:root {
  --c-primary: #534AB7;
  --c-primary-dark: #3C3489;
  --c-primary-light: #EEEDFE;
  --c-accent: #378ADD;
  --c-warn: #EF9F27;
  --c-success: #1D9E75;
  --c-bg: #F7F7FA;
  --c-surface: #FFFFFF;
  --c-text: #1F1F29;
  --c-text-2: #5F5E5A;
  --c-text-3: #8A8A93;
  --c-border: #E6E6EC;
  --radius-sm: 8px;
  --radius: 12px;
  --radius-lg: 16px;
  --shadow: 0 1px 3px rgba(31, 31, 41, 0.06), 0 8px 24px rgba(31, 31, 41, 0.05);
  --shadow-hover: 0 4px 12px rgba(83, 74, 183, 0.12), 0 16px 40px rgba(31, 31, 41, 0.10);
  --font: "PingFang SC", "Microsoft YaHei", "Hiragino Sans GB", "Source Han Sans CN", system-ui, -apple-system, sans-serif;
}

/* ---------- Dark / 护眼模式 ---------- */
:root[data-theme="dark"] {
  --c-primary: #8B83E6;
  --c-primary-dark: #A9A2F0;
  --c-primary-light: #2A2654;
  --c-accent: #85B7EB;
  --c-warn: #FAC775;
  --c-success: #5DCAA5;
  --c-bg: #14141B;
  --c-surface: #1E1E28;
  --c-text: #ECECF4;
  --c-text-2: #B4B4C4;
  --c-text-3: #7E7E90;
  --c-border: #2E2E3A;
  --shadow: 0 1px 3px rgba(0, 0, 0, 0.4), 0 8px 24px rgba(0, 0, 0, 0.35);
  --shadow-hover: 0 4px 12px rgba(139, 131, 230, 0.22), 0 16px 40px rgba(0, 0, 0, 0.5);
}

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

html { scroll-behavior: smooth; }

body {
  font-family: var(--font);
  color: var(--c-text);
  background: var(--c-bg);
  line-height: 1.6;
  -webkit-font-smoothing: antialiased;
  transition: background .3s, color .3s;
}

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

.container {
  max-width: 1180px;
  margin: 0 auto;
  padding: 0 24px;
}

/* ---------- Top Nav ---------- */
.nav {
  position: sticky;
  top: 0;
  z-index: 50;
  background: rgba(255, 255, 255, 0.86);
  backdrop-filter: saturate(180%) blur(12px);
  border-bottom: 1px solid var(--c-border);
  transition: background .3s, border-color .3s;
}
:root[data-theme="dark"] .nav { background: rgba(20, 20, 28, 0.85); }
.nav-inner {
  display: flex;
  align-items: center;
  justify-content: space-between;
  height: 64px;
}
.brand {
  display: flex;
  align-items: center;
  gap: 10px;
  font-weight: 700;
  font-size: 19px;
  color: var(--c-primary-dark);
}
:root[data-theme="dark"] .brand { color: var(--c-primary); }
.brand .logo {
  width: 34px; height: 34px;
  border-radius: 9px;
  background: linear-gradient(135deg, var(--c-primary), var(--c-accent));
  display: flex; align-items: center; justify-content: center;
  color: #fff; font-weight: 700; font-size: 16px;
}
.nav-links { display: flex; gap: 30px; align-items: center; }
.nav-links a { color: var(--c-text-2); font-size: 15px; transition: color .2s; }
.nav-links a:hover, .nav-links a.active { color: var(--c-primary); }
.nav-cta { display: flex; gap: 12px; align-items: center; }
.menu-toggle { display: none; background: none; border: none; font-size: 22px; cursor: pointer; color: var(--c-text); }

/* Theme toggle button (醒目) */
.btn-theme {
  display: inline-flex; align-items: center; gap: 6px;
  padding: 8px 14px; border-radius: 999px;
  font-size: 14px; font-weight: 600;
  background: var(--c-warn); color: #3a2a05;
  border: 1px solid var(--c-warn); cursor: pointer;
  transition: all .2s; white-space: nowrap;
}
.btn-theme:hover { filter: brightness(1.05); transform: translateY(-1px); box-shadow: 0 4px 12px rgba(239,159,39,.35); }
.btn-theme .ic { font-size: 16px; line-height: 1; }

/* ---------- Buttons ---------- */
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 8px;
  padding: 11px 22px;
  border-radius: var(--radius-sm);
  font-size: 15px;
  font-weight: 600;
  cursor: pointer;
  border: 1px solid transparent;
  transition: all .2s;
  white-space: nowrap;
}
.btn-primary { background: var(--c-primary); color: #fff; }
.btn-primary:hover { background: var(--c-primary-dark); box-shadow: var(--shadow-hover); transform: translateY(-1px); }
.btn-outline { background: transparent; color: var(--c-primary); border-color: var(--c-primary); }
.btn-outline:hover { background: var(--c-primary-light); }
.btn-ghost { background: rgba(255,255,255,.15); color: #fff; border-color: rgba(255,255,255,.4); }
.btn-ghost:hover { background: rgba(255,255,255,.25); }
.btn-sm { padding: 8px 16px; font-size: 14px; }

/* ---------- Hero ---------- */
.hero {
  background: radial-gradient(1200px 500px at 80% -10%, var(--c-primary-light), transparent 60%),
              linear-gradient(180deg, #fff, var(--c-bg));
  padding: 72px 0 56px;
  overflow: hidden;
  transition: background .3s;
}
:root[data-theme="dark"] .hero { background: linear-gradient(180deg, #1A1A24, var(--c-bg)); }
.hero-grid { display: grid; grid-template-columns: 1.1fr 0.9fr; gap: 40px; align-items: center; }
.hero h1 { font-size: 42px; line-height: 1.25; font-weight: 700; color: var(--c-text); letter-spacing: -0.5px; }
.hero h1 .hl { color: var(--c-primary); }
.hero p.sub { font-size: 17px; color: var(--c-text-2); margin: 20px 0 30px; max-width: 520px; }
.hero-actions { display: flex; gap: 14px; flex-wrap: wrap; }
.hero-stats { display: flex; gap: 36px; margin-top: 44px; }
.hero-stats .num { font-size: 28px; font-weight: 700; color: var(--c-primary-dark); }
:root[data-theme="dark"] .hero-stats .num { color: var(--c-primary); }
.hero-stats .lbl { font-size: 13px; color: var(--c-text-3); }
.hero-visual {
  background: linear-gradient(135deg, var(--c-primary), var(--c-accent));
  border-radius: var(--radius-lg);
  height: 340px;
  position: relative;
  overflow: hidden;
  box-shadow: var(--shadow-hover);
}
.hero-visual .badge {
  position: absolute; background: rgba(255,255,255,.16); backdrop-filter: blur(6px);
  border: 1px solid rgba(255,255,255,.3); color: #fff;
  padding: 10px 14px; border-radius: 10px; font-size: 13px;
}
.hero-visual .b1 { top: 28px; left: 28px; }
.hero-visual .b2 { bottom: 36px; left: 36px; }
.hero-visual .b3 { top: 90px; right: 30px; }

/* ---------- Section ---------- */
section { padding: 64px 0; }
.section-head { text-align: center; margin-bottom: 44px; }
.section-head .eyebrow { color: var(--c-primary); font-weight: 600; font-size: 14px; letter-spacing: 1px; }
.section-head h2 { font-size: 30px; font-weight: 700; margin: 10px 0 12px; }
.section-head p { color: var(--c-text-2); font-size: 16px; max-width: 640px; margin: 0 auto; }

/* ---------- Cards ---------- */
.card {
  background: var(--c-surface);
  border: 1px solid var(--c-border);
  border-radius: var(--radius);
  padding: 24px;
  transition: all .2s, background .3s, border-color .3s;
}
.card:hover { box-shadow: var(--shadow-hover); transform: translateY(-3px); border-color: transparent; }

.app-grid { display: grid; grid-template-columns: repeat(3, 1fr); gap: 22px; }
.app-card { display: flex; flex-direction: column; }
.app-icon {
  width: 56px; height: 56px; border-radius: 14px;
  display: flex; align-items: center; justify-content: center;
  font-size: 26px; color: #fff; margin-bottom: 16px;
}
.app-card h3 { font-size: 18px; margin-bottom: 6px; }
.app-card .desc { color: var(--c-text-2); font-size: 14px; flex: 1; margin-bottom: 16px; }
.app-tags { display: flex; gap: 8px; flex-wrap: wrap; margin-bottom: 16px; }
.tag { font-size: 12px; color: var(--c-primary); background: var(--c-primary-light); padding: 4px 10px; border-radius: 999px; }
.app-meta { display: flex; justify-content: space-between; align-items: center; font-size: 13px; color: var(--c-text-3); border-top: 1px solid var(--c-border); padding-top: 14px; }

/* ---------- Capability ---------- */
.cap-grid { display: grid; grid-template-columns: repeat(3, 1fr); gap: 22px; }
.cap-card { text-align: left; }
.cap-icon { width: 52px; height: 52px; border-radius: 12px; display: flex; align-items: center; justify-content: center; font-size: 24px; margin-bottom: 16px; }
.cap-card h3 { font-size: 19px; margin-bottom: 8px; }
.cap-card p { color: var(--c-text-2); font-size: 14px; margin-bottom: 16px; }
.cap-list { list-style: none; font-size: 14px; color: var(--c-text-2); }
.cap-list li { padding: 6px 0; display: flex; gap: 8px; align-items: center; }
.cap-list li::before { content: ""; width: 6px; height: 6px; border-radius: 50%; background: var(--c-primary); }

/* ---------- Process steps ---------- */
.steps { display: grid; grid-template-columns: repeat(4, 1fr); gap: 18px; }
.step { background: var(--c-surface); border: 1px solid var(--c-border); border-radius: var(--radius); padding: 22px; position: relative; transition: background .3s, border-color .3s; }
.step .idx { width: 34px; height: 34px; border-radius: 50%; background: var(--c-primary-light); color: var(--c-primary); font-weight: 700; display: flex; align-items: center; justify-content: center; margin-bottom: 12px; }
.step h4 { font-size: 16px; margin-bottom: 6px; }
.step p { font-size: 13px; color: var(--c-text-2); }

/* ---------- Community banner ---------- */
.community {
  background: linear-gradient(135deg, var(--c-primary-dark), var(--c-primary));
  border-radius: var(--radius-lg);
  padding: 48px;
  color: #fff;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 30px;
  flex-wrap: wrap;
}
.community h2 { font-size: 26px; margin-bottom: 10px; }
.community p { color: rgba(255,255,255,.85); max-width: 560px; }

/* ---------- Filters ---------- */
.filters { display: flex; gap: 10px; flex-wrap: wrap; margin-bottom: 30px; }
.filter-chip {
  padding: 8px 18px; border-radius: 999px; border: 1px solid var(--c-border);
  background: var(--c-surface); cursor: pointer; font-size: 14px; color: var(--c-text-2); transition: all .2s;
}
.filter-chip:hover { border-color: var(--c-primary); color: var(--c-primary); }
.filter-chip.active { background: var(--c-primary); color: #fff; border-color: var(--c-primary); }
.search-box {
  display: flex; align-items: center; gap: 8px; background: var(--c-surface);
  border: 1px solid var(--c-border); border-radius: var(--radius-sm); padding: 9px 14px; max-width: 320px; margin-left: auto;
  transition: background .3s, border-color .3s;
}
.search-box input { border: none; outline: none; font-size: 14px; width: 100%; font-family: var(--font); background: transparent; color: var(--c-text); }

/* ---------- Detail page ---------- */
.detail-hero { display: grid; grid-template-columns: 200px 1fr; gap: 30px; align-items: center; background: var(--c-surface); border: 1px solid var(--c-border); border-radius: var(--radius-lg); padding: 32px; transition: background .3s, border-color .3s; }
.detail-hero .big-icon { width: 120px; height: 120px; border-radius: 24px; display: flex; align-items: center; justify-content: center; font-size: 56px; color: #fff; }
.detail-hero h1 { font-size: 30px; margin-bottom: 8px; }
.detail-hero .meta-row { display: flex; gap: 18px; color: var(--c-text-3); font-size: 14px; margin: 12px 0 20px; flex-wrap: wrap; }
.download-btns { display: flex; gap: 12px; flex-wrap: wrap; }
.dl-btn {
  display: flex; align-items: center; gap: 12px; background: var(--c-surface); border: 1px solid var(--c-border);
  border-radius: var(--radius-sm); padding: 12px 18px; min-width: 170px; transition: all .2s, background .3s, border-color .3s;
}
.dl-btn:hover { border-color: var(--c-primary); box-shadow: var(--shadow); }
.dl-btn .plat { font-size: 13px; color: var(--c-text-3); }
.dl-btn .sz { font-size: 15px; font-weight: 600; }
.dl-btn .ic { font-size: 22px; }
.screenshot-grid { display: grid; grid-template-columns: repeat(3, 1fr); gap: 16px; margin-top: 20px; }
.shot { background: linear-gradient(135deg, #EDEDF5, #E3EEF9); border-radius: var(--radius); height: 180px; display: flex; align-items: center; justify-content: center; color: var(--c-text-3); font-size: 14px; transition: background .3s; }
:root[data-theme="dark"] .shot { background: linear-gradient(135deg, #26263A, #20202E); }

/* ---------- Forms ---------- */
.form-grid { display: grid; grid-template-columns: 1fr 1fr; gap: 18px; }
.field { display: flex; flex-direction: column; gap: 6px; }
.field.full { grid-column: 1 / -1; }
.field label { font-size: 14px; color: var(--c-text-2); }
.field input, .field textarea, .field select {
  border: 1px solid var(--c-border); border-radius: var(--radius-sm); padding: 11px 14px;
  font-size: 15px; font-family: var(--font); outline: none; transition: border .2s, background .3s; background: var(--c-surface); color: var(--c-text);
}
.field input:focus, .field textarea:focus, .field select:focus { border-color: var(--c-primary); }

/* ---------- Footer ---------- */
footer { background: #1C1B27; color: #cfcfe0; padding: 56px 0 28px; margin-top: 40px; transition: background .3s; }
:root[data-theme="dark"] footer { background: #0F0F15; }
.footer-grid { display: grid; grid-template-columns: 1.5fr 1fr 1fr 1fr; gap: 30px; }
footer h4 { color: #fff; font-size: 15px; margin-bottom: 14px; }
footer a { color: #a9a9c0; font-size: 14px; display: block; padding: 5px 0; }
footer a:hover { color: #fff; }
.footer-bottom { border-top: 1px solid #34334a; margin-top: 36px; padding-top: 20px; font-size: 13px; color: #8a8aa0; display: flex; justify-content: space-between; flex-wrap: wrap; gap: 10px; }

/* ---------- Toast 提示 ---------- */
.toast {
  position: fixed; left: 50%; bottom: 40px;
  transform: translateX(-50%) translateY(20px);
  background: var(--c-text); color: var(--c-bg);
  padding: 12px 22px; border-radius: 999px;
  font-size: 14px; font-weight: 600;
  box-shadow: var(--shadow-hover);
  opacity: 0; pointer-events: none; transition: all .3s; z-index: 999;
}
.toast.show { opacity: 1; transform: translateX(-50%) translateY(0); }

/* ---------- Responsive ---------- */
@media (max-width: 880px) {
  .nav-links { display: none; }
  .menu-toggle { display: block; }
  .hero-grid, .detail-hero { grid-template-columns: 1fr; }
  .hero-visual { height: 220px; }
  .app-grid, .cap-grid { grid-template-columns: 1fr 1fr; }
  .steps { grid-template-columns: 1fr 1fr; }
  .footer-grid { grid-template-columns: 1fr 1fr; }
  .hero h1 { font-size: 32px; }
  .form-grid { grid-template-columns: 1fr; }
  .search-box { margin-left: 0; max-width: 100%; }
  .btn-theme .txt { display: none; }
}
@media (max-width: 560px) {
  .app-grid, .cap-grid, .steps, .screenshot-grid, .footer-grid { grid-template-columns: 1fr; }
  .hero-stats { gap: 22px; }
}