:root {
  --bg1: #0f0f1a;
  --bg2: #1a1a2e;
  --bg3: #16213e;
  --cyan: #00d4ff;
  --purple: #7b2ff7;
  --text: #eef1f7;
  --muted: #9aa3b2;
  --card: rgba(255, 255, 255, 0.05);
  --card-border: rgba(255, 255, 255, 0.10);
  --maxw: 1180px;
}
* { margin: 0; padding: 0; box-sizing: border-box; }
html { scroll-behavior: smooth; }
body {
  font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, "Helvetica Neue", Arial, "Microsoft YaHei", "PingFang SC", sans-serif;
  background: linear-gradient(135deg, var(--bg1) 0%, var(--bg2) 50%, var(--bg3) 100%);
  background-attachment: fixed;
  min-height: 100vh;
  color: var(--text);
  line-height: 1.7;
}
a { color: inherit; text-decoration: none; }
.container { max-width: var(--maxw); margin: 0 auto; padding: 0 20px; }
.gradient-text {
  background: linear-gradient(90deg, var(--cyan), var(--purple));
  -webkit-background-clip: text; background-clip: text;
  -webkit-text-fill-color: transparent;
}

/* 导航 */
.nav {
  position: sticky; top: 0; z-index: 50;
  backdrop-filter: blur(14px);
  background: rgba(15, 15, 26, 0.72);
  border-bottom: 1px solid var(--card-border);
}
.nav .container { display: flex; align-items: center; justify-content: space-between; height: 66px; }
.logo { display: flex; align-items: center; }
.logo img { height: 40px; width: auto; object-fit: contain; }
.nav-links { display: flex; gap: 26px; list-style: none; }
.nav-links a { color: var(--muted); font-size: 15px; transition: color .2s; position: relative; }
.nav-links a:hover, .nav-links a.active { color: var(--text); }
.nav-links a.active::after {
  content: ''; position: absolute; left: 0; bottom: -8px; width: 100%; height: 2px;
  background: linear-gradient(90deg, var(--cyan), var(--purple)); border-radius: 2px;
}
/* 后台入口已从导航移除，保留此样式无副作用 */

/* 按钮 */
.btn {
  display: inline-block; padding: 13px 34px; border-radius: 30px; font-weight: 600;
  background: linear-gradient(90deg, var(--cyan), var(--purple)); color: #fff; border: none;
  cursor: pointer; font-size: 15px; transition: transform .2s, box-shadow .2s;
}
.btn:hover { transform: translateY(-3px); box-shadow: 0 14px 30px rgba(0, 212, 255, .28); }
.btn-ghost { background: transparent; border: 1px solid var(--card-border); color: var(--text); }
.btn-ghost:hover { border-color: var(--cyan); box-shadow: none; }

/* Hero */
.hero { padding: 110px 0 80px; text-align: center; }
.hero h1 { font-size: 52px; line-height: 1.25; margin-bottom: 22px; font-weight: 800; }
.hero .sub { font-size: 19px; color: var(--muted); max-width: 680px; margin: 0 auto 40px; }
.hero-actions { display: flex; gap: 16px; justify-content: center; flex-wrap: wrap; }

/* Section */
.section { padding: 80px 0; }
.section-head { text-align: center; margin-bottom: 54px; }
.section-head h2 { font-size: 36px; font-weight: 700; margin-bottom: 12px; }
.section-head p { color: var(--muted); font-size: 16px; }

/* Grid */
.grid-2 { display: grid; grid-template-columns: repeat(2, 1fr); gap: 28px; }
.grid-3 { display: grid; grid-template-columns: repeat(3, 1fr); gap: 28px; }
.grid-4 { display: grid; grid-template-columns: repeat(4, 1fr); gap: 20px; }

/* Card */
.card {
  background: var(--card); border: 1px solid var(--card-border); border-radius: 18px;
  padding: 38px 30px; transition: transform .25s, border-color .25s, box-shadow .25s;
}
.card:hover { transform: translateY(-6px); border-color: rgba(0, 212, 255, .35); box-shadow: 0 18px 40px rgba(0, 212, 255, .10); }
.card .icon { font-size: 42px; margin-bottom: 18px; }
.card h3 { font-size: 21px; margin-bottom: 12px; }
.card p { color: var(--muted); font-size: 15px; }

/* Stats */
.stats { display: grid; grid-template-columns: repeat(3, 1fr); gap: 24px; max-width: 760px; margin: 0 auto; }
.stat { text-align: center; padding: 30px; background: var(--card); border: 1px solid var(--card-border); border-radius: 16px; }
.stat .num { font-size: 44px; font-weight: 800; color: var(--cyan); }
.stat .lab { color: var(--muted); margin-top: 6px; }

/* Tags */
.tags { display: flex; flex-wrap: wrap; gap: 12px; justify-content: center; }
.tag { background: rgba(123, 47, 247, .12); border: 1px solid rgba(123, 47, 247, .3); color: #b388ff; padding: 9px 20px; border-radius: 25px; font-size: 14px; }

/* News / Case list */
.news-item, .case-item { background: var(--card); border: 1px solid var(--card-border); border-radius: 16px; padding: 26px; transition: transform .2s, border-color .2s; }
.news-item:hover, .case-item:hover { transform: translateY(-4px); border-color: rgba(0, 212, 255, .3); }
.news-date { color: var(--cyan); font-size: 13px; margin-bottom: 8px; }
.news-item h3, .case-item h3 { font-size: 19px; margin-bottom: 10px; }
.news-item p, .case-item p { color: var(--muted); font-size: 15px; }
.case-tag { display: inline-block; margin-top: 12px; font-size: 12px; color: var(--purple); border: 1px solid rgba(123,47,247,.3); padding: 3px 12px; border-radius: 20px; }

/* Form */
.form { max-width: 560px; margin: 0 auto; display: flex; flex-direction: column; gap: 16px; }
.form input, .form textarea {
  width: 100%; padding: 14px 16px; border-radius: 12px; border: 1px solid var(--card-border);
  background: rgba(255,255,255,.04); color: var(--text); font-size: 15px; font-family: inherit;
}
.form input:focus, .form textarea:focus { outline: none; border-color: var(--cyan); }
.form textarea { min-height: 130px; resize: vertical; }

/* Footer */
.footer { border-top: 1px solid var(--card-border); padding: 44px 0; text-align: center; color: var(--muted); font-size: 14px; margin-top: 40px; }
.footer a { color: var(--cyan); }

/* 页面小标题区 */
.page-hero { padding: 70px 0 30px; text-align: center; }
.page-hero h1 { font-size: 40px; font-weight: 800; margin-bottom: 10px; }
.page-hero p { color: var(--muted); }

/* Toast */
.toast {
  position: fixed; bottom: 30px; left: 50%; transform: translateX(-50%);
  background: linear-gradient(90deg, var(--cyan), var(--purple)); color: #fff;
  padding: 12px 26px; border-radius: 30px; font-size: 15px; opacity: 0; transition: opacity .3s; z-index: 99; pointer-events: none;
}
.toast.show { opacity: 1; }

/* 响应式 */
@media (max-width: 900px) {
  .grid-4 { grid-template-columns: repeat(2, 1fr); }
  .grid-3 { grid-template-columns: 1fr; }
}
@media (max-width: 768px) {
  .nav-links { gap: 14px; font-size: 13px; }
  .hero h1 { font-size: 34px; }
  .grid-2, .grid-4 { grid-template-columns: 1fr; }
  .stats { grid-template-columns: 1fr; }
  .section { padding: 56px 0; }
}