:root {
  --navy: #0f172a;
  --navy-soft: #17213b;
  --blue: #2563eb;
  --blue-dark: #1d4ed8;
  --blue-soft: #eff6ff;
  --green: #10b981;
  --text: #172033;
  --muted: #64748b;
  --line: #e2e8f0;
  --surface: #ffffff;
  --surface-soft: #f8fafc;
  --container: 1180px;
  --shadow: 0 24px 70px rgba(15, 23, 42, .13);
  --shadow-sm: 0 12px 34px rgba(15, 23, 42, .08);
}

* { box-sizing: border-box; }
html { scroll-behavior: smooth; scroll-padding-top: 86px; }
body {
  margin: 0;
  color: var(--text);
  background: #fff;
  font-family: "Be Vietnam Pro", system-ui, sans-serif;
  font-size: 16px;
  line-height: 1.65;
  -webkit-font-smoothing: antialiased;
}
img { display: block; max-width: 100%; }
a { color: inherit; text-decoration: none; }
button, a { -webkit-tap-highlight-color: transparent; }
.container { width: min(calc(100% - 40px), var(--container)); margin-inline: auto; }

.reading-progress { position: fixed; z-index: 100; top: 0; right: 0; left: 0; height: 3px; background: transparent; }
.reading-progress span { display: block; width: 0; height: 100%; background: linear-gradient(90deg, #60a5fa, var(--blue)); }

.topbar {
  position: sticky;
  z-index: 50;
  top: 0;
  display: flex;
  align-items: center;
  justify-content: space-between;
  min-height: 74px;
  padding: 10px max(22px, calc((100% - var(--container)) / 2));
  color: #fff;
  background: rgba(15, 23, 42, .96);
  border-bottom: 1px solid rgba(255,255,255,.08);
  backdrop-filter: blur(16px);
}
.brand { display: flex; align-items: center; gap: 11px; font-size: 16px; font-weight: 600; }
.brand img { width: 40px; height: 40px; border-radius: 10px; box-shadow: 0 7px 18px rgba(0,0,0,.22); }
.brand strong { color: #60a5fa; }
.top-actions { display: flex; align-items: center; gap: 22px; }
.link-muted { color: #cbd5e1; font-size: 14px; }
.link-muted:hover { color: #fff; }

.button {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 7px;
  min-height: 46px;
  padding: 11px 18px;
  border: 1px solid transparent;
  border-radius: 12px;
  font: inherit;
  font-size: 14px;
  font-weight: 700;
  transition: transform .2s ease, background .2s ease, border-color .2s ease;
}
.button:hover { transform: translateY(-2px); }
.button-primary { color: #fff; background: var(--blue); box-shadow: 0 10px 25px rgba(37, 99, 235, .24); }
.button-primary:hover { background: var(--blue-dark); }
.button-ghost { color: #fff; border-color: rgba(255,255,255,.25); background: rgba(255,255,255,.06); }
.button-ghost:hover { background: rgba(255,255,255,.12); }
.button-small { min-height: 40px; padding: 9px 14px; font-size: 13px; }
.button-large { min-height: 52px; padding: 13px 22px; }

.hero {
  position: relative;
  overflow: hidden;
  padding: 88px 0 98px;
  color: #fff;
  background:
    radial-gradient(circle at 78% 18%, rgba(37, 99, 235, .34), transparent 28%),
    radial-gradient(circle at 12% 90%, rgba(59, 130, 246, .18), transparent 28%),
    linear-gradient(135deg, #0b1225, #111c36 62%, #14244a);
}
.hero::after { content: ""; position: absolute; inset: auto 0 0; height: 1px; background: linear-gradient(90deg, transparent, rgba(96,165,250,.8), transparent); }
.hero-grid { position: relative; z-index: 1; display: grid; grid-template-columns: 1.08fr .92fr; align-items: center; gap: 76px; }
.eyebrow { display: flex; align-items: center; gap: 10px; color: #bfdbfe; font-size: 13px; font-weight: 800; letter-spacing: .12em; text-transform: uppercase; }
.eyebrow span { width: 24px; height: 2px; background: #60a5fa; }
.hero h1 { max-width: 710px; margin: 18px 0 20px; font-size: clamp(42px, 5vw, 67px); line-height: 1.08; letter-spacing: -.045em; }
.hero-lead { max-width: 690px; margin: 0; color: #cbd5e1; font-size: 17px; line-height: 1.8; }
.hero-actions { display: flex; flex-wrap: wrap; gap: 12px; margin-top: 30px; }
.hero-note { display: flex; align-items: center; gap: 9px; margin: 22px 0 0; color: #94a3b8; font-size: 14px; }
.hero-note span { display: grid; place-items: center; width: 22px; height: 22px; border-radius: 50%; color: #a7f3d0; background: rgba(16,185,129,.15); }

.start-card { padding: 28px; border: 1px solid rgba(255,255,255,.13); border-radius: 24px; background: rgba(255,255,255,.07); box-shadow: var(--shadow); backdrop-filter: blur(18px); }
.start-card-head { display: flex; align-items: center; justify-content: space-between; gap: 16px; margin-bottom: 18px; font-weight: 700; }
.time-pill { padding: 5px 10px; border-radius: 999px; color: #bfdbfe; background: rgba(37,99,235,.25); font-size: 12px; letter-spacing: .06em; text-transform: uppercase; }
.check-list { display: grid; gap: 15px; margin: 0; padding: 0; list-style: none; }
.check-list li { display: grid; grid-template-columns: 36px 1fr; gap: 12px; align-items: center; }
.check { display: grid; place-items: center; width: 32px; height: 32px; border-radius: 10px; color: #93c5fd; background: rgba(37,99,235,.16); font-size: 13px; font-weight: 800; }
.check-list strong, .check-list small { display: block; }
.check-list strong { font-size: 14px; }
.check-list small { margin-top: 1px; color: #94a3b8; font-size: 13px; }
.app-address { display: flex; align-items: center; justify-content: space-between; gap: 12px; margin-top: 22px; padding: 14px; border-radius: 14px; background: rgba(0,0,0,.18); }
.app-address div { min-width: 0; }
.app-address small, .app-address span { display: block; }
.app-address small { color: #94a3b8; font-size: 11px; font-weight: 700; letter-spacing: .08em; text-transform: uppercase; }
.app-address span { overflow: hidden; margin-top: 2px; color: #e2e8f0; font-size: 12px; text-overflow: ellipsis; white-space: nowrap; }
.copy-button { flex: 0 0 auto; padding: 8px 11px; border: 0; border-radius: 9px; color: #dbeafe; background: rgba(37,99,235,.24); font: inherit; font-size: 12px; font-weight: 700; cursor: pointer; }

.platform-picker { position: relative; z-index: 3; margin-top: -34px; }
.platform-grid { display: grid; grid-template-columns: 1fr 1fr; gap: 14px; }
.platform-choice { display: grid; grid-template-columns: 52px 1fr auto; align-items: center; gap: 15px; min-height: 96px; padding: 18px 20px; border: 1px solid var(--line); border-radius: 18px; background: #fff; box-shadow: var(--shadow-sm); transition: transform .2s ease, border-color .2s ease; }
.platform-choice:hover { transform: translateY(-3px); border-color: #bfdbfe; }
.platform-icon { display: grid; place-items: center; width: 48px; height: 48px; border-radius: 14px; color: var(--blue-dark); background: var(--blue-soft); font-size: 13px; font-weight: 800; }
.platform-choice strong, .platform-choice small { display: block; }
.platform-choice strong { font-size: 16px; }
.platform-choice small { margin-top: 2px; color: var(--muted); font-size: 13px; }
.choice-arrow { color: var(--blue); font-size: 22px; }

.page-layout { display: grid; grid-template-columns: 220px minmax(0, 1fr); gap: 58px; padding-top: 84px; padding-bottom: 90px; }
.toc { position: sticky; top: 102px; align-self: start; }
.toc-label { margin: 0 0 13px 14px; color: #94a3b8; font-size: 11px; font-weight: 800; letter-spacing: .1em; text-transform: uppercase; }
.toc nav { display: grid; }
.toc nav a { display: grid; grid-template-columns: 28px 1fr; gap: 6px; padding: 11px 13px; border-left: 2px solid transparent; color: var(--muted); font-size: 13px; transition: color .2s ease, background .2s ease; }
.toc nav a span { color: #cbd5e1; font-size: 11px; }
.toc nav a.active { border-left-color: var(--blue); color: var(--blue-dark); background: linear-gradient(90deg, var(--blue-soft), transparent); font-weight: 700; }
.toc-help { display: grid; gap: 6px; margin-top: 26px; padding: 17px; border-radius: 16px; background: var(--surface-soft); }
.toc-help strong { font-size: 13px; }
.toc-help span { color: var(--muted); font-size: 12px; }
.toc-help a { color: var(--blue-dark); font-size: 12px; font-weight: 700; }
.guide-content { min-width: 0; }
.guide-section { padding-bottom: 86px; }
.guide-section + .guide-section { padding-top: 86px; border-top: 1px solid var(--line); }
.section-kicker { color: var(--blue); font-size: 12px; font-weight: 800; letter-spacing: .1em; text-transform: uppercase; }
.section-kicker.light { color: #93c5fd; }
.section-heading { display: grid; grid-template-columns: 58px 1fr; gap: 18px; align-items: start; margin-bottom: 32px; }
.section-heading h2, .usage-section h2, .support-section h2 { margin: 7px 0 7px; color: var(--navy); font-size: clamp(30px, 4vw, 43px); line-height: 1.2; letter-spacing: -.035em; }
.section-heading p, .section-intro { margin: 0; color: var(--muted); font-size: 16px; }
.section-intro { max-width: 760px; margin-top: 10px; margin-bottom: 30px; }
.platform-mark { display: grid; place-items: center; width: 58px; height: 58px; border-radius: 17px; color: var(--blue-dark); background: var(--blue-soft); box-shadow: inset 0 0 0 1px #dbeafe; font-size: 14px; font-weight: 800; }
.android-mark { color: #047857; background: #ecfdf5; box-shadow: inset 0 0 0 1px #a7f3d0; }

.install-layout { display: block; }
.install-steps { display: grid; grid-template-columns: repeat(2, minmax(0, 1fr)); gap: 12px; margin: 0; padding: 0; list-style: none; }
.install-steps li { display: grid; grid-template-columns: 42px 1fr; gap: 14px; padding: 18px; border: 1px solid var(--line); border-radius: 16px; background: #fff; }
.install-steps li.step-highlight { border-color: #93c5fd; background: var(--blue-soft); box-shadow: 0 10px 28px rgba(37,99,235,.09); }
.step-number { display: grid; place-items: center; width: 40px; height: 40px; border-radius: 12px; color: var(--blue-dark); background: var(--blue-soft); font-size: 14px; font-weight: 800; }
.step-highlight .step-number { color: #fff; background: var(--blue); }
.install-steps h3 { margin: 0 0 4px; font-size: 16px; }
.install-steps p { margin: 0; color: var(--muted); font-size: 14px; line-height: 1.7; }
.install-gallery { display: grid; grid-template-columns: repeat(3, minmax(0, 1fr)); gap: 14px; margin-top: 24px; }
.install-visual { position: relative; overflow: hidden; margin: 0; border: 1px solid #dbeafe; border-radius: 20px; background: #f1f5f9; box-shadow: var(--shadow-sm); }
.install-visual img { width: 100%; aspect-ratio: 4 / 5; object-fit: cover; object-position: center top; }
.install-visual img.ios-phone { display: block; object-fit: contain; background: #f8fafc; }
.install-visual img.ios-phone-wide { transform: scaleX(.82); transform-origin: center top; }
.visual-badge { position: absolute; z-index: 2; top: 14px; left: 14px; padding: 7px 10px; border-radius: 999px; color: #fff; background: rgba(15,23,42,.85); font-size: 11px; font-weight: 700; backdrop-filter: blur(8px); }
.success-badge { background: rgba(5, 150, 105, .9); }
.install-visual figcaption { display: grid; gap: 3px; min-height: 84px; padding: 14px 16px; border-top: 1px solid var(--line); color: var(--muted); background: #fff; text-align: center; }
.install-visual figcaption strong { color: var(--blue-dark); font-size: 13px; }
.install-visual figcaption span { font-size: 12px; line-height: 1.55; }
.gallery-hint { display: none; }
.success-strip { display: grid; grid-template-columns: 44px 1fr; gap: 14px; align-items: center; margin-top: 20px; padding: 18px; border: 1px solid #a7f3d0; border-radius: 16px; background: #ecfdf5; }
.success-icon { display: grid; place-items: center; width: 42px; height: 42px; border-radius: 50%; color: #fff; background: var(--green); font-size: 20px; font-weight: 800; }
.success-strip strong { display: block; color: #065f46; font-size: 14px; }
.success-strip p { margin: 2px 0 0; color: #047857; font-size: 13px; }
.install-note { margin-top: 12px; padding: 16px 18px; border-left: 3px solid #f59e0b; color: #713f12; background: #fffbeb; font-size: 13px; line-height: 1.75; }

.usage-flow { display: grid; grid-template-columns: repeat(4, minmax(0, 1fr)); gap: 13px; }
.usage-step { position: relative; overflow: hidden; margin: 0; border: 1px solid var(--line); border-radius: 18px; background: #fff; box-shadow: 0 10px 28px rgba(15,23,42,.06); }
.usage-step > span { position: absolute; z-index: 2; top: 11px; left: 11px; display: grid; place-items: center; width: 34px; height: 34px; border: 2px solid #fff; border-radius: 50%; color: #fff; background: var(--blue); box-shadow: 0 7px 18px rgba(37,99,235,.3); font-size: 12px; font-weight: 800; }
.usage-step img { width: 100%; aspect-ratio: 9 / 14; object-fit: cover; object-position: top; background: var(--surface-soft); }
.usage-step figcaption { display: grid; gap: 4px; min-height: 108px; padding: 15px; border-top: 1px solid var(--line); }
.usage-step strong { font-size: 14px; }
.usage-step small { color: var(--muted); font-size: 12px; line-height: 1.55; }
.swipe-hint { display: none; }
.illustration-note { margin: 14px 0 0; color: #94a3b8; font-size: 12px; text-align: center; }
.desktop-note { display: grid; grid-template-columns: 48px 1fr auto; align-items: center; gap: 15px; margin-top: 22px; padding: 20px; border-radius: 17px; background: var(--surface-soft); }
.desktop-icon { display: grid; place-items: center; width: 48px; height: 48px; border-radius: 14px; color: var(--blue-dark); background: #fff; box-shadow: inset 0 0 0 1px #dbeafe; font-size: 13px; font-weight: 800; }
.desktop-note strong { font-size: 14px; }
.desktop-note p { margin: 2px 0 0; color: var(--muted); font-size: 13px; }
.desktop-note a { color: var(--blue-dark); font-size: 13px; font-weight: 700; white-space: nowrap; }

.faq-list { display: grid; gap: 10px; margin-top: 28px; }
.faq-list details { border: 1px solid var(--line); border-radius: 15px; background: #fff; transition: border-color .2s ease, box-shadow .2s ease; }
.faq-list details[open] { border-color: #bfdbfe; box-shadow: 0 10px 28px rgba(37,99,235,.07); }
.faq-list summary { display: flex; align-items: center; justify-content: space-between; gap: 18px; padding: 18px 20px; color: var(--navy); font-size: 14px; font-weight: 700; cursor: pointer; list-style: none; }
.faq-list summary::-webkit-details-marker { display: none; }
.faq-list summary span { color: var(--blue); font-size: 22px; font-weight: 400; transition: transform .2s ease; }
.faq-list details[open] summary span { transform: rotate(45deg); }
.faq-list details > div { padding: 0 20px 20px; color: var(--muted); font-size: 14px; line-height: 1.8; }
.help-card { display: flex; align-items: center; justify-content: space-between; gap: 28px; margin-top: 24px; padding: 26px; border-radius: 20px; color: #fff; background: linear-gradient(135deg, var(--navy), #1e3a8a); }
.help-card span { color: #93c5fd; font-size: 12px; font-weight: 800; letter-spacing: .08em; text-transform: uppercase; }
.help-card h3 { margin: 5px 0 4px; color: #fff; font-size: 20px; }
.help-card p { margin: 0; color: #cbd5e1; font-size: 13px; }

.final-cta { display: flex; align-items: center; justify-content: space-between; gap: 34px; padding: 36px; border-radius: 24px; color: #fff; background: var(--navy); box-shadow: var(--shadow); }
.final-cta h2 { margin: 7px 0; color: #fff; font-size: clamp(28px, 4vw, 38px); line-height: 1.2; letter-spacing: -.035em; }
.final-cta p { margin: 0; color: #94a3b8; font-size: 14px; }
.final-cta .button { flex: 0 0 auto; }

footer { border-top: 1px solid var(--line); background: var(--surface-soft); }
.footer-inner { display: flex; align-items: center; justify-content: space-between; gap: 30px; min-height: 118px; padding-block: 28px; }
.footer-inner > div:first-child { display: grid; gap: 2px; }
.footer-inner strong { color: var(--navy); font-size: 15px; }
.footer-inner span { color: var(--muted); font-size: 12px; }
.footer-inner > div:last-child { display: flex; flex-wrap: wrap; gap: 20px; }
.footer-inner a { color: var(--muted); font-size: 13px; }
.footer-inner a:hover { color: var(--blue); }
.toast { position: fixed; z-index: 90; right: 24px; bottom: 24px; padding: 12px 16px; border-radius: 12px; color: #fff; background: var(--navy); box-shadow: var(--shadow); font-size: 13px; font-weight: 600; opacity: 0; transform: translateY(14px); pointer-events: none; transition: opacity .25s ease, transform .25s ease; }
.toast.show { opacity: 1; transform: translateY(0); }

@media (max-width: 1000px) {
  .hero-grid { grid-template-columns: 1fr; gap: 42px; }
  .hero-copy { max-width: 760px; }
  .start-card { max-width: 720px; }
  .page-layout { grid-template-columns: 1fr; gap: 0; }
  .toc { display: none; }
  .guide-content { width: 100%; max-width: 900px; margin-inline: auto; }
  .final-cta { align-items: flex-start; flex-direction: column; }
}

@media (max-width: 760px) {
  html { scroll-padding-top: 72px; }
  .container { width: min(calc(100% - 28px), var(--container)); }
  .topbar { min-height: 64px; padding-inline: 14px; }
  .brand { font-size: 15px; }
  .brand img { width: 34px; height: 34px; }
  .hide-mobile { display: none; }
  .button-small { min-height: 40px; padding: 9px 12px; font-size: 12px; }
  .hero { padding: 66px 0 72px; }
  .hero h1 { font-size: 40px; }
  .hero-lead { font-size: 15px; }
  .hero-actions { display: grid; grid-template-columns: 1fr; }
  .hero-actions .button { width: 100%; }
  .hero-note { align-items: flex-start; font-size: 13px; }
  .start-card { padding: 20px; border-radius: 20px; }
  .app-address { align-items: flex-end; }
  .app-address span { max-width: 205px; }
  .platform-picker { margin-top: -25px; }
  .platform-grid { grid-template-columns: 1fr; gap: 9px; }
  .platform-choice { min-height: 80px; padding: 14px 16px; }
  .page-layout { padding-top: 62px; padding-bottom: 70px; }
  .guide-section { padding-bottom: 64px; }
  .guide-section + .guide-section { padding-top: 64px; }
  .section-heading { grid-template-columns: 48px 1fr; gap: 13px; margin-bottom: 24px; }
  .platform-mark { width: 48px; height: 48px; border-radius: 14px; }
  .section-heading h2, .usage-section h2, .support-section h2 { font-size: 31px; }
  .section-heading p, .section-intro { font-size: 14px; }
  .install-steps { grid-template-columns: 1fr; }
  .install-steps li { grid-template-columns: 38px 1fr; gap: 12px; padding: 16px; }
  .step-number { width: 36px; height: 36px; }
  .install-gallery { grid-template-columns: repeat(3, minmax(250px, 78vw)); overflow-x: auto; margin-right: -14px; margin-left: -14px; padding: 0 14px 14px; scroll-snap-type: x mandatory; scrollbar-width: thin; }
  .install-visual { scroll-snap-align: center; }
  .gallery-hint { display: flex; align-items: center; justify-content: center; gap: 7px; margin: 3px 0 0; color: var(--muted); font-size: 12px; }
  .success-strip { grid-template-columns: 38px 1fr; padding: 15px; }
  .success-icon { width: 36px; height: 36px; }
  .usage-flow { grid-template-columns: repeat(4, minmax(238px, 78vw)); overflow-x: auto; margin-right: -14px; margin-left: -14px; padding: 0 14px 14px; scroll-snap-type: x mandatory; scrollbar-width: thin; }
  .usage-step { scroll-snap-align: center; }
  .swipe-hint { display: flex; align-items: center; justify-content: center; gap: 7px; margin: 4px 0 0; color: var(--muted); font-size: 12px; }
  .desktop-note { grid-template-columns: 44px 1fr; }
  .desktop-icon { width: 44px; height: 44px; }
  .desktop-note a { grid-column: 2; }
  .help-card { align-items: flex-start; flex-direction: column; padding: 22px; }
  .help-card .button { width: 100%; }
  .final-cta { padding: 28px 22px; }
  .final-cta .button { width: 100%; }
  .footer-inner { align-items: flex-start; flex-direction: column; min-height: 0; }
  .toast { right: 14px; bottom: 14px; left: 14px; text-align: center; }
}

@media (prefers-reduced-motion: reduce) {
  html { scroll-behavior: auto; }
  *, *::before, *::after { animation-duration: .01ms !important; animation-iteration-count: 1 !important; transition-duration: .01ms !important; }
}