/* RadioBurn — radioburn.com */

:root {
  color-scheme: dark;
  --bg: #0b0a0e;
  --bg-2: #121016;
  --surface: #1c1b1f;
  --surface-2: #25232a;
  --text: #f4eef8;
  --muted: #b5aebf;
  --faint: #8a8394;
  --line: rgba(243, 238, 248, 0.1);
  --line-strong: rgba(243, 238, 248, 0.18);
  --g3: #ff8a4c;
  --g4: #4ea3ff;
  --g5: #b794f6;
  --g5plus: #f5d0fe;
  --accent: #d0bcff;
  --danger: #ff6b6b;
  --ok: #7dcea0;
  --shadow: 0 40px 80px rgba(0, 0, 0, 0.45);
  --card-bg: linear-gradient(180deg, rgba(255, 255, 255, 0.04), rgba(255, 255, 255, 0.015));
  --grain-opacity: 0.045;
  --radius: 18px;
  --header-h: 72px;
  --font-display: "Syne", ui-sans-serif, system-ui, sans-serif;
  --font-body: "IBM Plex Sans", ui-sans-serif, system-ui, sans-serif;
}

[data-theme="light"] {
  color-scheme: light;
  --bg: #faf8fc;
  --bg-2: #f3f0f7;
  --surface: #ffffff;
  --surface-2: #ebe6f0;
  --text: #1a1524;
  --muted: #4a4458;
  --faint: #6b6478;
  --line: rgba(26, 21, 36, 0.1);
  --line-strong: rgba(26, 21, 36, 0.16);
  --accent: #5c3d9e;
  --shadow: 0 24px 48px rgba(26, 21, 36, 0.12);
  --card-bg: #ffffff;
  --grain-opacity: 0.02;
}

@media (prefers-color-scheme: light) {
  :root:not([data-theme="dark"]) {
    color-scheme: light;
    --bg: #faf8fc;
    --bg-2: #f3f0f7;
    --surface: #ffffff;
    --surface-2: #ebe6f0;
    --text: #1a1524;
    --muted: #4a4458;
    --faint: #6b6478;
    --line: rgba(26, 21, 36, 0.1);
    --line-strong: rgba(26, 21, 36, 0.16);
    --accent: #5c3d9e;
    --shadow: 0 24px 48px rgba(26, 21, 36, 0.12);
    --card-bg: #ffffff;
    --grain-opacity: 0.02;
  }
}

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

html {
  scroll-behavior: smooth;
}

html,
body {
  margin: 0;
  padding: 0;
  background: var(--bg);
  color: var(--text);
  font-family: var(--font-body);
  font-size: 18px;
  line-height: 1.6;
  -webkit-font-smoothing: antialiased;
  text-rendering: optimizeLegibility;
}

body {
  min-height: 100vh;
  overflow-x: hidden;
}

::selection {
  background: color-mix(in srgb, var(--g5) 55%, transparent);
  color: var(--text);
}

a {
  color: inherit;
  text-decoration: none;
}

img,
svg {
  display: block;
  max-width: 100%;
}

button,
.btn {
  font: inherit;
  cursor: pointer;
}

.grain {
  pointer-events: none;
  position: fixed;
  inset: 0;
  z-index: 80;
  opacity: var(--grain-opacity);
  background-image: url("data:image/svg+xml,%3Csvg viewBox='0 0 200 200' xmlns='http://www.w3.org/2000/svg'%3E%3Cfilter id='n'%3E%3CfeTurbulence type='fractalNoise' baseFrequency='.85' numOctaves='4' stitchTiles='stitch'/%3E%3C/filter%3E%3Crect width='100%25' height='100%25' filter='url(%23n)'/%3E%3C/svg%3E");
}

.wrap {
  width: min(1180px, calc(100% - 40px));
  margin-inline: auto;
}

.skip {
  position: absolute;
  left: 12px;
  top: -48px;
  z-index: 100;
  background: var(--accent);
  color: #fff;
  padding: 12px 16px;
  border-radius: 8px;
  font-weight: 600;
}

[data-theme="light"] .skip,
:root:not([data-theme="dark"]) .skip {
  color: #fff;
}

@media (prefers-color-scheme: light) {
  :root:not([data-theme="dark"]) .skip {
    color: #fff;
  }
}

.skip:focus {
  top: 12px;
}

/* Header */

.header {
  position: sticky;
  top: 0;
  z-index: 50;
  height: var(--header-h);
  display: flex;
  align-items: center;
  backdrop-filter: blur(18px);
  background: color-mix(in srgb, var(--bg) 82%, transparent);
  border-bottom: 1px solid var(--line);
}

.header-inner {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 16px;
  width: min(1180px, calc(100% - 40px));
  margin-inline: auto;
}

.brand {
  display: flex;
  align-items: center;
  gap: 10px;
  font-family: var(--font-display);
  font-weight: 700;
  letter-spacing: 0.02em;
  font-size: 1.05rem;
}

.brand img {
  width: 32px;
  height: 32px;
}

.nav {
  display: flex;
  align-items: center;
  gap: 20px;
}

.nav a:not(.btn) {
  color: var(--muted);
  font-size: 0.94rem;
}

.nav a:not(.btn):hover {
  color: var(--text);
}

/* Theme toggle */

.theme-toggle {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  width: 48px;
  height: 48px;
  padding: 0;
  border: 1px solid var(--line-strong);
  border-radius: 50%;
  background: transparent;
  color: var(--muted);
  transition: background 0.15s ease, color 0.15s ease;
}

.theme-toggle:hover {
  background: var(--surface-2);
  color: var(--text);
}

.theme-toggle:focus-visible {
  outline: 2px solid var(--g4);
  outline-offset: 3px;
}

.theme-toggle svg {
  width: 20px;
  height: 20px;
}

.theme-toggle .icon-sun {
  display: none;
}

.theme-toggle .icon-moon {
  display: block;
}

[data-theme="light"] .theme-toggle .icon-sun,
:root:not([data-theme="dark"]) .theme-toggle .icon-sun {
  display: block;
}

[data-theme="light"] .theme-toggle .icon-moon,
:root:not([data-theme="dark"]) .theme-toggle .icon-moon {
  display: none;
}

@media (prefers-color-scheme: light) {
  :root:not([data-theme="dark"]) .theme-toggle .icon-sun {
    display: block;
  }

  :root:not([data-theme="dark"]) .theme-toggle .icon-moon {
    display: none;
  }
}

[data-theme="dark"] .theme-toggle .icon-sun {
  display: none;
}

[data-theme="dark"] .theme-toggle .icon-moon {
  display: block;
}

/* Buttons */

.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 10px;
  border: 0;
  border-radius: 999px;
  min-height: 48px;
  padding: 12px 22px;
  font-weight: 600;
  letter-spacing: 0.01em;
  transition: transform 0.15s ease, background 0.15s ease, box-shadow 0.15s ease;
}

.btn:focus-visible {
  outline: 2px solid var(--g4);
  outline-offset: 3px;
}

.btn-primary {
  background: var(--text);
  color: var(--bg);
  box-shadow: 0 0 0 1px rgba(255, 255, 255, 0.08), 0 10px 30px rgba(183, 148, 246, 0.18);
}

[data-theme="light"] .btn-primary,
:root:not([data-theme="dark"]) .btn-primary {
  box-shadow: 0 4px 16px rgba(92, 61, 158, 0.2);
}

@media (prefers-color-scheme: light) {
  :root:not([data-theme="dark"]) .btn-primary {
    box-shadow: 0 4px 16px rgba(92, 61, 158, 0.2);
  }
}

.btn-primary:hover {
  transform: translateY(-1px);
  filter: brightness(1.05);
}

.btn-ghost {
  background: transparent;
  color: var(--text);
  border: 1px solid var(--line-strong);
}

.btn-ghost:hover {
  background: var(--surface-2);
}

.btn-play,
.btn-apk {
  background: linear-gradient(180deg, #f7f4fb 0%, #e4dcf3 100%);
  color: #1a1524;
  padding: 14px 24px;
  font-size: 1.02rem;
}

.btn-play svg,
.btn-apk svg {
  width: 20px;
  height: 20px;
}

.install-note {
  color: var(--faint);
  font-size: 0.88rem;
  margin: 12px 0 0;
  line-height: 1.55;
  max-width: 36em;
}

.btn-lg {
  min-height: 52px;
  padding: 16px 28px;
  font-size: 1.05rem;
}

/* Hero */

.hero {
  position: relative;
  padding: 64px 0 48px;
  isolation: isolate;
}

.hero-burn {
  position: absolute;
  inset: auto 0 0;
  height: 200px;
  width: min(600px, 80%);
  left: 50%;
  transform: translateX(-50%);
  opacity: 0.45;
  z-index: 0;
  pointer-events: none;
}

.hero-grid {
  position: relative;
  z-index: 1;
  display: grid;
  grid-template-columns: minmax(0, 1.05fr) minmax(260px, 0.85fr);
  gap: 56px;
  align-items: center;
}

.kicker {
  display: inline-block;
  font-size: 0.88rem;
  font-weight: 600;
  letter-spacing: 0.06em;
  text-transform: uppercase;
  color: var(--accent);
  margin-bottom: 20px;
}

h1 {
  font-family: var(--font-display);
  font-weight: 800;
  font-size: clamp(2.6rem, 6.5vw, 4.8rem);
  line-height: 1.05;
  letter-spacing: -0.04em;
  margin: 0 0 24px;
}

.accent-word {
  background: linear-gradient(90deg, var(--g3) 0%, var(--g4) 48%, var(--g5) 100%);
  -webkit-background-clip: text;
  background-clip: text;
  color: transparent;
}

.lede {
  max-width: 36rem;
  color: var(--muted);
  font-size: 1.12rem;
  margin: 0 0 32px;
}

.hero-actions {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 14px;
  margin-bottom: 24px;
}

.fine {
  color: var(--faint);
  font-size: 0.9rem;
  margin: 0;
}

.network-legend {
  display: flex;
  flex-wrap: wrap;
  gap: 12px 20px;
  margin: 28px 0 0;
  padding: 0;
  list-style: none;
}

.network-legend li {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  padding: 8px 14px;
  border: 1px solid var(--line);
  border-radius: 999px;
  font-size: 0.88rem;
  color: var(--muted);
  background: var(--surface);
}

[data-theme="light"] .network-legend li,
:root:not([data-theme="dark"]) .network-legend li {
  box-shadow: 0 2px 8px rgba(26, 21, 36, 0.06);
}

@media (prefers-color-scheme: light) {
  :root:not([data-theme="dark"]) .network-legend li {
    box-shadow: 0 2px 8px rgba(26, 21, 36, 0.06);
  }
}

.dot {
  width: 10px;
  height: 10px;
  border-radius: 50%;
  flex-shrink: 0;
}

.dot-3g { background: var(--g3); }
.dot-4g { background: var(--g4); }
.dot-5g { background: var(--g5); }
.dot-5gplus { background: var(--g5); box-shadow: 0 0 0 2px var(--g5plus); }

/* Phone frame */

.hero-visual {
  display: flex;
  justify-content: center;
}

.phone-frame {
  width: min(100%, 280px);
  border-radius: 32px;
  overflow: hidden;
  border: 3px solid var(--line-strong);
  box-shadow: var(--shadow);
  background: var(--surface);
}

.phone-frame img {
  width: 100%;
  height: auto;
}

/* Why section */

.why {
  background: var(--bg-2);
  border-block: 1px solid var(--line);
}

.why-grid {
  display: grid;
  grid-template-columns: 1.1fr 0.9fr;
  gap: 48px;
  align-items: start;
  margin-top: 8px;
}

.why-copy p {
  color: var(--muted);
  margin: 0 0 18px;
}

.why-copy strong {
  color: var(--text);
}

.why-note {
  padding: 16px 20px;
  border-left: 3px solid var(--g3);
  background: var(--surface);
  border-radius: 0 var(--radius) var(--radius) 0;
  font-size: 0.95rem;
}

.why-list {
  list-style: none;
  margin: 0;
  padding: 0;
  display: flex;
  flex-direction: column;
  gap: 16px;
}

.why-list li {
  padding: 20px 22px;
  background: var(--card-bg);
  border: 1px solid var(--line);
  border-radius: var(--radius);
}

[data-theme="light"] .why-list li,
:root:not([data-theme="dark"]) .why-list li {
  box-shadow: 0 4px 16px rgba(26, 21, 36, 0.06);
}

@media (prefers-color-scheme: light) {
  :root:not([data-theme="dark"]) .why-list li {
    box-shadow: 0 4px 16px rgba(26, 21, 36, 0.06);
  }
}

.why-list strong {
  display: block;
  font-family: var(--font-display);
  font-size: 1.05rem;
  margin-bottom: 6px;
}

.why-list span {
  color: var(--muted);
  font-size: 0.95rem;
}

/* Sections */

section {
  padding: 96px 0;
}

.section-kicker {
  font-size: 0.88rem;
  font-weight: 600;
  letter-spacing: 0.08em;
  text-transform: uppercase;
  color: var(--g3);
  margin-bottom: 12px;
}

h2 {
  font-family: var(--font-display);
  font-weight: 700;
  font-size: clamp(2rem, 4vw, 2.8rem);
  letter-spacing: -0.03em;
  line-height: 1.1;
  margin: 0 0 20px;
}

.sub {
  color: var(--muted);
  max-width: 40rem;
  margin: 0 0 40px;
  font-size: 1.05rem;
}

.features {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 20px;
}

.card {
  background: var(--card-bg);
  border: 1px solid var(--line);
  border-radius: var(--radius);
  overflow: hidden;
}

[data-theme="light"] .card,
:root:not([data-theme="dark"]) .card {
  box-shadow: 0 4px 20px rgba(26, 21, 36, 0.07);
}

@media (prefers-color-scheme: light) {
  :root:not([data-theme="dark"]) .card {
    box-shadow: 0 4px 20px rgba(26, 21, 36, 0.07);
  }
}

.card-screen picture {
  display: block;
  background: var(--bg);
  padding: 16px 16px 0;
  text-align: center;
}

.card-screen img {
  width: auto;
  max-height: 280px;
  margin-inline: auto;
  border-radius: 16px 16px 0 0;
  border: 1px solid var(--line);
}

.card-body {
  padding: 22px 24px 24px;
}

.card h3 {
  font-family: var(--font-display);
  font-size: 1.2rem;
  margin: 0 0 10px;
  letter-spacing: -0.02em;
}

.card p {
  margin: 0;
  color: var(--muted);
  font-size: 0.98rem;
}

.steps {
  display: grid;
  grid-template-columns: repeat(3, minmax(0, 1fr));
  gap: 24px;
  counter-reset: step;
}

.step {
  padding: 24px;
  background: var(--card-bg);
  border: 1px solid var(--line);
  border-radius: var(--radius);
}

[data-theme="light"] .step,
:root:not([data-theme="dark"]) .step {
  box-shadow: 0 4px 16px rgba(26, 21, 36, 0.06);
}

@media (prefers-color-scheme: light) {
  :root:not([data-theme="dark"]) .step {
    box-shadow: 0 4px 16px rgba(26, 21, 36, 0.06);
  }
}

.step::before {
  counter-increment: step;
  content: counter(step);
  display: flex;
  align-items: center;
  justify-content: center;
  width: 36px;
  height: 36px;
  border-radius: 50%;
  background: color-mix(in srgb, var(--accent) 20%, var(--surface));
  color: var(--accent);
  font-weight: 700;
  font-size: 0.95rem;
  margin-bottom: 16px;
}

.step h3 {
  font-family: var(--font-display);
  margin: 0 0 10px;
  font-size: 1.2rem;
}

.step p {
  margin: 0;
  color: var(--muted);
  font-size: 0.98rem;
}

/* FAQ */

.faq-list {
  margin: 0;
  display: flex;
  flex-direction: column;
  gap: 0;
}

.faq-item {
  border-top: 1px solid var(--line);
  padding: 28px 0;
}

.faq-item:last-child {
  border-bottom: 1px solid var(--line);
}

.faq-item dt {
  font-family: var(--font-display);
  font-size: 1.15rem;
  font-weight: 600;
  margin-bottom: 10px;
}

.faq-item dd {
  margin: 0;
  color: var(--muted);
  font-size: 0.98rem;
  max-width: 52rem;
}

/* Download band */

.get {
  padding: 32px 0 112px;
}

.get-panel {
  position: relative;
  overflow: hidden;
  border-radius: 28px;
  padding: clamp(36px, 6vw, 60px);
  background:
    radial-gradient(800px 280px at 90% 0%, color-mix(in srgb, var(--g5) 18%, transparent), transparent 60%),
    radial-gradient(600px 240px at 0% 100%, color-mix(in srgb, var(--g3) 12%, transparent), transparent 55%),
    var(--surface);
  border: 1px solid var(--line-strong);
  display: grid;
  grid-template-columns: 1.2fr 0.8fr;
  gap: 32px;
  align-items: center;
}

[data-theme="light"] .get-panel,
:root:not([data-theme="dark"]) .get-panel {
  box-shadow: 0 8px 32px rgba(26, 21, 36, 0.08);
}

@media (prefers-color-scheme: light) {
  :root:not([data-theme="dark"]) .get-panel {
    box-shadow: 0 8px 32px rgba(26, 21, 36, 0.08);
  }
}

.get-panel h2 {
  margin-bottom: 12px;
}

.get-panel p {
  color: var(--muted);
  margin: 0 0 28px;
  font-size: 1.02rem;
}

.get-panel .install-note {
  margin: 12px 0 0;
  font-size: 0.88rem;
  color: var(--faint);
}

.get-side {
  display: flex;
  flex-direction: column;
  align-items: flex-end;
  gap: 10px;
}

.store-note {
  font-size: 0.92rem;
  color: var(--faint);
  text-align: right;
  line-height: 1.7;
}

/* Footer */

.footer {
  border-top: 1px solid var(--line);
  padding: 32px 0 48px;
  color: var(--faint);
  font-size: 0.92rem;
}

.footer-inner {
  display: flex;
  justify-content: space-between;
  gap: 20px;
  flex-wrap: wrap;
  align-items: center;
}

.footer-brand {
  display: flex;
  flex-direction: column;
  gap: 4px;
}

.footer-made {
  font-size: 0.85rem;
}

.footer a:hover {
  color: var(--text);
}

/* Sticky download */

.dock {
  display: none;
  position: fixed;
  left: 12px;
  right: 12px;
  bottom: calc(12px + env(safe-area-inset-bottom));
  z-index: 60;
  background: var(--text);
  color: var(--bg);
  border-radius: 999px;
  min-height: 52px;
  padding: 14px 20px;
  font-weight: 700;
  justify-content: center;
  align-items: center;
  gap: 8px;
  box-shadow: 0 16px 40px rgba(0, 0, 0, 0.25);
}

/* Legal pages */

.legal {
  padding: 56px 0 112px;
  max-width: 720px;
}

.legal h1 {
  font-size: clamp(2.2rem, 5vw, 3rem);
  margin-bottom: 8px;
}

.legal h2 {
  font-size: 1.3rem;
  margin: 36px 0 10px;
}

.legal p,
.legal li {
  color: var(--muted);
}

.legal ul {
  padding-left: 1.3rem;
}

.tldr {
  margin: 28px 0 36px;
  padding: 24px 28px;
  background: var(--surface);
  border: 1px solid var(--line);
  border-radius: var(--radius);
  border-left: 4px solid var(--accent);
}

[data-theme="light"] .tldr,
:root:not([data-theme="dark"]) .tldr {
  box-shadow: 0 4px 16px rgba(26, 21, 36, 0.06);
}

@media (prefers-color-scheme: light) {
  :root:not([data-theme="dark"]) .tldr {
    box-shadow: 0 4px 16px rgba(26, 21, 36, 0.06);
  }
}

.tldr h2 {
  font-size: 1.1rem;
  margin: 0 0 12px;
  text-transform: uppercase;
  letter-spacing: 0.06em;
}

.tldr ul {
  margin: 0;
  padding-left: 1.2rem;
}

.tldr li {
  margin-bottom: 8px;
}

.tldr li:last-child {
  margin-bottom: 0;
}

/* Reduced motion */

@media (prefers-reduced-motion: reduce) {
  html { scroll-behavior: auto; }
  .btn,
  .theme-toggle { transition: none; }
  .hero-burn { display: none; }
}

/* Responsive */

@media (max-width: 900px) {
  .hero-grid,
  .why-grid,
  .get-panel {
    grid-template-columns: 1fr;
  }

  .hero {
    padding-top: 40px;
  }

  .hero-burn {
    height: 140px;
    opacity: 0.3;
  }

  .hero-visual {
    order: -1;
  }

  .phone-frame {
    width: min(100%, 240px);
  }

  .get-side,
  .store-note {
    align-items: flex-start;
    text-align: left;
  }

  .features,
  .steps {
    grid-template-columns: 1fr;
  }

  .nav .hide-sm,
  .header .btn-primary {
    display: none;
  }

  .hero-actions {
    flex-direction: column;
    align-items: stretch;
  }

  .hero-actions .btn {
    width: 100%;
  }

  .dock {
    display: flex;
  }

  body {
    padding-bottom: 80px;
  }
}

@media (max-width: 520px) {
  .wrap,
  .header-inner {
    width: calc(100% - 28px);
  }

  h1 {
    font-size: 2.4rem;
  }

  .lede {
    font-size: 1.02rem;
  }

  section {
    padding: 72px 0;
  }
}