:root {
    --primary-color: #4a90e2;
    --secondary-color: #2c3e50;
    --success-color: #2ecc71;
    --danger-color: #e74c3c;
    --light-gray: #f5f6fa;
    --dark-gray: #2c3e50;
    --white: #ffffff;
}

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

body {
    font-family: 'Poppins', sans-serif;
    background-color: var(--light-gray);
    color: var(--dark-gray);
    line-height: 1.6;
}

.container {
    max-width: 1200px;
    margin: 0 auto;
    padding: 2rem;
}

header {
    text-align: center;
    margin-bottom: 3rem;
}

header h1 {
    font-size: 3rem;
    color: var(--primary-color);
    margin-bottom: 0.5rem;
}

.login-container {
    background-color: var(--white);
    border-radius: 10px;
    box-shadow: 0 4px 6px rgba(0, 0, 0, 0.1);
    padding: 2rem;
    max-width: 500px;
    margin: 0 auto;
}

.login-options {
    display: flex;
    margin-bottom: 2rem;
    border-bottom: 1px solid var(--light-gray);
}

.tab-btn {
    flex: 1;
    padding: 1rem;
    background: none;
    border: none;
    cursor: pointer;
    font-size: 1.1rem;
    color: var(--dark-gray);
    transition: all 0.3s ease;
}

.tab-btn.active {
    color: var(--primary-color);
    border-bottom: 2px solid var(--primary-color);
}

.login-form {
    display: none;
}

.login-form.active {
    display: block;
}

.form-group {
    margin-bottom: 1.5rem;
}

label {
    display: block;
    margin-bottom: 0.5rem;
    font-weight: 500;
}

input {
    width: 100%;
    padding: 0.8rem;
    border: 1px solid #ddd;
    border-radius: 5px;
    font-size: 1rem;
    transition: border-color 0.3s ease;
}

input:focus {
    outline: none;
    border-color: var(--primary-color);
}

.btn {
    width: 100%;
    padding: 1rem;
    background-color: var(--primary-color);
    color: var(--white);
    border: none;
    border-radius: 5px;
    font-size: 1rem;
    cursor: pointer;
    transition: background-color 0.3s ease;
}

.btn:hover {
    background-color: #357abd;
}

.register-link {
    text-align: center;
    margin-top: 1rem;
}

.register-link a {
    color: var(--primary-color);
    text-decoration: none;
}

.register-link a:hover {
    text-decoration: underline;
}

footer {
    text-align: center;
    margin-top: 2rem;
    color: var(--dark-gray);
}

footer a {
    color: var(--primary-color);
    text-decoration: none;
}

footer a:hover {
    text-decoration: underline;
}

/* Responsive Design */
@media (max-width: 768px) {
    .container {
        padding: 1rem;
    }

    header h1 {
        font-size: 2.5rem;
    }

    .login-container {
        padding: 1.5rem;
    }
}

/* Alert Messages */
.alert {
    padding: 1rem;
    border-radius: 5px;
    margin-bottom: 1rem;
    display: none;
}

.alert-success {
    background-color: #d4edda;
    color: #155724;
    border: 1px solid #c3e6cb;
}

.alert-danger {
    background-color: #f8d7da;
    color: #721c24;
    border: 1px solid #f5c6cb;
}