* { margin: 0; padding: 0; box-sizing: border-box; }
        body {
            font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", "PingFang SC", "Microsoft YaHei", sans-serif;
            min-height: 100vh;
            display: flex; align-items: center; justify-content: center;
            padding: 20px;
            background: linear-gradient(135deg, #e0e7ff 0%, #c7d2fe 25%, #e0c3fc 50%, #fbcfe8 75%, #fde68a 100%);
            position: relative; overflow: hidden;
        }
        /* 装饰圆形 */
        .deco { position: fixed; border-radius: 50%; pointer-events: none; z-index: 0; }
        .deco-1 { width: 300px; height: 300px; background: radial-gradient(circle, rgba(99,102,241,0.25), transparent); top: -80px; right: -60px; }
        .deco-2 { width: 200px; height: 200px; background: radial-gradient(circle, rgba(236,72,153,0.2), transparent); bottom: -50px; left: -50px; }
        .deco-3 { width: 150px; height: 150px; background: radial-gradient(circle, rgba(245,158,11,0.18), transparent); top: 50%; left: 10%; }
        .deco-4 { width: 180px; height: 180px; background: radial-gradient(circle, rgba(34,197,94,0.15), transparent); bottom: 20%; right: 15%; }
        .container {
            background: rgba(255,255,255,0.55);
            backdrop-filter: blur(24px);
            -webkit-backdrop-filter: blur(24px);
            border-radius: 24px;
            border: 1px solid rgba(255,255,255,0.7);
            box-shadow: 0 8px 40px rgba(0,0,0,0.08), 0 0 0 1px rgba(255,255,255,0.4) inset;
            width: 100%; max-width: 420px;
            overflow: hidden;
            position: relative; z-index: 1;
        }
        .header { padding: 36px 32px 20px; text-align: center; }
        .header .logo { height: 80px; width: auto; margin: 0 auto 20px; display: block; }
        .header p { color: #8b8ba7; font-size: 13px; letter-spacing: 2px; }
        .body { padding: 8px 32px 32px; }
        .tabs { display: flex; border-bottom: 1px solid rgba(0,0,0,0.08); margin-bottom: 24px; }
        .tabs a {
            flex: 1; text-align: center; padding: 10px;
            color: #a5a5c0; text-decoration: none; font-size: 15px; font-weight: 500;
            border-bottom: 2px solid transparent; margin-bottom: -1px; transition: all 0.2s;
        }
        .tabs a.active { color: #6366f1; border-bottom-color: #6366f1; }
        .tabs a:hover { color: #6366f1; }
        .form-group { margin-bottom: 18px; }
        .form-group label { display: block; font-size: 13px; color: #6b6b8a; margin-bottom: 6px; font-weight: 500; }
        .form-group input {
            width: 100%; padding: 11px 16px;
            border: 1px solid rgba(0,0,0,0.08); border-radius: 12px;
            font-size: 15px; transition: all 0.2s; outline: none;
            background: rgba(255,255,255,0.6); color: #1f2937;
        }
        .form-group input:focus {
            border-color: #6366f1; background: rgba(255,255,255,0.9);
            box-shadow: 0 0 0 4px rgba(99,102,241,0.1);
        }
        .form-group input::placeholder { color: #c4c4d8; }
        .captcha-row { display: flex; gap: 8px; }
        .captcha-refresh-btn {
            white-space: nowrap; padding: 10px 14px;
            border: 1px solid rgba(0,0,0,0.08); border-radius: 12px;
            font-size: 13px; cursor: pointer; color: #667eea;
            background: rgba(255,255,255,0.6); transition: all 0.2s;
        }
        .captcha-refresh-btn:hover { background: rgba(99,102,241,0.1); border-color: #6366f1; }
        .btn {
            width: 100%; padding: 13px; border: none; border-radius: 12px;
            font-size: 15px; font-weight: 600; cursor: pointer; transition: all 0.25s;
            color: #fff;
            background: linear-gradient(135deg, #6366f1 0%, #8b5cf6 50%, #a855f7 100%);
            box-shadow: 0 4px 20px rgba(99,102,241,0.25);
        }
        .btn:hover { transform: translateY(-2px); box-shadow: 0 8px 30px rgba(99,102,241,0.4); }
        .btn:active { transform: translateY(0); }
        .message { padding: 12px 16px; border-radius: 12px; font-size: 14px; margin-bottom: 20px; backdrop-filter: blur(8px); }
        .message.error { background: rgba(254,226,226,0.7); color: #dc2626; border: 1px solid rgba(239,68,68,0.25); }
        .message.success { background: rgba(220,252,231,0.7); color: #16a34a; border: 1px solid rgba(34,197,94,0.25); }
        .message.info { background: rgba(254,249,195,0.7); color: #d97706; border: 1px solid rgba(251,191,36,0.25); }
        /* Android 客户端下载入口（v1.42.0） */
        .app-download { margin-top: 18px; }
        .app-download a {
            display: flex; align-items: center; justify-content: center; gap: 8px;
            padding: 11px 14px;
            border: 1px dashed rgba(99,102,241,0.35);
            border-radius: 12px;
            color: #6366f1; font-size: 13px; font-weight: 500;
            text-decoration: none; transition: all 0.2s;
        }
        .app-download a:hover {
            background: rgba(99,102,241,0.08);
            border-color: rgba(99,102,241,0.55);
            border-style: solid;
        }
        .app-download svg { flex-shrink: 0; }
        .app-download .app-download-meta { color: #a5a5c0; font-size: 12px; font-weight: 400; }
        .footer { text-align: center; padding: 0 32px 20px; }
        .footer a { color: #b0b0c8; font-size: 12px; text-decoration: none; transition: color 0.2s; }
        .footer a:hover { color: #6366f1; }
        .step-indicator { display: flex; align-items: center; justify-content: center; gap: 0; margin-bottom: 8px; }
        .step { display: flex; flex-direction: column; align-items: center; gap: 4px; opacity: 0.3; transition: opacity 0.3s; }
        .step.active { opacity: 1; }
        .step-num {
            width: 28px; height: 28px; border-radius: 50%;
            background: rgba(0,0,0,0.05); color: #a5a5c0;
            display: flex; align-items: center; justify-content: center;
            font-size: 13px; font-weight: 600; transition: all 0.3s;
        }
        .step.active .step-num { background: linear-gradient(135deg, #6366f1, #a855f7); color: #fff; }
        .step-label { font-size: 11px; color: #a5a5c0; white-space: nowrap; }
        .step-line { width: 32px; height: 2px; background: rgba(0,0,0,0.05); margin: 0 4px 16px; transition: background 0.3s; }
        .step-line.active { background: #a855f7; }

        /* ===== 移动端适配 ===== */
        @media (max-width: 480px) {
            body {
                padding: 12px;
                background: linear-gradient(135deg, #e0e7ff 0%, #c7d2fe 50%, #fbcfe8 100%);
            }
            .card {
                width: 100%;
                border-radius: 16px;
            }
            .header {
                padding: 24px 20px 16px;
            }
            .header .logo {
                height: 56px;
                margin-bottom: 10px;
            }
            .header p { font-size: 12px; }
            .body { padding: 8px 20px 24px; }
            .footer { padding: 0 20px 16px; }
            .app-download { margin-top: 16px; }
            .app-download a { padding: 10px 12px; font-size: 12px; }
            .form-group { margin-bottom: 14px; }
            .form-group label { font-size: 12px; }
            .form-group input {
                padding: 12px 14px;
                font-size: 16px;
            }
            .btn {
                padding: 12px 20px;
                font-size: 15px;
            }
            .btn-back {
                padding: 10px 16px;
                font-size: 13px;
            }
            .tabs { margin-bottom: 18px; }
            .tabs a { font-size: 15px; padding-bottom: 8px; }
            .message { font-size: 13px; padding: 10px 14px; }
            .step-label { font-size: 10px; }
            .step-line { width: 20px; }
            /* 缩小装饰圈 */
            .deco-1 { width: 150px; height: 150px; }
            .deco-2 { width: 100px; height: 100px; }
            .deco-3 { width: 80px; height: 80px; }
            .deco-4 { width: 100px; height: 100px; }
        }