:root {
  color-scheme: light;
  --bg: #f7f5ef;
  --panel: rgba(255, 255, 252, .9);
  --line: #dce3de;
  --text: #1d2933;
  --muted: #71808a;
  --teal: #278f87;
  --amber: #e59b45;
  --violet: #7d72b5;
  --shadow: 0 14px 34px rgba(52, 68, 65, .08);
}

* { box-sizing: border-box; }
html { background: var(--bg); }
body {
  min-height: 100vh;
  margin: 0;
  color: var(--text);
  background: radial-gradient(620px 360px at 92% 3%, #e3f2ec 0%, transparent 68%), radial-gradient(560px 350px at 4% 22%, #fae8cf 0%, transparent 66%), linear-gradient(180deg, #fbfaf6 0%, #f5f4ef 100%);
  font: 15px/1.65 Inter, -apple-system, BlinkMacSystemFont, "PingFang SC", "Microsoft YaHei", sans-serif;
}
body::before {
  position: fixed;
  z-index: -1;
  inset: 0;
  content: "";
  pointer-events: none;
  opacity: .28;
  background-image: linear-gradient(#d9e4df 1px, transparent 1px), linear-gradient(90deg, #d9e4df 1px, transparent 1px);
  background-size: 42px 42px;
  mask-image: linear-gradient(180deg, #000 0%, transparent 54%);
}
main { width: min(1240px, calc(100% - 56px)); margin: 0 auto; padding: 24px 0 76px; }

.site-header, .header {
  position: sticky;
  top: 14px;
  z-index: 4;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 18px;
  padding: 10px 14px;
  border: 1px solid rgba(211, 217, 211, .88);
  border-radius: 15px;
  background: rgba(255, 254, 250, .84);
  box-shadow: 0 10px 26px rgba(43, 55, 61, .07);
  backdrop-filter: blur(18px);
}
.brand { display: flex; align-items: center; gap: 10px; color: var(--text); font-weight: 800; letter-spacing: .02em; text-decoration: none; white-space: nowrap; }
.brandicon { width: 36px; height: 36px; border-radius: 50%; object-fit: cover; box-shadow: 0 4px 13px rgba(39, 143, 135, .22); }
.brand-mark, .mark { display: inline-block; width: 36px; height: 36px; overflow: hidden; border-radius: 50%; color: transparent; background: url('/zhiyong-ai-icon.jpg') center / cover no-repeat; box-shadow: 0 4px 13px rgba(39, 143, 135, .22); font-size: 0; }
.site-nav, .nav { display: flex; gap: 4px; margin-left: auto; }
.site-nav a, .nav a, .lang { padding: 6px 9px; border-radius: 8px; color: #6c7980; font-size: 13px; text-decoration: none; }
.site-nav a:hover, .site-nav a:focus-visible, .nav a:hover, .nav a:focus-visible, .lang:hover, .lang:focus-visible { color: #216f6a; background: #e7f2ee; outline: none; }
.top-actions { display: flex; align-items: center; gap: 8px; }
.youtube-link, .pricing-link, .language-toggle, .header-action { display: inline-flex; align-items: center; gap: 6px; padding: 6px 10px; border: 1px solid #d4dcd8; border-radius: 999px; color: #43525b; background: #fffefa; font-size: 12px; font-weight: 750; text-decoration: none; }
.youtube-link { color: #a14d5b; border-color: #f0c9ca; background: #fff3f1; }
.pricing-link { color: #9b681e; border-color: #efd29d; background: #fff7e8; }
.youtube-link:hover, .pricing-link:hover, .language-toggle:hover, .header-action:hover { border-color: #72b9ae; }
.ytmark { display: grid; place-items: center; width: 17px; height: 13px; border-radius: 4px; color: #fff; background: #ff0033; font-size: 8px; }

.eyebrow { position: relative; margin-top: 72px; color: #238c83; font-size: 12px; font-weight: 800; letter-spacing: .2em; text-transform: uppercase; }
.eyebrow::after { display: inline-block; width: 58px; height: 1px; margin: 0 0 4px 12px; content: ""; background: #e3b56f; }
h1 { max-width: 900px; margin: 14px 0 18px; color: #1a2831; font-size: clamp(43px, 5.5vw, 72px); line-height: 1.06; letter-spacing: -.06em; }
h1 span { color: #c57b24; }
.lede { max-width: 820px; margin: 0; color: #65747c; font-size: 18px; }
.actions { display: flex; flex-wrap: wrap; gap: 10px; margin: 28px 0 38px; }
.button { display: inline-flex; align-items: center; min-height: 42px; padding: 8px 15px; border: 1px solid #d2ded8; border-radius: 10px; color: #4f646a; background: rgba(255, 255, 252, .84); box-shadow: 0 5px 14px rgba(64, 84, 78, .04); text-decoration: none; transition: transform .18s ease, border-color .18s ease, background .18s ease; }
.button:hover, .button:focus-visible { border-color: #70b9ae; background: #eef8f4; outline: none; transform: translateY(-1px); }
.button.primary { border-color: #3ba99d; color: #fff; background: #3ba99d; font-weight: 800; }
.button.primary:hover, .button.primary:focus-visible { border-color: #278f87; color: #fff; background: #278f87; }

.section { margin-top: 36px; padding-top: 25px; border-top: 1px solid #d8e1dc; }
.section h2 { margin: 0 0 13px; color: #29474c; font-size: 23px; letter-spacing: -.025em; }
.grid { display: grid; grid-template-columns: repeat(2, minmax(0, 1fr)); gap: 16px; }
.card { min-height: 142px; padding: 19px 20px; border: 1px solid #dce3de; border-radius: 16px; color: var(--text); background: var(--panel); box-shadow: var(--shadow); transition: transform .18s ease, border-color .18s ease, box-shadow .18s ease; }
.card:hover { border-color: #92c7bd; box-shadow: 0 18px 34px rgba(52, 91, 83, .12); transform: translateY(-3px); }
.card h3 { margin: 0 0 7px; color: #25383e; font-size: 19px; line-height: 1.3; }
.card p { margin: 0; color: #66777e; font-size: 14px; }
.tag { display: inline-block; margin-bottom: 8px; padding: 3px 8px; border-radius: 999px; color: #a26b20; background: #fff5e5; font-size: 11px; font-weight: 800; letter-spacing: .04em; }
.checklist { display: grid; grid-template-columns: repeat(3, minmax(0, 1fr)); gap: 12px; margin: 0; padding: 0; list-style: none; }
.checklist li { min-height: 108px; padding: 15px 16px; border: 1px solid #d5e2dc; border-radius: 14px; color: #66777e; background: #f4faf7; font-size: 14px; }
.checklist b { display: block; margin-bottom: 5px; color: #39716d; font-size: 14px; }
.notice { padding: 17px 19px; border: 1px solid #ead6b2; border-radius: 15px; color: #66777e; background: linear-gradient(135deg, #fffaf0, #f7fbf6); box-shadow: 0 10px 24px rgba(69, 74, 57, .05); }
.notice strong { color: #a26b20; }
footer { margin-top: 44px; color: #849198; font-size: 13px; }
footer a { color: #278f87; }

@media (max-width: 1060px) { .top-actions .youtube-link, .top-actions .pricing-link { display: none; } }
@media (max-width: 900px) { .checklist { grid-template-columns: 1fr; } }
@media (max-width: 680px) {
  main { width: min(100% - 28px, 1240px); padding-top: 18px; }
  .site-header, .header { top: 8px; flex-wrap: wrap; padding: 8px 10px; }
  .site-nav, .nav { order: 3; width: 100%; justify-content: center; margin-left: 0; }
  .eyebrow { margin-top: 48px; }
  .eyebrow::after { width: 34px; }
  h1 { font-size: 44px; }
  .lede { font-size: 16px; }
  .grid { grid-template-columns: 1fr; }
  .actions { margin-bottom: 30px; }
}