/* ================= 基础变量 ================= */

:root{
  /* 暗黑模式（默认） */
  --bg:#0b0f14;
  --panel:#0f172a;
  --panel2:#0b1222;
  --border:#1f2937;
  --text:#e5e7eb;
  --muted:#9ca3af;
  --primary:#3b82f6;
  --gold:#ffd36a;
  --shadow: 0 18px 60px rgba(0,0,0,.45);
  --radius: 14px;
}

/* ================= 明亮模式 ================= */

body.light{
  --bg:#f4f7fb;        /* 雾感背景 */
  --panel:#ffffff;     /* 卡片 */
  --panel2:#f8fafc;
  --border:#e5e7eb;
  --text:#0f172a;
  --muted:#475569;
  --primary:#2563eb;
  --gold:#b8860b;
  --shadow: 0 18px 60px rgba(2,6,23,.10);
}

/* ================= Reset ================= */

*{
  box-sizing:border-box;
}

body{
  margin:0;
  font-family:-apple-system,BlinkMacSystemFont,"Segoe UI",Roboto,"PingFang SC","Microsoft YaHei",sans-serif;
  background:var(--bg);
  color:var(--text);
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
}

::selection{ background: rgba(59,130,246,.25); }

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

.container{
  max-width:1200px;
  margin:0 auto;
  padding:0 20px;
}

/* ================= Button ================= */

.btn{
  display:inline-block;
  padding:10px 16px;
  border-radius:999px;
  background:var(--primary);
  color:#fff;
  font-size:14px;
  font-weight:600;
  letter-spacing:.2px;
  box-shadow: 0 10px 30px rgba(59,130,246,.22);
  transition: transform .18s, filter .18s, box-shadow .18s;
}

.btn:hover{ transform: translateY(-1px); filter: brightness(1.02); }

.btn.ghost{
  background:transparent;
  border:1px solid var(--border);
  color:var(--text);
  box-shadow:none;
}

.btn.gold{
  background: linear-gradient(90deg, rgba(255,211,106,1), rgba(255,183,0,1));
  color:#111;
  box-shadow: 0 14px 40px rgba(255,200,0,.18);
}

/* ================= Theme Toggle ================= */

.theme-toggle{
  display:inline-flex;
  align-items:center;
  justify-content:center;
  height:32px;
  padding:0 10px;
  border-radius:999px;
  border:1px solid var(--border);
  background:rgba(255,255,255,.06);
  color:var(--text);
  cursor:pointer;
  transition:.2s;
}

.theme-toggle:hover{
  background:rgba(255,255,255,.14);
}

body.light .theme-toggle{
  background:rgba(0,0,0,.05);
  color:#111;
}

body.light .theme-toggle:hover{
  background:rgba(0,0,0,.1);
}