/* デザインはオーナー様のオリジナルを完全維持 */
        * { margin: 0; padding: 0; box-sizing: border-box; }
        body { font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, sans-serif; background: white; min-height: 100vh; display: flex; align-items: center; justify-content: center; padding: 20px; }
        .container { background: white; border-radius: 20px; padding: 50px 40px; max-width: 500px; width: 100%; box-shadow: 0 20px 60px rgba(0, 0, 0, 0.2); }
        .title { font-size: 28px; font-weight: 700; color: #111827; margin-bottom: 12px; text-align: center; }
        .subtitle { font-size: 18px; color: #6b7280; margin-bottom: 40px; text-align: center; }
        .form-group { margin-bottom: 20px; }
        label { display: block; font-size: 18px; font-weight: 700; color: #374151; letter-spacing: 0.5px; margin-bottom: 10px; }
        .password-wrapper { position: relative; width: 100%; }
        input { width: 100%; padding: 14px 16px; border: 2px solid #e5e7eb; border-radius: 12px; font-size: 20px; font-weight: 500; color: #111827; background: #f9fafb; transition: all 0.2s; font-family: inherit; }
        input:focus { outline: none; border-color: #2563eb; background: white; box-shadow: 0 0 0 4px rgba(37, 99, 235, 0.1); }
        input::placeholder { color: #d1d5db; }
        .toggle-password { position: absolute; right: 12px; top: 50%; transform: translateY(-50%); background: none; border: none; cursor: pointer; padding: 4px 8px; color: #6b7280; font-size: 22px; transition: color 0.2s; }
        .toggle-password:hover { color: #374151; }
        .help-text { font-size: 16px; color: #6b7280; margin-top: 8px; margin-bottom: 0; line-height: 1.6; }
        .help-text-item { margin-bottom: 4px; }
        .account-error { font-size: 16px; color: #dc2626; margin-top: 6px; line-height: 1.8; }
        input.input-error { border-color: #dc2626 !important; background: #fff5f5 !important; }
        .error-message { font-size: 16px; color: #dc2626; margin-top: 6px; display: none; }
        .error-message.show { display: block; }
        .validation-alert { background: #fef2f2; border: 1px solid #fecaca; border-radius: 8px; padding: 12px; margin-bottom: 16px; font-size: 17px; color: #dc2626; line-height: 1.5; }
        .validation-alert-item { margin-bottom: 6px; }
        .validation-alert-item:last-child { margin-bottom: 0; }
        .btn { width: 100%; padding: 14px 24px; background: linear-gradient(135deg, #2563eb 0%, #1d4ed8 100%); color: white; border: none; border-radius: 12px; font-size: 19px; font-weight: 700; cursor: pointer; transition: all 0.2s; box-shadow: 0 4px 15px rgba(37, 99, 235, 0.3); text-transform: uppercase; letter-spacing: 0.5px; margin-top: 10px; }
        .btn:hover:not(:disabled) { transform: translateY(-2px); box-shadow: 0 6px 20px rgba(37, 99, 235, 0.4); }
        .btn:active { transform: translateY(0); }
        .btn:disabled { opacity: 0.6; cursor: not-allowed; pointer-events: auto !important; }
        .btn-secondary { background: #e5e7eb; color: #374151; box-shadow: none; }
        .btn-secondary:hover:not(:disabled) { background: #d1d5db; }
        .btn-payment { background: linear-gradient(135deg, #10b981 0%, #059669 100%); box-shadow: 0 4px 15px rgba(16, 185, 129, 0.3); }
        .loader { display: none; text-align: center; margin-top: 20px; }
        .spinner { width: 24px; height: 24px; border: 3px solid #e5e7eb; border-top-color: #2563eb; border-radius: 50%; animation: spin 0.8s linear infinite; margin: 0 auto 10px; }
        @keyframes spin { to { transform: rotate(360deg); } }
        .loader-text { font-size: 17px; color: #6b7280; }
        .signup-form { display: none; margin-top: 40px; padding-top: 40px; border-top: 2px solid #e5e7eb; animation: slideDown 0.3s ease-out; }
        .signup-form.show { display: block; }
        .info-box { background: white; border: 1px solid #e5e7eb; padding: 16px; border-radius: 8px; margin-bottom: 16px; }
        .info-label { font-size: 16px; color: #6b7280; font-weight: 600; text-transform: uppercase; margin-bottom: 8px; }
        .strength-meter { height: 6px; background: #e5e7eb; border-radius: 3px; margin-top: 8px; overflow: hidden; }
        .strength-bar { height: 100%; width: 0%; border-radius: 3px; transition: all 0.3s; }
        .strength-bar.weak { background: #ef4444; width: 33%; }
        .strength-bar.medium { background: #f59e0b; width: 66%; }
        .strength-bar.strong { background: #10b981; width: 100%; }
        .checkbox-group { display: flex; align-items: center; margin-bottom: 24px; gap: 8px; }
        input[type="checkbox"] {
            -webkit-appearance: none; appearance: none;
            width: 18px !important; height: 18px !important; min-height: 0;
            padding: 0 !important; margin: 0; flex-shrink: 0; cursor: pointer;
            border: 1.5px solid #9ca3af !important; border-radius: 3px;
            background: #fff !important; box-shadow: none !important;
            display: inline-grid; place-content: center;
        }
        input[type="checkbox"]:focus { box-shadow: none !important; }
        input[type="checkbox"]::after {
            content: ''; width: 10px; height: 10px;
            clip-path: polygon(14% 44%, 0 65%, 50% 100%, 100% 16%, 80% 0%, 43% 62%);
            background: #fff; transform: scale(0); transition: transform 0.1s ease;
        }
        input[type="checkbox"]:checked { background: #2563eb !important; border-color: #2563eb !important; }
        input[type="checkbox"]:checked::after { transform: scale(1); }
        .checkbox-label { font-size: 18px; color: #374151; font-weight: 500; line-height: 1; margin-bottom: 0; }
        .checkbox-label a { color: #2563eb; text-decoration: none; border-bottom: 2px solid #2563eb; }
        .form-section-title { font-size: 20px; font-weight: 700; color: #111827; margin-bottom: 24px; }
        .results-box { display: none; margin-top: 20px; padding: 16px; background: #f9fafb; border-radius: 8px; }
        .results-box.show { display: block; }
        .result-item { padding: 12px 16px; margin-bottom: 8px; border-radius: 6px; font-size: 22px; font-weight: 500; display: flex; justify-content: space-between; align-items: center; min-height: 50px; }
        .result-item.available { background: #d1fae5; color: #065f46; border: 1px solid #6ee7b7; }
        .result-item.unavailable { background: #fee2e2; color: #7f1d1d; border: 1px solid #fca5a5; }
        .result-item-left { flex: 1; }
        .result-item-right label { font-size: 22px; font-weight: 500; cursor: pointer; display: inline-flex; align-items: center; gap: 6px; margin-bottom: 0; }
        .confirmation-page, .complete-page, .payment-page, .verification-page { text-align: center; display: none; }
        .confirmation-page.show, .complete-page.show, .payment-page.show, .verification-page.show { display: block; }
        .payment-summary { background: #fff; border: 1px solid #e5e7eb; border-radius: 8px; padding: 16px; margin-bottom: 20px; text-align: left; }
        .payment-summary-row { display: flex; justify-content: space-between; align-items: center; margin-bottom: 8px; }
        .payment-summary-label { font-size: 18px; color: #374151; font-weight: 600; }
        .payment-summary-amount { font-size: 24px; font-weight: 700; color: #111827; }
        .payment-summary-note { font-size: 16px; color: #6b7280; }
        #card-container { min-height: 90px; margin-bottom: 12px; }
        #payment-status-container { font-size: 17px; color: #dc2626; min-height: 20px; text-align: left; }
        .complete-box { background: #f3f4f6; padding: 20px; border-radius: 12px; margin-bottom: 30px; text-align: left; }
        .account-group { background: #e5e7eb; padding: 12px; border-radius: 6px; margin-bottom: 12px; }
        .account-group-title { font-weight: 600; font-size: 22px; margin-bottom: 4px; }
        .forward-email-confirm { margin-top: 8px; }
        .forward-match-error { font-size: 16px; color: #dc2626; margin-top: 4px; }
        /* カテゴリ選択パネル */
        .category-panels { display: flex; flex-direction: column; gap: 16px; }
        .category-panel {
            display: block; width: 100%; text-align: center;
            background: #f9fafb; border: 2px solid #e5e7eb; border-radius: 16px;
            padding: 28px 20px; cursor: pointer;
            transition: all 0.25s ease;
            font-family: inherit; font-size: inherit; color: inherit; line-height: normal;
        }
        .category-panel:hover {
            border-color: #2563eb; background: #eff6ff;
            transform: translateY(-3px); box-shadow: 0 8px 25px rgba(37, 99, 235, 0.15);
        }
        .category-panel:active { transform: translateY(0); }
        .category-icon { font-size: 36px; margin-bottom: 12px; line-height: 1; }
        .category-name { font-size: 22px; font-weight: 700; color: #111827; margin-bottom: 6px; }
        .category-count { font-size: 21px; font-weight: 600; color: #2563eb; margin-bottom: 8px; }
        .category-examples { font-size: 20px; color: #6b7280; line-height: 1.5; }
        .category-badge {
            display: inline-block; background: #eff6ff; color: #2563eb;
            font-size: 17px; font-weight: 600; padding: 6px 14px;
            border-radius: 20px; margin-bottom: 20px; border: 1px solid #bfdbfe;
        }
        @keyframes slideDown { from { opacity: 0; transform: translateY(-10px); } to { opacity: 1; transform: translateY(0); } }