:root {
  --bg: #0b0b0d;
  --panel: #16161a;
  --panel-2: #1d1d22;
  --line: rgba(255, 255, 255, 0.09);
  --ink: #f3f3f7;
  --muted: #a0a0ab;
  --red: #ff5a4d;
  --red-deep: #c92a1f;
  --amber: #ffd25a;
  --radius: 18px;
}

* { box-sizing: border-box; }
html { scroll-behavior: smooth; }

body {
  margin: 0;
  font-family: -apple-system, BlinkMacSystemFont, "Inter", "Segoe UI", "Noto Sans TC", "Noto Sans JP", sans-serif;
  background: radial-gradient(1200px 600px at 80% -10%, rgba(255, 90, 77, 0.16), transparent 60%), var(--bg);
  color: var(--ink);
  line-height: 1.6;
  -webkit-font-smoothing: antialiased;
}

a { color: var(--red); text-decoration: none; }
a:hover { text-decoration: underline; }

/* language switching: elements carry class "en" or "zh" */
html[data-lang="en"] .zh, html[data-lang="en"] .ja { display: none !important; }
html[data-lang="zh"] .en, html[data-lang="zh"] .ja { display: none !important; }
html[data-lang="ja"] .en, html[data-lang="ja"] .zh { display: none !important; }

.site-header {
  position: sticky;
  top: 0;
  z-index: 20;
  background: rgba(11, 11, 13, 0.82);
  backdrop-filter: blur(14px);
  -webkit-backdrop-filter: blur(14px);
  border-bottom: 1px solid var(--line);
}

.nav {
  max-width: 1080px;
  margin: 0 auto;
  padding: 12px 20px;
  display: flex;
  align-items: center;
  gap: 20px;
}

.brand {
  display: flex;
  align-items: center;
  gap: 10px;
  color: var(--ink);
  font-weight: 800;
  font-size: 1.1rem;
  letter-spacing: 0.2px;
}
.brand:hover { text-decoration: none; }

.brand-mark {
  width: 32px;
  height: 32px;
  border-radius: 9px;
  background: linear-gradient(140deg, var(--red), var(--red-deep));
  display: grid;
  place-items: center;
  font-size: 1rem;
}

.nav-links {
  margin-left: auto;
  display: flex;
  gap: 18px;
  font-size: 0.92rem;
}
.nav-links a { color: var(--muted); }
.nav-links a:hover { color: var(--ink); text-decoration: none; }

.lang-switch {
  display: flex;
  gap: 4px;
  padding: 3px;
  border-radius: 999px;
  background: var(--panel);
  border: 1px solid var(--line);
}
.lang-button {
  border: 0;
  background: transparent;
  color: var(--muted);
  font: inherit;
  font-size: 0.8rem;
  font-weight: 700;
  padding: 4px 11px;
  border-radius: 999px;
  cursor: pointer;
}
html[data-lang="en"] .lang-button[data-lang-switch="en"],
html[data-lang="zh"] .lang-button[data-lang-switch="zh"],
html[data-lang="ja"] .lang-button[data-lang-switch="ja"] {
  background: var(--red);
  color: #fff;
}

main { max-width: 1080px; margin: 0 auto; padding: 0 20px 40px; }

.eyebrow {
  margin: 0 0 10px;
  color: var(--red);
  font-size: 0.8rem;
  font-weight: 800;
  letter-spacing: 1.4px;
  text-transform: uppercase;
}

/* ---------- hero ---------- */
.hero {
  display: grid;
  grid-template-columns: 1.1fr 0.9fr;
  gap: 40px;
  align-items: center;
  padding: 64px 0 40px;
}
.hero h1 {
  margin: 0 0 16px;
  font-size: clamp(2.4rem, 6vw, 4rem);
  line-height: 1.05;
  letter-spacing: -1px;
}
.hero h1 .accent { color: var(--red); }
.hero-subtitle { margin: 0 0 24px; color: var(--muted); font-size: 1.1rem; max-width: 34em; }

.cta-row { display: flex; flex-wrap: wrap; gap: 12px; align-items: center; }
.button {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  padding: 13px 22px;
  border-radius: 999px;
  font-weight: 800;
  border: 1px solid var(--line);
  color: var(--ink);
  background: var(--panel);
}
.button:hover { text-decoration: none; border-color: rgba(255, 255, 255, 0.25); }
.button.primary { background: var(--red); border-color: var(--red); color: #fff; }
.button.disabled { opacity: 0.85; cursor: default; }
.small-note { margin-top: 14px; color: var(--muted); font-size: 0.88rem; }

/* CSS phone mock: flips between face-down and the face-up alarm */
.phone {
  justify-self: center;
  width: min(300px, 78vw);
  aspect-ratio: 9 / 18.5;
  border-radius: 44px;
  padding: 12px;
  background: #050505;
  border: 2px solid #2a2a30;
  box-shadow: 0 30px 80px rgba(255, 90, 77, 0.25), 0 0 0 1px rgba(255, 255, 255, 0.05);
  perspective: 1400px;
}
.phone-flip {
  position: relative;
  width: 100%;
  height: 100%;
  transform-style: preserve-3d;
  /* Keep this in sync with FLIP_DURATION in the phone-mock script below. */
  transition: transform 0.7s cubic-bezier(0.65, 0, 0.35, 1);
}
.phone.is-down .phone-flip { transform: rotateY(180deg); }
.phone-front, .phone-back {
  position: absolute;
  inset: 0;
  border-radius: 34px;
  overflow: hidden;
  backface-visibility: hidden;
  -webkit-backface-visibility: hidden;
}
.phone-back {
  transform: rotateY(180deg);
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  gap: 10px;
  background: linear-gradient(160deg, #26262d, #101013);
  color: rgba(255, 255, 255, 0.55);
  text-align: center;
  padding: 22px;
}
.phone-back-icon { font-size: 2.4rem; opacity: 0.7; }
.phone-back-label { font-size: 0.82rem; font-weight: 700; }
.phone-success {
  position: absolute;
  inset: 0;
  display: none;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  gap: 12px;
  background: #1f9d55;
  color: #fff;
  text-align: center;
  padding: 22px;
}
.phone-success-icon { font-size: 3rem; }
.phone-success-label { font-size: 0.95rem; font-weight: 800; }
.phone.is-success .phone-success { display: flex; }
.phone-screen {
  height: 100%;
  border-radius: 34px;
  overflow: hidden;
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  gap: 8px;
  padding: 22px;
  text-align: center;
  background: #d92d20;
  animation: alarm 0.6s steps(1) infinite;
}
@keyframes alarm {
  0%, 100% { background: #d92d20; }
  50% { background: #0b0b0d; }
}
.phone-left { font-size: 0.78rem; font-weight: 700; color: rgba(255, 255, 255, 0.75); }
.phone-count { font-size: 5.2rem; line-height: 1; font-weight: 900; }
.phone-hint { font-size: 0.78rem; color: rgba(255, 255, 255, 0.75); }
.phone-pledge { font-size: 1rem; font-weight: 800; }
.phone-modes { position: relative; width: 100%; height: 118px; margin-top: 10px; }
.phone-mode {
  position: absolute;
  inset: 0;
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  gap: 8px;
  opacity: 0;
}
.mode-type { animation: showType 8s infinite; }
.mode-voice { animation: showVoice 8s infinite; }
@keyframes showType {
  0%, 44% { opacity: 1; }
  50%, 94% { opacity: 0; }
  100% { opacity: 1; }
}
@keyframes showVoice {
  0%, 44% { opacity: 0; }
  50%, 94% { opacity: 1; }
  100% { opacity: 0; }
}
.phone-input {
  width: 100%;
  display: flex;
  align-items: center;
  padding: 11px 12px;
  border-radius: 10px;
  background: rgba(255, 255, 255, 0.16);
  font-size: 0.85rem;
  font-weight: 700;
  color: #fff;
  text-align: left;
}
.caret {
  width: 2px;
  height: 1em;
  margin-left: 2px;
  background: #fff;
  animation: blink 0.9s steps(1) infinite;
}
@keyframes blink { 50% { opacity: 0; } }
.voice-row { display: flex; align-items: center; gap: 10px; }
.mic {
  display: grid;
  place-items: center;
  width: 44px;
  height: 44px;
  border-radius: 50%;
  background: #fff;
  font-size: 1.3rem;
  box-shadow: 0 0 0 0 rgba(255, 255, 255, 0.6);
  animation: pulse 1.2s ease-out infinite;
}
@keyframes pulse {
  to { box-shadow: 0 0 0 16px rgba(255, 255, 255, 0); }
}
.bars { display: flex; align-items: center; gap: 4px; height: 34px; }
.bars i {
  width: 5px;
  height: 100%;
  border-radius: 3px;
  background: #fff;
  transform-origin: center;
  animation: bar 0.9s ease-in-out infinite;
}
.bars i:nth-child(2) { animation-delay: 0.12s; }
.bars i:nth-child(3) { animation-delay: 0.24s; }
.bars i:nth-child(4) { animation-delay: 0.36s; }
.bars i:nth-child(5) { animation-delay: 0.48s; }
@keyframes bar {
  0%, 100% { transform: scaleY(0.25); }
  50% { transform: scaleY(1); }
}
.phone-heard { font-size: 0.95rem; font-weight: 800; }
.phone-mode-label {
  padding: 3px 10px;
  border-radius: 999px;
  background: rgba(0, 0, 0, 0.32);
  font-size: 0.7rem;
  font-weight: 800;
  color: #fff;
}
.mode-voice .phone-mode-label { background: var(--amber); color: #000; }
@media (prefers-reduced-motion: reduce) {
  .phone-screen, .mic, .bars i, .caret { animation: none; }
  .phone-modes { height: auto; display: grid; gap: 14px; }
  .phone-mode { position: static; opacity: 1; animation: none; }
  .phone-flip { transition: none; }
}

/* ---------- sections ---------- */
.section { padding: 56px 0 8px; }
.section-heading { max-width: 640px; margin-bottom: 28px; }
.section-heading h2 { margin: 0 0 10px; font-size: clamp(1.7rem, 4vw, 2.4rem); line-height: 1.15; letter-spacing: -0.5px; }
.section-heading p { margin: 0; color: var(--muted); }

.steps { display: grid; grid-template-columns: repeat(3, 1fr); gap: 16px; }
.card {
  background: var(--panel);
  border: 1px solid var(--line);
  border-radius: var(--radius);
  padding: 22px;
}
.card h3 { margin: 0 0 8px; font-size: 1.1rem; }
.card p { margin: 0; color: var(--muted); font-size: 0.96rem; }
.step-number {
  display: inline-grid;
  place-items: center;
  width: 34px;
  height: 34px;
  margin-bottom: 12px;
  border-radius: 50%;
  background: var(--red);
  font-weight: 900;
}
.feature-icon { font-size: 1.6rem; margin-bottom: 10px; }
.grid-3 { display: grid; grid-template-columns: repeat(3, 1fr); gap: 16px; }

.pro-card {
  display: grid;
  grid-template-columns: 1.1fr 0.9fr;
  gap: 32px;
  align-items: center;
  background: linear-gradient(140deg, rgba(255, 90, 77, 0.16), var(--panel) 55%);
  border: 1px solid rgba(255, 90, 77, 0.35);
  border-radius: 24px;
  padding: 32px;
}
.pro-card h2 { margin: 0 0 10px; font-size: clamp(1.6rem, 4vw, 2.2rem); }
.pro-card p { margin: 0 0 12px; color: var(--muted); }
.pro-list { list-style: none; margin: 0; padding: 0; display: grid; gap: 12px; }
.pro-list li { display: flex; gap: 10px; align-items: flex-start; }
.pro-list li::before { content: "✓"; color: var(--amber); font-weight: 900; }
.badge {
  display: inline-block;
  margin-bottom: 12px;
  padding: 4px 12px;
  border-radius: 999px;
  background: var(--amber);
  color: #000;
  font-size: 0.75rem;
  font-weight: 900;
}

details.faq {
  background: var(--panel);
  border: 1px solid var(--line);
  border-radius: 14px;
  padding: 16px 20px;
  margin-bottom: 10px;
}
details.faq summary { cursor: pointer; font-weight: 800; }
details.faq p { margin: 10px 0 0; color: var(--muted); }

/* ---------- legal pages ---------- */
.legal-hero { padding: 56px 0 24px; max-width: 760px; }
.legal-hero h1 { margin: 0 0 12px; font-size: clamp(2rem, 5vw, 3rem); letter-spacing: -0.5px; }
.legal-hero p { margin: 0; color: var(--muted); }
.legal-layout { display: grid; gap: 14px; max-width: 760px; }
.legal-card {
  background: var(--panel);
  border: 1px solid var(--line);
  border-radius: var(--radius);
  padding: 22px 24px;
}
.legal-card h2 { margin: 0 0 10px; font-size: 1.15rem; }
.legal-card p { margin: 0 0 10px; color: #d2d2da; }
.legal-card ul { margin: 0 0 10px; padding-left: 20px; color: #d2d2da; }
.legal-card li { margin-bottom: 6px; }
.legal-card p:last-child, .legal-card ul:last-child { margin-bottom: 0; }

/* ---------- study scene ---------- */
.scene {
  display: grid;
  grid-template-columns: 1.15fr 0.85fr;
  gap: 32px;
  align-items: center;
}
.scene-art {
  border: 1px solid var(--line);
  border-radius: 24px;
  overflow: hidden;
  box-shadow: 0 24px 60px rgba(0, 0, 0, 0.4);
}
.scene-art svg { display: block; width: 100%; height: auto; }
.scene-copy h2 { margin: 0 0 12px; font-size: clamp(1.7rem, 4vw, 2.4rem); line-height: 1.15; letter-spacing: -0.5px; }
.scene-copy p { margin: 0 0 16px; color: var(--muted); }
.scene-copy .eyebrow { color: var(--red); margin-bottom: 10px; }
.scene-list { list-style: none; margin: 0; padding: 0; display: grid; gap: 10px; }
.scene-list li { display: flex; gap: 10px; align-items: center; font-weight: 700; }
.scene-list li::before { content: "✓"; color: var(--amber); font-weight: 900; }

.ring { transform-box: fill-box; transform-origin: center; animation: ringPulse 2.4s ease-out infinite; }
@keyframes ringPulse {
  0% { transform: scale(0.7); opacity: 0.8; }
  100% { transform: scale(1.25); opacity: 0; }
}
.notif { animation: floatAway 4s ease-in infinite; }
.notif.n2 { animation-delay: 1.3s; }
.notif.n3 { animation-delay: 2.6s; }
@keyframes floatAway {
  0% { transform: translateY(8px); opacity: 0; }
  30% { opacity: 1; }
  100% { transform: translateY(-14px); opacity: 0; }
}
.steam { animation: steam 3s ease-in-out infinite; }
@keyframes steam {
  0%, 100% { opacity: 0.2; transform: translateY(2px); }
  50% { opacity: 0.6; transform: translateY(-3px); }
}
@media (prefers-reduced-motion: reduce) {
  .ring, .notif, .steam { animation: none; }
  .notif { opacity: 1; }
}

/* ---------- footer ---------- */
.footer {
  max-width: 1080px;
  margin: 0 auto;
  padding: 32px 20px 48px;
  display: flex;
  flex-wrap: wrap;
  gap: 12px 24px;
  justify-content: space-between;
  border-top: 1px solid var(--line);
  color: var(--muted);
  font-size: 0.9rem;
}
.footer-links { display: flex; flex-wrap: wrap; gap: 8px 20px; }
.footer a { color: var(--muted); }
.footer a:hover { color: var(--ink); }

@media (max-width: 860px) {
  .hero, .pro-card, .scene { grid-template-columns: 1fr; }
  .steps, .grid-3 { grid-template-columns: 1fr; }
  .nav-links { display: none; }
  .lang-switch { margin-left: auto; }
  .hero { padding-top: 40px; }
}