:root {
  --bg: #0f1115; --panel: #171a21; --panel-2: #1d212b; --border: #2a2f3a;
  --text: #e6e8ee; --muted: #9aa3b2; --accent: #4f8cff; --radius: 14px;
}
* { box-sizing: border-box; }
html, body { margin: 0; }
body {
  font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", "PingFang TC",
    "Noto Sans TC", "Microsoft JhengHei", sans-serif;
  background: var(--bg); color: var(--text); line-height: 1.6;
}
a { color: var(--accent); text-decoration: none; }
a:hover { text-decoration: underline; }
.app-header {
  display: flex; align-items: center; justify-content: space-between; gap: 1rem;
  padding: 0.85rem 1.25rem; border-bottom: 1px solid var(--border); background: var(--panel);
}
.app-header .brand { font-weight: 700; color: var(--text); font-size: 1.05rem; }
.app-header .header__right { display: flex; align-items: center; gap: 1rem; }
.app-header .who, .app-header .logout { color: var(--muted); font-size: 0.9rem; }
.container { max-width: 880px; margin: 0 auto; padding: 2rem 1.25rem 4rem; }
h1 { font-size: 1.6rem; margin: 0 0 0.25rem; }
.subtitle { color: var(--muted); margin: 0 0 1.75rem; }
.tool-grid { display: grid; gap: 1rem; grid-template-columns: repeat(auto-fill, minmax(220px, 1fr)); }
.tool-card {
  display: flex; flex-direction: column; gap: 0.4rem; padding: 1.1rem;
  border: 1px solid var(--border); border-radius: var(--radius); background: var(--panel);
  color: var(--text); transition: border-color .15s, transform .15s;
}
.tool-card:hover { border-color: var(--accent); transform: translateY(-2px); text-decoration: none; }
.tool-card__icon { font-size: 1.6rem; }
.tool-card__name { font-weight: 600; }
.tool-card__desc { color: var(--muted); font-size: 0.9rem; }
.empty { color: var(--muted); }
.card { padding: 1.25rem; border: 1px solid var(--border); border-radius: var(--radius); background: var(--panel); margin: 1.25rem 0; }
.card h2 { margin-top: 0; font-size: 1.15rem; }
label { display: block; margin-bottom: 0.6rem; }
input, button { font: inherit; padding: 0.5rem 0.7rem; border-radius: 8px; border: 1px solid var(--border); background: var(--panel-2); color: var(--text); }
button { cursor: pointer; border-color: var(--accent); }
button:hover { background: #243049; }
.out { color: var(--muted); margin-top: 0.75rem; min-height: 1.5rem; }
code { background: var(--panel-2); padding: 0.1rem 0.35rem; border-radius: 6px; font-size: 0.85em; }
ol { padding-left: 1.2rem; }
.app-footer { border-top: 1px solid var(--border); color: var(--muted); padding: 1.25rem; text-align: center; font-size: 0.85rem; }