamp(1rem, 1.4vw, 1.15rem);
  color: var(--color-text-soft);
  max-width: 32em;
  margin: 0 auto var(--space-8);
}

.final-cta-actions {
  display: inline-flex;
  flex-wrap: wrap;
  gap: var(--space-4);
  justify-content: center;
}

.final-cta-meta {
  margin-top: var(--space-8);
  font-family: var(--font-mono);
  font-size: 0.78rem;
  color: var(--color-text-muted);
  letter-spacing: 0.08em;
  text-transform: uppercase;
  display: flex;
  flex-wrap: wrap;
  justify-content: center;
  gap: var(--space-4);
}

.final-cta-meta span::before {
  content: '◆';
  margin-right: var(--space-2);
  color: var(--color-accent);
  opacity: 0.6;
}

/* ============================================================
 * 11. Element 11: Footer
 * ============================================================ */
.site-footer {
  border-top: 1px solid var(--color-border);
  padding: var(--space-16) 0 var(--space-8);
  background: linear-gradient(180deg, transparent, rgba(0, 0, 0, 0.4));
}

.footer-grid {
  display: grid;
  grid-template-columns: 1fr;
  gap: var(--space-8);
  margin-bottom: var(--space-12);
}

@media (min-width: 720px) { .footer-grid { grid-template-columns: 2fr 1fr 1fr 1fr; } }

.footer-brand p {
  margin-top: var(--space-4);
  color: var(--color-text-muted);
  font-size: 0.92rem;
  line-height: 1.6;
  max-width: 28em;
}

.footer-col h4 {
  font-family: var(--font-mono);
  font-size: 0.72rem;
  letter-spacing: 0.14em;
  text-transform: uppercase;
  color: var(--color-text-muted);
  margin-bottom: var(--space-4);
  font-weight: 500;
}

.footer-col ul {
  list-style: none;
  margin: 0;
  padding: 0;
  display: flex;
  flex-direction: column;
  gap: var(--space-3);
}

.footer-col a {
  color: var(--color-text-soft);
  font-size: 0.92rem;
}

.footer-col a:hover { color: var(--color-accent); }

.footer-bottom {
  display: flex;
  flex-wrap: wrap;
  gap: var(--space-4);
  justify-content: space-between;
  align-items: center;
  padding-top: var(--space-6);
  border-top: 1px solid var(--color-border);
  font-family: var(--font-mono);
  font-size: 0.75rem;
  color: var(--color-text-faint);
}

/* ============================================================
 * 12. A11y: reduced motion
 * ============================================================ */
@media (prefers-reduced-motion: reduce) {
  *,
  *::before,
  *::after {
    animation-duration: 0.01ms !important;
    animation-iteration-count: 1 !important;
    transition-duration: 0.01ms !important;
    scroll-behavior: auto !important;
  }

  .hero-title .word {
    opacity: 1;
    transform: none;
  }

  .reveal,
  .reveal-stagger > * {
    opacity: 1;
    transform: none;
  }
}

/* ============================================================
 * 13. Tiny utilities
 * ============================================================ */
.muted { color: var(--color-text-muted); }
.mono { font-family: var(--font-mono); }
.center { text-align: center; }
.mx-auto { margin-left: auto; margin-right: auto; }
.mt-2 { margin-top: var(--space-2); }
.mt-4 { margin-top: var(--space-4); }
.mt-8 { margin-top: var(--space-8); }