/* ============================================================
   AudioConvert — official website stylesheet
   Apple-style light theme, mobile-first, motion-rich but calm
   ============================================================ */

:root {
  --bg: #ffffff;
  --bg-soft: #f5f5f7;
  --surface: #ffffff;
  --surface-2: #f5f5f7;
  --border: #e8e8ed;
  --border-strong: #d2d2d7;
  --text: #1d1d1f;
  --text-dim: #6e6e73;
  --text-faint: #86868b;
  --accent: #0071e3;
  --accent-hover: #0077ed;
  --accent-press: #0060df;
  --brand: #ef4444;
  --ok: #34c759;
  --radius: 18px;
  --maxw: 1120px;
  --font: -apple-system, BlinkMacSystemFont, "SF Pro Display", "SF Pro Text", "Segoe UI", Roboto, "Helvetica Neue", Arial, sans-serif;
  --font-mono: ui-monospace, "SF Mono", "Cascadia Code", Consolas, monospace;
  --shadow-card: 0 2px 12px rgba(0, 0, 0, 0.06), 0 8px 32px rgba(0, 0, 0, 0.06);
  --shadow-hover: 0 6px 20px rgba(0, 0, 0, 0.08), 0 18px 48px rgba(0, 0, 0, 0.10);
}

* { margin: 0; padding: 0; box-sizing: border-box; }

html { scroll-behavior: smooth; }

body {
  background: var(--bg);
  color: var(--text);
  font-family: var(--font);
  font-size: 16px;
  line-height: 1.6;
  -webkit-font-smoothing: antialiased;
  text-rendering: optimizeLegibility;
}

img { max-width: 100%; display: block; }
a { color: var(--accent); text-decoration: none; }
a:hover { text-decoration: underline; }

::selection { background: rgba(0, 113, 227, 0.14); }

/* ---------- layout ---------- */
.container { width: 100%; max-width: var(--maxw); margin: 0 auto; padding: 0 22px; }
.section { padding: 88px 0; }
.section-tight { padding: 48px 0; }

.eyebrow {
  display: block;
  font-size: 13px;
  font-weight: 600;
  letter-spacing: 0.02em;
  color: var(--text-faint);
  text-transform: uppercase;
  margin-bottom: 12px;
}

h1, h2, h3 { font-weight: 700; line-height: 1.1; letter-spacing: -0.02em; }

h1 { font-size: clamp(40px, 7vw, 68px); }
h2 { font-size: clamp(30px, 4.6vw, 46px); margin-bottom: 14px; letter-spacing: -0.03em; }
h3 { font-size: 20px; }

.lead { color: var(--text-dim); font-size: clamp(17px, 2.4vw, 21px); line-height: 1.45; max-width: 58ch; }

p + p { margin-top: 12px; }

/* ---------- header ---------- */
.site-header {
  position: sticky; top: 0; z-index: 50;
  background: rgba(255, 255, 255, 0.82);
  backdrop-filter: saturate(180%) blur(20px);
  -webkit-backdrop-filter: saturate(180%) blur(20px);
  border-bottom: 1px solid transparent;
  transition: border-color 0.25s ease, background 0.25s ease;
}
.site-header.scrolled { border-bottom-color: var(--border); }
.nav { display: flex; align-items: center; justify-content: space-between; height: 56px; gap: 16px; }
.brand { display: flex; align-items: center; gap: 10px; color: var(--text); font-weight: 700; font-size: 18px; letter-spacing: -0.02em; }
.brand:hover { text-decoration: none; }
.brand svg { width: 24px; height: 24px; }

.nav-links { display: flex; align-items: center; gap: 30px; }
.nav-links a { color: var(--text-dim); font-size: 14px; font-weight: 500; position: relative; padding: 4px 0; }
.nav-links a:hover { color: var(--text); text-decoration: none; }
.nav-links a::after {
  content: ""; position: absolute; left: 0; right: 0; bottom: 0; height: 2px;
  background: var(--accent); border-radius: 2px; transform: scaleX(0); transform-origin: left;
  transition: transform 0.25s ease;
}
.nav-links a:hover::after, .nav-links a.active::after { transform: scaleX(1); }
.nav-links a.active { color: var(--text); }

.nav-cta {
  display: inline-flex; align-items: center; gap: 6px;
  background: var(--accent); color: #fff !important;
  font-weight: 500; font-size: 13.5px;
  padding: 8px 16px; border-radius: 980px;
  transition: background 0.2s ease;
}
.nav-cta::after { display: none; }
.nav-cta:hover { background: var(--accent-hover); color: #fff !important; }

/* ---------- buttons (Apple pill style) ---------- */
.btn {
  display: inline-flex; align-items: center; justify-content: center; gap: 8px;
  font-family: var(--font); font-weight: 500; font-size: 17px;
  padding: 13px 26px; border-radius: 980px;
  border: 1px solid transparent; cursor: pointer;
  transition: transform 0.15s ease, background 0.2s ease, border-color 0.2s ease, box-shadow 0.2s ease;
  -webkit-tap-highlight-color: transparent;
}
.btn:active { transform: scale(0.97); }
.btn-primary { background: var(--accent); color: #fff; }
.btn-primary:hover { background: var(--accent-hover); text-decoration: none; }
.btn-primary:active { background: var(--accent-press); }
.btn-secondary { background: transparent; color: var(--accent); border-color: var(--accent); }
.btn-secondary:hover { background: rgba(0, 113, 227, 0.06); text-decoration: none; }
.btn-dark { background: #1d1d1f; color: #fff; }
.btn-dark:hover { background: #000; text-decoration: none; }
.btn .ico { width: 16px; height: 16px; }
.btn-block { width: 100%; }

/* ---------- hero ---------- */
.hero { position: relative; overflow: hidden; padding: 110px 0 90px; text-align: center; }
.hero::before {
  content: ""; position: absolute; inset: 0; pointer-events: none;
  background:
    radial-gradient(800px 460px at 80% -12%, rgba(0, 113, 227, 0.10), transparent 62%),
    radial-gradient(640px 400px at 12% 4%, rgba(239, 68, 68, 0.06), transparent 58%);
}
.hero-inner { position: relative; max-width: 900px; margin: 0 auto; }

.hero-badge {
  display: inline-flex; align-items: center; gap: 8px;
  font-size: 14px; font-weight: 500; color: var(--text-dim);
  background: rgba(255, 255, 255, 0.8);
  border: 1px solid var(--border);
  padding: 8px 16px; border-radius: 980px;
  margin-bottom: 26px;
  box-shadow: 0 1px 4px rgba(0, 0, 0, 0.04);
}
.hero-badge .dot { width: 8px; height: 8px; border-radius: 50%; background: var(--ok); }

.hero h1 { margin-bottom: 20px; }
.hero .lead { margin: 0 auto 34px; }
.hero-ctas { display: flex; flex-wrap: wrap; gap: 14px; justify-content: center; }
.hero-note { margin-top: 18px; font-size: 14px; color: var(--text-faint); }

/* staggered title entrance */
.fade-up { opacity: 0; transform: translateY(22px); animation: fadeUp 0.9s cubic-bezier(0.22, 0.61, 0.36, 1) forwards; }
.fade-up.d1 { animation-delay: 0.05s; }
.fade-up.d2 { animation-delay: 0.15s; }
.fade-up.d3 { animation-delay: 0.28s; }
.fade-up.d4 { animation-delay: 0.42s; }
@keyframes fadeUp { to { opacity: 1; transform: none; } }

/* app mockup — dark product window on light canvas */
.mockup {
  margin: 60px auto 0; max-width: 700px; text-align: left;
  border-radius: 22px;
  background: linear-gradient(180deg, #1c1c1e, #101012);
  border: 1px solid rgba(255, 255, 255, 0.08);
  box-shadow: 0 40px 100px rgba(0, 0, 0, 0.35), 0 4px 16px rgba(0, 0, 0, 0.12);
  overflow: hidden;
  transition: transform 0.45s cubic-bezier(0.22, 0.61, 0.36, 1), box-shadow 0.45s ease;
}
.mockup:hover { transform: translateY(-6px); box-shadow: 0 50px 120px rgba(0, 0, 0, 0.42), 0 6px 20px rgba(0, 0, 0, 0.14); }
.mockup-bar { display: flex; align-items: center; gap: 7px; padding: 13px 18px; border-bottom: 1px solid rgba(255, 255, 255, 0.07); }
.mockup-bar i { width: 12px; height: 12px; border-radius: 50%; display: block; }
.mockup-bar i:nth-child(1) { background: #ff5f57; }
.mockup-bar i:nth-child(2) { background: #febc2e; }
.mockup-bar i:nth-child(3) { background: #28c840; }
.mockup-title { margin-left: 10px; font-size: 13px; color: rgba(255, 255, 255, 0.55); }
.mockup-body { padding: 30px; }
.mockup-row { display: flex; flex-direction: column; gap: 16px; }
.mockup-field {
  display: flex; align-items: center; gap: 13px;
  border: 1px solid rgba(255, 255, 255, 0.14); border-radius: 13px;
  background: rgba(255, 255, 255, 0.06); padding: 13px 15px;
}
.mockup-field .play {
  width: 38px; height: 38px; border-radius: 11px; flex: none;
  background: linear-gradient(135deg, var(--brand), #0ea5e9);
  display: flex; align-items: center; justify-content: center;
}
.mockup-field .play svg { width: 16px; height: 16px; color: #fff; }
.mockup-field .txt { font-size: 14px; color: rgba(255, 255, 255, 0.72); overflow: hidden; white-space: nowrap; text-overflow: ellipsis; }
.mockup-meta { font-size: 13px; color: rgba(255, 255, 255, 0.5); }
.mockup-meta b { color: rgba(255, 255, 255, 0.85); font-weight: 600; }
.mockup-actions { display: flex; flex-wrap: wrap; gap: 10px; }
.mockup-pill {
  font-size: 13.5px; font-weight: 500; padding: 9px 15px; border-radius: 980px;
  background: rgba(255, 255, 255, 0.10); border: 1px solid rgba(255, 255, 255, 0.16);
  color: rgba(255, 255, 255, 0.85);
}
.mockup-pill.primary {
  background: linear-gradient(135deg, var(--accent), #0ea5e9); border-color: transparent; color: #fff;
}
.mockup-progress { height: 7px; border-radius: 6px; background: rgba(255, 255, 255, 0.12); overflow: hidden; }
.mockup-progress span {
  display: block; height: 100%; width: 72%;
  background: linear-gradient(90deg, var(--brand), var(--accent));
  border-radius: 6px;
  animation: progressGrow 2.2s cubic-bezier(0.22, 0.61, 0.36, 1) 0.6s both;
}
@keyframes progressGrow { from { width: 0; } to { width: 72%; } }

/* ---------- feature cards ---------- */
.grid { display: grid; grid-template-columns: 1fr; gap: 20px; }
@media (min-width: 768px) { .grid-2 { grid-template-columns: repeat(2, 1fr); } }
@media (min-width: 960px) { .grid-3 { grid-template-columns: repeat(3, 1fr); } .grid-4 { grid-template-columns: repeat(2, 1fr); } }

.card {
  position: relative;
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 34px 30px;
  transition: transform 0.35s cubic-bezier(0.22, 0.61, 0.36, 1), box-shadow 0.35s ease, border-color 0.35s ease;
}
.card:hover { transform: translateY(-5px); box-shadow: var(--shadow-hover); border-color: var(--border-strong); }
.card .card-ico {
  width: 44px; height: 44px; border-radius: 12px;
  display: flex; align-items: center; justify-content: center;
  background: rgba(0, 113, 227, 0.08);
  margin-bottom: 18px;
  transition: transform 0.3s ease, background 0.3s ease;
}
.card:hover .card-ico { transform: scale(1.08); background: rgba(0, 113, 227, 0.14); }
.card .card-ico svg { width: 22px; height: 22px; color: var(--accent); }
.card h3 { margin-bottom: 10px; font-size: 22px; }
.card p { color: var(--text-dim); font-size: 15px; }

/* ---------- capabilities ---------- */
.caps { display: grid; grid-template-columns: 1fr; gap: 20px; }
@media (min-width: 960px) { .caps { grid-template-columns: 1.1fr 0.9fr; } }
.caps-panel {
  background: var(--surface); border: 1px solid var(--border); border-radius: var(--radius);
  padding: 34px 32px;
  transition: transform 0.35s cubic-bezier(0.22, 0.61, 0.36, 1), box-shadow 0.35s ease;
}
.caps-panel:hover { transform: translateY(-4px); box-shadow: var(--shadow-hover); }
.caps-panel h3 { margin-bottom: 20px; font-size: 21px; }
.chips { display: flex; flex-wrap: wrap; gap: 10px; }
.chip {
  font-size: 14px; font-weight: 500; color: var(--text);
  background: var(--surface-2); border: 1px solid var(--border);
  padding: 9px 16px; border-radius: 980px;
  transition: border-color 0.2s ease, background 0.2s ease;
}
.chip:hover { border-color: var(--accent); color: var(--accent); }
.chip.hot { border-color: rgba(239, 68, 68, 0.35); color: #c0272d; background: rgba(239, 68, 68, 0.05); }
.chip.acc { border-color: rgba(0, 113, 227, 0.35); color: var(--accent); background: rgba(0, 113, 227, 0.05); }
.caps-list { list-style: none; display: grid; gap: 15px; }
.caps-list li { display: flex; gap: 12px; align-items: flex-start; color: var(--text-dim); font-size: 15.5px; }
.caps-list svg { width: 18px; height: 18px; color: var(--ok); flex: none; margin-top: 4px; }

/* ---------- cta band ---------- */
.band {
  text-align: center; padding: 100px 0;
  background: var(--bg-soft);
  border-top: 1px solid var(--border); border-bottom: 1px solid var(--border);
}
.band h2 { margin-bottom: 14px; }
.band .lead { margin: 0 auto 32px; }

/* ---------- download page ---------- */
.dl-grid { display: grid; grid-template-columns: 1fr; gap: 22px; }
@media (min-width: 900px) { .dl-grid { grid-template-columns: repeat(2, 1fr); } }
.dl-card {
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: 22px;
  padding: 38px 34px;
  display: flex; flex-direction: column; gap: 18px;
  transition: transform 0.35s cubic-bezier(0.22, 0.61, 0.36, 1), box-shadow 0.35s ease, border-color 0.35s ease;
}
.dl-card:hover { transform: translateY(-6px); box-shadow: var(--shadow-hover); border-color: var(--border-strong); }
.dl-os { display: flex; align-items: center; gap: 14px; }
.dl-os svg { width: 34px; height: 34px; }
.dl-os h3 { font-size: 26px; }
.dl-os small { display: block; font-weight: 400; font-size: 13px; color: var(--text-faint); }
.dl-specs { display: grid; gap: 8px; font-size: 15px; color: var(--text-dim); }
.dl-specs b { color: var(--text); font-weight: 600; }
.dl-actions { margin-top: auto; display: grid; gap: 12px; }
.dl-hash {
  font-family: var(--font-mono); font-size: 11.5px; color: var(--text-faint);
  background: var(--surface-2); border: 1px solid var(--border);
  border-radius: 10px; padding: 11px 14px; word-break: break-all; line-height: 1.5;
}
.note {
  font-size: 14px; color: var(--text-dim);
  background: var(--bg-soft); border: 1px solid var(--border); border-radius: 14px;
  padding: 16px 20px;
}
.note b { color: var(--text); }

.changelog { list-style: none; display: grid; gap: 12px; }
.changelog li { display: flex; gap: 16px; font-size: 15px; color: var(--text-dim); }
.changelog .ver { font-weight: 700; color: var(--accent); flex: none; width: 60px; }

/* ---------- legal pages ---------- */
.legal { max-width: 720px; margin: 0 auto; }
.legal h1 { margin-bottom: 10px; }
.legal .updated { color: var(--text-faint); font-size: 14px; margin-bottom: 40px; }
.legal h2 { font-size: 26px; margin-top: 48px; margin-bottom: 12px; }
.legal h3 { font-size: 18px; margin-top: 26px; margin-bottom: 8px; color: var(--text); }
.legal p, .legal li { color: var(--text-dim); font-size: 15.5px; }
.legal ul, .legal ol { padding-left: 22px; display: grid; gap: 9px; margin-top: 10px; }
.legal hr { border: none; border-top: 1px solid var(--border); margin: 40px 0; }

/* ---------- footer ---------- */
.site-footer { border-top: 1px solid var(--border); background: var(--bg-soft); padding: 56px 0 40px; }
.foot-grid { display: grid; grid-template-columns: 1fr; gap: 28px; }
@media (min-width: 768px) { .foot-grid { grid-template-columns: 1.5fr 1fr 1fr; } }
.foot-brand { display: flex; align-items: center; gap: 10px; font-weight: 700; font-size: 17px; margin-bottom: 12px; }
.foot-brand svg { width: 22px; height: 22px; }
.foot-brand a { color: var(--text); }
.foot-brand a:hover { text-decoration: none; }
.site-footer p { color: var(--text-faint); font-size: 14px; }
.foot-col h4 { font-size: 13px; letter-spacing: 0.01em; color: var(--text-dim); margin-bottom: 14px; }
.foot-col a { display: block; color: var(--text-dim); font-size: 14px; margin-bottom: 11px; }
.foot-col a:hover { color: var(--text); }
.foot-bottom { margin-top: 36px; padding-top: 24px; border-top: 1px solid var(--border); display: flex; flex-wrap: wrap; gap: 12px; justify-content: space-between; font-size: 13px; color: var(--text-faint); }

/* ---------- rv on scroll ---------- */
.rv { opacity: 0; transform: translateY(24px); transition: opacity 0.8s ease, transform 0.8s cubic-bezier(0.22, 0.61, 0.36, 1); }
.rv.in { opacity: 1; transform: none; }

/* ---------- mobile nav ---------- */
.nav-toggle { display: none; background: none; border: none; color: var(--text); cursor: pointer; padding: 6px; }
.nav-toggle svg { width: 24px; height: 24px; }

@media (max-width: 767px) {
  .nav-toggle { display: block; }
  .nav-links {
    position: absolute; top: 56px; left: 0; right: 0;
    flex-direction: column; align-items: stretch; gap: 0;
    background: rgba(255, 255, 255, 0.98);
    backdrop-filter: blur(20px);
    border-bottom: 1px solid var(--border);
    padding: 10px 22px 18px; display: none;
  }
  .nav-links.open { display: flex; }
  .nav-links a { padding: 13px 0; border-bottom: 1px solid var(--border); font-size: 16px; }
  .nav-links a:last-child { border-bottom: none; }
  .nav-cta { justify-content: center; margin-top: 12px; }
  .hero { padding: 84px 0 70px; }
  .section { padding: 64px 0; }
  .band { padding: 72px 0; }
}

@media (prefers-reduced-motion: reduce) {
  html { scroll-behavior: auto; }
  .fade-up, .mockup-progress span, .rv { opacity: 1 !important; transform: none !important; animation: none !important; transition: none !important; }
  * { transition: none !important; }
}