.body {
            min-height: 80vh;
            display: flex;
            justify-content: center;
            align-items: center;
            padding: 20px;
        }

    .container {
        width: 100%;
        max-width: 420px;
        background: white;
        border-radius: 20px;
        box-shadow: 0 10px 30px rgba(37, 99, 235, 0.15);
        overflow: hidden;
        border: 1px solid #e2e8f0;
    }
    .red-box {
        background-color: #ffe6e6; /* قرمز ملایم */
        border: 1px solid #ff6b6b; /* لبه قرمز */
        border-radius: 5px; /* گوشه‌های گرد */
        padding: 15px; /* فاصله داخلی */
        margin: 20px 0; /* فاصله خارجی */
        color: #333; /* رنگ متن */
    }
    .header {
        background: linear-gradient(135deg, #2563eb 0%, #3b82f6 100%);
        padding: 35px 25px;
        text-align: center;
        color: white;
        position: relative;
    }

    .header::before {
        content: "";
        position: absolute;
        top: 0;
        left: 0;
        right: 0;
        bottom: 0;
        background: url('data:image/svg+xml,<svg xmlns="http://www.w3.org/2000/svg" viewBox="0 0 100 100" preserveAspectRatio="none"><path d="M0,0 L100,0 L100,100 Z" fill="rgba(255,255,255,0.1)"/></svg>');
        background-size: cover;
    }

    .header h1 {
        font-size: 26px;
        font-weight: 700;
        margin-bottom: 10px;
        position: relative;
    }

    .header p {
        font-size: 15px;
        opacity: 0.9;
        position: relative;
    }

    .tabs {
        display: flex;
        background: #f8fafc;
        border-bottom: 1px solid #e2e8f0;
    }

    .tab {
        flex: 1;
        text-align: center;
        padding: 18px;
        cursor: pointer;
        font-weight: 600;
        font-size: 16px;
        color: #64748b;
        transition: all 0.3s ease;
        position: relative;
    }

    .tab.active {
        color: #2563eb;
    }

    .tab.active::after {
        content: "";
        position: absolute;
        bottom: 0;
        left: 25%;
        width: 50%;
        height: 3px;
        background: #2563eb;
        border-radius: 3px 3px 0 0;
    }

    .form-container {
        padding: 35px 25px;
    }

    .form {
        display: none;
    }

    .form.active {
        display: block;
        animation: fadeIn 0.5s ease;
    }

    @keyframes fadeIn {
        from { opacity: 0; transform: translateY(10px); }
        to { opacity: 1; transform: translateY(0); }
    }

    .input-group {
        margin-bottom: 25px;
        position: relative;
    }

    .input-group label {
        display: block;
        margin-bottom: 10px;
        font-weight: 500;
        color: #334155;
        font-size: 15px;
    }

    .input-group input {
        width: 100%;
        padding: 16px 20px;
        border: 2px solid #e2e8f0;
        border-radius: 12px;
        font-size: 16px;
        transition: all 0.3s ease;
        direction: ltr;
        text-align: left;
        background-color: #f8fafc;
    }

    .input-group input:focus {
        outline: none;
        border-color: #2563eb;
        background-color: white;
        box-shadow: 0 0 0 4px rgba(37, 99, 235, 0.1);
    }

    .error-message {
        color: #ef4444;
        font-size: 13px;
        margin-top: 8px;
        display: none;
        font-weight: 500;
    }

    .btn {
        width: 100%;
        padding: 16px;
        background: linear-gradient(135deg, #2563eb 0%, #3b82f6 100%);
        color: white;
        border: none;
        border-radius: 12px;
        font-size: 17px;
        font-weight: 600;
        cursor: pointer;
        transition: all 0.3s ease;
        box-shadow: 0 4px 15px rgba(37, 99, 235, 0.2);
    }

    .btn:hover {
        transform: translateY(-2px);
        box-shadow: 0 8px 20px rgba(37, 99, 235, 0.3);
    }

    .btn:active {
        transform: translateY(0);
    }

    .btn-change-phone {
        background: none;
        border: none;
        color: #2563eb;
        cursor: pointer;
        font-weight: 600;
        margin-top: 20px;
        padding: 10px 16px;
        font-size: 15px;
        border-radius: 8px;
        transition: all 0.2s ease;
    }

    .btn-change-phone:hover {
        background-color: rgba(37, 99, 235, 0.05);
    }

    .otp-section {
        text-align: center;
        margin-top: 20px;
        padding: 25px;
        background: #f8fafc;
        border-radius: 15px;
        display: none;
        animation: fadeIn 0.5s ease;
    }

    .otp-section.active {
        display: block;
    }

    .otp-inputs {
        display: flex;
        justify-content: center;
        gap: 5px;
        margin: 25px 0;
        direction: ltr;
    }

    .otp-input {
        width: 55px;
        height: 55px;
        text-align: center;
        font-size: 22px;
        font-weight: 600;
        border: 2px solid #cbd5e1;
        border-radius: 12px;
        transition: all 0.3s ease;
        background-color: white;
    }

    .otp-input:focus {
        outline: none;
        border-color: #2563eb;
        box-shadow: 0 0 0 4px rgba(37, 99, 235, 0.1);
    }

    .resend-btn {
        background: none;
        border: none;
        color: #2563eb;
        cursor: pointer;
        font-weight: 600;
        margin-top: 15px;
        padding: 8px 16px;
        border-radius: 6px;
        transition: all 0.2s ease;
    }

    .resend-btn:hover {
        background-color: rgba(37, 99, 235, 0.05);
    }

    .resend-btn:disabled {
        color: #94a3b8;
        cursor: not-allowed;
    }

    .timer {
        color: #64748b;
        font-size: 14px;
        margin-top: 8px;
        font-weight: 500;
    }

    .success-message {
        text-align: center;
        padding: 30px;
        background: #dcfce7;
        border-radius: 15px;
        color: #166534;
        margin-top: 20px;
        display: none;
        animation: fadeIn 0.5s ease;
    }

    .success-message.active {
        display: block;
    }

    .success-message h3 {
        font-size: 22px;
        margin-bottom: 10px;
        font-weight: 700;
    }

    .success-message p {
        font-size: 16px;
        font-weight: 500;
    }

    @media (max-width: 480px) {
        .container {
            margin: 15px;
        }
        
        .header {
            padding: 25px 20px;
        }
        
        .header h1 {
            font-size: 22px;
        }
        
        .form-container {
            padding: 25px 20px;
        }
        
        .tab {
            padding: 15px;
            font-size: 15px;
        }
        
        .otp-input {
            width: 45px;
            height: 45px;
            font-size: 20px;
        }
    }