/* ==========================================================================
   AI质量专家 — 全站样式
   Design language: 参照 Apple.com — single Action Blue、parchment + near-black tile
   交替、SF Pro 节奏、pill CTAs、单一投影。
   ========================================================================== */

/* --- 设计变量 --------------------------------------------------------- */
:root {
  /* 色彩 — Apple palette */
  --color-primary: #0066cc;          /* Action Blue */
  --color-primary-hover: #0050a3;
  --color-primary-focus: #0071e3;    /* Focus Blue */
  --color-primary-on-dark: #2997ff;  /* Sky Link Blue */

  --color-canvas: #ffffff;           /* Pure white */
  --color-parchment: #f5f5f7;        /* 签名 off-white */
  --color-pearl: #fafafc;            /* Pearl Button */

  --color-tile-dark: #1d1d1f;        /* Near-black tile (ink) */
  --color-tile-dark-2: #272729;      /* 微变体 */
  --color-surface-black: #000000;

  --color-ink: #1d1d1f;              /* 全部正文/标题 */
  --color-ink-muted-80: #333333;
  --color-ink-muted-48: #7a7a7a;
  --color-body-muted: #555558;       /* 正文软调 */
  --color-on-dark: #ffffff;
  --color-on-dark-muted: #cccccc;

  --color-hairline: #e0e0e0;         /* 卡片 / 表单边框 */
  --color-hairline-soft: rgba(0, 0, 0, 0.08);
  --color-divider-soft: rgba(0, 0, 0, 0.04);

  /* 单一投影 — 仅用于产品摄影 */
  --shadow-product: 0 3px 5px rgba(0, 0, 0, 0.04),
                    0 5px 30px rgba(0, 0, 0, 0.22);

  /* 圆角 */
  --radius-sm: 8px;                  /* compact utility */
  --radius-md: 11px;                 /* pearl capsule */
  --radius-lg: 18px;                 /* utility card */
  --radius-pill: 9999px;             /* primary CTA、search */

  /* 间距 — 8px base */
  --space-1: 4px;
  --space-2: 8px;
  --space-3: 12px;
  --space-4: 16px;
  --space-5: 20px;
  --space-6: 24px;
  --space-7: 32px;
  --space-8: 48px;
  --space-section: 80px;

  /* 容器 */
  --container: 1140px;
  --container-narrow: 880px;

  /* 字体栈 — SF Pro first, Inter fallback */
  --font-sans: -apple-system, BlinkMacSystemFont, "SF Pro Display",
    "SF Pro Text", "Inter", "Helvetica Neue", "PingFang SC",
    "Hiragino Sans GB", "Microsoft YaHei", Arial, sans-serif;

  --ease: cubic-bezier(0.16, 1, 0.3, 1);
}

/* --- Reset ------------------------------------------------------------- */
*, *::before, *::after { box-sizing: border-box; }
* { margin: 0; padding: 0; }
html { scroll-behavior: smooth; -webkit-text-size-adjust: 100%; }
body {
  overflow-x: hidden;
  font-family: var(--font-sans);
  font-size: 17px;
  line-height: 1.47;
  letter-spacing: -0.374px;
  color: var(--color-ink);
  background: var(--color-canvas);
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
  font-feature-settings: "ss03", "kern";
}
img, svg { display: block; max-width: 100%; }
a { color: inherit; text-decoration: none; }
button { font: inherit; cursor: pointer; border: none; background: none; }
input, textarea, select { font: inherit; }
ul, ol { list-style: none; }

/* --- 容器 ------------------------------------------------------------- */
.container {
  width: 100%;
  max-width: var(--container);
  margin: 0 auto;
  padding: 0 24px;
}
.container--narrow { max-width: var(--container-narrow); padding: 0 24px; }

/* --- 排版 ------------------------------------------------------------- */
h1, h2, h3, h4 {
  font-weight: 600;
  line-height: 1.07;
  letter-spacing: -0.003em;
  color: var(--color-ink);
}
h1 { font-size: clamp(2.5rem, 5vw, 4rem); letter-spacing: -0.005em; }
h2 { font-size: clamp(1.875rem, 3.4vw, 2.75rem); letter-spacing: -0.004em; }
h3 { font-size: 1.25rem; letter-spacing: -0.002em; line-height: 1.2; }
h4 { font-size: 1.0625rem; letter-spacing: -0.002em; }
p  { color: var(--color-body-muted); overflow-wrap: break-word; word-break: break-word; }

.eyebrow {
  display: inline-block;
  font-size: 0.8125rem;
  font-weight: 500;
  color: var(--color-primary);
  letter-spacing: 0.04em;
  text-transform: uppercase;
  margin-bottom: 16px;
}

.lede {
  font-size: 1.1875rem;
  line-height: 1.47;
  color: var(--color-body-muted);
  letter-spacing: -0.003em;
  max-width: 640px;
  overflow-wrap: break-word;
  word-break: break-word;
}

/* --- 按钮 ------------------------------------------------------------- */
/* 全部 CTA = 胶囊圆角，文字 17px / 400，padding 11×22 */
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 6px;
  height: 44px;
  padding: 0 22px;
  border-radius: var(--radius-pill);
  font-size: 1rem;
  font-weight: 400;
  letter-spacing: -0.003em;
  white-space: nowrap;
  transition: opacity 0.15s var(--ease), transform 0.15s var(--ease),
              background 0.15s var(--ease), border-color 0.15s var(--ease);
}
.btn:active { transform: scale(0.96); }

/* 旧 class 兼容：primary 旧为深色，新版改为蓝色胶囊主按钮 */
.btn--primary {
  background: var(--color-ink);
  color: #fff;
}
.btn--primary:hover { background: #000; }

/* 主蓝色实心胶囊（Apple button-primary） */
.btn--accent {
  background: var(--color-primary);
  color: #fff;
}
.btn--accent:hover { background: var(--color-primary-hover); }

/* 蓝色幽灵胶囊（Apple button-secondary-pill） */
.btn--ghost {
  background: transparent;
  color: var(--color-primary);
  border: 1px solid var(--color-primary);
}
.btn--ghost:hover { background: rgba(0, 102, 204, 0.08); }

/* 暗背景上的浅色幽灵（Apple text-link-on-dark 行为） */
.section--dark .btn--ghost,
.nav .btn--ghost {
  color: var(--color-ink);
  border-color: var(--color-hairline);
}
.section--dark .btn--ghost {
  color: var(--color-on-dark);
  border-color: rgba(255, 255, 255, 0.4);
}
.section--dark .btn--ghost:hover { background: rgba(255, 255, 255, 0.08); border-color: rgba(255, 255, 255, 0.7); }
.nav .btn--ghost:hover { background: var(--color-parchment); border-color: var(--color-ink); }

.btn--lg { height: 52px; padding: 0 28px; font-size: 1.0625rem; }
.btn--sm { height: 36px; padding: 0 16px; font-size: 0.875rem; }
.btn--block { width: 100%; }

/* --- 导航栏 — Apple 风格 ------------------------------------------------- */
.nav {
  position: sticky;
  top: 0;
  z-index: 50;
  background: rgba(255, 255, 255, 0.8);
  backdrop-filter: saturate(180%) blur(20px);
  -webkit-backdrop-filter: saturate(180%) blur(20px);
  border-bottom: 1px solid var(--color-hairline-soft);
}
.nav__inner {
  display: flex;
  align-items: center;
  justify-content: space-between;
  height: 52px;
}
.nav__brand {
  display: flex;
  align-items: center;
  gap: 8px;
  font-weight: 600;
  font-size: 0.9375rem;
  letter-spacing: -0.003em;
  color: var(--color-ink);
}
/* 标志: 盾牌图 + AI 质量专家 文字 */
.nav__logo {
  height: 36px;
  width: auto;
  display: block;
  flex-shrink: 0;
}
.nav__wordmark {
  display: inline-flex;
  align-items: baseline;
  font-weight: 700;
  font-size: 1.125rem;        /* 18px */
  letter-spacing: -0.01em;
  color: var(--color-ink);
  line-height: 1;
  white-space: nowrap;
}
.nav__wordmark strong {
  font-weight: 700;
  color: var(--color-ink);
  margin-left: 2px;
}
.nav__brand--logo {
  padding: 0;
  gap: 8px;
}
.nav__links {
  display: flex;
  align-items: center;
  gap: 28px;
}
.nav__link {
  font-size: 0.8125rem;
  font-weight: 400;
  color: var(--color-ink-muted-80);
  letter-spacing: -0.003em;
  transition: color 0.15s;
}
.nav__link:hover { color: var(--color-ink); }
.nav__link.is-active { color: var(--color-ink); font-weight: 500; }
.nav__cta { display: flex; align-items: center; gap: 10px; }
.nav__cta .btn { font-size: 0.8125rem; }
.nav__toggle {
  display: none;
  width: 40px; height: 40px;
  align-items: center; justify-content: center;
}
.nav__toggle span,
.nav__toggle span::before,
.nav__toggle span::after {
  content: "";
  display: block;
  width: 18px; height: 1.5px;
  background: var(--color-ink);
  position: relative;
  transition: transform 0.2s;
}
.nav__toggle span::before { position: absolute; top: -6px; }
.nav__toggle span::after { position: absolute; top: 6px; }

/* --- 通用 Section — 80px padding，tile 交替 ----------------------------- */
.section {
  padding: var(--space-section) 0;
}
.section--soft { background: var(--color-parchment); }
.section--muted { background: var(--color-parchment); }
.section--dark {
  background: var(--color-tile-dark);
  color: var(--color-on-dark);
}
.section--dark h1, .section--dark h2, .section--dark h3 { color: var(--color-on-dark); }
.section--dark p { color: var(--color-on-dark-muted); }
.section--dark .eyebrow { color: var(--color-primary-on-dark); }
.section--dark .lede { color: var(--color-on-dark-muted); }

.section__head {
  text-align: center;
  max-width: 720px;
  margin: 0 auto 64px;
}
.section__head .lede { margin: 16px auto 0; }

/* --- 卡片 — 18px 圆角 + 1px hairline，无投影 ----------------------------- */
.card {
  background: #fff;
  border: 1px solid var(--color-hairline);
  border-radius: var(--radius-lg);
  padding: var(--space-6);
  transition: border-color 0.2s var(--ease);
}
.card:hover {
  border-color: var(--color-ink-muted-48);
}
.card__icon {
  width: 44px; height: 44px;
  border-radius: 10px;
  background: rgba(0, 102, 204, 0.08);
  color: var(--color-primary);
  display: flex; align-items: center; justify-content: center;
  font-size: 1.25rem;
  margin-bottom: 20px;
}
.card h3 { margin-bottom: 8px; }
.card p { font-size: 0.9375rem; line-height: 1.47; }

/* --- 网格工具 -------------------------------------------------------- */
.grid { display: grid; gap: var(--space-6); }
.grid--2 { grid-template-columns: repeat(2, 1fr); }
.grid--3 { grid-template-columns: repeat(3, 1fr); }
.grid--4 { grid-template-columns: repeat(4, 1fr); }

/* --- Hero (首页) ----------------------------------------------------- */
.hero {
  padding: 96px 0 var(--space-section);
  text-align: center;
}
.hero__inner { position: relative; z-index: 2; }
.hero h1 {
  max-width: 1080px;
  margin: 0 auto 20px;
  text-align: center;
}
.hero h1 .grad {
  display: block;
  color: var(--color-ink-muted-80);
  font-weight: 500;
}
/* 通用 .grad：若非在 hero 内，提供蓝色细强调 */
.grad-blue { color: var(--color-primary); }
.hero .lede { margin: 0 auto 40px; }
.hero__cta {
  display: flex;
  gap: 12px;
  justify-content: center;
  flex-wrap: wrap;
}
.hero__bg { display: none; } /* Apple 风无装饰渐变 */

/* --- 气泡图展示区 — 仅此处允许产品投影 ---------------------------------- */
.bubble-demo {
  margin-top: var(--space-7);
  border-radius: 18px;
  background: var(--color-parchment);
  border: 1px solid var(--color-hairline);
  padding: 16px;
  overflow: hidden;
}
.bubble-demo__chrome {
  display: flex;
  align-items: center;
  gap: 6px;
  margin-bottom: 12px;
  padding: 4px 8px;
}
.bubble-demo__chrome i {
  width: 10px; height: 10px;
  border-radius: 50%;
  background: var(--color-hairline);
}
.bubble-demo__title {
  margin-left: 12px;
  font-size: 0.75rem;
  color: var(--color-ink-muted-48);
  font-family: ui-monospace, SFMono-Regular, Menlo, monospace;
}
.bubble-demo .demo-split {
  display: grid;
  grid-template-columns: 1.15fr 1fr;
  gap: 0;
  background: #ffffff;
  border-radius: 12px;
  overflow: hidden;
  border: 1px solid var(--color-hairline);
}
.bubble-demo .demo-split__drawing {
  background: #f8fafc;
  border-right: 1px solid var(--color-hairline);
  padding: 8px;
}
.bubble-demo .demo-split__drawing svg { width: 100%; height: auto; display: block; }
.bubble-demo .demo-split__table {
  background: #ffffff;
  padding: 12px 14px;
  display: flex;
  flex-direction: column;
  gap: 10px;
}
.bubble-demo .fai-head {
  display: flex;
  align-items: center;
  gap: 8px;
  font-size: 0.75rem;
  color: var(--color-primary);
  font-weight: 500;
}
.bubble-demo .fai-head__dot {
  width: 8px; height: 8px; border-radius: 50%;
  background: var(--color-primary);
  animation: fai-pulse 1.6s ease-in-out infinite;
}
@keyframes fai-pulse { 0%,100%{ opacity:1; } 50%{ opacity:.35; } }
.bubble-demo .fai-table {
  display: flex;
  flex-direction: column;
  border: 1px solid var(--color-hairline);
  border-radius: 8px;
  overflow: hidden;
  font-size: 0.75rem;
}
.bubble-demo .fai-row {
  display: grid;
  grid-template-columns: 24px 28px 28px 1.4fr 1.2fr 0.6fr 0.6fr 48px;
  align-items: center;
  padding: 7px 10px;
  border-bottom: 1px solid var(--color-hairline-soft);
  background: #fff;
}
.bubble-demo .fai-row:last-child { border-bottom: none; }
.bubble-demo .fai-row--head {
  background: var(--color-parchment);
  font-weight: 600;
  color: var(--color-ink-muted-80);
}
.bubble-demo .fai-row:nth-child(even) { background: #fafafc; }
.bubble-demo .fai-col { font-size: 0.75rem; }
.bubble-demo .fai-col--num { color: var(--color-ink-muted-48); font-weight: 500; }
.bubble-demo .fai-col--val { font-family: ui-monospace, SFMono-Regular, Menlo, monospace, "PingFang SC", "Microsoft YaHei", sans-serif; }
.bubble-demo .fai-tick {
  display: inline-flex; align-items: center; justify-content: center;
  width: 14px; height: 14px; border-radius: 50%;
  background: #16a34a; color: #fff; font-size: 9px; font-weight: 700; font-style: normal;
}
.bubble-demo .fai-bubble {
  display: inline-flex; align-items: center; justify-content: center;
  width: 18px; height: 18px; border-radius: 50%;
  background: var(--color-primary); color: #fff;
  font-size: 10px; font-weight: 700; font-style: normal;
}
.bubble-demo .fai-bubble--hot { background: #ea580c; }
.bubble-demo .fai-bubble--warn { background: #f59e0b; }
.bubble-demo .fai-switch {
  display: inline-block;
  width: 30px; height: 16px;
  background: #d1d5db;
  border-radius: 999px;
  position: relative;
  font-style: normal;
}
.bubble-demo .fai-switch::after {
  content: ""; position: absolute; top: 2px; left: 2px;
  width: 12px; height: 12px; background: #fff; border-radius: 50%;
  transition: transform .2s var(--ease);
}
.bubble-demo .fai-switch.is-on { background: #16a34a; }
.bubble-demo .fai-switch.is-on::after { transform: translateX(14px); }

@media (max-width: 860px) {
  .bubble-demo .demo-split { grid-template-columns: 1fr; }
  .bubble-demo .demo-split__drawing { border-right: none; border-bottom: 1px solid var(--color-hairline); }
}

/* --- Feature list ---------------------------------------------------- */
.feature-row {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 64px;
  align-items: center;
  padding: 64px 0;
}
.feature-row:nth-child(even) { direction: rtl; }
.feature-row:nth-child(even) > * { direction: ltr; }
.feature-row h2 { margin-bottom: 16px; }
.feature-row p { line-height: 1.47; }
.feature-row__visual {
  background: var(--color-parchment);
  border: 1px solid var(--color-hairline);
  border-radius: var(--radius-lg);
  padding: 32px;
  min-height: 280px;
  display: flex; align-items: center; justify-content: center;
}

/* --- 定价表 --------------------------------------------------------- */
.pricing-grid {
  display: grid;
  grid-template-columns: minmax(0, 640px);
  justify-content: center;
  gap: 24px;
  align-items: start;
  max-width: 1200px;
  margin: 0 auto;
}
/* 让左卡（企业版）视觉更突出 */
.plan--featured {
  align-self: stretch;
}
.plan {
  background: #fff;
  border: 1px solid var(--color-hairline);
  border-radius: var(--radius-lg);
  padding: 40px 32px 32px;
  display: flex;
  flex-direction: column;
  align-items: center;
  text-align: center;
}
.plan__name, .plan__desc, .plan__price, .plan__price-note, .plan__features { width: 100%; }
.plan--featured {
  border-color: var(--color-ink);
  position: relative;
}
.plan--featured::before {
  content: "推荐";
  position: absolute;
  top: -10px; left: 50%;
  transform: translateX(-50%);
  background: var(--color-ink);
  color: #fff;
  font-size: 0.6875rem;
  font-weight: 500;
  padding: 3px 12px;
  border-radius: var(--radius-pill);
  letter-spacing: 0.05em;
  text-transform: uppercase;
}
.plan__name { font-weight: 600; margin-bottom: 4px; }
.plan__desc { color: var(--color-ink-muted-48); font-size: 0.875rem; margin-bottom: 24px; }
.plan__price { font-size: 2.5rem; font-weight: 600; letter-spacing: -0.004em; }
.plan__price small { font-size: 0.9375rem; font-weight: 400; color: var(--color-ink-muted-48); }
.plan__price-note { font-size: 0.8125rem; color: var(--color-ink-muted-48); margin-top: 4px; line-height: 1.5; }
.plan__features {
  flex: 1;
  margin: 24px 0;
  display: flex; flex-direction: column; gap: 12px;
  font-size: 0.9375rem;
}
.plan__features li {
  display: flex; align-items: flex-start; gap: 10px;
  color: var(--color-body-muted);
  justify-content: center;
  text-align: left;
}
.plan__features li::before {
  content: "✓";
  color: var(--color-primary);
  font-weight: 600;
  flex-shrink: 0;
}

/* --- 证言 ------------------------------------------------------------ */
.quote {
  background: var(--color-parchment);
  border: 1px solid var(--color-hairline);
  border-radius: var(--radius-lg);
  padding: 32px;
}
.quote__text {
  font-size: 1.0625rem;
  color: var(--color-ink);
  line-height: 1.47;
  margin-bottom: 20px;
  letter-spacing: -0.003em;
}
.quote__author {
  display: flex; align-items: center; gap: 12px;
  font-size: 0.875rem;
}
.quote__avatar {
  width: 36px; height: 36px;
  border-radius: 50%;
  background: var(--color-pearl);
  border: 1px solid var(--color-hairline);
  overflow: hidden;
  flex-shrink: 0;
}
.quote__avatar svg { display: block; }
.quote__name { font-weight: 500; color: var(--color-ink); }
.quote__role { color: var(--color-ink-muted-48); }

/* --- 表单 ------------------------------------------------------------ */
.form { display: flex; flex-direction: column; gap: 20px; }
.field { display: flex; flex-direction: column; gap: 6px; }
.field label {
  font-size: 0.8125rem;
  font-weight: 500;
  color: var(--color-ink);
  letter-spacing: -0.002em;
}
.field input,
.field textarea,
.field select {
  height: 44px;
  padding: 0 14px;
  border: 1px solid var(--color-hairline);
  border-radius: var(--radius-sm);
  background: #fff;
  color: var(--color-ink);
  font-size: 0.9375rem;
  transition: border-color 0.15s, box-shadow 0.15s;
}
.field textarea { height: 140px; padding: 12px 14px; resize: vertical; }
.field input:focus,
.field textarea:focus,
.field select:focus {
  outline: none;
  border-color: var(--color-primary);
  box-shadow: 0 0 0 4px rgba(0, 102, 204, 0.15);
}
.field__hint { font-size: 0.8125rem; color: var(--color-ink-muted-48); }
.field--consent { display: block; }
.consent {
  display: flex;
  align-items: flex-start;
  gap: 10px;
  font-weight: 400 !important;
  font-size: 0.9375rem !important;
  line-height: 1.5;
  cursor: pointer;
}
.field .consent input[type="checkbox"] {
  appearance: auto;
  width: 18px;
  height: 18px;
  min-width: 18px;
  padding: 0;
  margin: 2px 0 0;
  border: 0;
  border-radius: 3px;
  box-shadow: none;
  flex: 0 0 18px;
  accent-color: var(--color-primary);
}

/* --- 页脚 — Apple 风格的多列细密链接 ----------------------------------- */
.footer {
  background: var(--color-parchment);
  border-top: 1px solid var(--color-hairline);
  padding: 64px 0 24px;
}
.footer__grid {
  display: grid;
  grid-template-columns: 1.5fr 1fr 1fr 1fr;
  gap: 48px;
  margin-bottom: 48px;
}
.footer__brand .nav__logo { height: 52px; }
.footer__brand .nav__wordmark { font-size: 1.5rem; }
.footer__brand p {
  font-size: 0.8125rem;
  line-height: 1.47;
  max-width: 280px;
  margin-top: 12px;
  color: var(--color-body-muted);
}
.footer__col h4 {
  font-size: 0.75rem;
  text-transform: uppercase;
  letter-spacing: 0.04em;
  color: var(--color-ink-muted-48);
  margin-bottom: 12px;
  font-weight: 600;
}
.footer__col ul { display: flex; flex-direction: column; gap: 8px; }
.footer__col a {
  font-size: 0.8125rem;
  line-height: 1.8;
  color: var(--color-ink-muted-80);
  letter-spacing: -0.002em;
}
.footer__col a:hover { color: var(--color-ink); }
.footer__bottom {
  display: flex;
  justify-content: space-between;
  align-items: center;
  padding-top: 24px;
  border-top: 1px solid var(--color-hairline);
  font-size: 0.75rem;
  color: var(--color-ink-muted-48);
  letter-spacing: -0.002em;
}

/* --- FAQ ------------------------------------------------------------- */
.faq { max-width: 760px; margin: 0 auto; }
.faq details {
  border-bottom: 1px solid var(--color-hairline);
  padding: 20px 0;
}
.faq summary {
  font-weight: 500;
  cursor: pointer;
  list-style: none;
  display: flex;
  justify-content: space-between;
  align-items: center;
  font-size: 1.0625rem;
  letter-spacing: -0.003em;
}
.faq summary::-webkit-details-marker { display: none; }
.faq summary::after {
  content: "+";
  font-size: 1.5rem;
  color: var(--color-ink-muted-48);
  transition: transform 0.2s;
  font-weight: 300;
}
.faq details[open] summary::after { transform: rotate(45deg); }
.faq details p { margin-top: 12px; font-size: 0.9375rem; line-height: 1.47; }

/* --- 统计数字 -------------------------------------------------------- */
.stats {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 32px;
  text-align: center;
  margin-top: 48px;
}
.stat__num {
  font-size: 3rem;
  font-weight: 600;
  letter-spacing: -0.004em;
  color: var(--color-ink);
  line-height: 1;
}
.stat__num small {
  font-size: 0.45em;
  font-weight: 500;
  color: var(--color-ink-muted-48);
  margin-left: 2px;
  letter-spacing: 0;
}
.stat__label { color: var(--color-ink-muted-48); font-size: 0.875rem; margin-top: 8px; }

/* --- 时间线 — PDF 第 15 页风格 ---------------------------------------- */
.timeline {
  max-width: 760px;
  width: 100%;
  margin: 0 auto;
  position: relative;
  padding-left: 0;
}
.timeline::before {
  content: "";
  position: absolute;
  left: 96px;
  top: 8px;
  bottom: 8px;
  width: 1px;
  background: var(--color-hairline);
}
.timeline__item {
  display: grid;
  grid-template-columns: 96px minmax(0, 1fr);
  gap: 32px;
  padding: 20px 0;
  position: relative;
}
.timeline__item::before {
  content: "";
  position: absolute;
  left: 92px;
  top: 32px;
  width: 9px; height: 9px;
  border-radius: 50%;
  background: var(--color-primary);
  box-shadow: 0 0 0 4px var(--color-parchment);
}
.timeline__year {
  font-size: 1.0625rem;
  font-weight: 600;
  color: var(--color-primary);
  letter-spacing: -0.003em;
  text-align: right;
  padding-right: 8px;
  padding-top: 4px;
}
.timeline__body { min-width: 0; overflow-wrap: break-word; word-break: break-word; }
.timeline__body h3 {
  font-size: 1.0625rem;
  margin-bottom: 6px;
}
.timeline__body p {
  font-size: 0.9375rem;
  line-height: 1.6;
  color: var(--color-body-muted);
}
@media (max-width: 700px) {
  .timeline::before { left: 44px; }
  .timeline__item { grid-template-columns: 44px minmax(0, 1fr); gap: 12px; }
  .timeline__item::before { left: 40px; }
  .timeline__year { font-size: 0.875rem; padding-right: 4px; }
  .timeline__body p { font-size: 0.875rem; }
}

/* --- 团队 ----------------------------------------------------------- */
.team {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 32px;
}
.team__member { text-align: center; }
.team__avatar {
  width: 96px; height: 96px;
  border-radius: 50%;
  background: var(--color-pearl);
  border: 1px solid var(--color-hairline);
  margin: 0 auto 16px;
}
.team__name { font-weight: 500; margin-bottom: 2px; }
.team__role { font-size: 0.8125rem; color: var(--color-ink-muted-48); }

/* --- 移动端 --------------------------------------------------------- */
@media (max-width: 900px) {
  .grid--3, .grid--4 { grid-template-columns: 1fr; }
  .grid--2 { grid-template-columns: 1fr; }
  .pricing-grid { grid-template-columns: 1fr; }
  .stats { grid-template-columns: repeat(2, 1fr); }
  .team { grid-template-columns: repeat(2, 1fr); }
  .footer__grid { grid-template-columns: 1fr 1fr; }
  .feature-row { grid-template-columns: 1fr; gap: 32px; padding: 40px 0; }
  .feature-row:nth-child(even) { direction: ltr; }
  .section { padding: 64px 0; }
  .hero { padding: 64px 0 56px; }
  .section__head { margin-bottom: 48px; }
  .nav__links { display: none; }
  .nav__toggle { display: flex; }
  .nav.is-open .nav__links {
    display: flex;
    position: absolute;
    top: 52px; left: 0; right: 0;
    flex-direction: column;
    background: rgba(255, 255, 255, 0.96);
    backdrop-filter: saturate(180%) blur(20px);
    -webkit-backdrop-filter: saturate(180%) blur(20px);
    border-bottom: 1px solid var(--color-hairline-soft);
    padding: 16px 24px;
    gap: 14px;
    align-items: flex-start;
  }
  .nav.is-open .nav__link { font-size: 1rem; }
  .nav__cta .btn--ghost { display: none; }
  .footer__bottom { flex-direction: column; gap: 12px; text-align: center; }
}

/* --- 工具类 --------------------------------------------------------- */
.text-center { text-align: center; }
.mt-8 { margin-top: 32px; }
.mt-12 { margin-top: 48px; }
.mb-8 { margin-bottom: 32px; }