:root {
  --bg: #f4f6f1;
  --surface: #ffffff;
  --text: #17221a;
  --muted: #5d6b60;
  --line: #dfe6dc;
  --green: #2f6b35;
  --green-deep: #234f28;
  --green-pale: #e7f0e3;
  --accent-text: #2f6b35;
  --danger: #a3332b;
  --shadow: 0 10px 30px rgba(23, 34, 26, 0.08);
}
@media (prefers-color-scheme: dark) {
  :root:not([data-theme="light"]) {
    --bg: #0f1511;
    --surface: #18201a;
    --text: #e8efe7;
    --muted: #9aa99c;
    --line: #2a352c;
    --green: #4f9a57;
    --green-deep: #3d7f45;
    --green-pale: #1f2c21;
    --accent-text: #8fd197;
    --danger: #f08a80;
    --shadow: 0 10px 30px rgba(0, 0, 0, 0.35);
  }
}
:root[data-theme="dark"] {
  --bg: #0f1511;
  --surface: #18201a;
  --text: #e8efe7;
  --muted: #9aa99c;
  --line: #2a352c;
  --green: #4f9a57;
  --green-deep: #3d7f45;
  --green-pale: #1f2c21;
  --accent-text: #8fd197;
  --danger: #f08a80;
  --shadow: 0 10px 30px rgba(0, 0, 0, 0.35);
}
* { box-sizing: border-box; }
html { -webkit-text-size-adjust: 100%; }
body {
  margin: 0;
  background: var(--bg);
  color: var(--text);
  font: 16px/1.6 -apple-system, BlinkMacSystemFont, "SF Pro Text", "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei", "Helvetica Neue", Arial, sans-serif;
}
a { color: var(--accent-text); }
.wrap { max-width: 1080px; margin: 0 auto; padding: 0 16px; }
.wrap.narrow { max-width: 760px; }

/* language: both languages ship in the page, one is hidden */
[data-lang="en"] .zh, [data-lang="zh"] .en { display: none !important; }

/* header */
header.top {
  position: sticky; top: 0; z-index: 10;
  background: color-mix(in srgb, var(--bg) 88%, transparent);
  backdrop-filter: saturate(1.4) blur(12px);
  -webkit-backdrop-filter: saturate(1.4) blur(12px);
  border-bottom: 1px solid var(--line);
}
header.top .wrap { display: flex; align-items: center; gap: 10px; height: 56px; }
header.top .brand { display: flex; align-items: center; gap: 10px; color: var(--text); text-decoration: none; }
header.top .brand img { width: 30px; height: 30px; border-radius: 7px; }
header.top .brand b { font-size: 17px; }
header.top .spacer { flex: 1; }
nav.main { display: flex; gap: 4px; }
nav.main a {
  color: var(--muted); text-decoration: none; font-size: 15px;
  padding: 6px 10px; border-radius: 999px;
}
nav.main a:hover { color: var(--text); }
nav.main a[aria-current="page"] { color: var(--accent-text); background: var(--green-pale); font-weight: 600; }
.lang {
  border: 1px solid var(--line); background: var(--surface); color: var(--text);
  border-radius: 999px; padding: 6px 12px; font: inherit; font-size: 14px; cursor: pointer;
  white-space: nowrap;
}
@media (max-width: 620px) {
  header.top .brand b { display: none; }
  nav.main a { padding: 6px 8px; font-size: 14px; }
}

/* buttons */
.cta { display: flex; gap: 12px; justify-content: center; flex-wrap: wrap; margin: 24px 0 8px; }
.btn {
  display: inline-flex; align-items: center; justify-content: center; gap: 8px;
  padding: 12px 22px; border-radius: 999px; text-decoration: none; font: inherit; font-weight: 700;
  border: 0; cursor: pointer;
  transition: transform .15s ease, box-shadow .15s ease, opacity .15s ease;
}
.btn:active { transform: scale(0.97); }
.btn.primary { background: var(--green-deep); color: #fff; box-shadow: var(--shadow); }
.btn.secondary { background: var(--surface); color: var(--accent-text); border: 1px solid var(--line); }
.btn[disabled] { opacity: .55; cursor: default; transform: none; }
.btn svg { width: 18px; height: 18px; fill: currentColor; }
.note { font-size: 13px; color: var(--muted); }

/* landing */
.hero { padding: 48px 0 24px; text-align: center; }
.hero .icon { width: 96px; height: 96px; border-radius: 22px; box-shadow: var(--shadow); }
.hero h1 { margin: 18px 0 6px; font-size: clamp(32px, 6vw, 48px); line-height: 1.15; letter-spacing: -0.01em; }
.hero p.tag { margin: 0 auto; max-width: 640px; font-size: clamp(17px, 2.6vw, 21px); color: var(--muted); }
.heroimg { margin: 24px auto 0; border-radius: 20px; overflow: hidden; box-shadow: var(--shadow); }
.heroimg img { display: block; width: 100%; height: auto; }

section { padding: 48px 0 8px; }
section h2 { font-size: clamp(24px, 4vw, 32px); margin: 0 0 6px; }
section p.lead { margin: 0 0 24px; color: var(--muted); }

.grid { display: grid; gap: 14px; grid-template-columns: repeat(auto-fit, minmax(240px, 1fr)); }
.grid .card.wide { grid-column: 1 / -1; }
@media (min-width: 720px) { .grid .card.wide ul { display: flex; flex-wrap: wrap; gap: 6px 28px; } }
.card {
  background: var(--surface); border: 1px solid var(--line); border-radius: 18px;
  padding: 20px; box-shadow: var(--shadow);
}
.card h3 { margin: 10px 0 6px; font-size: 18px; }
.card ul { margin: 0; padding-left: 18px; color: var(--muted); }
.card li { margin: 4px 0; }
.badge {
  display: inline-flex; width: 40px; height: 40px; border-radius: 12px; align-items: center; justify-content: center;
  background: var(--green-pale); color: var(--accent-text); font-size: 20px;
}

.shots {
  display: flex; gap: 14px; overflow-x: auto; scroll-snap-type: x mandatory;
  padding: 4px 16px 16px; margin: 0 -16px;
}
@media (min-width: 760px) { .shots { margin: 0; padding-left: 2px; padding-right: 2px; } }
.shots figure { margin: 0; flex: 0 0 auto; width: min(62vw, 230px); scroll-snap-align: start; text-align: center; }
.shots img { width: 100%; height: auto; border-radius: 22px; border: 1px solid var(--line); box-shadow: var(--shadow); display: block; }
.shots figcaption { margin-top: 8px; font-size: 14px; color: var(--muted); }

.soon { background: var(--green-pale); border-radius: 18px; padding: 20px; }
.soon h2 { font-size: 22px; margin: 0; }
.soon .chips { display: flex; flex-wrap: wrap; gap: 8px; margin-top: 12px; }
.chip { background: var(--surface); border: 1px solid var(--line); border-radius: 999px; padding: 6px 12px; font-size: 14px; }

.tech { columns: 2 280px; column-gap: 28px; color: var(--muted); padding-left: 18px; margin: 0; }
.tech li { break-inside: avoid; margin: 0 0 8px; }

/* document pages (support, privacy, terms, about) */
.doc { padding-top: 40px; padding-bottom: 8px; }
.doc h1 { font-size: clamp(28px, 5vw, 38px); line-height: 1.2; margin: 0 0 6px; letter-spacing: -0.01em; }
.doc .sub { color: var(--muted); margin: 0 0 28px; }
.doc h2 { font-size: 21px; margin: 36px 0 8px; }
.doc h3 { font-size: 17px; margin: 24px 0 4px; }
.doc p, .doc li { color: var(--text); }
.doc ul { padding-left: 20px; }
.doc li { margin: 6px 0; }
.doc .card { margin: 20px 0; }
.doc .card h2 { margin-top: 0; }
.doc .toc, .toc { display: flex; flex-wrap: wrap; gap: 8px; margin: 0 0 8px; padding: 0; list-style: none; }
.toc a { display: inline-block; font-size: 14px; padding: 4px 10px; border-radius: 999px; background: var(--surface); border: 1px solid var(--line); text-decoration: none; }

/* about */
.author { display: flex; gap: 18px; align-items: center; margin: 0 0 24px; }
.author .mono {
  flex: 0 0 auto; width: 72px; height: 72px; border-radius: 50%;
  display: flex; align-items: center; justify-content: center;
  background: var(--green-deep); color: #fff; font-weight: 800; font-size: 26px; letter-spacing: .02em;
}
.author h1 { margin: 0; }
.author p { margin: 2px 0 0; color: var(--muted); }

/* contact form */
form.contact { display: grid; gap: 14px; grid-template-columns: minmax(0, 1fr); }
form.contact > *, .field, .row2 > * { min-width: 0; }
.field { display: grid; gap: 6px; }
.field label { font-weight: 600; font-size: 15px; }
.field input, .field select, .field textarea {
  font: inherit; color: var(--text); background: var(--bg);
  border: 1px solid var(--line); border-radius: 12px; padding: 10px 12px; width: 100%;
}
.field textarea { min-height: 150px; resize: vertical; }
.field input:focus, .field select:focus, .field textarea:focus { outline: 2px solid var(--green); outline-offset: 1px; }
.row2 { display: grid; gap: 14px; grid-template-columns: minmax(0, 1fr); }
@media (min-width: 620px) { .row2 { grid-template-columns: minmax(0, 1fr) minmax(0, 1fr); } }
.hp { position: absolute; left: -9999px; width: 1px; height: 1px; overflow: hidden; }
.turnstile-slot { min-height: 65px; max-width: 100%; }
#emailTurnstile { max-width: 100%; }
.reveal-email output { overflow-wrap: anywhere; }
.doc p, .doc li { overflow-wrap: break-word; }
@media (max-width: 420px) { .doc .card { padding: 16px; } }
.status { min-height: 1.6em; font-size: 15px; margin: 0; }
.status.ok { color: var(--accent-text); }
.status.err { color: var(--danger); }
.formfoot { display: flex; flex-wrap: wrap; align-items: center; gap: 12px 16px; }
.reveal-email { display: flex; flex-wrap: wrap; align-items: center; gap: 10px; }
.reveal-email output { font-weight: 600; }

footer { margin-top: 56px; padding: 28px 0 40px; border-top: 1px solid var(--line); color: var(--muted); font-size: 14px; }
footer .links { display: flex; gap: 16px; flex-wrap: wrap; margin-bottom: 10px; }

.reveal { opacity: 0; transform: translateY(14px); transition: opacity .6s ease, transform .6s ease; }
.reveal.in { opacity: 1; transform: none; }
.no-js .reveal { opacity: 1; transform: none; }
@media (prefers-reduced-motion: reduce) {
  .reveal { opacity: 1; transform: none; transition: none; }
  .btn { transition: none; }
}