:root {
    --primary: #6366f1;
    --secondary: #4f46e5;
    --background: #f8fafc;
    --text: #1e293b;
    --error: #dc2626;
    --success: #16a34a;
}

* {
    box-sizing: border-box;
    margin: 0;
    padding: 0;
}

body {
    background: var(--background);
    font-family: 'Inter', sans-serif;
    min-height: 100vh;
    display: flex;
    justify-content: center;
    align-items: center;
    padding: 1rem;
}

.container-wrapper {
    width: 100%;
    max-width: 480px;
}

.verification-card {
    background: white;
    border-radius: 1.5rem;
    box-shadow: 0 10px 30px rgba(0,0,0,0.1);
    overflow: hidden;
    margin: 1rem;
}

.card-header {
    background: var(--primary);
    color: white;
    padding: 2rem;
    text-align: center;
}

.header-icon {
    width: 64px;
    margin-bottom: 1rem;
}

.card-header h1 {
    font-weight: 600;
    margin-bottom: 0.5rem;
}

.card-header p {
    opacity: 0.9;
}

.card-body {
    padding: 2rem;
}

.form-group {
    position: relative;
    margin-bottom: 1.25rem;
}

.form-group i {
    position: absolute;
    left: 1rem;
    top: 50%;
    transform: translateY(-50%);
    color: var(--primary);
    z-index: 2;
}

.form-control {
    width: 100%;
    padding: 0.875rem 1rem 0.875rem 2.75rem;
    border: 2px solid #e2e8f0;
    border-radius: 0.75rem;
    font-size: 1rem;
    transition: all 0.3s ease;
}

.form-control.is-invalid {
    border-color: var(--error);
    padding-right: calc(1.5em + 0.75rem);
    background-image: none;
}

.form-control:focus {
    border-color: var(--primary);
    box-shadow: 0 0 0 3px rgba(99, 102, 241, 0.2);
    outline: none;
}

.invalid-feedback {
    display: none;
    width: 100%;
    margin-top: 0.25rem;
    font-size: 0.875rem;
    color: var(--error);
}

.is-invalid ~ .invalid-feedback {
    display: block;
}

.captcha-section {
    margin: 2rem 0;
    background: #f1f5f9;
    border-radius: 1rem;
    padding: 1.5rem;
}

.captcha-image {
    position: relative;
    margin-bottom: 1rem;
    background: white;
    border-radius: 0.75rem;
    padding: 0.5rem;
    display: flex;
    justify-content: center;
}

#captchaImage {
    height: 65px;
    border-radius: 0.5rem;
}

.captcha-refresh {
    position: absolute;
    right: -10px;
    bottom: -10px;
    background: white;
    width: 40px;
    height: 40px;
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    box-shadow: 0 2px 8px rgba(0,0,0,0.1);
    border: none;
    cursor: pointer;
    transition: all 0.3s ease;
}

.captcha-refresh:hover {
    background: var(--primary);
    color: white;
}

.submit-btn {
    width: 100%;
    padding: 1rem;
    background: var(--primary);
    color: white;
    border: none;
    border-radius: 0.75rem;
    font-size: 1rem;
    font-weight: 500;
    cursor: pointer;
    transition: all 0.3s ease;
    position: relative;
}

.submit-btn:disabled {
    background: #a5b4fc;
    cursor: not-allowed;
}

.submit-spinner {
    display: none;
    position: absolute;
    right: 1rem;
    top: 50%;
    transform: translateY(-50%);
}

@media (max-width: 576px) {
    .card-header {
        padding: 1.5rem;
    }
    
    .card-body {
        padding: 1.5rem;
    }
    
    .form-control {
        padding-left: 2.5rem;
    }
    
    .captcha-section {
        padding: 1rem;
    }
    
    .submit-spinner {
        right: 0.5rem;
    }
}

.btn-gradient {
    background: linear-gradient(135deg, #0061ff, #60efff);
    color: white;
    font-weight: 500;
    border-radius: 8px;
    transition: all 0.3s ease;
}

.btn-gradient:hover {
    background: linear-gradient(135deg, #0051d4, #44d3d3);
    transform: translateY(-2px);
    box-shadow: 0 6px 15px rgba(0, 0, 0, 0.2);
}

.btn-gradient:active {
    transform: scale(0.97);
}