:root {
  --bg: #f4f6fb;
  --bg-grad-1: #eef2fb;
  --bg-grad-2: #f7f9fc;
  --surface: #ffffff;
  --surface-2: #f8fafc;
  --border: #e5e9f2;
  --text: #0f172a;
  --text-2: #64748b;
  --text-3: #94a3b8;
  --brand: #2456c9;
  --brand-2: #4f80ff;
  --brand-soft: #eaf0ff;
  --shadow: 0 1px 2px rgba(15,23,42,.04), 0 8px 24px rgba(15,23,42,.06);
  --shadow-hover: 0 4px 12px rgba(36,86,201,.10), 0 16px 40px rgba(15,23,42,.10);
  --radius: 16px;
}
:root[data-theme="dark"] {
  --bg: #0b1120;
  --bg-grad-1: #0d1526;
  --bg-grad-2: #0b1120;
  --surface: #131c2e;
  --surface-2: #1a2437;
  --border: #26324a;
  --text: #e8edf7;
  --text-2: #9aa7bd;
  --text-3: #6b7890;
  --brand: #6f9bff;
  --brand-2: #4f80ff;
  --brand-soft: #17233d;
  --shadow: 0 1px 2px rgba(0,0,0,.3), 0 10px 30px rgba(0,0,0,.35);
  --shadow-hover: 0 4px 14px rgba(79,128,255,.18), 0 18px 44px rgba(0,0,0,.45);
}

* { box-sizing: border-box; }
html, body { margin: 0; padding: 0; }
body {
  font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", "PingFang TC",
    "Noto Sans TC", "Microsoft JhengHei", Roboto, Helvetica, Arial, sans-serif;
  color: var(--text);
  background:
    radial-gradient(1200px 600px at 100% -10%, var(--bg-grad-1), transparent 60%),
    radial-gradient(1000px 500px at -10% 110%, var(--bg-grad-1), transparent 55%),
    var(--bg);
  min-height: 100vh;
  -webkit-font-smoothing: antialiased;
}

.wrap { max-width: 1120px; margin: 0 auto; padding: 28px 24px 56px; }

/* ---------- 頁首 ---------- */
.topbar {
  display: flex; align-items: center; gap: 14px;
  padding: 8px 2px 26px;
}
.brand { display: flex; align-items: center; gap: 12px; }
.logo {
  width: 42px; height: 42px; border-radius: 12px; flex: 0 0 auto;
  background: linear-gradient(135deg, var(--brand-2), var(--brand));
  color: #fff; display: grid; place-items: center;
  font-weight: 800; font-size: 18px; letter-spacing: .5px;
  box-shadow: 0 6px 18px rgba(36,86,201,.35);
}
.brand-name { font-size: 20px; font-weight: 800; letter-spacing: .2px; }
.brand-sub { font-size: 12.5px; color: var(--text-2); margin-top: 1px; }
.spacer { flex: 1; }
.iconbtn {
  border: 1px solid var(--border); background: var(--surface);
  color: var(--text-2); width: 40px; height: 40px; border-radius: 11px;
  cursor: pointer; font-size: 17px; display: grid; place-items: center;
  transition: .15s; box-shadow: var(--shadow);
}
.iconbtn:hover { color: var(--text); border-color: var(--brand); }
.textbtn {
  border: 1px solid var(--border); background: var(--surface);
  color: var(--text-2); height: 40px; padding: 0 14px; border-radius: 11px;
  cursor: pointer; font-size: 13.5px; font-weight: 600;
  transition: .15s; box-shadow: var(--shadow);
}
.textbtn:hover { color: var(--text); border-color: var(--brand); }

/* ---------- Hero + 搜尋 ---------- */
.hero { margin: 4px 2px 22px; }
.hero h1 { font-size: 26px; margin: 0 0 6px; letter-spacing: .2px; }
.hero p { margin: 0; color: var(--text-2); font-size: 14.5px; }
.searchbox {
  margin-top: 18px; position: relative; max-width: 460px;
}
.searchbox input {
  width: 100%; height: 46px; padding: 0 16px 0 44px;
  border-radius: 13px; border: 1px solid var(--border);
  background: var(--surface); color: var(--text); font-size: 15px;
  box-shadow: var(--shadow); outline: none; transition: .15s;
}
.searchbox input:focus { border-color: var(--brand); box-shadow: 0 0 0 4px var(--brand-soft); }
.searchbox svg { position: absolute; left: 15px; top: 13px; color: var(--text-3); }

/* ---------- 卡片 ---------- */
.grid {
  display: grid; gap: 18px;
  grid-template-columns: repeat(auto-fill, minmax(320px, 1fr));
}
.card {
  background: var(--surface); border: 1px solid var(--border);
  border-radius: var(--radius); padding: 22px 22px 18px;
  box-shadow: var(--shadow); transition: .18s;
  display: flex; flex-direction: column;
}
.card:hover { transform: translateY(-3px); box-shadow: var(--shadow-hover); border-color: var(--brand); }
.card-head { display: flex; align-items: center; gap: 14px; margin-bottom: 12px; }
.badge {
  width: 48px; height: 48px; border-radius: 13px; flex: 0 0 auto;
  display: grid; place-items: center; font-weight: 800; font-size: 20px; color: #fff;
}
.badge.f { background: linear-gradient(135deg, #f0883e, #d9642a); }
.badge.c { background: linear-gradient(135deg, #38bdf8, #2563eb); }
.badge.q { background: linear-gradient(135deg, #34d399, #059669); }
.card-title { font-size: 17px; font-weight: 800; }
.tags { display: flex; gap: 6px; margin-top: 5px; flex-wrap: wrap; }
.tag {
  font-size: 11px; color: var(--text-2); background: var(--surface-2);
  border: 1px solid var(--border); padding: 2px 8px; border-radius: 999px;
}
.card-desc { color: var(--text-2); font-size: 13.5px; line-height: 1.6; margin: 2px 0 16px; flex: 1; }

.enter {
  display: flex; align-items: center; justify-content: center; gap: 8px;
  text-decoration: none; height: 44px; border-radius: 12px;
  background: linear-gradient(135deg, var(--brand-2), var(--brand)); color: #fff;
  font-weight: 700; font-size: 14.5px; transition: .15s;
  box-shadow: 0 6px 16px rgba(36,86,201,.28);
}
.enter:hover { filter: brightness(1.06); transform: translateY(-1px); }
.kbd {
  margin-left: 2px; font-size: 11px; opacity: .8;
  border: 1px solid rgba(255,255,255,.5); border-radius: 5px; padding: 0 5px; line-height: 15px;
}

.links { display: flex; flex-wrap: wrap; gap: 8px; margin-top: 12px; }
.chip {
  text-decoration: none; font-size: 12.5px; color: var(--text-2);
  background: var(--surface-2); border: 1px solid var(--border);
  padding: 6px 11px; border-radius: 9px; transition: .15s;
}
.chip:hover { color: var(--brand); border-color: var(--brand); background: var(--brand-soft); }

.foot { margin-top: 34px; text-align: center; color: var(--text-3); font-size: 12.5px; }
.foot a { color: var(--text-2); }
.empty { color: var(--text-3); font-size: 14px; padding: 24px 2px; }

/* ---------- 登入頁 ---------- */
.login-wrap { min-height: 100vh; display: grid; place-items: center; padding: 24px; }
.login-card {
  width: 100%; max-width: 380px; background: var(--surface);
  border: 1px solid var(--border); border-radius: 20px; padding: 34px 30px;
  box-shadow: var(--shadow);
}
.login-card .logo { width: 52px; height: 52px; font-size: 22px; border-radius: 15px; margin: 0 auto 16px; }
.login-card h1 { text-align: center; font-size: 20px; margin: 0 0 4px; }
.login-card .sub { text-align: center; color: var(--text-2); font-size: 13.5px; margin: 0 0 22px; }
.field { position: relative; margin-bottom: 12px; }
.field input {
  width: 100%; height: 48px; padding: 0 16px; border-radius: 12px;
  border: 1px solid var(--border); background: var(--surface-2);
  color: var(--text); font-size: 15px; outline: none; transition: .15s;
}
.field input:focus { border-color: var(--brand); box-shadow: 0 0 0 4px var(--brand-soft); background: var(--surface); }
.login-card button {
  width: 100%; height: 48px; border: 0; border-radius: 12px; cursor: pointer;
  background: linear-gradient(135deg, var(--brand-2), var(--brand)); color: #fff;
  font-weight: 700; font-size: 15px; transition: .15s; box-shadow: 0 6px 16px rgba(36,86,201,.28);
}
.login-card button:hover { filter: brightness(1.06); }
.login-card button:disabled { opacity: .6; cursor: default; }
.err { color: #e5484d; font-size: 13px; text-align: center; min-height: 18px; margin-top: 10px; }

@media (max-width: 560px) {
  .grid { grid-template-columns: 1fr; }
  .hero h1 { font-size: 22px; }
}