:root {
  --purple: #6c5ce7;
  --purple-2: #7261e8;
  --purple-dark: #5848c2;
  --grad: linear-gradient(180deg, #7c6bf0 0%, #6a58e0 100%);
  --ink: #2c2540;
  --ink-2: #6b6478;
  --ink-3: #9c95aa;
  --bg: #ffffff;
  --bg-alt: #f6f2fb;
  --line: #ece6f1;
  --radius: 18px;
  --shadow: 0 18px 48px rgba(70, 58, 107, 0.12);
  --serif: "Noto Serif SC", "Songti SC", serif;
  --sans: "Noto Sans SC", -apple-system, "PingFang SC", "Microsoft YaHei", sans-serif;
}

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

html { scroll-behavior: smooth; }

body {
  font-family: var(--sans);
  color: var(--ink);
  background: var(--bg);
  line-height: 1.6;
  -webkit-font-smoothing: antialiased;
}

.container { width: 100%; max-width: 1120px; margin: 0 auto; padding: 0 24px; }
.container-narrow { max-width: 760px; }

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

.skip-link {
  position: absolute; left: -999px; top: 0;
  background: var(--purple); color: #fff; padding: 10px 16px; z-index: 100;
}
.skip-link:focus { left: 12px; top: 12px; border-radius: 10px; }

/* ---------- Buttons ---------- */
.btn {
  display: inline-flex; align-items: center; justify-content: center;
  gap: 8px; border: none; cursor: pointer; font-family: var(--sans);
  font-weight: 700; border-radius: 999px; transition: transform .15s ease, box-shadow .2s ease, background .2s ease;
  white-space: nowrap;
}
.btn:active { transform: translateY(1px); }
.btn-sm { padding: 9px 18px; font-size: 14px; }
.btn-lg { padding: 15px 28px; font-size: 16px; }
.btn-primary { background: var(--purple); color: #fff; box-shadow: 0 10px 24px rgba(108, 92, 231, .35); }
.btn-primary:hover { background: var(--purple-dark); }
.btn-ghost { background: transparent; color: var(--purple); border: 1.5px solid rgba(108,92,231,.35); }
.btn-ghost:hover { background: rgba(108,92,231,.07); }
.btn-white { background: #fff; color: var(--purple); box-shadow: 0 12px 30px rgba(0,0,0,.18); }
.btn-white:hover { transform: translateY(-2px); }

/* ---------- Header ---------- */
.site-header {
  position: sticky; top: 0; z-index: 50;
  background: rgba(255,255,255,.82);
  backdrop-filter: saturate(180%) blur(12px);
  border-bottom: 1px solid var(--line);
}
.header-inner { display: flex; align-items: center; gap: 24px; height: 64px; }
.brand { display: flex; align-items: center; gap: 10px; }
.brand-mark { border-radius: 9px; display: block; }
.nav { margin-left: auto; display: flex; gap: 26px; font-size: 15px; color: var(--ink-2); }
.nav a:hover { color: var(--purple); }
.header-inner .btn { flex: none; }

/* ---------- Hero ---------- */
.hero {
  background: var(--grad);
  color: #fff;
  text-align: center;
  padding: 84px 0 96px;
  position: relative;
  overflow: hidden;
}
.hero-inner { display: flex; flex-direction: column; align-items: center; }
.hero-title {
  font-family: var(--serif); font-weight: 700;
  font-size: clamp(32px, 6vw, 56px); letter-spacing: 2px; margin-top: 30px;
}
.hero-sub { margin-top: 18px; font-size: clamp(15px, 2.4vw, 18px); color: rgba(255,255,255,.9); max-width: 620px; }
.cta-row { display: flex; flex-wrap: wrap; gap: 14px; justify-content: center; margin-top: 34px; }
.hero .btn-ghost { color: #fff; border-color: rgba(255,255,255,.55); }
.hero .btn-ghost:hover { background: rgba(255,255,255,.12); }
.hero-note { margin-top: 18px; font-size: 13px; color: rgba(255,255,255,.72); }

/* ---------- Sound wave ---------- */
.wave { display: flex; align-items: center; justify-content: center; gap: 7px; height: 120px; }
.wave span {
  width: 9px; border-radius: 999px; background: #fff;
  animation: bar 1.1s ease-in-out infinite;
}
.wave span:nth-child(1),
.wave span:nth-child(13) { height: 12px; opacity: .85; }
.wave span:nth-child(2),
.wave span:nth-child(12) { height: 16px; }
.wave span:nth-child(3),
.wave span:nth-child(11) { height: 26px; }
.wave span:nth-child(4),
.wave span:nth-child(10) { height: 44px; }
.wave span:nth-child(5),
.wave span:nth-child(9)  { height: 70px; }
.wave span:nth-child(6),
.wave span:nth-child(8)  { height: 96px; }
.wave span:nth-child(7)  { height: 120px; }
.wave span:nth-child(1) { animation-delay: -.05s; }
.wave span:nth-child(2),  .wave span:nth-child(12) { animation-delay: -.12s; }
.wave span:nth-child(3),  .wave span:nth-child(11) { animation-delay: -.2s; }
.wave span:nth-child(4),  .wave span:nth-child(10) { animation-delay: -.3s; }
.wave span:nth-child(5),  .wave span:nth-child(9)  { animation-delay: -.42s; }
.wave span:nth-child(6),  .wave span:nth-child(8)  { animation-delay: -.55s; }
.wave span:nth-child(7) { animation-delay: -.7s; }
@keyframes bar { 0%, 100% { transform: scaleY(.78); } 50% { transform: scaleY(1); } }
@media (prefers-reduced-motion: reduce) { .wave span { animation: none; } }

.wave-sm { height: 72px; gap: 5px; }
.wave-sm span { width: 6px; }
.wave-sm span:nth-child(7) { height: 72px; }
.wave-sm span:nth-child(6), .wave-sm span:nth-child(8) { height: 58px; }
.wave-sm span:nth-child(5), .wave-sm span:nth-child(9) { height: 42px; }
.wave-sm span:nth-child(4), .wave-sm span:nth-child(10) { height: 27px; }
.wave-sm span:nth-child(3), .wave-sm span:nth-child(11) { height: 16px; }
.wave-sm span:nth-child(2), .wave-sm span:nth-child(12) { height: 10px; }
.wave-sm span:nth-child(1), .wave-sm span:nth-child(13) { height: 7px; }

/* ---------- Sections ---------- */
.section { padding: 84px 0; }
.section-alt { background: var(--bg-alt); }
.eyebrow { color: var(--purple); font-weight: 700; font-size: 14px; letter-spacing: 1px; text-align: center; }
.section-title {
  font-family: var(--serif); font-weight: 700; text-align: center;
  font-size: clamp(24px, 4vw, 38px); margin-top: 8px; margin-bottom: 48px; color: var(--ink);
}

.grid { display: grid; gap: 22px; }
.features { grid-template-columns: repeat(3, 1fr); }
.card {
  background: #fff; border: 1px solid var(--line); border-radius: var(--radius);
  padding: 30px 26px; box-shadow: var(--shadow); transition: transform .2s ease, box-shadow .2s ease;
}
.card:hover { transform: translateY(-4px); box-shadow: 0 24px 56px rgba(70,58,107,.16); }
.card-ic {
  width: 54px; height: 54px; border-radius: 16px; display: grid; place-items: center;
  font-size: 26px; background: linear-gradient(135deg, #efeafe, #e3dbfb); margin-bottom: 16px;
}
.card h3 { font-size: 19px; margin-bottom: 8px; }
.card p { color: var(--ink-2); font-size: 15px; }

.steps { grid-template-columns: repeat(3, 1fr); }
.step { text-align: center; padding: 16px; }
.step-num {
  display: inline-grid; place-items: center; width: 52px; height: 52px; border-radius: 50%;
  background: var(--purple); color: #fff; font-family: var(--serif); font-size: 22px; font-weight: 700;
  margin-bottom: 16px; box-shadow: 0 10px 22px rgba(108,92,231,.32);
}
.step h3 { font-size: 18px; margin-bottom: 6px; }
.step p { color: var(--ink-2); font-size: 15px; }

.who { grid-template-columns: repeat(2, 1fr); }
.pill {
  background: #fff; border: 1px solid var(--line); border-radius: 14px; padding: 20px 24px;
  font-size: 16px; font-weight: 500; box-shadow: var(--shadow);
}

/* ---------- FAQ ---------- */
.faq { display: flex; flex-direction: column; gap: 14px; }
.faq details {
  background: #fff; border: 1px solid var(--line); border-radius: 14px; padding: 4px 22px;
  box-shadow: 0 8px 20px rgba(70,58,107,.06);
}
.faq summary {
  list-style: none; cursor: pointer; padding: 16px 0; font-weight: 700; font-size: 17px;
  display: flex; justify-content: space-between; align-items: center;
}
.faq summary::-webkit-details-marker { display: none; }
.faq summary::after { content: "+"; color: var(--purple); font-size: 24px; font-weight: 400; }
.faq details[open] summary::after { content: "–"; }
.faq details p { padding: 0 0 18px; color: var(--ink-2); font-size: 15px; }

/* ---------- CTA band ---------- */
.cta-band { background: var(--grad); color: #fff; text-align: center; padding: 80px 0; }
.cta-inner { display: flex; flex-direction: column; align-items: center; }
.cta-band h2 { font-family: var(--serif); font-size: clamp(26px, 4vw, 40px); margin: 18px 0 10px; }
.cta-band p { color: rgba(255,255,255,.88); margin-bottom: 28px; }

/* ---------- Footer ---------- */
.site-footer { background: #1f1b2e; color: rgba(255,255,255,.8); padding: 48px 0 28px; }
.footer-inner { display: flex; flex-wrap: wrap; gap: 24px; justify-content: space-between; align-items: flex-start; padding-bottom: 28px; border-bottom: 1px solid rgba(255,255,255,.12); }
.footer-brand p { color: rgba(255,255,255,.6); font-size: 14px; margin-top: 10px; }
.footer-links { display: flex; flex-wrap: wrap; gap: 22px; font-size: 15px; }
.footer-links a:hover { color: #fff; }
.footer-bottom { display: flex; flex-wrap: wrap; gap: 12px; justify-content: space-between; padding-top: 20px; font-size: 13px; color: rgba(255,255,255,.55); }
.footer-legal a:hover { color: #fff; }

/* ---------- Toast ---------- */
.toast {
  position: fixed; left: 50%; bottom: 32px; transform: translate(-50%, 24px);
  background: #1f1b2e; color: #fff; padding: 14px 22px; border-radius: 999px;
  font-size: 15px; box-shadow: 0 16px 40px rgba(0,0,0,.3); opacity: 0; pointer-events: none;
  transition: opacity .25s ease, transform .25s ease; z-index: 100;
}
.toast.show { opacity: 1; transform: translate(-50%, 0); }

/* ---------- Screens showcase ---------- */
.screens { display: flex; flex-wrap: wrap; justify-content: center; gap: 36px 26px; }
.device-wrap { display: flex; flex-direction: column; align-items: center; width: 248px; }
.device-wrap figcaption { margin-top: 18px; font-weight: 700; color: var(--ink); font-size: 15px; text-align: center; }
.device {
  width: 248px; background: #15111f; border-radius: 36px; padding: 9px;
  box-shadow: 0 34px 64px rgba(40, 30, 80, .28); position: relative;
}
.device::after {
  content: ""; position: absolute; top: 17px; left: 50%; transform: translateX(-50%);
  width: 9px; height: 9px; border-radius: 50%; background: #000; opacity: .5; z-index: 4;
}
.device-screen {
  aspect-ratio: 9 / 19.3; border-radius: 28px; overflow: hidden; position: relative;
  display: flex; flex-direction: column; font-size: 11px; line-height: 1.5;
}

/* Login screen */
.scr-login { background: var(--grad); color: #fff; align-items: center; text-align: center; padding: 30px 22px 22px; }
.scr-login .wave-xs { margin-top: 26px; }
.login-logo { width: 86px; margin-top: 20px; }
.login-slogan { color: rgba(255,255,255,.9); letter-spacing: 2px; margin-top: 9px; font-size: 11px; }
.login-btn { margin-top: auto; background: #fff; color: var(--purple); font-weight: 700; border-radius: 999px; padding: 10px 0; width: 100%; font-size: 12px; }
.login-or { color: rgba(255,255,255,.7); margin: 11px 0; }
.login-trial { color: #fff; font-weight: 600; }
.login-agree { color: rgba(255,255,255,.7); margin-top: 14px; font-size: 9px; }

.wave-xs { height: 66px; gap: 3px; }
.wave-xs span { width: 4px; }
.wave-xs span:nth-child(7) { height: 66px; }
.wave-xs span:nth-child(6), .wave-xs span:nth-child(8) { height: 52px; }
.wave-xs span:nth-child(5), .wave-xs span:nth-child(9) { height: 38px; }
.wave-xs span:nth-child(4), .wave-xs span:nth-child(10) { height: 24px; }
.wave-xs span:nth-child(3), .wave-xs span:nth-child(11) { height: 14px; }
.wave-xs span:nth-child(2), .wave-xs span:nth-child(12) { height: 9px; }
.wave-xs span:nth-child(1), .wave-xs span:nth-child(13) { height: 6px; }

/* Home feed screen */
.scr-home { background: #f3eef9; color: var(--ink); padding: 28px 13px 14px; gap: 11px; }
.home-head h4 { font-family: var(--serif); font-size: 15px; }
.home-head p { color: var(--ink-3); font-size: 9.5px; margin-top: 4px; line-height: 1.4; }
.pcard { background: #fff; border-radius: 14px; padding: 10px; display: flex; gap: 10px; box-shadow: 0 8px 18px rgba(70,58,107,.08); }
.pcover { width: 52px; height: 70px; border-radius: 8px; flex: none; position: relative; background: linear-gradient(135deg, #8e7bf5, #6c5ce7); }
.pcover-2 { background: linear-gradient(135deg, #7bd0f5, #4a8fe7); }
.pcover-3 { background: linear-gradient(135deg, #f5a6c8, #e8638c); }
.pcover-play {
  position: absolute; inset: 0; margin: auto; width: 22px; height: 22px; display: grid; place-items: center;
  border-radius: 50%; background: rgba(0,0,0,.42); border: 1.4px solid #fff; color: #fff; font-size: 9px;
}
.ptitle { font-family: var(--serif); font-weight: 600; font-size: 12px; line-height: 1.35; }
.pauthors { color: var(--ink-2); font-size: 9.5px; margin-top: 5px; }
.pjournal { color: var(--ink-3); font-size: 9px; margin-top: 5px; }

/* Player screen */
.scr-player { background: linear-gradient(180deg, #3b2e73, #1e1740); color: #fff; align-items: center; padding: 28px 16px 14px; }
.pl-top { display: flex; align-items: center; justify-content: space-between; width: 100%; }
.pl-ic { width: 26px; height: 26px; border-radius: 50%; background: rgba(255,255,255,.14); display: grid; place-items: center; font-size: 13px; }
.pl-seg { background: rgba(255,255,255,.12); border-radius: 9px; padding: 3px; display: flex; gap: 2px; font-size: 10px; }
.pl-seg b { background: #fff; color: #5848c2; border-radius: 6px; padding: 3px 11px; font-weight: 600; }
.pl-seg i { color: rgba(255,255,255,.8); padding: 3px 11px; font-style: normal; }
.pl-cover { width: 104px; height: 138px; border-radius: 9px; margin: 18px 0 16px; background: linear-gradient(135deg, #9a8bf7, #5848c2); box-shadow: 0 16px 32px rgba(0,0,0,.45); }
.pl-title { font-family: var(--serif); font-weight: 700; font-size: 13px; text-align: center; line-height: 1.4; }
.pl-en { color: rgba(255,255,255,.55); font-size: 9.5px; text-align: center; margin-top: 5px; }
.pl-authors { color: rgba(255,255,255,.75); font-size: 9.5px; text-align: center; margin-top: 8px; }
.pl-actions { display: flex; gap: 16px; color: rgba(255,255,255,.8); font-size: 9.5px; margin: 14px 0 10px; }
.pl-progress { width: 100%; height: 3px; background: rgba(255,255,255,.24); border-radius: 2px; }
.pl-progress i { display: block; width: 26%; height: 100%; background: #fff; border-radius: 2px; }
.pl-times { width: 100%; display: flex; justify-content: space-between; color: rgba(255,255,255,.5); font-size: 9px; margin-top: 5px; }
.pl-controls { display: flex; align-items: center; gap: 22px; margin: 12px 0; }
.pl-controls > span { color: rgba(255,255,255,.85); font-size: 17px; }
.pl-play { width: 44px; height: 44px; background: #fff; color: #5848c2; border-radius: 50%; display: grid; place-items: center; font-size: 16px; box-shadow: 0 8px 18px rgba(0,0,0,.35); }
.pl-ask { margin-top: auto; width: 100%; text-align: center; border: 1px solid rgba(255,255,255,.35); border-radius: 999px; padding: 9px 0; color: #fff; font-size: 11px; font-weight: 600; }

/* Ask (问一问) screen */
.scr-ask { background: linear-gradient(180deg, #2a2150, #1b1438); color: #fff; padding: 26px 12px 12px; }
.ask-head { display: flex; justify-content: space-between; align-items: center; font-weight: 600; font-size: 13px; padding: 0 4px 12px; }
.ask-mute { opacity: .7; font-size: 15px; }
.ask-body { flex: 1; display: flex; flex-direction: column; gap: 8px; overflow: hidden; justify-content: flex-end; }
.bubble { max-width: 86%; padding: 8px 10px; border-radius: 13px; font-size: 10.5px; line-height: 1.55; }
.bubble.user { align-self: flex-end; background: #6c5ce7; border-bottom-right-radius: 4px; }
.bubble.bot { align-self: flex-start; background: #362b63; border-bottom-left-radius: 4px; }
.bot-name { display: block; color: #b8a9ff; font-weight: 600; font-size: 9px; margin-bottom: 3px; }
.bot-typing { display: inline-flex; align-items: center; }
.dots { display: inline-flex; gap: 4px; padding: 2px 0; }
.dots i { width: 5px; height: 5px; border-radius: 50%; background: #b8a9ff; animation: blink 1s infinite; }
.dots i:nth-child(2) { animation-delay: .2s; }
.dots i:nth-child(3) { animation-delay: .4s; }
@keyframes blink { 0%, 100% { opacity: .3; } 50% { opacity: 1; } }
.ask-input { display: flex; align-items: center; gap: 8px; background: #241c49; border-radius: 999px; padding: 7px 12px; margin-top: 10px; }
.ask-mic, .ask-kb { color: #b8a9ff; font-size: 14px; }
.ask-hold { flex: 1; text-align: center; color: rgba(255,255,255,.85); border: 1px solid rgba(255,255,255,.18); border-radius: 999px; padding: 5px 0; font-size: 10px; }
@media (prefers-reduced-motion: reduce) { .dots i { animation: none; } }

/* ---------- Responsive ---------- */
@media (max-width: 880px) {
  .features, .steps { grid-template-columns: 1fr 1fr; }
  .nav { display: none; }
}
@media (max-width: 560px) {
  .features, .steps, .who { grid-template-columns: 1fr; }
  .section { padding: 60px 0; }
  .hero { padding: 64px 0 72px; }
  .cta-row { flex-direction: column; width: 100%; }
  .cta-row .btn { width: 100%; }
}