:root {
    --primary-color: #2c3e50;
    --accent-color: #3498db;
}
body {
    background-color: #f4f7f6;
    font-family: 'Segoe UI', Tahoma, Geneva, Verdana, sans-serif;
    color: var(--primary-color);
}
.hero-section {
    background: linear-gradient(135deg, var(--primary-color) 0%, #34495e 100%);
    color: white;
    padding: 80px 0;
    text-align: center;
}
.hero-section h1 {
    font-weight: 700;
    font-size: 3.5rem;
    margin-bottom: 1rem;
}
.hero-section p {
    font-size: 1.25rem;
    opacity: 0.9;
}
.main-container {
    margin-top: -50px;
    margin-bottom: 50px;
}
.form-card {
    border: none;
    border-radius: 15px;
    box-shadow: 0 10px 30px rgba(0,0,0,0.1);
    overflow: hidden;
}
.card-header {
    background-color: white;
    border-bottom: 1px solid #eee;
    padding: 25px;
    text-align: center;
}
.card-header h2 {
    margin: 0;
    font-weight: 600;
    color: var(--primary-color);
}
.card-body {
    padding: 40px;
}
.btn-submit {
    background-color: var(--accent-color);
    border: none;
    padding: 12px;
    font-weight: 600;
    transition: all 0.3s;
}
.btn-submit:hover {
    background-color: #2980b9;
    transform: translateY(-2px);
}
.input-group-text {
    background-color: #f8f9fa;
    border-right: none;
}
.form-control {
    border-left: none;
}
.form-control:focus {
    box-shadow: none;
    border-color: #dee2e6;
}
.input-group:focus-within .input-group-text,
.input-group:focus-within .form-control {
    border-color: var(--accent-color);
}
@media (max-width: 768px) {
    .hero-section h1 { font-size: 2.5rem; }
    .card-body { padding: 25px; }
}