:root {
  --accent: #3AA0FF;
  --accent-end: #36E0E0;
  --bg: #0B0B0F;
  --surface: #16161C;
  --elevated: #1F1F27;
  --line: rgba(255,255,255,.10);
  --ink: #F2F3F5;
  --muted: rgba(255,255,255,.58);
  --faint: rgba(255,255,255,.38);
}
* { box-sizing: border-box; }
html { -webkit-text-size-adjust: 100%; }
body {
  margin: 0;
  font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", "PingFang SC",
    "Hiragino Sans GB", "Microsoft YaHei", Roboto, Helvetica, Arial, sans-serif;
  color: var(--ink);
  background: var(--bg);
  line-height: 1.7;
}
a { color: var(--accent); text-decoration: none; }
a:hover { text-decoration: underline; }

.hero {
  position: relative;
  text-align: center;
  padding: 64px 20px 52px;
  background:
    radial-gradient(60% 90% at 50% 0%, rgba(58,160,255,.22) 0%, rgba(58,160,255,0) 70%),
    linear-gradient(180deg, #12131A 0%, #0B0B0F 100%);
  border-bottom: 1px solid var(--line);
}
.hero.small { padding: 52px 20px 40px; }
.hero img {
  width: 96px; height: 96px;
  border-radius: 22px;
  border: 1px solid var(--line);
  box-shadow: 0 10px 30px rgba(0,0,0,.5), 0 0 40px rgba(58,160,255,.25);
}
.hero h1 {
  font-size: 30px; margin: 20px 0 8px; font-weight: 700; letter-spacing: .5px;
  background: linear-gradient(135deg, var(--accent), var(--accent-end));
  -webkit-background-clip: text; background-clip: text;
  -webkit-text-fill-color: transparent;
}
.hero.small h1 { font-size: 26px; }
.hero p { margin: 0; color: var(--muted); font-size: 16px; }

.wrap { max-width: 760px; margin: 0 auto; padding: 32px 20px 64px; }
.card {
  background: var(--surface);
  border: 1px solid var(--line);
  border-radius: 18px;
  padding: 24px 22px;
  margin: 18px 0;
}
h2 { font-size: 20px; margin: 34px 0 10px; font-weight: 700; }
h3 { font-size: 16px; margin: 22px 0 6px; color: var(--ink); }
.muted { color: var(--muted); font-size: 14px; }
ul { padding-left: 20px; margin: 8px 0; }
li { margin: 5px 0; }
strong { color: var(--ink); }

.features { display: grid; grid-template-columns: 1fr 1fr; gap: 14px; }
@media (max-width: 560px) { .features { grid-template-columns: 1fr; } }
.feature {
  background: var(--elevated);
  border: 1px solid var(--line);
  border-radius: 14px;
  padding: 18px;
}
.feature h3 { margin: 0 0 4px; color: var(--accent); }
.feature p { margin: 0; color: var(--muted); font-size: 14px; }

.btn {
  display: inline-block;
  background: linear-gradient(135deg, var(--accent), var(--accent-end));
  color: #fff;
  padding: 12px 28px; border-radius: 999px;
  font-weight: 600; margin-top: 14px;
  box-shadow: 0 8px 22px rgba(58,160,255,.35);
}
.btn:hover { text-decoration: none; opacity: .92; }

.nav { text-align: center; padding: 14px 20px 0; }
.nav a { margin: 0 12px; font-size: 14px; color: var(--muted); }
.nav a:hover { color: var(--accent); }

/* 语言切换 */
.langswitch {
  display: inline-flex; vertical-align: middle;
  margin-left: 8px; border: 1px solid var(--line);
  border-radius: 999px; overflow: hidden; background: var(--surface);
}
.langswitch button {
  appearance: none; -webkit-appearance: none;
  border: 0; background: transparent; cursor: pointer;
  color: var(--muted); font-size: 13px; font-weight: 600;
  padding: 5px 12px; line-height: 1.4;
  font-family: inherit;
}
.langswitch button + button { border-left: 1px solid var(--line); }
.langswitch button:hover { color: var(--ink); }
.langswitch button[aria-pressed="true"] {
  background: linear-gradient(135deg, var(--accent), var(--accent-end));
  color: #fff;
}
/* 默认（无 JS）两种语言都显示；有 JS 时按 html 类切换 */
html.lang-zh .en { display: none !important; }
html.lang-en .zh { display: none !important; }

footer {
  text-align: center; color: var(--faint);
  font-size: 13px; padding: 30px 20px 48px;
  border-top: 1px solid var(--line); background: #0E0E13;
}