/* 屏方 site. Layout: one calm column (max 1040px); the hero splits words | drawing and
   everything stacks to one column under 760px. System fonts only: nothing loads from
   outside our own domain, so the page opens the same in mainland China. */
:root {
  --bg: #fbfbfd;
  --surface: #ffffff;
  --ink: #1d1d1f;
  --muted: #6e6e73;
  --line: #e3e3e8;
  --accent: #0071e3;
  --accent-soft: #eaf3ff;
  --on-accent: #ffffff;
  --font: -apple-system, BlinkMacSystemFont, "PingFang SC", "Hiragino Sans GB",
    "Microsoft YaHei", "Helvetica Neue", Arial, sans-serif;
  --radius: 18px;
  color-scheme: light;
}

@media (prefers-color-scheme: dark) {
  :root:not([data-theme="light"]) {
    --bg: #0b0b0c;
    --surface: #1c1c1e;
    --ink: #f5f5f7;
    --muted: #a1a1a6;
    --line: #2c2c2e;
    --accent: #2997ff;
    --accent-soft: #0f2740;
    --on-accent: #ffffff;
    color-scheme: dark;
  }
}

:root[data-theme="dark"] {
  --bg: #0b0b0c;
  --surface: #1c1c1e;
  --ink: #f5f5f7;
  --muted: #a1a1a6;
  --line: #2c2c2e;
  --accent: #2997ff;
  --accent-soft: #0f2740;
  --on-accent: #ffffff;
  color-scheme: dark;
}

* { box-sizing: border-box; }

body {
  margin: 0;
  background: var(--bg);
  color: var(--ink);
  font: 17px/1.65 var(--font);
  -webkit-font-smoothing: antialiased;
  text-rendering: optimizeLegibility;
}

img, svg { max-width: 100%; height: auto; display: block; }
a { color: var(--accent); text-decoration: none; }
a:hover { text-decoration: underline; }
:focus-visible { outline: 2px solid var(--accent); outline-offset: 3px; border-radius: 6px; }

.wrap { max-width: 1040px; margin: 0 auto; padding: 0 24px; }

.preview-note {
  background: var(--accent-soft);
  color: var(--ink);
  font-size: 14px;
  text-align: center;
  padding: 8px 16px;
}

/* Top bar */
.topbar { border-bottom: 1px solid var(--line); background: var(--bg); }
.topbar .wrap { display: flex; align-items: center; justify-content: space-between; gap: 16px; min-height: 56px; }
.brand { display: flex; align-items: center; gap: 10px; color: var(--ink); font-weight: 600; font-size: 18px; }
.brand:hover { text-decoration: none; }
.brand img { width: 30px; height: 30px; }
.topbar nav { display: flex; gap: 20px; font-size: 15px; }
.topbar nav a { color: var(--muted); }
.topbar nav a:hover { color: var(--ink); text-decoration: none; }

/* Type */
h1, h2, h3 { margin: 0; text-wrap: balance; }
h1 { font-size: clamp(38px, 6.2vw, 64px); line-height: 1.08; letter-spacing: -0.02em; font-weight: 700; }
h2 { font-size: clamp(28px, 4vw, 40px); line-height: 1.15; letter-spacing: -0.015em; font-weight: 700; }
h3 { font-size: 19px; line-height: 1.35; font-weight: 600; }
p { margin: 0; }
.lead { font-size: clamp(18px, 2.1vw, 21px); color: var(--muted); max-width: 34em; }
.small { font-size: 14px; color: var(--muted); }

/* Buttons: feedback on press, nothing else moves. */
.actions { display: flex; flex-wrap: wrap; gap: 12px; }
.btn {
  display: inline-flex; align-items: center; justify-content: center;
  min-height: 46px; padding: 0 24px; border-radius: 999px;
  font: inherit; font-size: 17px; font-weight: 600; cursor: pointer;
  border: 1px solid transparent; transition: background-color 0.15s ease, transform 0.1s ease;
}
.btn:hover { text-decoration: none; }
.btn:active { transform: scale(0.97); }
.btn-primary { background: var(--accent); color: var(--on-accent); }
.btn-primary:hover { filter: brightness(1.06); }
.btn-secondary { background: var(--surface); color: var(--accent); border-color: var(--line); }
.status { font-size: 15px; color: var(--muted); }
.status:empty { display: none; }

/* Hero */
.hero { padding: 64px 0 72px; }
.hero .wrap { display: grid; grid-template-columns: 1.05fr 1fr; gap: 48px; align-items: center; }
.hero-words { display: grid; gap: 22px; }
.hero-drawing { width: 100%; }

/* Sections */
.install-art { margin: 0 0 28px; }
.install-art img { width: 100%; max-width: 640px; border-radius: var(--radius); border: 1px solid var(--line); background: #f5f4f0; box-shadow: none; }

section.block { padding: 80px 0; border-top: 1px solid var(--line); }
.block-head { display: grid; gap: 14px; margin-bottom: 40px; max-width: 40em; }

.steps { list-style: none; margin: 0; padding: 0; display: grid; grid-template-columns: repeat(3, 1fr); gap: 20px; }
.steps li { background: var(--surface); border: 1px solid var(--line); border-radius: var(--radius); padding: 24px; display: grid; gap: 8px; align-content: start; }
.step-no {
  width: 32px; height: 32px; border-radius: 50%; background: var(--accent-soft); color: var(--accent);
  display: grid; place-items: center; font-weight: 700; font-size: 16px; font-variant-numeric: tabular-nums;
}
.steps p { color: var(--muted); font-size: 16px; }
.pairing-note { margin-top: 24px; color: var(--muted); max-width: 40em; }

.shots { display: grid; grid-template-columns: repeat(2, 1fr); gap: 24px; margin-top: 40px; }
figure { margin: 0; display: grid; gap: 12px; }
figure img {
  border-radius: 14px; border: 1px solid var(--line); background: #ffffff;
  box-shadow: 0 1px 2px rgba(0, 0, 0, 0.04), 0 8px 24px rgba(0, 0, 0, 0.06);
}
figcaption { font-size: 15px; color: var(--muted); }

.features { display: grid; grid-template-columns: 1.3fr 1fr; gap: 40px; align-items: start; }
.cards { display: grid; grid-template-columns: repeat(2, 1fr); gap: 16px; }
.card { background: var(--surface); border: 1px solid var(--line); border-radius: var(--radius); padding: 22px; display: grid; gap: 6px; align-content: start; }
.card p { color: var(--muted); font-size: 16px; }

.plans { display: grid; grid-template-columns: repeat(2, 1fr); gap: 20px; }
.plan { background: var(--surface); border: 1px solid var(--line); border-radius: var(--radius); padding: 28px; display: grid; gap: 16px; align-content: start; }
.plan.featured { border: 2px solid var(--accent); }
.plan-name { font-size: 15px; font-weight: 600; color: var(--muted); }
.price { font-size: 44px; font-weight: 700; letter-spacing: -0.02em; line-height: 1; font-variant-numeric: tabular-nums; }
.price small { font-size: 16px; font-weight: 500; color: var(--muted); letter-spacing: 0; margin-left: 8px; }
.plan ul { margin: 0; padding-left: 1.2em; display: grid; gap: 6px; }
.plans-note { margin-top: 20px; }

.privacy { display: grid; gap: 16px; max-width: 40em; }
.privacy p { color: var(--muted); }

.models-wrap { overflow-x: auto; }
table.models { width: 100%; border-collapse: collapse; }
table.models th, table.models td { text-align: left; padding: 14px 12px; border-bottom: 1px solid var(--line); vertical-align: top; }
table.models th { font-size: 14px; color: var(--muted); font-weight: 600; }
table.models td:first-child { font-weight: 600; }
.models-note { margin-top: 16px; }

.faq { display: grid; gap: 0; max-width: 46em; border-top: 1px solid var(--line); }
.faq details { border-bottom: 1px solid var(--line); padding: 18px 0; }
.faq summary { cursor: pointer; font-weight: 600; list-style: none; display: flex; justify-content: space-between; gap: 16px; }
.faq summary::-webkit-details-marker { display: none; }
.faq summary::after { content: "+"; color: var(--muted); font-weight: 400; font-size: 22px; line-height: 1; }
.faq details[open] summary::after { content: "−"; }
.faq details p { margin-top: 10px; color: var(--muted); }

.why { max-width: 36em; display: grid; gap: 16px; font-size: 19px; line-height: 1.8; }
.why p:last-child { color: var(--muted); font-size: 16px; }

footer { border-top: 1px solid var(--line); padding: 40px 0 56px; }
footer .wrap { display: grid; gap: 12px; }
footer nav { display: flex; flex-wrap: wrap; gap: 8px 20px; font-size: 15px; }
footer nav a { color: var(--muted); }

/* Sub pages */
.doc { max-width: 40em; padding: 56px 0 80px; display: grid; gap: 18px; }
.doc h1 { font-size: clamp(32px, 5vw, 44px); }
.doc h2 { font-size: 22px; margin-top: 18px; }
.doc p, .doc li { color: var(--ink); }
.doc .small { margin-top: 12px; }

@media (max-width: 760px) {
  .hero .wrap, .features, .shots, .plans { grid-template-columns: 1fr; }
  .steps { grid-template-columns: 1fr; }
  .hero { padding: 40px 0 56px; }
  section.block { padding: 56px 0; }
  .topbar nav { display: none; }
}

@media (max-width: 480px) {
  .wrap { padding: 0 16px; }
  body { font-size: 16px; }
  .cards { grid-template-columns: 1fr; }
  .actions .btn { flex: 1 1 100%; }
}

@media (prefers-reduced-motion: reduce) {
  .btn { transition: none; }
  .btn:active { transform: none; }
}