body {
    min-height: 100vh;
    display: flex;
    align-items: center;
    justify-content: center;
    background: linear-gradient(135deg, #1a237e 0%, #0d47a1 50%, #01579b 100%);
    font-family: 'Segoe UI', Tahoma, Geneva, Verdana, sans-serif;
}

.login-container {
    width: 100%;
    max-width: 420px;
    padding: 15px;
}

.login-card {
    background: #fff;
    border-radius: 12px;
    padding: 35px 30px;
    box-shadow: 0 10px 40px rgba(0, 0, 0, 0.25);
}

.login-logo {
    width: 70px;
    height: 70px;
    background: linear-gradient(135deg, #1565c0, #0d47a1);
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    margin: 0 auto;
    color: #fff;
    font-size: 32px;
}

.login-header h4 {
    font-size: 1.1rem;
    line-height: 1.5;
}

.form-label {
    font-weight: 600;
    font-size: 0.85rem;
    color: #333;
}

.form-control {
    border-radius: 8px;
    padding: 10px 14px;
    border: 1px solid #ddd;
    transition: border-color 0.2s, box-shadow 0.2s;
}

.form-control:focus {
    border-color: #1565c0;
    box-shadow: 0 0 0 0.2rem rgba(21, 101, 192, 0.15);
}

.captcha-img {
    height: 50px;
    min-width: 160px;
    background: #f5f5f5;
    object-fit: contain;
}

.btn-primary {
    background: linear-gradient(135deg, #1565c0, #0d47a1);
    border: none;
    border-radius: 8px;
    font-weight: 600;
    letter-spacing: 0.5px;
    transition: transform 0.15s, box-shadow 0.15s;
}

.btn-primary:hover {
    transform: translateY(-1px);
    box-shadow: 0 4px 12px rgba(13, 71, 161, 0.4);
}

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

#login-error {
    font-size: 0.85rem;
    border-radius: 8px;
}

@media (max-width: 576px) {
    .login-card {
        padding: 25px 20px;
    }
    .login-header h4 {
        font-size: 0.95rem;
    }
}