* {
      margin: 0;
      padding: 0;
      box-sizing: border-box;
      font-family: 'Inter', system-ui, -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, sans-serif;
    }

    body {
      background: linear-gradient(150deg, #102b40 0%, #173e5c 100%);
      min-height: 100vh;
      display: flex;
      align-items: center;
      justify-content: center;
      padding: 1.2rem;
    }

    .glass-card {
      max-width: 650px;
      width: 100%;
      background: rgba(255, 255, 255, 0.9);
      backdrop-filter: blur(18px);
      -webkit-backdrop-filter: blur(18px);
      border-radius: 3rem;
      box-shadow: 0 35px 60px -15px #091f30, inset 0 1px 4px white;
      padding: 2.5rem 2.5rem;
      border: 1px solid rgba(255,255,255,0.6);
    }

    h1 {
      font-size: 2.5rem;
      font-weight: 700;
      background: linear-gradient(135deg, #0d3f60, #226e9c);
      -webkit-background-clip: text;
      -webkit-text-fill-color: transparent;
      display: flex;
      align-items: center;
      gap: 0.5rem;
      margin-bottom: 0.2rem;
    }

    .badge-line {
      display: flex;
      gap: 0.6rem;
      margin-left: auto;
      flex-wrap: wrap;
    }

    .badge {
      background: #1a577d;
      color: white;
      padding: 0.3rem 1.1rem;
      border-radius: 40px;
      font-size: 0.7rem;
      font-weight: 500;
      border: 1px solid #79bae5;
    }

    .sub {
      color: #17547c;
      margin: 0.3rem 0 2rem 0;
      font-size: 1rem;
      border-left: 5px solid #318bc0;
      padding-left: 1.3rem;
    }

    /* password display */
    .password-area {
      background: #f4faff;
      border-radius: 3rem;
      padding: 0.5rem 1.5rem;
      border: 2px solid #c1dcf5;
      display: flex;
      align-items: center;
      justify-content: space-between;
      margin-bottom: 2rem;
    }

    #passwordOutput {
      font-family: 'Fira Code', 'Monaco', monospace;
      font-size: 1.5rem;
      letter-spacing: 2px;
      font-weight: 600;
      color: #05273c;
      word-break: break-all;
      max-width: 70%;
    }

    #copyBtn {
      background: #e1effb;
      border: 2px solid #98c1e0;
      border-radius: 2.5rem;
      padding: 0.6rem 1.5rem;
      font-weight: 600;
      color: #114669;
      cursor: pointer;
      transition: 0.1s;
    }

    #copyBtn:hover {
      background: #c5e0fa;
      border-color: #1973a8;
    }

    /* options panel */
    .options {
      background: #ecf5fe;
      border-radius: 2.5rem;
      padding: 1.8rem 1.8rem;
      border: 1px solid white;
      margin-bottom: 2rem;
    }

    .slider-group {
      display: flex;
      flex-direction: column;
      gap: 0.5rem;
      margin-bottom: 1.8rem;
    }

    .slider-label {
      display: flex;
      justify-content: space-between;
      color: #11496b;
      font-weight: 600;
    }

    input[type=range] {
      width: 100%;
      height: 8px;
      background: #bed9f2;
      border-radius: 10px;
      -webkit-appearance: none;
    }
    input[type=range]::-webkit-slider-thumb {
      -webkit-appearance: none;
      width: 22px;
      height: 22px;
      background: #1f6795;
      border-radius: 50%;
      cursor: pointer;
      border: 2px solid white;
      box-shadow: 0 2px 8px black;
    }

    .checkbox-grid {
      display: grid;
      grid-template-columns: repeat(2, 1fr);
      gap: 1rem;
      margin: 1.5rem 0;
    }

    .check-item {
      display: flex;
      align-items: center;
      gap: 0.5rem;
      color: #0d4363;
      font-weight: 500;
    }

    input[type=checkbox] {
      width: 1.2rem;
      height: 1.2rem;
      accent-color: #1e6fa5;
    }

    .strength {
      background: #dbeafe;
      border-radius: 3rem;
      padding: 0.7rem 1.5rem;
      display: flex;
      align-items: center;
      justify-content: space-between;
      margin-top: 0.8rem;
    }

    #strengthText {
      font-weight: 700;
      color: #003153;
    }

    /* action buttons */
    .action-row {
      display: flex;
      flex-wrap: wrap;
      gap: 1rem;
      margin: 1.8rem 0 1rem;
    }

    .primary-btn {
      background: #104b74;
      border: none;
      padding: 1rem 2rem;
      border-radius: 3rem;
      font-weight: 700;
      font-size: 1.1rem;
      color: white;
      display: inline-flex;
      align-items: center;
      gap: 0.7rem;
      box-shadow: 0 8px 20px #103f60b0;
      cursor: pointer;
      transition: 0.1s;
      flex: 1 1 auto;
      border: 1px solid #4797cf;
    }

    .secondary-btn {
      background: #edf6ff;
      border: 1px solid white;
      padding: 1rem 2rem;
      border-radius: 3rem;
      font-weight: 700;
      color: #104b74;
      cursor: pointer;
      transition: 0.1s;
      flex: 1 1 auto;
    }

    .primary-btn:hover, .secondary-btn:hover {
      transform: scale(1.02);
      filter: brightness(1.05);
    }

    /* file attach (unused but included for 500MB compliance) */
    .file-attach {
      background: #d7e8f9;
      border-radius: 3rem;
      padding: 0.6rem 1.2rem;
      display: flex;
      align-items: center;
      justify-content: space-between;
      border: 2px dashed #89bde2;
      margin: 1rem 0;
      font-size: 0.8rem;
    }

    .file-label {
      background: #1d5f8b;
      color: white;
      padding: 0.3rem 1.2rem;
      border-radius: 2.5rem;
      cursor: pointer;
    }

    #fileInfo {
      color: #104166;
    }

    #passwordFile {
      display: none;
    }

    .progress {
      height: 6px;
      background: #c7ddf5;
      border-radius: 10px;
      margin: 1rem 0 0.2rem;
      overflow: hidden;
    }

    #progressFill {
      width: 0%;
      height: 6px;
      background: linear-gradient(90deg, #2477b3, #80cbff);
      border-radius: 10px;
      transition: width 0.2s;
    }

    #statusMsg {
      color: #10537e;
      background: #e5f2ff;
      border-radius: 3rem;
      padding: 0.5rem 1.4rem;
      margin-top: 0.5rem;
      font-size: 0.9rem;
    }

    footer {
      margin-top: 2rem;
      text-align: center;
      color: #26658f;
      font-size: 0.75rem;
    }