:root {
  --bg: #0b1020;
  --bg-soft: #10162a;
  --card: rgba(18, 24, 42, 0.55);
  --card-solid: #12182a;
  --border: rgba(255, 255, 255, 0.08);
  --border-strong: rgba(255, 255, 255, 0.14);
  --text: #eef2fa;
  --text-2: #c3cad9;
  --muted: #8b94a7;
  --accent: #7fb2f0;
  --accent-light: #a8c8f5;
  --accent-dark: #5b8fd6;
  --shadow: 0 24px 60px -20px rgba(0, 0, 0, 0.55);
}

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

html { scroll-behavior: smooth; background: #0b1020; }

body {
  font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", "PingFang SC",
    "Hiragino Sans GB", "Microsoft YaHei", "Helvetica Neue", Arial, sans-serif;
  color: var(--text);
  background: transparent;
  line-height: 1.8;
  -webkit-font-smoothing: antialiased;
  overflow-x: hidden;
}

/* ===== 动态极光背景 ===== */
.aurora {
  position: fixed; inset: 0; z-index: -1;
  overflow: hidden; pointer-events: none;
  animation: auroraIn 1.6s ease both;
}
.aurora .blob {
  position: absolute;
  border-radius: 50%;
  filter: blur(100px);
  opacity: 0.5;
  will-change: transform;
}
.aurora .b1 {
  width: 700px; height: 700px;
  background: #2a5a9e;
  top: -220px; left: -160px;
  animation: drift1 26s ease-in-out infinite alternate;
}
.aurora .b2 {
  width: 620px; height: 620px;
  background: #3a4a9e;
  bottom: -200px; right: -140px;
  animation: drift2 32s ease-in-out infinite alternate;
}
.aurora .b3 {
  width: 540px; height: 540px;
  background: #1e3a6e;
  top: 34%; left: 34%;
  animation: drift3 40s ease-in-out infinite alternate;
}

@keyframes auroraIn {
  from { opacity: 0; }
  to { opacity: 1; }
}
@keyframes drift1 {
  0%   { transform: translate(0, 0) scale(1); }
  50%  { transform: translate(9vw, 7vh) scale(1.18); }
  100% { transform: translate(-4vw, 12vh) scale(0.94); }
}
@keyframes drift2 {
  0%   { transform: translate(0, 0) scale(1); }
  50%  { transform: translate(-7vw, -6vh) scale(1.12); }
  100% { transform: translate(4vw, -10vh) scale(0.9); }
}
@keyframes drift3 {
  0%   { transform: translate(0, 0) scale(1); }
  50%  { transform: translate(-6vw, 5vh) scale(1.22); }
  100% { transform: translate(7vw, -4vh) scale(0.95); }
}

#particles {
  position: fixed; inset: 0; z-index: -1;
  pointer-events: none;
}

.wrap { max-width: 880px; margin: 0 auto; padding: 0 24px; }

/* ===== 导航（毛玻璃，入场滑入） ===== */
nav {
  position: sticky; top: 0; z-index: 20;
  background: rgba(11, 16, 32, 0.72);
  backdrop-filter: saturate(180%) blur(18px);
  -webkit-backdrop-filter: saturate(180%) blur(18px);
  border-bottom: 1px solid var(--border);
  animation: navIn .8s cubic-bezier(0.16, 1, 0.3, 1) both;
}
.nav-inner {
  max-width: 880px; margin: 0 auto; padding: 16px 24px;
  display: flex; align-items: center; justify-content: space-between; gap: 16px;
}
.logo {
  font-weight: 600; font-size: 17px; letter-spacing: 0.4px;
  color: var(--text); text-decoration: none;
  display: flex; align-items: center; gap: 10px;
}
.logo .dot {
  width: 11px; height: 11px; border-radius: 50%; flex-shrink: 0;
  background: linear-gradient(135deg, var(--accent-light), var(--accent-dark));
  box-shadow: 0 0 14px rgba(127, 178, 240, 0.7);
}
.nav-right { display: flex; align-items: center; gap: 18px; }
.nav-links { display: flex; gap: 18px; flex-wrap: wrap; }
.nav-links a { color: var(--muted); text-decoration: none; font-size: 14px; transition: color .2s; }
.nav-links a:hover { color: var(--accent-light); }

.lang-toggle {
  border: 1px solid var(--border-strong);
  background: rgba(255, 255, 255, 0.04);
  color: var(--text-2);
  padding: 7px 16px;
  border-radius: 20px;
  cursor: pointer;
  font-size: 13px;
  font-weight: 500;
  white-space: nowrap;
  transition: all .2s;
  backdrop-filter: blur(8px);
}
.lang-toggle:hover { color: var(--accent-light); border-color: var(--accent-dark); }
.music-toggle.on {
  color: var(--accent-light);
  border-color: var(--accent-dark);
  background: rgba(127, 178, 240, 0.12);
  box-shadow: 0 0 14px rgba(127, 178, 240, 0.35);
}

/* ===== 双语切换 ===== */
.zh-content, .en-content { display: revert; }
html[data-lang="en"] .zh-content { display: none !important; }
html[data-lang="zh"] .en-content,
html:not([data-lang]) .en-content { display: none !important; }

/* ===== 主内容 ===== */
main { padding: 56px 0 96px; }

.card {
  background: var(--card);
  backdrop-filter: blur(14px);
  -webkit-backdrop-filter: blur(14px);
  border: 1px solid var(--border);
  border-radius: 18px;
  padding: 36px;
  margin-bottom: 28px;
  box-shadow: var(--shadow);
  opacity: 0;
  transform: translateY(26px);
  transition: opacity .7s cubic-bezier(0.22, 0.61, 0.36, 1), transform .7s cubic-bezier(0.22, 0.61, 0.36, 1);
}
.card.visible { opacity: 1; transform: none; }

h1 { font-size: 30px; font-weight: 700; letter-spacing: -0.5px; margin-bottom: 10px; animation: heroIn .8s cubic-bezier(0.16, 1, 0.3, 1) both; }
main h1::after {
  content: ''; display: block;
  width: 52px; height: 2px;
  margin-top: 14px;
  background: linear-gradient(90deg, var(--accent), transparent);
  border-radius: 2px;
}
h2 { font-size: 20px; font-weight: 600; letter-spacing: -0.2px; margin: 30px 0 14px; }
h3 { font-size: 16px; font-weight: 600; margin: 20px 0 8px; color: var(--text); }
p { margin-bottom: 14px; color: var(--text-2); }
.lead { font-size: 16px; color: var(--muted); animation: heroIn .8s .1s cubic-bezier(0.16, 1, 0.3, 1) both; }

.section { border-top: 1px solid var(--border); padding-top: 20px; margin-top: 24px; }
.section:first-of-type { border-top: none; padding-top: 0; margin-top: 0; }
.section h2 { color: var(--accent-light); }

.badge {
  display: inline-block;
  border: 1px solid rgba(127, 178, 240, 0.35);
  background: rgba(127, 178, 240, 0.08);
  color: var(--accent-light);
  font-size: 12px; padding: 5px 13px; border-radius: 20px; font-weight: 500;
  letter-spacing: 0.4px;
}

.btn {
  display: inline-block;
  background: linear-gradient(135deg, var(--accent-light), var(--accent) 55%, var(--accent-dark));
  color: #0a0f1e; text-decoration: none;
  padding: 12px 28px; border-radius: 12px; font-weight: 600; font-size: 15px;
  box-shadow: 0 10px 30px -8px rgba(127, 178, 240, 0.5);
  transition: transform .2s, box-shadow .2s;
}
.btn:hover { transform: translateY(-2px); box-shadow: 0 16px 36px -8px rgba(127, 178, 240, 0.6); }

ul { margin: 0 0 14px 20px; }
li { margin-bottom: 10px; color: var(--text-2); }

.contact {
  background: linear-gradient(135deg, rgba(127, 178, 240, 0.10), rgba(127, 178, 240, 0.03));
  border: 1px solid rgba(127, 178, 240, 0.25);
  border-radius: 14px;
  padding: 20px 22px;
}
.contact a { color: var(--accent-light); font-weight: 500; text-decoration: none; }
.contact a:hover { text-decoration: underline; }

footer {
  border-top: 1px solid var(--border); padding: 32px 0; text-align: center;
  color: var(--muted); font-size: 13px;
}
footer a { color: var(--muted); text-decoration: none; margin: 0 12px; transition: color .2s; }
footer a:hover { color: var(--accent-light); }

/* ===== 首页 Hero ===== */
.hero {
  text-align: center; padding: 72px 0 40px;
  position: relative;
}
.hero .appname {
  font-size: 54px; font-weight: 800; letter-spacing: 2px; line-height: 1.15;
  background-image:
    linear-gradient(120deg, transparent 0%, transparent 42%, rgba(255, 255, 255, 0.6) 50%, transparent 58%, transparent 100%),
    linear-gradient(120deg, #eef2fa 0%, var(--accent-light) 40%, var(--accent) 70%, var(--accent-dark) 100%);
  background-size: 250% 100%, 100% 100%;
  background-position: -150% 0, 0 0;
  background-repeat: no-repeat;
  -webkit-background-clip: text; background-clip: text;
  -webkit-text-fill-color: transparent;
  position: relative;
  animation: heroIn 1s cubic-bezier(0.16, 1, 0.3, 1) both, shimmer 5s ease-in-out 1.5s infinite;
}
.hero .tagline { font-size: 18px; color: var(--muted); margin-top: 14px; letter-spacing: 1px; animation: heroIn 1s .16s cubic-bezier(0.16, 1, 0.3, 1) both; }
.hero .divider {
  width: 44px; height: 1px; margin: 22px auto 0;
  background: linear-gradient(90deg, transparent, var(--accent), transparent);
  animation: heroIn 1s .28s cubic-bezier(0.16, 1, 0.3, 1) both;
}
.hero .badges { margin-top: 26px; display: flex; gap: 10px; justify-content: center; flex-wrap: wrap; animation: heroIn 1s .4s cubic-bezier(0.16, 1, 0.3, 1) both; }

.features { display: grid; grid-template-columns: repeat(auto-fit, minmax(230px, 1fr)); gap: 18px; margin-top: 36px; }
.feature {
  background: var(--card);
  backdrop-filter: blur(14px);
  border: 1px solid var(--border);
  border-radius: 16px;
  padding: 26px;
  opacity: 0;
  transform: translateY(26px);
  transition: opacity .7s cubic-bezier(0.22, 0.61, 0.36, 1), transform .7s cubic-bezier(0.22, 0.61, 0.36, 1), border-color .25s, box-shadow .25s;
}
.feature.visible { opacity: 1; transform: none; }
.feature.visible:hover {
  transform: translateY(-5px);
  border-color: rgba(127, 178, 240, 0.4);
  box-shadow: 0 20px 44px -18px rgba(0, 0, 0, 0.6);
}
.feature h3 { margin-top: 0; color: var(--accent-light); font-size: 17px; }
.feature p { font-size: 14px; margin-bottom: 0; color: var(--muted); }

/* ===== 动画 ===== */
@keyframes navIn {
  from { opacity: 0; transform: translateY(-14px); }
  to { opacity: 1; transform: translateY(0); }
}
@keyframes heroIn {
  from { opacity: 0; transform: translateY(30px); filter: blur(8px); }
  to { opacity: 1; transform: translateY(0); filter: blur(0); }
}
@keyframes fadeUp {
  from { opacity: 0; transform: translateY(20px); }
  to { opacity: 1; transform: translateY(0); }
}

@keyframes shimmer {
  0% { background-position: -150% 0, 0 0; }
  55%, 100% { background-position: 150% 0, 0 0; }
}

::-webkit-scrollbar { width: 10px; }
::-webkit-scrollbar-track { background: var(--bg); }
::-webkit-scrollbar-thumb { background: #2a3040; border-radius: 6px; }
::-webkit-scrollbar-thumb:hover { background: #3a4152; }

@media (max-width: 600px) {
  .card { padding: 24px 20px; }
  h1 { font-size: 24px; }
  .hero .appname { font-size: 38px; }
  .nav-inner { flex-wrap: wrap; }
  .nav-links { gap: 13px; }
}