:root {
  --bg: #050d23;
  --bg-2: #0a1430;
  --bg-3: #0f1d44;
  --card: rgba(255, 255, 255, 0.05);
  --card-border: rgba(255, 255, 255, 0.12);
  --text: #eaf0ff;
  --text-dim: #9fb0d6;
  --accent: #5b6cff;
  --accent-2: #c44cff;
  --accent-3: #33d6c8;
  --grad: linear-gradient(120deg, #5b6cff 0%, #c44cff 50%, #33d6c8 100%);
  --grad-soft: linear-gradient(120deg, rgba(91, 108, 255, 0.18), rgba(196, 76, 255, 0.18));
  --radius: 18px;
  --shadow: 0 20px 60px rgba(0, 0, 0, 0.45);
}

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

html { scroll-behavior: smooth; }

body {
  font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", "PingFang SC",
    "Hiragino Sans GB", "Microsoft YaHei", "Helvetica Neue", Arial, sans-serif;
  background: radial-gradient(1200px 700px at 80% -10%, rgba(91, 108, 255, 0.25), transparent 60%),
    radial-gradient(900px 600px at 0% 10%, rgba(196, 76, 255, 0.18), transparent 55%),
    var(--bg);
  color: var(--text);
  line-height: 1.65;
  min-height: 100vh;
  -webkit-font-smoothing: antialiased;
}

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

.container { width: min(1120px, 92vw); margin: 0 auto; }

/* ---------- Nav ---------- */
.nav {
  position: sticky; top: 0; z-index: 50;
  backdrop-filter: blur(14px);
  background: rgba(5, 13, 35, 0.7);
  border-bottom: 1px solid var(--card-border);
}
.nav-inner { display: flex; align-items: center; justify-content: space-between; height: 64px; }
.brand { display: flex; align-items: center; gap: 10px; font-weight: 800; font-size: 19px; letter-spacing: .5px; }
.brand img { width: 34px; height: 34px; border-radius: 9px; }
.brand .dot { background: var(--grad); -webkit-background-clip: text; background-clip: text; color: transparent; }

/* ---------- Buttons ---------- */
.btn {
  display: inline-flex; align-items: center; gap: 9px;
  padding: 15px 30px; border-radius: 999px; font-weight: 700; font-size: 16px;
  border: none; cursor: pointer; transition: transform .15s ease, box-shadow .15s ease, filter .15s;
  text-align: center;
}
.btn-primary { background: var(--grad); color: #fff; box-shadow: 0 12px 30px rgba(120, 80, 255, 0.45); }
.btn-primary:hover { transform: translateY(-2px); filter: brightness(1.07); }
.btn-ghost { background: var(--card); color: var(--text); border: 1px solid var(--card-border); }
.btn-ghost:hover { background: rgba(255, 255, 255, 0.1); }
.btn-sm { padding: 10px 20px; font-size: 14px; }

/* ---------- Hero ---------- */
.hero { padding: 76px 0 56px; text-align: center; position: relative; }
.badge {
  display: inline-flex; align-items: center; gap: 8px; font-size: 13px;
  padding: 7px 15px; border-radius: 999px; border: 1px solid var(--card-border);
  background: var(--card); color: var(--text-dim); margin-bottom: 22px;
}
.badge b { color: var(--accent-3); }
.hero h1 {
  font-size: clamp(34px, 6vw, 60px); line-height: 1.1; font-weight: 900; letter-spacing: -1px;
  background: linear-gradient(180deg, #fff, #b9c6ff);
  -webkit-background-clip: text; background-clip: text; color: transparent;
  margin-bottom: 18px;
}
.hero .tag { font-size: clamp(17px, 2.4vw, 22px); color: var(--text-dim); margin-bottom: 12px; }
.hero .sub { font-size: 15px; color: var(--text-dim); opacity: .85; margin-bottom: 34px; }
.hero-meta { font-size: 13px; color: var(--text-dim); }

/* ---------- Section ---------- */
.section { padding: 58px 0; }
.section-head { text-align: center; margin-bottom: 40px; }
.section-head .eyebrow { color: var(--accent-3); font-weight: 700; letter-spacing: 2px; font-size: 13px; text-transform: uppercase; }
.section-head h2 { font-size: clamp(26px, 4vw, 38px); font-weight: 850; margin: 10px 0 8px; }
.section-head p { color: var(--text-dim); }

/* ---------- Features grid ---------- */
.grid { display: grid; grid-template-columns: repeat(3, 1fr); gap: 20px; }
@media (max-width: 860px) { .grid { grid-template-columns: repeat(2, 1fr); } }
@media (max-width: 560px) { .grid { grid-template-columns: 1fr; } }
.card {
  background: var(--card); border: 1px solid var(--card-border); border-radius: var(--radius);
  padding: 26px; transition: transform .18s ease, border-color .18s ease, background .18s;
  position: relative; overflow: hidden;
}
.card::before {
  content: ""; position: absolute; inset: 0; background: var(--grad-soft);
  opacity: 0; transition: opacity .2s; pointer-events: none;
}
.card:hover { transform: translateY(-4px); border-color: rgba(255, 255, 255, 0.28); }
.card:hover::before { opacity: 1; }
.card .ico { font-size: 34px; margin-bottom: 14px; }
.card h3 { font-size: 18px; margin-bottom: 8px; position: relative; }
.card p { color: var(--text-dim); font-size: 14.5px; position: relative; }

/* ---------- Device cards (Android / iOS) ---------- */
.device-grid { display: grid; grid-template-columns: 1fr 1fr; gap: 22px; align-items: start; }
@media (max-width: 760px) { .device-grid { grid-template-columns: 1fr; } }
.device-card {
  background: var(--card); border: 1px solid var(--card-border); border-radius: 22px;
  padding: 30px 28px; display: flex; flex-direction: column; gap: 14px;
}
.device-head { display: flex; align-items: center; gap: 12px; }
.device-head h2 { font-size: 24px; font-weight: 850; }
.device-ico { font-size: 34px; }
.device-desc { color: var(--text-dim); font-size: 15px; }
.device-card .btn { justify-content: center; }
.device-note { font-size: 13px; color: var(--text-dim); line-height: 1.6; }
.steps { margin: 4px 0 2px; padding-left: 22px; color: var(--text-dim); font-size: 14.5px; line-height: 1.9; }
.steps li { margin-bottom: 2px; }
.steps b { color: var(--text); }

/* ---------- Video ---------- */
.video-box { margin-top: 6px; }
.video-wrap { position: relative; width: 100%; aspect-ratio: 16 / 9; border-radius: 14px; overflow: hidden; background: #000; border: 1px solid var(--card-border); }
.video-wrap iframe { position: absolute; inset: 0; width: 100%; height: 100%; border: 0; }
.video-el { width: 100%; border-radius: 14px; background: #000; border: 1px solid var(--card-border); display: block; }
.video-box .hint { margin-top: 8px; }

/* ---------- 安装说明 & 教程按钮 ---------- */
.install-tip {
  background: rgba(255, 255, 255, 0.04);
  border: 1px solid var(--card-border);
  border-radius: 14px;
  padding: 14px 16px;
  font-size: 13.5px;
  color: var(--text-dim);
  line-height: 1.75;
  white-space: pre-line;
}
.btn-tutorial {
  background: rgba(91, 108, 255, 0.16);
  color: var(--text);
  border: 1px solid rgba(91, 108, 255, 0.5);
  justify-content: center;
}
.btn-tutorial:hover { background: rgba(91, 108, 255, 0.28); transform: translateY(-2px); }

/* ---------- Footer ---------- */
.footer { border-top: 1px solid var(--card-border); padding: 34px 0; color: var(--text-dim); font-size: 13.5px; text-align: center; }
.footer a { color: var(--accent-3); }

/* ---------- Admin ---------- */
.admin-wrap { max-width: 880px; margin: 40px auto; }
.login-box {
  max-width: 380px; margin: 80px auto; text-align: center;
  background: var(--card); border: 1px solid var(--card-border); border-radius: var(--radius); padding: 34px;
}
.login-box input {
  width: 100%; padding: 13px 16px; border-radius: 12px; margin: 14px 0; font-size: 15px;
  background: rgba(0, 0, 0, 0.25); border: 1px solid var(--card-border); color: var(--text);
}
.field { margin-bottom: 18px; }
.field label { display: block; font-size: 13px; color: var(--text-dim); margin-bottom: 7px; font-weight: 600; }
.field input, .field textarea {
  width: 100%; padding: 12px 14px; border-radius: 12px; font-size: 15px;
  background: rgba(0, 0, 0, 0.25); border: 1px solid var(--card-border); color: var(--text); font-family: inherit;
}
.field textarea { resize: vertical; min-height: 70px; }
.field-row { display: grid; grid-template-columns: 1fr 1fr; gap: 14px; }
@media (max-width: 640px) { .field-row { grid-template-columns: 1fr; } }
.item-card {
  background: rgba(255, 255, 255, 0.04); border: 1px solid var(--card-border);
  border-radius: 14px; padding: 16px; margin-bottom: 14px; position: relative;
}
.item-card .del { position: absolute; top: 12px; right: 12px; background: rgba(255, 80, 80, 0.15); color: #ff9a9a; border: none; border-radius: 8px; padding: 6px 11px; cursor: pointer; font-size: 13px; }
.item-card .del:hover { background: rgba(255, 80, 80, 0.3); }
.add-btn { background: var(--grad-soft); border: 1px dashed var(--card-border); color: var(--text); border-radius: 12px; padding: 12px; width: 100%; cursor: pointer; font-size: 14px; margin-bottom: 26px; }
.add-btn:hover { border-color: var(--accent); }
.group-title { font-size: 15px; font-weight: 800; margin: 26px 0 14px; display: flex; align-items: center; gap: 10px; }
.group-title::before { content: ""; width: 4px; height: 18px; border-radius: 3px; background: var(--grad); }
.save-bar { display: flex; gap: 14px; align-items: center; justify-content: flex-end; margin-top: 20px; padding-top: 20px; border-top: 1px solid var(--card-border); }
.status { font-size: 14px; color: var(--accent-3); }
.status.err { color: #ff9a9a; }
.admin-head { display: flex; justify-content: space-between; align-items: center; margin-bottom: 10px; }
.admin-head a { color: var(--accent-3); font-size: 14px; }
.hint { font-size: 12.5px; color: var(--text-dim); margin-top: 4px; }

/* ---------- 移动端紧凑布局（下载用户主要在手机上查看） ---------- */
@media (max-width: 760px) {
  .nav-inner { height: 56px; }
  .brand { font-size: 17px; }
  .brand img { width: 30px; height: 30px; }
  .hero { padding: 42px 0 30px; }
  .hero h1 { font-size: clamp(28px, 8vw, 40px); }
  .hero .tag { font-size: 16px; }
  .hero .sub { font-size: 13px; }
  .hero-meta { font-size: 13px; }
  .badge { font-size: 12px; padding: 6px 12px; }
  .section { padding: 34px 0; }
  .section-head { margin-bottom: 24px; }
  .section-head h2 { font-size: 22px; }
  .device-grid { gap: 14px; }
  .device-card { padding: 20px 18px; gap: 12px; border-radius: 18px; }
  .device-head h2 { font-size: 20px; }
  .device-ico { font-size: 28px; }
  .device-desc { font-size: 14px; }
  .device-note { font-size: 12.5px; }
  .grid { gap: 12px; }
  .card { padding: 18px; }
  .card .ico { font-size: 28px; margin-bottom: 10px; }
  .card h3 { font-size: 16px; }
  .card p { font-size: 13.5px; }
  .steps { font-size: 13.5px; line-height: 1.75; }
  .footer { padding: 24px 0; font-size: 12.5px; }
  .btn { padding: 13px 24px; font-size: 15px; }
}