/* Spark Agent (火花 Agent) marketing site.
   Dark-first sibling of the SIR brand: same navy/orange family, AI-product tone. */

@font-face {
  font-family: "Inter";
  src: url("../fonts/inter-latin-wght-normal.woff2") format("woff2");
  font-weight: 100 900;
  font-style: normal;
  font-display: swap;
  unicode-range: U+0000-00FF, U+0131, U+0152-0153, U+02BB-02BC, U+02C6, U+02DA, U+02DC, U+0304, U+0308, U+0329, U+2000-206F, U+20AC, U+2122, U+2191, U+2193, U+2212, U+2215, U+FEFF, U+FFFD;
}

:root {
  --navy-950: #030b1a;
  --navy-900: #061630;
  --navy-850: #071c3c;
  --navy-800: #0b2344;
  --navy-700: #102a50;
  --navy-600: #17345e;
  --line: rgba(169, 184, 202, 0.14);
  --line-strong: rgba(169, 184, 202, 0.26);
  --text: #eef3f9;
  --text-2: #a9b8ca;
  --text-3: #71839b;
  --orange: #ff6508;
  --orange-2: #ff9b5c;
  --orange-soft: rgba(255, 101, 8, 0.14);
  --orange-glow: rgba(255, 101, 8, 0.38);
  --radius: 14px;
  --radius-sm: 8px;
  --container: 1200px;
  --gutter: 24px;
  --font: "Inter", "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei", "Noto Sans SC", system-ui, -apple-system, sans-serif;
  --mono: ui-monospace, "SF Mono", "JetBrains Mono", Menlo, Consolas, "Liberation Mono", monospace;
  color-scheme: dark;
}

*,
*::before,
*::after { box-sizing: border-box; }

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

body {
  margin: 0;
  background: var(--navy-950);
  color: var(--text);
  font-family: var(--font);
  font-size: 16px;
  line-height: 1.7;
  -webkit-font-smoothing: antialiased;
  text-rendering: optimizeLegibility;
  overflow-x: hidden;
}

img, svg { display: block; max-width: 100%; }
a { color: inherit; text-decoration: none; }
p { margin: 0; }
h1, h2, h3 { margin: 0; line-height: 1.25; letter-spacing: 0.01em; }
code, pre { font-family: var(--mono); }

:focus-visible { outline: 2px solid var(--orange-2); outline-offset: 3px; border-radius: 4px; }

.container { width: 100%; max-width: calc(var(--container) + var(--gutter) * 2); margin: 0 auto; padding: 0 var(--gutter); }

.skip-link { position: absolute; left: -9999px; top: 8px; z-index: 100; background: var(--orange); color: #fff; padding: 8px 14px; border-radius: 6px; }
.skip-link:focus { left: 16px; }

/* ---------- Buttons ---------- */
.btn {
  display: inline-flex; align-items: center; justify-content: center; gap: 10px;
  min-height: 46px; padding: 0 22px;
  border-radius: 10px; border: 1px solid transparent;
  font-size: 15px; font-weight: 600; letter-spacing: 0.02em;
  cursor: pointer; white-space: nowrap;
  transition: background-color .2s ease, border-color .2s ease, color .2s ease, transform .2s ease, box-shadow .2s ease;
}
.btn .arrow { transition: transform .2s ease; }
.btn:hover .arrow { transform: translateX(3px); }
.btn-primary { background: var(--orange); color: #fff; box-shadow: 0 10px 30px -12px var(--orange-glow); }
.btn-primary:hover { background: #ff7424; box-shadow: 0 14px 34px -10px var(--orange-glow); }
.btn-outline { border-color: var(--line-strong); color: var(--text); background: rgba(255, 255, 255, 0.02); }
.btn-outline:hover { border-color: var(--orange-2); color: #fff; }
.btn-sm { min-height: 38px; padding: 0 16px; font-size: 14px; border-radius: 8px; }
.btn-ghost { color: var(--text-2); padding: 0 6px; min-height: 38px; font-size: 14px; font-weight: 500; }
.btn-ghost:hover { color: #fff; }

/* ---------- Header ---------- */
.site-header {
  position: sticky; top: 0; z-index: 50;
  background: rgba(3, 11, 26, 0.72);
  backdrop-filter: saturate(140%) blur(14px);
  -webkit-backdrop-filter: saturate(140%) blur(14px);
  border-bottom: 1px solid var(--line);
}
.header-inner { display: flex; align-items: center; justify-content: space-between; height: 72px; gap: 24px; }
.brand { display: flex; align-items: center; gap: 14px; flex-shrink: 0; }
.brand img { height: 38px; width: auto; }
.brand-divider { width: 1px; height: 28px; background: var(--orange); opacity: .85; }
.brand-name { display: flex; flex-direction: column; line-height: 1.15; }
.brand-name strong { font-size: 18px; font-weight: 700; letter-spacing: 0.04em; }
.brand-name span { font-size: 10.5px; color: var(--orange-2); letter-spacing: 0.16em; text-transform: uppercase; font-weight: 500; }
.site-nav { display: flex; align-items: center; gap: 34px; }
.site-nav a { font-size: 15px; color: var(--text-2); font-weight: 500; transition: color .2s ease; }
.site-nav a:hover, .site-nav a[aria-current="page"] { color: #fff; }
.header-actions { display: flex; align-items: center; gap: 10px; }
.menu-toggle { display: none; width: 42px; height: 42px; border-radius: 10px; border: 1px solid var(--line-strong); background: transparent; color: var(--text); cursor: pointer; align-items: center; justify-content: center; }
.menu-toggle svg { width: 20px; height: 20px; }
.mobile-nav { display: none; }

/* ---------- Section scaffolding ---------- */
.section { position: relative; padding: 104px 0; }
.models { padding-top: 56px; }
.section-tight { padding: 96px 0; }
.eyebrow {
  display: inline-flex; align-items: center; gap: 10px;
  color: var(--orange); font-size: 12px; font-weight: 600;
  letter-spacing: 0.22em; text-transform: uppercase; margin-bottom: 18px;
}
.eyebrow::before { content: ""; width: 7px; height: 7px; border-radius: 50%; background: var(--orange); box-shadow: 0 0 0 4px var(--orange-soft); }
.section-head { display: flex; align-items: flex-end; justify-content: space-between; gap: 40px; margin-bottom: 56px; }
.section-head h2 { font-size: clamp(28px, 3.4vw, 42px); font-weight: 700; }
.section-head p { max-width: 440px; color: var(--text-2); font-size: 15px; text-align: right; }
.hl { color: var(--orange); }

/* ---------- Hero ---------- */
.hero { position: relative; overflow: hidden; padding: 96px 0 104px; isolation: isolate; }
.hero::before {
  content: ""; position: absolute; inset: 0; z-index: -2;
  background:
    radial-gradient(620px 420px at 74% 48%, rgba(255, 101, 8, 0.16), transparent 70%),
    radial-gradient(900px 600px at 10% -10%, rgba(23, 52, 94, 0.9), transparent 70%),
    linear-gradient(180deg, var(--navy-900), var(--navy-950));
}
.hero::after {
  content: ""; position: absolute; inset: 0; z-index: -1; opacity: .5;
  background-image: radial-gradient(rgba(169, 184, 202, 0.16) 1px, transparent 1px);
  background-size: 28px 28px;
  mask-image: radial-gradient(ellipse 70% 60% at 50% 40%, #000 30%, transparent 75%);
  -webkit-mask-image: radial-gradient(ellipse 70% 60% at 50% 40%, #000 30%, transparent 75%);
}
.hero-grid { display: grid; grid-template-columns: minmax(0, 1.12fr) minmax(0, 0.88fr); gap: 40px; align-items: center; }
.hero h1 { font-size: clamp(32px, 4vw, 52px); font-weight: 800; line-height: 1.22; letter-spacing: 0.005em; }
.hero h1 .line { display: block; }
.hero h1 .nw { white-space: nowrap; }
@media (min-width: 901px) { .hero h1 .line { white-space: nowrap; } }
.hero h1 .hl { background: linear-gradient(92deg, var(--orange) 10%, var(--orange-2) 90%); -webkit-background-clip: text; background-clip: text; color: transparent; }
.hero-lead { margin-top: 26px; max-width: 540px; color: var(--text-2); font-size: 17px; line-height: 1.85; }
.hero-actions { display: flex; flex-wrap: wrap; gap: 14px; margin-top: 38px; }
.hero-meta { display: flex; flex-wrap: wrap; gap: 10px 22px; margin-top: 34px; color: var(--text-3); font-size: 13px; }
.hero-meta span { display: inline-flex; align-items: center; gap: 8px; }
.hero-meta span::before { content: ""; width: 5px; height: 5px; border-radius: 50%; background: var(--orange-2); }

.hero-visual { position: relative; }
.hero-visual svg { width: 100%; height: auto; overflow: visible; }
.trace { fill: none; stroke: url(#traceGrad); stroke-width: 1.6; stroke-linecap: round; }
.trace-glow { fill: none; stroke: var(--orange); stroke-width: 6; opacity: .06; stroke-linecap: round; }
.node-end { fill: var(--navy-850); stroke: var(--orange-2); stroke-width: 1.6; }
.endpoint-pill { fill: rgba(11, 35, 68, 0.88); stroke: var(--line-strong); stroke-width: 1; }
.endpoint-text { fill: var(--text); font-family: var(--mono); font-size: 12.5px; letter-spacing: 0.01em; }
.pulse { fill: #ffd2b3; }
.spark-core { fill: var(--orange); }
.spark-star { fill: #fff3ea; }
.spark-ring { fill: none; stroke: rgba(255, 155, 92, 0.35); stroke-width: 1; }
.spark-ring.faint { stroke: rgba(255, 155, 92, 0.14); stroke-dasharray: 2 6; }
.spark-label { fill: var(--text-2); font-family: var(--mono); font-size: 11px; letter-spacing: 0.18em; }
.hero-badge {
  margin: 18px 0 0 auto; width: fit-content;
  display: flex; align-items: center; gap: 10px;
  padding: 10px 18px; border-radius: 999px;
  background: rgba(6, 22, 48, 0.82); border: 1px solid var(--line-strong);
  color: var(--text-2); font-size: 13px; backdrop-filter: blur(8px); -webkit-backdrop-filter: blur(8px);
}
.hero-badge i { width: 7px; height: 7px; border-radius: 50%; background: var(--orange); box-shadow: 0 0 10px var(--orange); }

/* ---------- Models ---------- */
.models { background: var(--navy-950); }
.why { padding-bottom: 112px; }
.model-grid { display: grid; grid-template-columns: repeat(3, minmax(0, 1fr)); border: 1px solid var(--line); border-radius: var(--radius); overflow: hidden; }
.model-card { position: relative; padding: 34px 32px 36px; min-height: 280px; display: flex; flex-direction: column; border-right: 1px solid var(--line); background: linear-gradient(180deg, rgba(16, 42, 80, 0.32), rgba(3, 11, 26, 0)); transition: background-color .25s ease; }
.model-card:last-child { border-right: 0; }
.model-card:hover { background-color: rgba(16, 42, 80, 0.35); }
.card-top { display: flex; justify-content: space-between; align-items: center; font-size: 12px; margin-bottom: auto; }
.card-index { color: var(--text-3); font-family: var(--mono); letter-spacing: 0.08em; }
.card-tag { color: var(--orange-2); font-weight: 600; letter-spacing: 0.06em; }
.model-card h3 { margin-top: 56px; font-size: 22px; font-weight: 700; }
.model-card p { margin-top: 12px; color: var(--text-2); font-size: 14.5px; line-height: 1.8; }
.model-icon { width: 44px; height: 44px; border-radius: 12px; display: grid; place-items: center; background: var(--orange-soft); color: var(--orange-2); margin-top: 28px; }
.model-icon svg { width: 22px; height: 22px; }
.plaza-strip { margin-top: 18px; display: flex; align-items: center; justify-content: space-between; gap: 24px; padding: 26px 32px; border: 1px solid var(--line); border-radius: var(--radius); background: linear-gradient(90deg, rgba(255, 101, 8, 0.10), rgba(16, 42, 80, 0.25) 45%, rgba(3, 11, 26, 0)); }
.plaza-strip strong { font-size: 18px; }
.plaza-strip p { color: var(--text-2); font-size: 14.5px; margin-top: 4px; }
.fine-print { margin-top: 16px; color: var(--text-3); font-size: 13px; }

/* ---------- Why ---------- */
.why { background: linear-gradient(180deg, var(--navy-950), var(--navy-900)); }
.why-title { text-align: center; font-size: clamp(28px, 3.4vw, 42px); font-weight: 700; margin-bottom: 64px; }
.why-grid { display: grid; grid-template-columns: repeat(4, minmax(0, 1fr)); }
.why-item { padding: 6px 34px 8px; border-left: 1px solid var(--line); }
.why-item:first-child { border-left: 0; padding-left: 0; }
.why-icon { position: relative; width: 44px; height: 44px; color: var(--text); }
.why-icon svg { width: 36px; height: 36px; }
.why-icon sup { position: absolute; left: 44px; top: 26px; color: var(--orange); font-size: 11px; font-family: var(--mono); }
.why-item h3 { margin-top: 22px; font-size: 18px; font-weight: 700; }
.why-item p { margin-top: 10px; color: var(--text-2); font-size: 14.5px; line-height: 1.8; }

/* ---------- Quick start ---------- */
.quickstart { background: var(--navy-900); }
.qs-panel { display: grid; grid-template-columns: minmax(0, 0.9fr) minmax(0, 1.25fr); gap: 0; border: 1px solid var(--line); border-radius: 20px; overflow: hidden; background: radial-gradient(700px 360px at 0% 0%, rgba(23, 52, 94, 0.75), transparent 70%), var(--navy-850); }
.qs-steps { padding: 44px 40px; display: flex; flex-direction: column; gap: 30px; border-right: 1px solid var(--line); }
.qs-step { display: grid; grid-template-columns: 44px minmax(0, 1fr); gap: 16px; }
.qs-num { width: 40px; height: 40px; border-radius: 50%; border: 1px solid rgba(255, 155, 92, 0.55); color: var(--orange-2); display: grid; place-items: center; font-family: var(--mono); font-size: 13px; }
.qs-step h3 { font-size: 17px; font-weight: 700; margin-top: 7px; }
.qs-step p { margin-top: 6px; color: var(--text-2); font-size: 14.5px; }
.endpoint-row { margin-top: 4px; display: flex; align-items: center; gap: 8px; flex-wrap: wrap; }
.endpoint-row code { padding: 8px 12px; border-radius: 8px; background: rgba(3, 11, 26, 0.6); border: 1px solid var(--line); color: #ffd2b3; font-size: 13px; word-break: break-all; }
.copy-btn { min-height: 34px; padding: 0 12px; border-radius: 8px; border: 1px solid var(--line-strong); background: transparent; color: var(--text-2); font-size: 13px; cursor: pointer; font-family: var(--font); transition: color .2s ease, border-color .2s ease; }
.copy-btn:hover { color: #fff; border-color: var(--orange-2); }
.copy-btn.is-copied { color: var(--orange-2); border-color: var(--orange-2); }

.code-window { display: flex; flex-direction: column; min-width: 0; background: rgba(3, 11, 26, 0.55); }
.code-tabs { display: flex; align-items: center; gap: 4px; padding: 14px 16px 0; border-bottom: 1px solid var(--line); overflow-x: auto; scrollbar-width: none; }
.code-tabs::-webkit-scrollbar { display: none; }
.code-dots { display: flex; gap: 7px; margin-right: 12px; padding-bottom: 12px; }
.code-dots i { width: 10px; height: 10px; border-radius: 50%; background: rgba(169, 184, 202, 0.22); }
.code-tab { position: relative; padding: 8px 14px 14px; border: 0; background: transparent; color: var(--text-3); font-family: var(--font); font-size: 14px; font-weight: 500; cursor: pointer; white-space: nowrap; }
.code-tab[aria-selected="true"] { color: #fff; }
.code-tab[aria-selected="true"]::after { content: ""; position: absolute; left: 14px; right: 14px; bottom: -1px; height: 2px; background: var(--orange); border-radius: 2px; }
.code-body { position: relative; flex: 1; }
.code-body .copy-btn { position: absolute; top: 12px; right: 14px; background: rgba(6, 22, 48, 0.9); z-index: 1; }
.code-panel { margin: 0; padding: 56px 24px 28px; overflow-x: auto; font-size: 13.5px; line-height: 1.85; color: #d6e0ec; tab-size: 2; }
.code-panel[hidden] { display: none; }
.tok-c { color: #6f8099; }
.tok-k { color: #ff9b5c; }
.tok-s { color: #9fd6a8; }
.tok-v { color: #8fc3ff; }
.code-note { padding: 14px 24px 18px; border-top: 1px solid var(--line); color: var(--text-3); font-size: 13px; }

/* ---------- Membership ---------- */
.membership { background: linear-gradient(180deg, var(--navy-900), var(--navy-950)); }
.member-grid { display: grid; grid-template-columns: minmax(0, 1fr) minmax(0, 1fr); gap: 24px; }
.flow { border: 1px solid var(--line); border-radius: var(--radius); padding: 36px 34px; }
.flow h3, .tier-card h3 { font-size: 20px; font-weight: 700; }
.flow > p, .tier-card > p { margin-top: 10px; color: var(--text-2); font-size: 14.5px; }
.flow-list { list-style: none; margin: 30px 0 0; padding: 0; position: relative; }
.flow-list::before { content: ""; position: absolute; left: 19px; top: 18px; bottom: 18px; width: 1px; background: linear-gradient(180deg, var(--orange), rgba(255, 155, 92, 0.1)); }
.flow-list li { position: relative; display: grid; grid-template-columns: 40px minmax(0, 1fr); gap: 16px; padding: 0 0 26px; }
.flow-list li:last-child { padding-bottom: 0; }
.flow-list .qs-num { background: var(--navy-900); position: relative; }
.flow-list strong { display: block; font-size: 16px; margin-top: 7px; }
.flow-list div > span { display: block; color: var(--text-2); font-size: 14px; margin-top: 4px; }
.flow-list a { color: var(--orange-2); border-bottom: 1px solid rgba(255, 155, 92, 0.4); }
.flow-list a:hover { color: #fff; border-color: #fff; }
.tier-card { border: 1px solid var(--line); border-radius: var(--radius); padding: 36px 34px; background: radial-gradient(420px 260px at 100% 0%, rgba(255, 101, 8, 0.12), transparent 70%), rgba(11, 35, 68, 0.35); }
.meters { margin-top: 30px; display: grid; gap: 22px; }
.meter-head { display: flex; justify-content: space-between; font-size: 14.5px; }
.meter-head span { color: var(--text-3); font-size: 12.5px; }
.meter-track { margin-top: 10px; height: 8px; border-radius: 999px; background: rgba(169, 184, 202, 0.10); overflow: hidden; display: grid; grid-template-columns: repeat(4, 1fr); gap: 3px; }
.meter-track i { background: linear-gradient(90deg, rgba(255, 101, 8, 0.25), rgba(255, 155, 92, 0.25)); }
.meter-track i:nth-child(2) { background: rgba(255, 101, 8, 0.42); }
.meter-track i:nth-child(3) { background: rgba(255, 101, 8, 0.66); }
.meter-track i:nth-child(4) { background: var(--orange); }
.tier-note { margin-top: 28px; padding-top: 20px; border-top: 1px solid var(--line); color: var(--text-3); font-size: 13px; }

/* ---------- FAQ ---------- */
.faq { background: var(--navy-950); }
.faq-wrap { display: grid; grid-template-columns: minmax(0, 0.8fr) minmax(0, 1.5fr); gap: 64px; }
.faq-wrap h2 { font-size: clamp(28px, 3.4vw, 42px); font-weight: 700; }
.faq-wrap .lead { margin-top: 16px; color: var(--text-2); font-size: 15px; }
.faq-list { border-top: 1px solid var(--line); }
.faq-list details { border-bottom: 1px solid var(--line); }
.faq-list summary { list-style: none; cursor: pointer; display: flex; justify-content: space-between; align-items: center; gap: 20px; padding: 24px 0; font-size: 17px; font-weight: 600; }
.faq-list summary::-webkit-details-marker { display: none; }
.faq-list summary::after { content: ""; width: 12px; height: 12px; flex-shrink: 0; border-right: 1.6px solid var(--text-2); border-bottom: 1.6px solid var(--text-2); transform: rotate(45deg) translateY(-3px); transition: transform .2s ease; }
.faq-list details[open] summary::after { transform: rotate(225deg) translateY(-3px); border-color: var(--orange-2); }
.faq-list details p { padding: 0 40px 26px 0; color: var(--text-2); font-size: 15px; line-height: 1.9; }
.faq-list details a { color: var(--orange-2); }

/* ---------- CTA band ---------- */
.cta-band { position: relative; overflow: hidden; padding: 104px 0; background: radial-gradient(520px 320px at 82% 50%, rgba(255, 101, 8, 0.22), transparent 70%), linear-gradient(180deg, var(--navy-950), var(--navy-850)); border-top: 1px solid var(--line); }
.cta-inner { display: flex; align-items: center; justify-content: space-between; gap: 40px; }
.cta-inner h2 { font-size: clamp(28px, 3.6vw, 44px); font-weight: 800; line-height: 1.3; }
.cta-inner p { margin-top: 14px; color: var(--text-2); }
.cta-actions { display: flex; flex-wrap: wrap; gap: 14px; flex-shrink: 0; }

/* ---------- Footer ---------- */
.site-footer { background: var(--navy-950); border-top: 1px solid var(--line); padding: 72px 0 36px; color: var(--text-2); }
.footer-grid { display: grid; grid-template-columns: minmax(0, 1.4fr) repeat(3, minmax(0, 1fr)); gap: 40px; }
.footer-brand img { height: 52px; width: auto; }
.footer-brand p { margin-top: 18px; font-size: 14px; color: var(--text-3); }
.footer-col h4 { margin: 0 0 16px; color: var(--text); font-size: 15px; font-weight: 600; }
.footer-col ul { list-style: none; margin: 0; padding: 0; display: grid; gap: 10px; }
.footer-col a { font-size: 14px; color: var(--text-2); transition: color .2s ease; }
.footer-col a:hover { color: #fff; }
.footer-bottom { margin-top: 56px; padding-top: 24px; border-top: 1px solid var(--line); display: flex; justify-content: space-between; gap: 20px; flex-wrap: wrap; font-size: 12.5px; color: var(--text-3); }
.footer-bottom nav { display: flex; gap: 18px; }
.footer-bottom a:hover { color: #fff; }
.trademark { margin-top: 10px; font-size: 12px; color: var(--text-3); }

/* ---------- Legal pages ---------- */
.legal { padding: 88px 0 112px; background: linear-gradient(180deg, var(--navy-900), var(--navy-950) 320px); }
.legal-inner { max-width: 820px; }
.legal h1 { font-size: clamp(30px, 4vw, 44px); font-weight: 800; }
.legal .updated { margin-top: 12px; color: var(--text-3); font-size: 14px; }
.legal .draft { margin-top: 24px; padding: 14px 18px; border: 1px solid rgba(255, 155, 92, 0.4); border-radius: 10px; background: var(--orange-soft); color: #ffd2b3; font-size: 14px; }
.legal h2 { margin-top: 48px; font-size: 21px; font-weight: 700; }
.legal p, .legal li { color: var(--text-2); font-size: 15.5px; line-height: 1.9; }
.legal p { margin-top: 14px; }
.legal ul { margin: 14px 0 0; padding-left: 22px; }
.legal li + li { margin-top: 6px; }
.legal a { color: var(--orange-2); border-bottom: 1px solid rgba(255, 155, 92, 0.4); }

/* ---------- 404 ---------- */
.notfound { min-height: 70vh; display: grid; place-items: center; text-align: center; padding: 96px 0; }
.notfound .code { font-family: var(--mono); color: var(--orange); letter-spacing: 0.3em; font-size: 14px; }
.notfound h1 { margin-top: 16px; font-size: clamp(30px, 4vw, 44px); }
.notfound p { margin-top: 14px; color: var(--text-2); }
.notfound .btn { margin-top: 32px; }

/* ---------- Motion ---------- */
.reveal { opacity: 0; transform: translateY(18px); transition: opacity .7s ease, transform .7s ease; }
.reveal.is-visible { opacity: 1; transform: none; }
.no-js .reveal { opacity: 1; transform: none; }
@media print {
  .reveal { opacity: 1; transform: none; }
  .site-header { position: static; }
}
@media (prefers-reduced-motion: reduce) {
  html { scroll-behavior: auto; }
  .reveal { opacity: 1; transform: none; transition: none; }
  .pulse { display: none; }
  * { transition-duration: 0s !important; }
}

/* ---------- Responsive ---------- */
@media (max-width: 1080px) {
  .site-nav { gap: 22px; }
  .why-grid { grid-template-columns: repeat(2, minmax(0, 1fr)); row-gap: 44px; }
  .why-item:nth-child(3) { border-left: 0; padding-left: 0; }
  .footer-grid { grid-template-columns: repeat(3, minmax(0, 1fr)); }
  .footer-brand { grid-column: 1 / -1; }
}

@media (max-width: 900px) {
  .site-nav, .header-actions .btn-ghost { display: none; }
  .menu-toggle { display: inline-flex; }
  .mobile-nav { display: none; border-top: 1px solid var(--line); padding: 12px var(--gutter) 20px; }
  .mobile-nav.is-open { display: grid; gap: 4px; }
  .mobile-nav a { padding: 12px 4px; color: var(--text-2); font-size: 16px; border-bottom: 1px solid var(--line); }
  .mobile-nav a:last-child { border-bottom: 0; }
  .hero { padding: 64px 0 72px; }
  .hero-grid { grid-template-columns: minmax(0, 1fr); gap: 40px; }
  .hero-visual { max-width: 560px; }
  .hero-badge { margin-left: 0; }
  .section { padding: 88px 0; }
  .section-head { flex-direction: column; align-items: flex-start; gap: 14px; margin-bottom: 40px; }
  .section-head p { text-align: left; }
  .model-grid { grid-template-columns: minmax(0, 1fr); }
  .model-card { border-right: 0; border-bottom: 1px solid var(--line); min-height: 0; }
  .model-card:last-child { border-bottom: 0; }
  .model-card h3 { margin-top: 32px; }
  .plaza-strip { flex-direction: column; align-items: flex-start; }
  .qs-panel { grid-template-columns: minmax(0, 1fr); }
  .qs-steps { border-right: 0; border-bottom: 1px solid var(--line); }
  .member-grid, .faq-wrap { grid-template-columns: minmax(0, 1fr); gap: 32px; }
  .cta-inner { flex-direction: column; align-items: flex-start; }
}

@media (max-width: 600px) {
  :root { --gutter: 16px; }
  body { font-size: 15px; }
  .header-inner { height: 64px; }
  .brand img { height: 32px; }
  .brand-name strong { font-size: 16px; }
  .brand-name span { display: none; }
  .header-actions .btn-primary { display: none; }
  .hero-lead { font-size: 15.5px; }
  .hero-actions .btn { flex: 1 1 100%; }
  .why-grid { grid-template-columns: minmax(0, 1fr); }
  .why-item { border-left: 0; padding: 0; }
  .qs-steps { padding: 32px 22px; }
  .code-panel { padding: 54px 18px 22px; font-size: 12.5px; }
  .flow, .tier-card { padding: 28px 22px; }
  .plaza-strip { padding: 22px; }
  .model-card { padding: 28px 22px 30px; }
  .footer-grid { grid-template-columns: minmax(0, 1fr) minmax(0, 1fr); }
  .cta-actions .btn { flex: 1 1 100%; }
}