:root {
  --yellow: #fdba01;
  --ink: #111111;
  --cream: #f4f1ea;
  --white: #ffffff;
  --muted: #55524b;
  --muted-dark: #b9b6ae;
  --line: #d9d5cb;
  --line-dark: #3a3a3a;
  --zh: "Noto Sans SC", "PingFang SC", "Microsoft YaHei", sans-serif;
  --en: "Inter", "Noto Sans SC", sans-serif;
  --wrap: 1120px;
  --gutter: clamp(20px, 5vw, 48px);
}

* { box-sizing: border-box; }
html { scroll-behavior: smooth; scroll-padding-top: 76px; }
body {
  margin: 0;
  background: var(--white);
  color: var(--ink);
  font-family: var(--zh);
  font-size: 17px;
  line-height: 1.75;
  -webkit-font-smoothing: antialiased;
}
img, video { display: block; max-width: 100%; height: auto; }
a { color: inherit; }
h1, h2, h3, p, ol, ul, dl, dd { margin: 0; padding: 0; }
ol, ul { list-style: none; }
:focus-visible { outline: 3px solid var(--ink); outline-offset: 3px; }
.band-dark :focus-visible { outline-color: var(--yellow); }

.wrap { max-width: var(--wrap); margin: 0 auto; padding: 0 var(--gutter); }
.skip { position: absolute; left: -9999px; top: 0; background: var(--ink); color: var(--white); padding: 10px 16px; z-index: 100; }
.skip:focus { left: 12px; top: 12px; }

/* ---------- type ---------- */
h1 { font-size: clamp(38px, 5.6vw, 72px); line-height: 1.16; font-weight: 900; letter-spacing: -0.01em; }
h2 { font-size: clamp(30px, 4.2vw, 48px); line-height: 1.22; font-weight: 900; letter-spacing: -0.005em; }
h3 { font-size: 21px; line-height: 1.4; font-weight: 700; }
.eyebrow {
  display: flex; align-items: center; gap: 10px;
  font-size: 14px; font-weight: 700; letter-spacing: 0.06em; margin-bottom: 22px;
}
.eyebrow::before { content: ""; width: 6px; height: 18px; background: var(--yellow); }
.eyebrow.on-dark { color: var(--yellow); }
.eyebrow.on-dark::before { display: none; }
.eyebrow.on-yellow::before { background: var(--ink); }
.lead { font-size: clamp(18px, 2vw, 21px); color: var(--muted); margin-top: 22px; }
.note { color: var(--muted); margin-top: 18px; max-width: 34em; }

/* ---------- buttons ---------- */
.btn {
  display: inline-flex; align-items: center; justify-content: center;
  min-height: 52px; padding: 0 28px;
  font-family: var(--zh); font-size: 17px; font-weight: 700; text-decoration: none;
  border: 2px solid var(--ink); border-radius: 0; cursor: pointer;
  transition: background-color .15s ease, color .15s ease, transform .15s ease;
}
.btn:active { transform: translateY(1px); }
.btn-dark { background: var(--ink); color: var(--white); }
.btn-dark:hover { background: var(--yellow); color: var(--ink); }
.btn-ghost { background: transparent; color: var(--ink); }
.btn-ghost:hover { background: var(--ink); color: var(--white); }
.btn-yellow { background: var(--yellow); color: var(--ink); border-color: var(--yellow); }
.btn-yellow:hover { background: var(--white); border-color: var(--white); }
.btn-sm { min-height: 44px; padding: 0 18px; font-size: 15px; }
.cta-row { display: flex; flex-wrap: wrap; gap: 14px; margin-top: 36px; }

/* ---------- header ---------- */
.site-header { position: sticky; top: 0; z-index: 20; background: var(--white); border-bottom: 1px solid var(--line); }
.header-row { display: flex; align-items: center; gap: 24px; height: 68px; }
.brand img { height: 34px; width: auto; }
.nav { display: flex; gap: 28px; margin-left: auto; font-size: 15px; font-weight: 500; }
.nav a { text-decoration: none; padding: 10px 0; border-bottom: 2px solid transparent; }
.nav a:hover { border-bottom-color: var(--yellow); }

/* ---------- hero ---------- */
.hero { display: grid; grid-template-columns: 1fr 1fr; min-height: min(760px, calc(100vh - 68px)); }
.hero-copy {
  display: flex; flex-direction: column; justify-content: center;
  padding: clamp(48px, 7vw, 96px) var(--gutter) clamp(48px, 7vw, 96px) max(var(--gutter), calc((100vw - var(--wrap)) / 2 + var(--gutter)));
}
.hero-art { position: relative; background: var(--yellow); overflow: hidden; display: flex; align-items: flex-end; justify-content: center; }
.hero-art img { width: 100%; height: 100%; object-fit: cover; object-position: 50% 30%; }
.hero-tag {
  position: absolute; left: var(--gutter); bottom: 28px;
  font-size: 16px; font-weight: 700; background: var(--yellow); padding: 4px 10px;
}

/* ---------- sections ---------- */
.section { padding: clamp(64px, 9vw, 120px) 0; }
.section-cream { background: var(--cream); }
.section-yellow { background: var(--yellow); }
.band-dark { background: var(--ink); color: var(--white); padding: clamp(64px, 9vw, 120px) 0; }

/* pitch */
.pitch { font-size: clamp(32px, 5.4vw, 64px); }
.pitch .hl { color: var(--yellow); }
.chain { display: grid; grid-template-columns: repeat(3, 1fr); gap: 0; margin-top: 56px; border-top: 1px solid var(--line-dark); }
.chain li { padding: 28px 28px 28px 0; border-right: 1px solid var(--line-dark); display: flex; flex-direction: column; gap: 8px; }
.chain li + li { padding-left: 28px; }
.chain li:last-child { border-right: 0; }
.chain-n { font-family: var(--en); font-weight: 800; font-size: 14px; color: var(--muted-dark); }
.chain strong { font-size: 26px; font-weight: 900; color: var(--yellow); }
.chain span:last-child { color: var(--muted-dark); font-size: 16px; }
.platforms { display: flex; flex-wrap: wrap; gap: 10px; margin-top: 40px; }
.platforms li { font-family: var(--en); font-weight: 700; font-size: 15px; padding: 8px 16px; border: 1px solid var(--line-dark); }
.en-line { font-family: var(--en); font-weight: 800; font-size: clamp(22px, 3vw, 34px); line-height: 1.25; margin-top: 44px; }

/* demo */
.demo-grid { display: grid; grid-template-columns: minmax(240px, 340px) 1fr; gap: clamp(32px, 7vw, 96px); align-items: center; }
.phone { background: var(--ink); padding: 10px; border-radius: 28px; }
.phone video { width: 100%; aspect-ratio: 9 / 16; border-radius: 20px; background: #000; object-fit: cover; }
.features { margin-top: 32px; border-top: 1px solid var(--line); }
.features > div { padding: 20px 0; border-bottom: 1px solid var(--line); }
.features dt { font-size: 20px; font-weight: 700; }
.features dd { color: var(--muted); margin-top: 4px; }

/* steps */
.steps { display: grid; grid-template-columns: repeat(4, 1fr); gap: 32px; margin-top: 56px; }
.steps li { border-top: 3px solid var(--ink); padding-top: 20px; }
.step-n { font-family: var(--en); font-weight: 800; font-size: 15px; color: #8a6a00; }
.steps h3 { margin-top: 6px; }
.steps p { color: var(--muted); margin-top: 10px; font-size: 16px; }

/* topics */
.topics { display: grid; grid-template-columns: repeat(3, 1fr); gap: 20px; margin-top: 48px; }
.topics li { background: var(--ink); color: var(--white); padding: 28px; min-height: 180px; display: flex; flex-direction: column; justify-content: space-between; gap: 24px; }
.topics h3 { color: var(--yellow); font-size: 17px; }
.topics p { font-size: 22px; font-weight: 700; line-height: 1.5; }
.topics-note { margin-top: 28px; max-width: 36em; font-weight: 500; }

/* pricing */
.pricing-grid { display: grid; grid-template-columns: 1.1fr 1fr; gap: clamp(32px, 6vw, 80px); align-items: end; }
.price { display: flex; align-items: baseline; gap: 16px; flex-wrap: wrap; }
.price-n { font-family: var(--en); font-weight: 900; font-size: clamp(88px, 14vw, 168px); line-height: 0.95; letter-spacing: -0.04em; }
.price-u { font-family: var(--en); font-weight: 700; font-size: 20px; }
.price-what { font-size: clamp(22px, 2.6vw, 28px); font-weight: 700; margin-top: 16px; }
.price-incl { color: var(--muted-dark); margin-top: 20px; padding-top: 20px; border-top: 1px solid var(--line-dark); max-width: 26em; }
.trial h3 { font-size: clamp(26px, 3.4vw, 36px); font-weight: 900; color: var(--yellow); }
.trial p { color: var(--muted-dark); margin: 14px 0 28px; max-width: 24em; }

/* form */
.apply-grid { display: grid; grid-template-columns: 1fr 1.1fr; gap: clamp(32px, 6vw, 80px); align-items: start; }
.form { background: var(--white); padding: clamp(24px, 4vw, 40px); border: 2px solid var(--ink); display: grid; gap: 20px; }
.field { display: grid; gap: 8px; }
.field label { font-weight: 700; font-size: 16px; }
.hint { font-weight: 400; color: var(--muted); font-size: 14px; margin-left: 6px; }
.field input, .field textarea {
  font: inherit; font-size: 17px; color: var(--ink); background: var(--white);
  border: 1.5px solid #8b877d; border-radius: 0; padding: 12px 14px; width: 100%;
}
.field input::placeholder, .field textarea::placeholder { color: #6f6b62; }
.field input:focus, .field textarea:focus { outline: 3px solid var(--yellow); outline-offset: 0; border-color: var(--ink); }
.field input[aria-invalid="true"], .field textarea[aria-invalid="true"] { border-color: #b3261e; }
.hp { position: absolute; left: -9999px; width: 1px; height: 1px; overflow: hidden; }
.form .btn { justify-self: start; }
.form .btn[disabled] { opacity: .55; cursor: default; }
.form-msg { min-height: 1.75em; font-weight: 500; }
.form-msg.ok { color: #1b6b2f; }
.form-msg.err { color: #b3261e; }

/* footer */
.site-footer { background: var(--white); border-top: 1px solid var(--line); padding: 36px 0; }
.footer-row { display: flex; align-items: center; gap: 28px; flex-wrap: wrap; }
.footer-logo { height: 30px; width: auto; }
.footer-logo-me { height: 38px; }
.footer-meta { margin-left: auto; font-family: var(--en); font-weight: 700; font-size: 15px; }

/* ---------- responsive ---------- */
@media (max-width: 900px) {
  .hero { grid-template-columns: 1fr; min-height: 0; }
  .hero-copy { padding: 48px var(--gutter) 40px; }
  .hero-art { aspect-ratio: 5 / 4; }
  .steps { grid-template-columns: 1fr 1fr; }
  .demo-grid, .pricing-grid, .apply-grid { grid-template-columns: 1fr; }
  .phone { max-width: 320px; margin: 0 auto; }
  .pricing-grid { align-items: start; }
}
@media (max-width: 640px) {
  body { font-size: 16px; }
  .nav { display: none; }
  .header-row { justify-content: space-between; }
  .chain, .topics, .steps { grid-template-columns: 1fr; }
  .chain li, .chain li + li { padding: 22px 0; border-right: 0; border-bottom: 1px solid var(--line-dark); }
  .chain li:last-child { border-bottom: 0; }
  .topics li { min-height: 0; }
  .cta-row .btn { flex: 1 1 100%; }
  .footer-meta { margin-left: 0; width: 100%; }
}
@media (prefers-reduced-motion: reduce) {
  html { scroll-behavior: auto; }
  .btn { transition: none; }
}

.nw { white-space: nowrap; }