:root {
  --bg: #ffffff;
  --bg-soft: #f4f6fb;
  --card: #ffffff;
  --text: #1c2033;
  --muted: #5b6275;
  --line: #e3e7f0;
  --accent: #326ef2;
  --accent-ink: #ffffff;
  --accent-soft: #e8efff;
  --navy: #1c2033;
  --yellow: #ffd23f;
  --shadow: 0 1px 2px rgba(28, 32, 51, .06), 0 8px 24px rgba(28, 32, 51, .06);
  --radius: 18px;
  color-scheme: light;
}
@media (prefers-color-scheme: dark) {
  :root:not([data-theme="light"]) {
    --bg: #0f1220;
    --bg-soft: #161a2b;
    --card: #181c2e;
    --text: #eef1f8;
    --muted: #a1a8bb;
    --line: #272c42;
    --accent: #5b8cff;
    --accent-soft: #1d2747;
    --shadow: 0 1px 2px rgba(0, 0, 0, .3), 0 8px 24px rgba(0, 0, 0, .25);
    color-scheme: dark;
  }
}
:root[data-theme="dark"] {
  --bg: #0f1220;
  --bg-soft: #161a2b;
  --card: #181c2e;
  --text: #eef1f8;
  --muted: #a1a8bb;
  --line: #272c42;
  --accent: #5b8cff;
  --accent-soft: #1d2747;
  --shadow: 0 1px 2px rgba(0, 0, 0, .3), 0 8px 24px rgba(0, 0, 0, .25);
  color-scheme: dark;
}

* { box-sizing: border-box; }
html { -webkit-text-size-adjust: 100%; scroll-behavior: smooth; }
body {
  margin: 0;
  background: var(--bg);
  color: var(--text);
  font: 16px/1.6 -apple-system, BlinkMacSystemFont, "SF Pro Text", "Segoe UI", Roboto, "Helvetica Neue", Arial, sans-serif;
  -webkit-font-smoothing: antialiased;
}
a { color: var(--accent); text-decoration: none; }
a:hover { text-decoration: underline; }
img { display: block; max-width: 100%; }
h1, h2, h3 { line-height: 1.2; margin: 0; letter-spacing: -.01em; }
p { margin: 0; }

/* Language switching: html.en shows .en, otherwise .vi */
html.en .vi, html:not(.en) .en { display: none !important; }

.wrap { max-width: 1080px; margin: 0 auto; padding: 0 16px; }
@media (min-width: 720px) { .wrap { padding: 0 28px; } }

/* Header */
.top {
  position: sticky; top: 0; z-index: 10;
  background: color-mix(in srgb, var(--bg) 85%, transparent);
  backdrop-filter: saturate(180%) blur(14px);
  -webkit-backdrop-filter: saturate(180%) blur(14px);
  border-bottom: 1px solid var(--line);
}
.top .wrap { display: flex; align-items: center; gap: 12px; height: 60px; }
.brand { display: flex; align-items: center; gap: 10px; color: var(--text); font-weight: 700; font-size: 17px; }
.brand:hover { text-decoration: none; }
.brand img { width: 30px; height: 30px; border-radius: 8px; box-shadow: 0 0 0 1px var(--line); }
.nav { margin-left: auto; display: flex; align-items: center; gap: 4px; }
.nav a { color: var(--muted); font-size: 15px; padding: 6px 10px; border-radius: 8px; }
.nav a:hover { color: var(--text); background: var(--bg-soft); text-decoration: none; }
.nav .hide-sm { display: none; }
@media (min-width: 640px) { .nav .hide-sm { display: inline-block; } }
.lang {
  display: inline-flex; border: 1px solid var(--line); border-radius: 999px; padding: 2px; margin-left: 4px;
}
.lang button {
  border: 0; background: none; color: var(--muted); font: 600 12px/1 inherit; padding: 6px 9px; border-radius: 999px; cursor: pointer;
}
html:not(.en) .lang [data-lang="vi"], html.en .lang [data-lang="en"] { background: var(--text); color: var(--bg); }

/* Hero */
.hero { padding: 56px 0 40px; }
.hero .wrap { display: grid; gap: 40px; align-items: center; }
@media (min-width: 900px) { .hero { padding: 80px 0 64px; } .hero .wrap { grid-template-columns: 1.1fr .9fr; } }
.app-icon { width: 96px; height: 96px; border-radius: 22px; box-shadow: var(--shadow), 0 0 0 1px var(--line); margin-bottom: 24px; }
.hero h1 { font-size: clamp(34px, 6vw, 54px); font-weight: 800; }
.hero h1 .tint { color: var(--accent); }
.lead { font-size: clamp(17px, 2.2vw, 20px); color: var(--muted); margin-top: 16px; max-width: 34em; }
.cta { display: flex; flex-wrap: wrap; gap: 10px; margin-top: 28px; }
.btn {
  display: inline-flex; align-items: center; gap: 8px; height: 46px; padding: 0 20px; border-radius: 999px;
  font-weight: 600; font-size: 15px; border: 1px solid transparent;
}
.btn:hover { text-decoration: none; }
.btn.primary { background: var(--text); color: var(--bg); }
/* App Store link: until href holds a real URL, show "coming soon" and make it inert */
[data-app-store]:not([href^="http"]) { pointer-events: none; cursor: default; }
footer [data-app-store]:not([href^="http"]) { display: none; }
[data-app-store]:not([href^="http"]) .get, [data-app-store][href^="http"] .soon { display: none; }
.btn.ghost { border-color: var(--line); color: var(--text); background: var(--card); }
.btn.ghost:hover { background: var(--bg-soft); }
.chips { display: flex; flex-wrap: wrap; gap: 8px; margin-top: 24px; }
.chip { font-size: 13px; color: var(--muted); background: var(--bg-soft); border: 1px solid var(--line); border-radius: 999px; padding: 4px 12px; }

/* Shortcuts-style mock */
.mock {
  background: var(--bg-soft); border: 1px solid var(--line); border-radius: 28px; padding: 18px;
  box-shadow: var(--shadow); max-width: 440px; width: 100%; justify-self: center;
}
.mock-title { font-size: 13px; font-weight: 600; color: var(--muted); margin: 2px 6px 12px; display: flex; justify-content: space-between; }
.step {
  display: flex; align-items: center; gap: 12px; background: var(--card); border: 1px solid var(--line);
  border-radius: 14px; padding: 12px 14px; font-size: 15px;
}
.step + .step { margin-top: 8px; }
.step .tok { color: var(--accent); background: var(--accent-soft); border-radius: 6px; padding: 1px 7px; font-weight: 600; white-space: nowrap; }
.step small { display: block; color: var(--muted); font-size: 12px; line-height: 1.3; }
.tile {
  flex: none; width: 32px; height: 32px; border-radius: 8px; display: grid; place-items: center; color: #fff;
}
.tile svg { width: 19px; height: 19px; }
.t-blue { background: #326ef2; } .t-orange { background: #ff9500; } .t-pink { background: #ff375f; }
.t-green { background: #30b158; } .t-purple { background: #8e5cf0; } .t-teal { background: #12a8c4; }
.t-red { background: #ff453a; } .t-indigo { background: #5856d6; } .t-gray { background: #6b7280; } .t-navy { background: #1c2033; }
.t-yellow { background: #ffd23f; color: #1c2033; }

/* Sections */
section { padding: 56px 0; }
@media (min-width: 900px) { section { padding: 80px 0; } }
.soft { background: var(--bg-soft); border-top: 1px solid var(--line); border-bottom: 1px solid var(--line); }
.eyebrow { color: var(--accent); font-weight: 700; font-size: 13px; letter-spacing: .06em; text-transform: uppercase; }
.sec-head { max-width: 640px; margin-bottom: 36px; }
.sec-head h2 { font-size: clamp(26px, 4vw, 36px); font-weight: 800; margin-top: 8px; }
.sec-head p { color: var(--muted); margin-top: 12px; font-size: 17px; }

.grid { display: grid; gap: 14px; grid-template-columns: 1fr; }
@media (min-width: 640px) { .grid { grid-template-columns: 1fr 1fr; } }
@media (min-width: 960px) { .grid.three { grid-template-columns: repeat(3, 1fr); } }
.card {
  background: var(--card); border: 1px solid var(--line); border-radius: var(--radius); padding: 22px;
}
.card .tile { width: 40px; height: 40px; border-radius: 10px; margin-bottom: 14px; }
.card .tile svg { width: 22px; height: 22px; }
.card h3 { font-size: 18px; font-weight: 700; }
.card p { color: var(--muted); margin-top: 6px; font-size: 15px; }
.tags { display: flex; flex-wrap: wrap; gap: 6px; margin-top: 14px; }
.tags span { font-size: 12.5px; background: var(--bg-soft); border: 1px solid var(--line); border-radius: 7px; padding: 2px 8px; color: var(--text); }

.points { display: grid; gap: 22px; grid-template-columns: 1fr; }
@media (min-width: 760px) { .points { grid-template-columns: repeat(3, 1fr); } }
.point h3 { font-size: 17px; font-weight: 700; display: flex; align-items: center; gap: 10px; }
.point p { color: var(--muted); margin-top: 8px; font-size: 15px; }
.point .tile { width: 30px; height: 30px; }

.band {
  background: var(--navy); color: #fff; border-radius: 26px; padding: 36px 24px; text-align: center;
}
@media (min-width: 720px) { .band { padding: 52px 40px; } }
.band h2 { font-size: clamp(24px, 3.6vw, 32px); font-weight: 800; }
.band p { color: #c3c8d8; margin: 12px auto 0; max-width: 34em; }
.band .btn { margin-top: 24px; background: #fff; color: #1c2033; }
.band .mail { display: block; margin-top: 14px; color: #fff; font-weight: 600; font-size: 18px; word-break: break-all; }

/* Docs pages */
.doc { padding: 48px 0 72px; }
.doc .wrap { max-width: 760px; }
.doc h1 { font-size: clamp(30px, 5vw, 42px); font-weight: 800; }
.doc .meta { color: var(--muted); margin-top: 10px; }
.doc h2 { font-size: 21px; font-weight: 700; margin-top: 40px; }
.doc p, .doc li { color: var(--text); margin-top: 12px; }
.doc ul { padding-left: 22px; margin: 0; }
.doc li { margin-top: 8px; }
.doc .note { background: var(--accent-soft); border-radius: 14px; padding: 16px 18px; margin-top: 24px; }
.faq details { border: 1px solid var(--line); border-radius: 14px; background: var(--card); padding: 0 18px; }
.faq details + details { margin-top: 10px; }
.faq summary { cursor: pointer; font-weight: 600; padding: 16px 0; list-style: none; display: flex; justify-content: space-between; gap: 12px; }
.faq summary::-webkit-details-marker { display: none; }
.faq summary::after { content: "+"; color: var(--muted); font-weight: 400; font-size: 20px; line-height: 1; }
.faq details[open] summary::after { content: "–"; }
.faq details p { margin: 0 0 16px; color: var(--muted); }
.contact-card { display: flex; flex-wrap: wrap; align-items: center; gap: 16px; justify-content: space-between; border: 1px solid var(--line); border-radius: var(--radius); padding: 22px; margin-top: 28px; background: var(--card); }
.contact-card strong { font-size: 18px; word-break: break-all; }

footer { border-top: 1px solid var(--line); padding: 28px 0 40px; color: var(--muted); font-size: 14px; }
footer .wrap { display: flex; flex-wrap: wrap; gap: 12px 20px; align-items: center; justify-content: space-between; }
footer nav { display: flex; flex-wrap: wrap; gap: 6px 18px; }
footer a { color: var(--muted); }