/* ============================================================================
   WaveTalk — landing site design system
   Brand gradient #FF8A3D -> #FF3D77. Orange owns the messenger space.
   ========================================================================= */

:root {
  --wt-orange: #FF8A3D;
  --wt-pink: #FF3D77;
  --wt-grad: linear-gradient(135deg, #FF8A3D 0%, #FF3D77 100%);
  --wt-grad-soft: linear-gradient(135deg, #FF8A3D22 0%, #FF3D7722 100%);

  --ink-900: #14161d;
  --ink-800: #1b1f2a;
  --ink-700: #2c3140;
  --ink-500: #5a6172;
  --ink-400: #828a9c;

  --bg: #ffffff;
  --bg-soft: #f6f7fb;
  --bg-card: #ffffff;
  --border: #e7e9f0;
  --shadow-sm: 0 1px 2px rgba(20, 22, 29, .06), 0 4px 16px rgba(20, 22, 29, .05);
  --shadow-md: 0 8px 30px rgba(20, 22, 29, .10);
  --shadow-lg: 0 24px 70px rgba(255, 61, 119, .18);

  --text: var(--ink-800);
  --text-dim: var(--ink-500);

  --radius: 18px;
  --radius-lg: 28px;
  --maxw: 1180px;
  --nav-h: 68px;

  --font: -apple-system, BlinkMacSystemFont, "SF Pro Display", "Segoe UI",
    Roboto, "Helvetica Neue", Arial, sans-serif;
}

@media (prefers-color-scheme: dark) {
  :root {
    --bg: #0d0f14;
    --bg-soft: #12151c;
    --bg-card: #161a23;
    --border: #242a36;
    --text: #eef0f5;
    --text-dim: #9aa3b4;
    --ink-800: #eef0f5;
    --shadow-sm: 0 1px 2px rgba(0, 0, 0, .4), 0 6px 20px rgba(0, 0, 0, .35);
    --shadow-md: 0 10px 36px rgba(0, 0, 0, .5);
  }
}
:root[data-theme="dark"] {
  --bg: #0d0f14; --bg-soft: #12151c; --bg-card: #161a23; --border: #242a36;
  --text: #eef0f5; --text-dim: #9aa3b4; --ink-800: #eef0f5;
  --shadow-sm: 0 1px 2px rgba(0,0,0,.4), 0 6px 20px rgba(0,0,0,.35);
  --shadow-md: 0 10px 36px rgba(0,0,0,.5);
}
:root[data-theme="light"] {
  --bg: #fff; --bg-soft: #f6f7fb; --bg-card: #fff; --border: #e7e9f0;
  --text: #1b1f2a; --text-dim: #5a6172; --ink-800: #1b1f2a;
}

* { box-sizing: border-box; }
html { scroll-behavior: smooth; -webkit-text-size-adjust: 100%; }
@media (prefers-reduced-motion: reduce) { html { scroll-behavior: auto; } }

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

a { color: inherit; text-decoration: none; }
img, svg { display: block; max-width: 100%; }

.wrap { max-width: var(--maxw); margin: 0 auto; padding: 0 24px; }
.eyebrow {
  font-size: 13px; font-weight: 700; letter-spacing: .14em;
  text-transform: uppercase; color: var(--wt-pink);
}
.grad-text {
  background: var(--wt-grad); -webkit-background-clip: text;
  background-clip: text; color: transparent;
}

h1, h2, h3 { line-height: 1.12; letter-spacing: -0.02em; font-weight: 700; color: var(--ink-800); }
h2.section-title { font-size: clamp(28px, 4vw, 44px); margin: 0 0 14px; }
.section-lead { font-size: clamp(16px, 2vw, 19px); color: var(--text-dim); max-width: 640px; }

section { padding: clamp(64px, 9vw, 120px) 0; }
.center { text-align: center; margin-inline: auto; }

/* ---- Nav ------------------------------------------------------------- */
.nav {
  position: sticky; top: 0; z-index: 50; height: var(--nav-h);
  display: flex; align-items: center;
  background: color-mix(in srgb, var(--bg) 72%, transparent);
  backdrop-filter: saturate(180%) blur(18px);
  -webkit-backdrop-filter: saturate(180%) blur(18px);
  border-bottom: 1px solid transparent; transition: border-color .3s, background .3s;
}
.nav.scrolled { border-bottom-color: var(--border); }
.nav .wrap { display: flex; align-items: center; justify-content: space-between; width: 100%; }
.brand { display: flex; align-items: center; gap: 11px; font-weight: 700; font-size: 19px; letter-spacing: -.01em; }
.brand img { width: 34px; height: 34px; border-radius: 9px; box-shadow: var(--shadow-sm); }
.nav-links { display: flex; align-items: center; gap: 30px; }
.nav-links a { color: var(--text-dim); font-weight: 550; font-size: 15px; transition: color .2s; }
.nav-links a:hover { color: var(--text); }
.nav-actions { display: flex; align-items: center; gap: 14px; }
.theme-toggle {
  width: 38px; height: 38px; border-radius: 11px; border: 1px solid var(--border);
  background: var(--bg-card); cursor: pointer; display: grid; place-items: center;
  color: var(--text-dim); transition: color .2s, border-color .2s;
}
.theme-toggle:hover { color: var(--text); border-color: var(--ink-400); }

.btn {
  display: inline-flex; align-items: center; gap: 9px; font-weight: 650; font-size: 15px;
  padding: 12px 22px; border-radius: 999px; border: 1px solid transparent;
  cursor: pointer; transition: transform .15s ease, box-shadow .2s, background .2s;
  white-space: nowrap;
}
.btn:active { transform: translateY(1px) scale(.99); }
.btn-primary { background: var(--wt-grad); color: #fff; box-shadow: 0 8px 24px rgba(255, 61, 119, .35); }
.btn-primary:hover { box-shadow: 0 12px 30px rgba(255, 61, 119, .45); }
.btn-ghost { background: var(--bg-card); color: var(--text); border-color: var(--border); }
.btn-ghost:hover { border-color: var(--ink-400); }

.menu-btn { display: none; background: none; border: 0; cursor: pointer; color: var(--text); }

/* ---- Hero ------------------------------------------------------------ */
.hero {
  position: relative; padding: clamp(40px, 7vw, 78px) 0 clamp(96px, 13vw, 150px);
  text-align: center; color: #fff; overflow: hidden;
  background: var(--wt-grad);
}
.hero::after { /* curved bottom divider */
  content: ""; position: absolute; left: -5%; right: -5%; bottom: -2px; height: 14vw; min-height: 90px;
  background: var(--bg); border-radius: 100% 100% 0 0 / 100% 100% 0 0;
}
.hero .wrap { position: relative; z-index: 2; }
.hero-mark { width: 104px; height: 104px; margin: 0 auto 26px; border-radius: 26px;
  box-shadow: 0 20px 60px rgba(0,0,0,.25); animation: floaty 6s ease-in-out infinite; }
@keyframes floaty { 0%,100%{ transform: translateY(0); } 50%{ transform: translateY(-9px); } }
.hero h1 { color: #fff; font-size: clamp(38px, 7vw, 76px); margin: 0 0 18px; letter-spacing: -.03em; }
.hero p.tag { font-size: clamp(17px, 2.4vw, 23px); color: rgba(255,255,255,.92); margin: 0 auto 8px; max-width: 620px; }
.hero p.sub { font-size: clamp(14px, 1.6vw, 17px); color: rgba(255,255,255,.78); margin: 0 auto 38px; max-width: 540px; }

/* ---- Platform download buttons -------------------------------------- */
.platforms { display: flex; flex-wrap: wrap; gap: 14px; justify-content: center; }
.plat {
  display: flex; align-items: center; gap: 12px; padding: 13px 22px; border-radius: 16px;
  background: rgba(255,255,255,.14); border: 1px solid rgba(255,255,255,.28);
  color: #fff; backdrop-filter: blur(8px); transition: background .2s, transform .15s;
  min-width: 168px;
}
.plat:hover { background: rgba(255,255,255,.24); transform: translateY(-2px); }
.plat svg { width: 26px; height: 26px; fill: #fff; flex: none; }
.plat .pl { text-align: left; line-height: 1.1; }
.plat .pl small { display: block; font-size: 11px; opacity: .82; font-weight: 500; }
.plat .pl strong { font-size: 16px; font-weight: 650; }
.plat[data-soon] { opacity: .82; }
.plat[data-soon] .pl small::after { content: " · soon"; }

/* on light sections, platform buttons invert */
.platforms.on-light .plat { background: var(--bg-card); border-color: var(--border); color: var(--text); box-shadow: var(--shadow-sm); }
.platforms.on-light .plat svg { fill: var(--text); }
.platforms.on-light .plat:hover { border-color: var(--ink-400); }

/* ---- Trust strip ----------------------------------------------------- */
.trust { display: flex; flex-wrap: wrap; gap: 14px 34px; justify-content: center; color: var(--text-dim); font-size: 14.5px; font-weight: 550; }
.trust span { display: inline-flex; align-items: center; gap: 8px; }
.trust svg { width: 18px; height: 18px; stroke: var(--wt-pink); }

/* ---- Feature grid ---------------------------------------------------- */
.features { background: var(--bg-soft); }
.grid { display: grid; gap: 22px; grid-template-columns: repeat(3, 1fr); margin-top: 54px; }
.card {
  background: var(--bg-card); border: 1px solid var(--border); border-radius: var(--radius-lg);
  padding: 30px 28px; box-shadow: var(--shadow-sm); transition: transform .25s ease, box-shadow .25s;
}
.card:hover { transform: translateY(-4px); box-shadow: var(--shadow-md); }
.card .ico { width: 54px; height: 54px; border-radius: 15px; display: grid; place-items: center;
  background: var(--wt-grad-soft); margin-bottom: 18px; }
.card .ico svg { width: 28px; height: 28px; stroke: var(--wt-pink); fill: none; stroke-width: 2; }
.card h3 { font-size: 20px; margin: 0 0 8px; }
.card p { margin: 0; color: var(--text-dim); font-size: 15.5px; }

/* ---- Showcase split -------------------------------------------------- */
.split { display: grid; grid-template-columns: 1.05fr 1fr; gap: 56px; align-items: center; }
.split .phone {
  aspect-ratio: 9/17; border-radius: 38px; background: var(--wt-grad);
  box-shadow: var(--shadow-lg); position: relative; max-width: 320px; margin: 0 auto; width: 100%;
  border: 10px solid #12141b;
}
.split .phone::before { content:""; position:absolute; top:14px; left:50%; transform:translateX(-50%);
  width: 96px; height: 22px; background:#12141b; border-radius: 0 0 14px 14px; }
.split .phone .scr { position:absolute; inset: 0; border-radius: 28px; display:grid; place-items:center; }
.split .phone .scr img { width: 46%; filter: drop-shadow(0 12px 30px rgba(0,0,0,.3)); }

/* ---- Cards row (Newsroom/Safety/Help) ------------------------------- */
.tiles { display: grid; grid-template-columns: repeat(3, 1fr); gap: 22px; margin-top: 48px; }
.tile { background: var(--bg-card); border: 1px solid var(--border); border-radius: var(--radius-lg);
  padding: 34px 30px; text-align: center; box-shadow: var(--shadow-sm); transition: transform .25s, box-shadow .25s; }
.tile:hover { transform: translateY(-4px); box-shadow: var(--shadow-md); }
.tile .ico { width: 60px; height: 60px; border-radius: 17px; margin: 0 auto 18px; display: grid; place-items: center; background: var(--wt-grad); }
.tile .ico svg { width: 30px; height: 30px; stroke: #fff; fill: none; stroke-width: 2; }
.tile h3 { font-size: 19px; margin: 0 0 6px; }
.tile p { margin: 0; color: var(--text-dim); font-size: 15px; }

/* ---- CTA ------------------------------------------------------------- */
.cta { background: var(--wt-grad); color: #fff; text-align: center; border-radius: var(--radius-lg); padding: clamp(48px,7vw,84px) 24px; }
.cta h2 { color: #fff; font-size: clamp(28px, 4.4vw, 46px); margin: 0 0 14px; }
.cta p { color: rgba(255,255,255,.9); margin: 0 auto 32px; max-width: 520px; font-size: 18px; }

/* ---- Footer ---------------------------------------------------------- */
.footer { background: var(--bg-soft); border-top: 1px solid var(--border); padding: 64px 0 40px; }
.footer .cols { display: grid; grid-template-columns: 1.4fr repeat(3, 1fr); gap: 40px; }
.footer .brand { margin-bottom: 14px; }
.footer .blurb { color: var(--text-dim); font-size: 14.5px; max-width: 300px; }
.footer h4 { font-size: 13px; text-transform: uppercase; letter-spacing: .1em; color: var(--text-dim); margin: 0 0 16px; }
.footer ul { list-style: none; padding: 0; margin: 0; display: grid; gap: 11px; }
.footer ul a { color: var(--text); font-size: 14.5px; opacity: .85; transition: opacity .2s, color .2s; }
.footer ul a:hover { opacity: 1; color: var(--wt-pink); }
.footer .legal { margin-top: 46px; padding-top: 26px; border-top: 1px solid var(--border);
  display: flex; flex-wrap: wrap; justify-content: space-between; gap: 14px; color: var(--text-dim); font-size: 13.5px; }

/* ---- Legal / doc pages ---------------------------------------------- */
.doc { padding: 56px 0 90px; }
.doc .wrap { max-width: 820px; }
.doc-hd { margin-bottom: 34px; }
.doc-hd h1 { font-size: clamp(30px, 5vw, 46px); margin: 0 0 10px; }
.doc-hd .meta { color: var(--text-dim); font-size: 14px; }
.doc-body { font-size: 16px; color: var(--text); }
.doc-body h2 { font-size: 25px; margin: 40px 0 12px; padding-top: 8px; }
.doc-body h3 { font-size: 19px; margin: 28px 0 8px; }
.doc-body h4 { font-size: 16px; margin: 22px 0 6px; }
.doc-body p, .doc-body li { color: var(--text); }
.doc-body a { color: var(--wt-pink); text-decoration: underline; text-underline-offset: 2px; }
.doc-body ul { padding-left: 22px; }
.doc-body blockquote { margin: 18px 0; padding: 14px 18px; background: var(--bg-soft);
  border-left: 3px solid var(--wt-pink); border-radius: 0 10px 10px 0; color: var(--text-dim); }
.doc-body table { width: 100%; border-collapse: collapse; margin: 18px 0; font-size: 14.5px; }
.doc-body th, .doc-body td { border: 1px solid var(--border); padding: 9px 12px; text-align: left; vertical-align: top; }
.doc-body th { background: var(--bg-soft); font-weight: 650; }
.doc-body hr { border: 0; border-top: 1px solid var(--border); margin: 32px 0; }
.doc-body code { background: var(--bg-soft); padding: 2px 6px; border-radius: 6px; font-size: .9em; }

.callout { background: var(--wt-grad-soft); border: 1px solid color-mix(in srgb, var(--wt-pink) 30%, transparent);
  border-radius: var(--radius); padding: 22px 24px; margin: 26px 0; }
.callout strong { color: var(--wt-pink); }

/* ---- Reveal animation ------------------------------------------------ */
.reveal { opacity: 0; transform: translateY(24px); transition: opacity .7s ease, transform .7s cubic-bezier(.2,.7,.2,1); }
.reveal.in { opacity: 1; transform: none; }
@media (prefers-reduced-motion: reduce) { .reveal { opacity: 1; transform: none; transition: none; } .hero-mark { animation: none; } }

/* ---- Responsive ------------------------------------------------------ */
@media (max-width: 900px) {
  .grid, .tiles { grid-template-columns: 1fr 1fr; }
  .split { grid-template-columns: 1fr; gap: 40px; }
  .footer .cols { grid-template-columns: 1fr 1fr; gap: 32px; }
}
@media (max-width: 640px) {
  .nav-links { gap: 14px; font-size: 14px; }
  .grid, .tiles { grid-template-columns: 1fr; }
  .plat { flex: 1 1 100%; }
  .plat-circles { gap: 20px 24px; }
  .home-cards { margin-top: 0; }
}

/* ---- Compact home: circular platform buttons + cards (WeChat-style) ---- */
.plat-circles { display: flex; flex-wrap: wrap; gap: 26px 38px; justify-content: center; margin-top: 34px; }
.plat-c { display: flex; flex-direction: column; align-items: center; gap: 11px; color: #fff; width: 84px; transition: transform .15s ease; }
.plat-c:hover { transform: translateY(-3px); }
.plat-c .circle {
  width: 66px; height: 66px; border-radius: 50%;
  background: rgba(255, 255, 255, .15); border: 1px solid rgba(255, 255, 255, .3);
  display: grid; place-items: center; backdrop-filter: blur(8px); transition: background .2s;
}
.plat-c:hover .circle { background: rgba(255, 255, 255, .26); }
.plat-c svg { width: 30px; height: 30px; fill: #fff; }
.plat-c span { font-size: 14px; font-weight: 550; letter-spacing: .01em; }
.plat-c[data-soon] { opacity: .85; }
.plat-c[data-soon] span::after { content: " · soon"; opacity: .7; font-weight: 400; }

.home-cards { padding: 0 0 clamp(40px, 6vw, 70px); margin-top: -36px; position: relative; z-index: 3; }
.home-cards .tiles { margin-top: 0; }

/* ---- Minimal footer (single row of links + copyright) ----------------- */
.footer-min { padding: 30px 0 36px; border-top: 1px solid var(--border); background: var(--bg); }
.footer-min .wrap { display: flex; flex-direction: column; align-items: center; gap: 14px; text-align: center; }
.foot-links { display: flex; flex-wrap: wrap; justify-content: center; gap: 8px 22px; }
.foot-links a { color: var(--text-dim); font-size: 14px; transition: color .2s; }
.foot-links a:hover { color: var(--wt-pink); }
.foot-copy { margin: 0; color: var(--text-dim); font-size: 13px; }