:root {
  --accent: #0b5fff;
  --ink: #0e0f11;
  --body: #4e555e;
  --muted: #f7f8fa;
  --line: #e1e5eb;
  --blue-soft: #f0f5ff;
}

* { box-sizing: border-box; }
html { scroll-behavior: smooth; -webkit-text-size-adjust: 100%; }
body {
  margin: 0;
  background: var(--muted);
  color: var(--ink);
  font-family: "Segoe UI", Arial, sans-serif;
  -webkit-font-smoothing: antialiased;
}
img, video { max-width: 100%; }
a { color: inherit; }
.container { width: min(100% - 32px, 880px); margin-inline: auto; }
.section { padding: clamp(34px, 6.5vw, 58px) 0; border-top: 1px solid var(--line); }
.section-white { background: #fff; }
.section-heading { display: flex; align-items: center; gap: 13px; margin-bottom: 14px; }
.section-number {
  display: inline-flex; align-items: center; justify-content: center; flex: none;
  width: 28px; height: 28px; border-radius: 8px; background: var(--accent); color: #fff;
  font-size: 12px; font-weight: 800;
}
h1, h2, h3, p { margin-top: 0; }
h1 { margin-bottom: 14px; font-size: clamp(34px, 7vw, 50px); line-height: 1.03; letter-spacing: -.04em; }
h2 { margin: 0; font-size: clamp(23px, 5vw, 30px); line-height: 1.12; letter-spacing: -.025em; }
h3 { margin-bottom: 10px; font-size: clamp(19px, 4.5vw, 26px); line-height: 1.22; }
.lead { max-width: 650px; color: var(--body); font-size: clamp(15px, 3.5vw, 18px); line-height: 1.62; }
.brand-pill { display: inline-flex; align-items: center; gap: 9px; margin-bottom: 18px; padding: 8px 14px; border: 1px solid var(--line); border-radius: 999px; background: #fff; color: var(--body); font-size: 13px; font-weight: 700; }
.brand-dot { width: 7px; height: 7px; border-radius: 50%; background: var(--accent); }
.hero { padding: clamp(36px, 7vw, 66px) 0 clamp(30px, 6vw, 48px); }
.hero-grid { display: grid; grid-template-columns: minmax(0, 1.25fr) minmax(250px, .75fr); align-items: center; gap: clamp(24px, 5vw, 48px); }
.hero-art { display: block; width: 100%; height: auto; }
.summary-badges { display: flex; flex-wrap: wrap; gap: 8px; margin-top: 24px; }
.summary-badge { display: inline-flex; align-items: baseline; gap: 7px; padding: 9px 15px; border: 1px solid var(--line); border-radius: 11px; background: #fff; white-space: nowrap; }
.summary-badge strong { font-size: 15px; }
.summary-badge span { color: #5c636b; font-size: 13px; }
.video-grid, .hook-grid { display: grid; grid-template-columns: repeat(3, minmax(0, 1fr)); gap: 16px; align-items: start; }
.video-card { margin: 0; min-width: 0; padding: 10px; border: 1px solid var(--line); border-radius: 17px; background: #fff; box-shadow: 0 12px 30px rgba(14,15,17,.07); }
.video-frame { position: relative; overflow: hidden; border-radius: 12px; background: #17182f; }
.video-player { display: block; width: 100%; height: auto; aspect-ratio: 9 / 16; object-fit: contain; border-radius: 12px; background: #17182f; }
.video-tap-target { position: absolute; inset: 0 0 58px; z-index: 2; display: block; background: transparent; cursor: pointer; touch-action: manipulation; pointer-events: none; -webkit-tap-highlight-color: transparent; }
.video-caption { padding: 12px 5px 3px; font-size: 15px; font-weight: 750; }
.equation { margin-bottom: 22px; color: var(--accent); }
.explain-grid { display: grid; grid-template-columns: repeat(2, minmax(0,1fr)); gap: 10px; margin-bottom: 18px; }
.info-card { padding: 18px; border: 1px solid var(--line); border-radius: 14px; background: #fff; }
.info-card strong { display: block; margin-bottom: 7px; font-size: 14px; }
.info-card p { margin: 0; color: var(--body); font-size: 14.5px; line-height: 1.62; }
.notice { margin: 0; padding: 14px 16px; border: 1px solid #c8daff; border-radius: 11px; background: #e8f0ff; color: #26313d; font-size: 14.5px; font-weight: 650; line-height: 1.6; }
.deliverables { margin: 10px 0 0; padding: 15px 17px; border-radius: 11px; background: var(--ink); color: #fff; text-align: center; font-size: 15px; font-weight: 800; line-height: 1.55; }
.hook-example { margin-top: 30px; padding: clamp(18px,4vw,26px); border: 1px solid #cfdeff; border-radius: 17px; background: var(--blue-soft); }
.eyebrow { margin-bottom: 7px; color: var(--accent); font-size: 11px; font-weight: 800; letter-spacing: .14em; text-transform: uppercase; }
.hook-intro { max-width: 690px; color: var(--body); font-size: 15.5px; line-height: 1.62; }
.hook-heading { display: flex; align-items: center; gap: 8px; margin: 11px 3px 9px; }
.hook-letter { display: inline-flex; align-items: center; justify-content: center; width: 24px; height: 24px; border-radius: 7px; background: var(--accent); color: #fff; font-size: 12px; font-weight: 800; }
.hook-name { font-size: 14.5px; font-weight: 750; }
.hook-timeline { display: flex; min-height: 32px; overflow: hidden; border-radius: 8px; font-size: 10px; font-weight: 800; text-align: center; }
.hook-timeline span { display: flex; align-items: center; justify-content: center; padding: 5px 6px; }
.hook-start { flex: 0 0 39%; background: #cfe0ff; color: #12386f; }
.hook-main { flex: 1; background: #f0f1f4; color: var(--body); }
.hook-summary { margin: 16px 0 0; padding: 12px 15px; border: 1px solid #cfdeff; border-radius: 10px; background: #fff; color: #26313d; text-align: center; font-size: 14px; font-weight: 800; line-height: 1.5; }
.stack { display: grid; gap: 9px; }
.dark-note { padding: 18px; border-radius: 13px; background: var(--ink); color: #fff; line-height: 1.6; }
.dark-note strong { color: #ff5a63; }
.feature-grid { display: grid; grid-template-columns: repeat(2, minmax(0,1fr)); gap: 8px; }
.feature, .shot, .expectation { display: flex; gap: 12px; align-items: flex-start; padding: 15px 17px; border: 1px solid var(--line); border-radius: 12px; background: #fff; font-size: 15px; font-weight: 650; line-height: 1.45; }
.index { flex: none; width: 20px; color: var(--accent); font-size: 12px; font-weight: 800; }
.shot-grid { display: grid; grid-template-columns: repeat(3, minmax(0,1fr)); gap: 8px; }
.shot { align-items: center; }
.expectations { margin-bottom: 28px; }
.dot { flex: none; width: 7px; height: 7px; margin-top: 7px; border-radius: 50%; background: var(--accent); }
.safe-zone-card { padding: clamp(20px,5vw,32px); border: 1px solid var(--line); border-radius: 16px; background: var(--muted); }
.safe-zone-intro { max-width: 700px; color: #3e454d; font-size: 15.5px; line-height: 1.65; }
.safe-zone-note { display: inline-block; margin: 0 0 28px; padding: 11px 15px; border-radius: 10px; background: #e3e6ea; color: #2e353c; font-size: 14px; font-weight: 750; line-height: 1.5; }
.safe-zone-layout { display: grid; grid-template-columns: 205px minmax(0,1fr); align-items: center; gap: clamp(28px,6vw,54px); }
.phone-block { width: 205px; justify-self: center; }
.phone-label { margin-bottom: 12px; color: var(--body); text-align: center; font-size: 11px; font-weight: 800; letter-spacing: .14em; text-transform: uppercase; }
.phone-shell { position: relative; width: 205px; padding: 9px; border-radius: 30px; background: var(--ink); }
.phone-speaker, .phone-home { position: absolute; left: 50%; z-index: 2; transform: translateX(-50%); border-radius: 4px; background: #3a3e44; }
.phone-speaker { top: 15px; width: 36px; height: 5px; }
.phone-home { bottom: 14px; width: 54px; height: 4px; }
.phone-screen { display: flex; flex-direction: column; width: 100%; aspect-ratio: 9/16; overflow: hidden; border-radius: 20px; }
.crop-zone { flex: 0 0 14.84%; display: flex; align-items: center; justify-content: center; background: #dde0e5; color: var(--body); font-size: 9px; font-weight: 800; letter-spacing: .04em; text-align: center; }
.crop-zone:first-child { border-bottom: 1px dashed var(--accent); }
.crop-zone:last-child { border-top: 1px dashed var(--accent); }
.safe-core { flex: 0 0 70.31%; display: grid; grid-template-rows: 1fr 1.45fr 1fr; padding: 12px 10px; background: #fff; }
.caption-slot { display: flex; align-items: center; justify-content: center; }
.caption-slot span { max-width: 100%; padding: 6px 8px; border-radius: 8px; background: var(--ink); color: #fff; font-size: 8px; font-weight: 800; line-height: 1.05; text-align: center; }
.visual-core { display: flex; flex-direction: column; align-items: center; justify-content: center; gap: 6px; margin: 4px 0; border: 1px solid #8cb0ff; border-radius: 12px; background: #e7efff; text-align: center; }
.visual-core strong { color: var(--ink); font-size: 9px; line-height: 1.15; letter-spacing: .03em; text-transform: uppercase; }
.visual-core span { color: var(--body); font-size: 7px; font-weight: 800; }
.rule-list { display: grid; gap: 14px; margin: 0; padding: 0; list-style: none; }
.rule-list li { display: flex; gap: 12px; color: #303740; font-size: 15.5px; font-weight: 650; line-height: 1.55; }
.selector-body { min-height: 100vh; display: grid; place-items: center; padding: 28px 0; }
.selector-shell { width: min(100% - 32px, 920px); }
.selector-header { margin-bottom: 26px; }
.selector-grid { display: grid; grid-template-columns: repeat(3, minmax(0,1fr)); gap: 10px; }
.language-card { display: flex; align-items: center; justify-content: space-between; gap: 14px; min-height: 82px; padding: 17px 18px; border: 1px solid var(--line); border-radius: 14px; background: #fff; text-decoration: none; box-shadow: 0 8px 24px rgba(14,15,17,.045); transition: border-color .15s ease, transform .15s ease, box-shadow .15s ease; }
.language-card:hover, .language-card:focus-visible { border-color: var(--accent); transform: translateY(-1px); box-shadow: 0 12px 28px rgba(11,95,255,.11); outline: none; }
.language-name { display: block; margin-bottom: 4px; font-size: 16px; font-weight: 800; }
.language-shop { color: var(--body); font-size: 13px; }
.language-arrow { color: var(--accent); font-size: 20px; font-weight: 800; }
.not-found { min-height: 100vh; display: grid; place-items: center; padding: 24px; text-align: center; }
.not-found a { display: inline-block; margin-top: 12px; padding: 11px 16px; border-radius: 10px; background: var(--accent); color: #fff; font-weight: 750; text-decoration: none; }

@media (max-width: 760px) {
  .video-frame.tap-toggle-ready .video-tap-target { pointer-events: auto; }
  .hero-grid { grid-template-columns: 1fr; }
  .hero-art { width: min(100%, 420px); margin-inline: auto; }
  .video-grid, .hook-grid { grid-template-columns: 1fr; }
  .video-card { width: min(100%, 360px); margin-inline: auto; }
  .feature-grid { grid-template-columns: 1fr; }
  .shot-grid { grid-template-columns: repeat(2, minmax(0,1fr)); }
  .safe-zone-layout { grid-template-columns: 1fr; }
  .phone-block { width: 205px; }
  .selector-grid { grid-template-columns: repeat(2, minmax(0,1fr)); }
}

@media (max-width: 520px) {
  .container { width: min(100% - 28px, 880px); }
  .section { padding: 34px 0; }
  .hero { padding-top: 32px; }
  .hero-grid { gap: 22px; }
  .hero-art { width: min(100%, 340px); }
  .explain-grid, .shot-grid, .selector-grid { grid-template-columns: 1fr; }
  .summary-badge { padding: 8px 12px; }
  .safe-zone-card { padding-inline: 16px; }
  .phone-block, .phone-shell { width: min(205px, 61vw); }
}

@media (prefers-reduced-motion: reduce) {
  html { scroll-behavior: auto; }
  .language-card { transition: none; }
}