* { box-sizing: border-box; margin: 0; padding: 0; }
  :root {
    --bg: #f4f6f9; --card: #fff; --primary: #4a90e2; --primary-soft: #e8f1fc;
    --text: #2c3e50; --text-sub: #7b8a99; --text-muted: #aab6c2;
    --border: #eef1f5; --shadow: 0 2px 12px rgba(0,0,0,.06); --radius: 16px;
    --weak: #e74c3c; --medium: #f39c12; --strong: #27ae60; --vstrong: #16a085;
  }
  body {
    font-family: -apple-system, BlinkMacSystemFont, "PingFang SC", "Microsoft YaHei", sans-serif;
    background: var(--bg); color: var(--text); min-height: 100vh;
    padding: 24px;
  }
  .app { max-width: 1440px; margin: 0 auto; }
  .card { background: var(--card); border-radius: var(--radius); box-shadow: var(--shadow); padding: 26px; }
  .header { display: flex; align-items: center; justify-content: space-between; margin-bottom: 22px; }
  .header h1 { font-size: 22px; font-weight: 600; }
  .back { font-size: 13px; color: var(--text-sub); text-decoration: none; padding: 6px 12px; background: var(--bg); border-radius: 8px; }
  .back:hover { background: var(--primary-soft); color: var(--primary); }

  .result-box {
    background: linear-gradient(135deg, var(--primary), #6aa9e9);
    border-radius: 14px; padding: 20px; color: #fff; font-size: 22px;
    font-family: "Consolas", monospace; font-weight: 600; word-break: break-all;
    min-height: 64px; display: flex; align-items: center; letter-spacing: 2px;
  }
  .result-box.empty { font-size: 14px; opacity: .7; font-family: inherit; letter-spacing: 0; }

  .actions { display: flex; gap: 10px; margin-top: 10px; }
  .copy-btn, .refresh-btn {
    padding: 9px 18px; border: none; border-radius: 10px;
    background: var(--primary-soft); color: var(--primary); font-size: 13px; cursor: pointer;
  }
  .copy-btn:hover, .refresh-btn:hover { opacity: .8; }
  .refresh-btn { background: #f0f2f5; color: var(--text-sub); }

  .strength { margin-top: 12px; }
  .strength-bar { height: 6px; background: var(--border); border-radius: 4px; overflow: hidden; }
  .strength-fill { height: 100%; width: 0%; border-radius: 4px; transition: all .3s; }
  .strength-label { font-size: 12px; color: var(--text-muted); margin-top: 6px; }

  .presets { display: flex; gap: 8px; margin-top: 18px; flex-wrap: wrap; }
  .preset { padding: 6px 14px; border: 1px solid var(--border); background: #fff; border-radius: 20px; font-size: 12px; cursor: pointer; color: var(--text-sub); }
  .preset:hover { border-color: var(--primary); color: var(--primary); }

  .options { margin-top: 22px; display: flex; flex-direction: column; gap: 16px; }
  .opt-row { display: flex; align-items: center; justify-content: space-between; }
  .opt-row label { font-size: 14px; color: var(--text); }
  .opt-row input[type="range"] { width: 180px; }
  .opt-row .len-val { font-size: 14px; color: var(--primary); font-weight: 600; min-width: 30px; text-align: right; }

  .check-row { display: flex; gap: 16px; flex-wrap: wrap; }
  .check-row label { display: flex; align-items: center; gap: 6px; font-size: 14px; color: var(--text-sub); cursor: pointer; }
  .check-row input[type="checkbox"] { accent-color: var(--primary); width: 16px; height: 16px; }

  .exclude-input { width: 100%; padding: 8px 12px; border: 1px solid var(--border); border-radius: 8px; font-size: 13px; font-family: inherit; }
  .exclude-input:focus { outline: none; border-color: var(--primary); }

  .batch-row { display: flex; align-items: center; gap: 10px; }
  .batch-row input[type="number"] { width: 60px; padding: 6px 10px; border: 1px solid var(--border); border-radius: 8px; font-size: 13px; }

  .btn { width: 100%; margin-top: 20px; padding: 13px; border: none; border-radius: 12px;
    background: var(--primary); color: #fff; font-size: 15px; font-weight: 500; cursor: pointer; }
  .btn:hover { opacity: .88; }

  .history { margin-top: 24px; }
  .history h3 { font-size: 14px; color: var(--text-sub); margin-bottom: 10px; display: flex; justify-content: space-between; align-items: center; }
  .history h3 a { font-size: 12px; color: var(--primary); cursor: pointer; text-decoration: none; }
  .history-list { display: flex; flex-direction: column; gap: 6px; max-height: 200px; overflow-y: auto; }
  .history-item {
    display: flex; align-items: center; justify-content: space-between;
    background: var(--bg); padding: 8px 12px; border-radius: 8px; font-family: "Consolas", monospace; font-size: 13px;
  }
  .history-item .pwd { color: var(--text); word-break: break-all; flex: 1; margin-right: 8px; }
  .history-item .h-copy { background: none; border: none; color: var(--primary); cursor: pointer; font-size: 12px; padding: 2px 8px; border-radius: 6px; }
  .history-item .h-copy:hover { background: var(--primary-soft); }

  .toast { position: fixed; bottom: 30px; left: 50%; transform: translateX(-50%) translateY(20px);
    background: var(--text); color: #fff; padding: 10px 20px; border-radius: 10px; font-size: 13px;
    opacity: 0; transition: all .3s; pointer-events: none; z-index: 100; }
  .toast.show { opacity: 1; transform: translateX(-50%) translateY(0); }