/* =========================================================
   WYH AI · Corporate Site
   Clean, light, Apple-inspired
   ========================================================= */

:root {
  --bg: #ffffff;
  --bg-soft: #f5f5f7;
  --text: #1d1d1f;
  --muted: #6e6e73;
  --muted-2: #86868b;
  --line: #d2d2d7;
  --line-soft: #e8e8ed;
  --accent: #0071e3;
  --accent-ink: #0066cc;
  --radius: 22px;
  --maxw: 1080px;
  --shadow: 0 24px 60px -32px rgba(0, 0, 0, 0.28);
  --ease: cubic-bezier(0.22, 1, 0.36, 1);
}

* { margin: 0; padding: 0; box-sizing: border-box; }

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

body {
  background: var(--bg);
  color: var(--text);
  font-family: -apple-system, BlinkMacSystemFont, "SF Pro Display", "SF Pro Text",
    "Segoe UI", "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei", "Helvetica Neue", Arial, sans-serif;
  line-height: 1.5;
  letter-spacing: -0.01em;
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
  overflow-x: hidden;
}

a { color: inherit; text-decoration: none; }
img, svg { display: block; }
svg { width: 100%; height: 100%; }
.svg-defs { position: absolute; width: 0; height: 0; overflow: hidden; }
::selection { background: rgba(0, 113, 227, 0.16); }

/* =========================================================
   通用
   ========================================================= */
.eyebrow {
  font-size: 14px;
  font-weight: 600;
  letter-spacing: 0;
  color: var(--accent);
  margin-bottom: 14px;
}

.section {
  max-width: var(--maxw);
  margin: 0 auto;
  padding: 120px 24px;
}
.section--soft { max-width: none; background: var(--bg-soft); padding: 0; }
.section__inner { max-width: var(--maxw); margin: 0 auto; padding: 120px 24px; }
.section--contact { max-width: none; }

.section__head { max-width: 680px; margin-bottom: 56px; }
.section__title {
  font-size: clamp(30px, 4vw, 48px);
  line-height: 1.1;
  letter-spacing: -0.022em;
  font-weight: 600;
}
.section__lead { color: var(--muted); font-size: clamp(16px, 1.5vw, 19px); margin-top: 16px; }

.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 8px;
  font-size: 15px;
  font-weight: 500;
  padding: 12px 24px;
  border-radius: 980px;
  border: 1px solid transparent;
  cursor: pointer;
  font-family: inherit;
  transition: background 0.25s, transform 0.25s var(--ease), box-shadow 0.25s;
}
.btn--primary { background: var(--accent); color: #fff; }
.btn--primary:hover { background: var(--accent-ink); }

.link-arrow {
  display: inline-flex;
  align-items: center;
  gap: 5px;
  color: var(--accent);
  font-size: 15px;
  font-weight: 500;
  transition: gap 0.25s var(--ease), color 0.2s;
}
.link-arrow svg { width: 15px; height: 15px; }
.link-arrow:hover { gap: 9px; color: var(--accent-ink); }

/* =========================================================
   导航
   ========================================================= */
.nav {
  position: fixed;
  inset: 0 0 auto 0;
  z-index: 100;
  transition: background 0.35s, border-color 0.35s, backdrop-filter 0.35s;
  border-bottom: 1px solid transparent;
}
.nav.is-scrolled {
  background: rgba(255, 255, 255, 0.72);
  backdrop-filter: saturate(180%) blur(20px);
  -webkit-backdrop-filter: saturate(180%) blur(20px);
  border-bottom-color: var(--line-soft);
}
.nav__inner {
  max-width: var(--maxw);
  margin: 0 auto;
  height: 60px;
  padding: 0 24px;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 24px;
}
.brand { display: inline-flex; align-items: center; gap: 9px; font-weight: 600; }
.brand__mark {
  width: 30px; height: 30px;
  display: block;
  flex: 0 0 auto;
}
.brand__text { font-size: 18px; font-weight: 700; letter-spacing: -0.02em; color: #4D6BFE; }

.nav__links { display: flex; align-items: center; gap: 32px; }
.nav__links a { font-size: 14px; color: #3a3a3c; transition: color 0.2s; }
.nav__links a:hover { color: var(--accent); }

.nav__actions { display: flex; align-items: center; gap: 22px; }
.nav__toggle {
  display: none;
  width: 40px; height: 40px;
  border: 0; background: transparent; cursor: pointer;
  flex-direction: column; align-items: center; justify-content: center; gap: 5px;
}
.nav__toggle span { width: 18px; height: 1.6px; background: var(--text); border-radius: 2px; transition: transform 0.3s, opacity 0.3s; }
.nav__toggle.is-open span:first-child { transform: translateY(3.3px) rotate(45deg); }
.nav__toggle.is-open span:last-child { transform: translateY(-3.3px) rotate(-45deg); }

.nav__mobile {
  display: none;
  flex-direction: column;
  padding: 6px 24px 20px;
  background: rgba(255, 255, 255, 0.96);
  backdrop-filter: blur(20px);
  border-bottom: 1px solid var(--line-soft);
}
.nav__mobile a { padding: 13px 0; font-size: 16px; border-bottom: 1px solid var(--line-soft); }
.nav__mobile a:last-child { border-bottom: 0; }
.nav__mobile.is-open { display: flex; }

/* =========================================================
   Hero
   ========================================================= */
.hero {
  max-width: var(--maxw);
  margin: 0 auto;
  padding: 150px 24px 90px;
  text-align: center;
}
.hero__content { max-width: 820px; margin: 0 auto; }
.hero__title {
  font-size: clamp(38px, 6.4vw, 76px);
  line-height: 1.05;
  letter-spacing: -0.03em;
  font-weight: 600;
  margin: 4px 0 22px;
}
.hero__title span { display: block; }
.hero__title em { font-style: normal; color: var(--accent); }
.hero__sub {
  font-size: clamp(16px, 1.8vw, 20px);
  color: var(--muted);
  max-width: 600px;
  margin: 0 auto;
}
.hero__cta {
  display: flex; gap: 26px; justify-content: center; align-items: center;
  flex-wrap: wrap; margin-top: 30px;
}
.hero__window { margin: 72px auto 0; max-width: 940px; will-change: transform; }

/* 窗口 / 卡片 */
.window {
  border: 1px solid var(--line-soft);
  border-radius: 18px;
  background: #fff;
  box-shadow: var(--shadow);
  overflow: hidden;
  text-align: left;
}
.window__bar {
  display: flex; align-items: center; gap: 7px;
  padding: 13px 18px;
  border-bottom: 1px solid var(--line-soft);
  background: #fbfbfd;
}
.window__bar .d { width: 11px; height: 11px; border-radius: 50%; background: #e0e0e5; }
.window__bar .d:nth-child(1) { background: #ff5f57; }
.window__bar .d:nth-child(2) { background: #febc2e; }
.window__bar .d:nth-child(3) { background: #28c840; }
.window__bar em { font-style: normal; font-size: 12px; color: var(--muted-2); margin-left: 10px; letter-spacing: 0; }

.window__body { display: grid; grid-template-columns: 180px 1fr; min-height: 300px; }
.window__side { border-right: 1px solid var(--line-soft); padding: 18px 12px; background: #fbfbfd; display: flex; flex-direction: column; gap: 4px; }
.side-item {
  display: flex; align-items: center; gap: 10px;
  padding: 9px 12px; border-radius: 9px;
  font-size: 13.5px; color: var(--muted);
}
.side-item svg { width: 17px; height: 17px; }
.side-item.is-active { background: #eef2f7; color: var(--text); }
.window__main { padding: 26px; display: flex; flex-direction: column; justify-content: space-between; gap: 22px; }
.chat { display: flex; flex-direction: column; gap: 14px; align-items: flex-start; }
.bubble { max-width: 78%; padding: 11px 16px; border-radius: 16px; font-size: 14px; }
.bubble--user { align-self: flex-end; background: var(--accent); color: #fff; border-bottom-right-radius: 5px; }
.bubble--ai { background: #f5f5f7; border-bottom-left-radius: 5px; width: 78%; padding: 15px 16px; }
.line { height: 9px; border-radius: 5px; background: #e3e4e8; margin-bottom: 10px; }
.line:last-child { margin-bottom: 0; }
.line.w92 { width: 92%; } .line.w98 { width: 98%; } .line.w74 { width: 74%; }
.chat__meta { display: flex; gap: 8px; flex-wrap: wrap; }
.chat__meta span { font-size: 12px; color: var(--muted); padding: 4px 10px; border: 1px solid var(--line-soft); border-radius: 980px; }
.composer {
  display: flex; align-items: center; justify-content: space-between;
  border: 1px solid var(--line); border-radius: 12px; padding: 10px 12px 10px 16px;
}
.composer__ph { color: var(--muted-2); font-size: 14px; }
.composer__send { width: 30px; height: 30px; border-radius: 8px; background: var(--text); color: #fff; display: grid; place-items: center; }
.composer__send svg { width: 16px; height: 16px; }

/* =========================================================
   数据带
   ========================================================= */
.stats { background: var(--bg-soft); }
.stats__inner {
  max-width: var(--maxw); margin: 0 auto; padding: 58px 24px;
  display: grid; grid-template-columns: repeat(4, 1fr); gap: 20px;
}
.stat { text-align: center; position: relative; }
.stat + .stat::before { content: ""; position: absolute; left: 0; top: 14%; height: 72%; width: 1px; background: var(--line); }
.stat__num { font-size: clamp(32px, 4vw, 46px); font-weight: 600; letter-spacing: -0.03em; display: inline-flex; align-items: baseline; gap: 2px; }
.stat__num i { font-style: normal; font-size: 0.5em; color: var(--muted); font-weight: 500; }
.stat p { color: var(--muted); font-size: 14px; margin-top: 4px; }

/* =========================================================
   核心能力
   ========================================================= */
.cards { display: grid; grid-template-columns: repeat(3, 1fr); gap: 18px; }
.card {
  background: #fff;
  border: 1px solid var(--line-soft);
  border-radius: 20px;
  padding: 30px 28px;
  transition: transform 0.4s var(--ease), box-shadow 0.4s, border-color 0.3s;
}
.card:hover { transform: translateY(-4px); box-shadow: 0 22px 44px -28px rgba(0, 0, 0, 0.28); border-color: transparent; }
.card__icon {
  width: 48px; height: 48px;
  display: grid; place-items: center;
  border-radius: 13px;
  background: var(--bg-soft);
  color: var(--text);
  margin-bottom: 20px;
}
.card__icon svg { width: 24px; height: 24px; }
.card h3 { font-size: 18px; font-weight: 600; margin-bottom: 8px; letter-spacing: -0.015em; }
.card p { color: var(--muted); font-size: 14.5px; }

/* =========================================================
   模型服务
   ========================================================= */
.models {
  background: #fff;
  border: 1px solid var(--line-soft);
  border-radius: 24px;
  overflow: hidden;
}
.models__tabs {
  display: flex; gap: 6px; padding: 6px;
  margin: 18px; margin-bottom: 0;
  background: var(--bg-soft); border-radius: 14px;
  width: fit-content; flex-wrap: wrap;
}
.models__tab {
  padding: 9px 18px; border: 0; border-radius: 10px;
  background: transparent; color: var(--muted);
  font-size: 14px; font-weight: 500; cursor: pointer;
  font-family: inherit;
  transition: background 0.25s, color 0.25s, box-shadow 0.25s;
}
.models__tab:hover { color: var(--text); }
.models__tab.is-active { background: #fff; color: var(--text); box-shadow: 0 1px 3px rgba(0, 0, 0, 0.1); }
.models__panel { display: grid; grid-template-columns: 1.15fr 0.85fr; }
.models__info { padding: 40px; display: flex; flex-direction: column; justify-content: center; }
.models__info h3 { font-size: 26px; font-weight: 600; letter-spacing: -0.02em; margin-bottom: 12px; }
.models__info p { color: var(--muted); font-size: 15px; margin-bottom: 26px; }
.models__specs { list-style: none; display: grid; grid-template-columns: repeat(3, 1fr); gap: 10px; margin-bottom: 28px; }
.models__specs li { background: var(--bg-soft); border-radius: 13px; padding: 14px; text-align: center; }
.models__specs span { display: block; font-size: 12px; color: var(--muted); margin-bottom: 4px; }
.models__specs b { font-size: 15px; font-weight: 600; }
.models__info .link-arrow { align-self: flex-start; }
.models__panel.is-switching .models__info > * { animation: fadeUp 0.45s var(--ease) both; }
@keyframes fadeUp { from { opacity: 0; transform: translateY(8px); } to { opacity: 1; transform: none; } }

.models__visual { background: var(--bg-soft); display: grid; place-items: center; padding: 40px; border-left: 1px solid var(--line-soft); }
.panel-demo {
  width: 100%; max-width: 300px;
  background: #fff; border: 1px solid var(--line-soft);
  border-radius: 14px; padding: 18px;
  font-family: "SF Mono", ui-monospace, SFMono-Regular, Menlo, Consolas, monospace;
  font-size: 13px;
  box-shadow: 0 18px 40px -26px rgba(0, 0, 0, 0.3);
}
.panel-demo__row { display: flex; justify-content: space-between; padding: 7px 2px; border-bottom: 1px dashed var(--line-soft); }
.panel-demo__row:last-of-type { border-bottom: 0; }
.panel-demo .k { color: var(--muted-2); }
.panel-demo .v { color: var(--accent); }
.panel-demo__cursor { width: 8px; height: 15px; background: var(--text); margin-top: 12px; animation: blink 1.1s steps(2) infinite; }
@keyframes blink { 50% { opacity: 0; } }

/* =========================================================
   落地场景
   ========================================================= */
.story { display: grid; grid-template-columns: 0.9fr 1.1fr; gap: 56px; align-items: center; }
.story__steps .step { padding: 26px 0; border-bottom: 1px solid var(--line-soft); }
.story__steps .step:first-child { padding-top: 0; }
.story__steps .step:last-child { border-bottom: 0; padding-bottom: 0; }
.step__no { font-size: 13px; font-weight: 600; color: var(--accent); }
.step h3 { font-size: 22px; font-weight: 600; margin: 6px 0; letter-spacing: -0.02em; }
.step p { color: var(--muted); font-size: 15px; }

.window--code .code {
  margin: 0; padding: 24px;
  font-family: "SF Mono", ui-monospace, SFMono-Regular, Menlo, Consolas, monospace;
  font-size: 13px; line-height: 1.75; color: #3a3a3c;
  overflow-x: auto;
}
.code .c-key { color: #a626a4; }
.code .c-str { color: #0a7d3a; }
.code .c-num { color: #b05a00; }

/* =========================================================
   行业方案
   ========================================================= */
.solutions { display: grid; grid-template-columns: repeat(3, 1fr); gap: 18px; }
.solution {
  background: #fff; border: 1px solid var(--line-soft);
  border-radius: 20px; padding: 28px 26px;
  transition: transform 0.4s var(--ease), box-shadow 0.4s, border-color 0.3s;
}
.solution:hover { transform: translateY(-4px); box-shadow: 0 22px 44px -28px rgba(0, 0, 0, 0.28); border-color: transparent; }
.solution .card__icon { width: 44px; height: 44px; margin-bottom: 16px; border-radius: 12px; }
.solution .card__icon svg { width: 22px; height: 22px; }
.solution h3 { font-size: 17px; font-weight: 600; margin-bottom: 5px; }
.solution p { color: var(--muted); font-size: 14px; }

/* =========================================================
   关于我们
   ========================================================= */
.about { display: grid; grid-template-columns: 1.05fr 0.95fr; gap: 60px; align-items: center; }
.about__text .section__title { margin-bottom: 20px; }
.about__text > p { color: var(--muted); font-size: 16px; margin-bottom: 16px; }
.about__points { display: grid; grid-template-columns: repeat(3, 1fr); gap: 16px; margin-top: 32px; }
.point { display: flex; gap: 10px; align-items: flex-start; }
.point svg { width: 21px; height: 21px; color: var(--accent); flex: none; margin-top: 2px; }
.point h4 { font-size: 15px; font-weight: 600; }
.point p { color: var(--muted); font-size: 13px; }

.about__visual { display: grid; place-items: center; }
.stack { position: relative; width: 100%; max-width: 340px; }
.stack__ghost { position: absolute; inset: 0; border-radius: 20px; border: 1px solid var(--line-soft); background: #fff; }
.stack__ghost--1 { transform: translate(14px, 14px) scale(0.97); opacity: 0.6; }
.stack__ghost--2 { transform: translate(7px, 7px) scale(0.985); opacity: 0.8; }
.stack__card {
  position: relative; border: 1px solid var(--line-soft); border-radius: 20px;
  background: #fff; padding: 26px; box-shadow: var(--shadow);
}
.stack__head { display: flex; align-items: center; gap: 9px; margin-bottom: 22px; }
.stack__head svg { width: 22px; height: 22px; color: var(--accent); }
.stack__head b { font-size: 16px; font-weight: 600; }
.stack__metrics { display: grid; grid-template-columns: repeat(3, 1fr); gap: 12px; margin-bottom: 20px; }
.stack__metrics > div { background: var(--bg-soft); border-radius: 12px; padding: 12px 10px; text-align: center; }
.stack__metrics b { display: block; font-size: 16px; font-weight: 600; letter-spacing: -0.02em; }
.stack__metrics span { font-size: 11.5px; color: var(--muted); }
.stack__foot { display: flex; gap: 8px; flex-wrap: wrap; }
.stack__foot .pill { font-size: 12px; color: var(--muted); border: 1px solid var(--line-soft); border-radius: 980px; padding: 4px 11px; }

/* =========================================================
   联系我们
   ========================================================= */
.contact {
  text-align: center;
  padding: 80px 32px;
  border-radius: 30px;
  background: var(--bg-soft);
}
.contact h2 { font-size: clamp(28px, 3.6vw, 44px); font-weight: 600; letter-spacing: -0.022em; margin-bottom: 14px; }
.contact > p { color: var(--muted); max-width: 520px; margin: 0 auto 28px; font-size: 17px; }
.contact__ways { display: flex; gap: 14px; justify-content: center; flex-wrap: wrap; margin-bottom: 30px; }
.contact__ways a {
  display: inline-flex; align-items: center; gap: 9px;
  padding: 11px 18px; border-radius: 980px;
  background: #fff; border: 1px solid var(--line-soft);
  font-size: 14.5px; transition: border-color 0.25s, transform 0.25s var(--ease);
}
.contact__ways a:hover { border-color: var(--line); transform: translateY(-2px); }
.contact__ways svg { width: 17px; height: 17px; color: var(--accent); }

/* =========================================================
   页脚
   ========================================================= */
.footer { border-top: 1px solid var(--line-soft); background: var(--bg-soft); }
.footer__inner {
  max-width: var(--maxw); margin: 0 auto; padding: 60px 24px 36px;
  display: grid; grid-template-columns: 1.4fr 2fr; gap: 46px;
}
.footer__brand p { color: var(--muted); font-size: 14px; margin-top: 12px; }
.footer__cols { display: grid; grid-template-columns: repeat(3, 1fr); gap: 24px; }
.footer__cols h4 { font-size: 13px; font-weight: 600; color: var(--text); margin-bottom: 14px; }
.footer__cols a { display: block; color: var(--muted); font-size: 14px; margin-bottom: 10px; transition: color 0.2s; }
.footer__cols a:hover { color: var(--accent); }

.footer__bottom {
  max-width: var(--maxw); margin: 0 auto;
  padding: 20px 24px 36px;
  border-top: 1px solid var(--line);
  display: flex; align-items: center; justify-content: space-between;
  gap: 16px; flex-wrap: wrap;
}
.footer__legal { display: flex; align-items: center; gap: 16px; flex-wrap: wrap; color: var(--muted); font-size: 13px; }
.footer__legal .icp { color: var(--muted); transition: color 0.2s; }
.footer__legal .icp:hover { color: var(--accent); }
.footer__visits {
  display: inline-flex; align-items: center; gap: 8px;
  font-size: 13px; color: var(--muted);
  padding: 8px 15px; border: 1px solid var(--line); border-radius: 980px; background: #fff;
}
.footer__visits svg { width: 15px; height: 15px; color: var(--accent); }
.footer__visits b { color: var(--text); font-weight: 600; font-variant-numeric: tabular-nums; }

/* =========================================================
   滚动出现
   ========================================================= */
.reveal { opacity: 0; transform: translateY(22px); transition: opacity 0.7s var(--ease), transform 0.7s var(--ease); }
.reveal.is-visible { opacity: 1; transform: none; }

@media (prefers-reduced-motion: reduce) {
  * { animation-duration: 0.001ms !important; animation-iteration-count: 1 !important; transition-duration: 0.001ms !important; }
  html { scroll-behavior: auto; }
  .reveal { opacity: 1; transform: none; }
}

/* =========================================================
   响应式
   ========================================================= */
@media (max-width: 920px) {
  .nav__links { display: none; }
  .nav__actions .link-arrow { display: none; }
  .nav__toggle { display: flex; }
  .cards { grid-template-columns: repeat(2, 1fr); }
  .solutions { grid-template-columns: repeat(2, 1fr); }
  .models__panel { grid-template-columns: 1fr; }
  .models__visual { border-left: 0; border-top: 1px solid var(--line-soft); }
  .window__body { grid-template-columns: 1fr; }
  .window__side { flex-direction: row; flex-wrap: wrap; border-right: 0; border-bottom: 1px solid var(--line-soft); }
  .story { grid-template-columns: 1fr; gap: 36px; }
  .about { grid-template-columns: 1fr; gap: 44px; }
  .about__visual { order: -1; }
  .footer__inner { grid-template-columns: 1fr; gap: 34px; }
}
@media (max-width: 600px) {
  .section, .section__inner { padding: 84px 20px; }
  .hero { padding: 124px 20px 64px; }
  .hero__window { margin-top: 48px; }
  .stats__inner { grid-template-columns: repeat(2, 1fr); gap: 30px 12px; padding: 44px 20px; }
  .stat:nth-child(3)::before { display: none; }
  .cards, .solutions { grid-template-columns: 1fr; }
  .models__info { padding: 28px 22px; }
  .models__specs { grid-template-columns: 1fr 1fr 1fr; gap: 8px; }
  .about__points { grid-template-columns: 1fr; }
  .window__side { display: none; }
  .footer__bottom { flex-direction: column; align-items: flex-start; }
}