:root {
    --nissan-red: #C3002F;
    --nissan-dark: #000000;
    --nissan-light: #FFFFFF;
    --nissan-gray: #333333;
    --nissan-light-gray: #F4F4F4;
    --border-radius: 4px;
    --transition: all 0.3s ease;
    --container-padding: 1.5rem;
    --shadow: 0 2px 10px rgba(0,0,0,0.1);
}

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

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

.header {
    background-color: var(--nissan-dark);
    padding: 2rem var(--container-padding);
    position: relative;
    overflow: hidden;
}

.header::after {
    content: '';
    position: absolute;
    bottom: 0;
    left: 0;
    width: 100%;
    height: 4px;
    background-color: var(--nissan-red);
}

.header h1 {
    color: var(--nissan-light);
    font-size: 2rem;
    text-align: center;
    text-transform: uppercase;
    letter-spacing: 2px;
    margin: 0;
}

.container {
    max-width: 1200px;
    margin: 0 auto;
    padding: var(--container-padding);
}

/* Form Styles */
.form-container {
    background: var(--nissan-light);
    padding: 2rem;
    border-radius: var(--border-radius);
    box-shadow: var(--shadow);
    margin: 2rem auto;
    max-width: 800px;
}

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

label {
    display: block;
    margin-bottom: 0.5rem;
    font-weight: 500;
    color: var(--nissan-gray);
}

input, 
select, 
textarea {
    width: 100%;
    padding: 0.75rem;
    border: 2px solid #ddd;
    border-radius: var(--border-radius);
    font-size: 1rem;
    transition: var(--transition);
}

input:focus, 
select:focus, 
textarea:focus {
    border-color: var(--nissan-red);
    outline: none;
    box-shadow: 0 0 0 3px rgba(195, 0, 47, 0.1);
}

/* Button Styles */
.btn {
    display: inline-block;
    padding: 0.75rem 1.5rem;
    background-color: var(--nissan-red);
    color: var(--nissan-light);
    border: none;
    border-radius: var(--border-radius);
    font-size: 1rem;
    cursor: pointer;
    transition: var(--transition);
    text-decoration: none;
    text-align: center;
    text-transform: uppercase;
    letter-spacing: 1px;
    font-weight: 500;
}

.btn:hover {
    background-color: #a30027;
    transform: translateY(-2px);
}

.btn-block {
    width: 100%;
}

.btn-secondary {
    background-color: var(--nissan-gray);
}

.btn-secondary:hover {
    background-color: #222;
}

/* Section Styles */
.section-title {
    color: var(--nissan-red);
    font-size: 1.75rem;
    margin: 2rem 0 1rem;
    padding-bottom: 0.5rem;
    border-bottom: 3px solid var(--nissan-red);
}

/* Card Grid */
.upgrades-grid {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(300px, 1fr));
    gap: 1.5rem;
    margin: 1.5rem 0;
}

.upgrade-card {
    background: var(--nissan-light);
    border-radius: var(--border-radius);
    overflow: hidden;
    transition: var(--transition);
    border: 1px solid #ddd;
    cursor: pointer;
}

.upgrade-card:hover {
    transform: translateY(-5px);
    box-shadow: var(--shadow);
}

.upgrade-header {
    background-color: var(--nissan-dark);
    color: var(--nissan-light);
    padding: 1rem;
}

.upgrade-content {
    padding: 1rem;
}

.upgrade-details {
    border-top: 1px solid #ddd;
    padding-top: 1rem;
    margin-top: 1rem;
    display: none;
}

/* Messages */
.message {
    padding: 1rem;
    margin: 1rem 0;
    border-radius: var(--border-radius);
    text-align: center;
}

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

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

/* Navigation */
.nav-links {
    margin: 1rem 0;
    text-align: center;
}

.nav-links .btn {
    margin: 0.5rem;
}

.top-bar {
    display: flex;
    justify-content: space-between;
    align-items: center;
    margin-bottom: 2rem;
    padding: 1rem 0;
    border-bottom: 2px solid var(--nissan-red);
}

.total-cost {
    font-size: 1.25rem;
    font-weight: bold;
    color: var(--nissan-red);
    padding: 0.5rem 1rem;
    background-color: var(--nissan-light);
    border-radius: var(--border-radius);
    box-shadow: var(--shadow);
}

@media (max-width: 768px) {
    .top-bar {
        flex-direction: column;
        gap: 1rem;
        text-align: center;
    }

    .total-cost {
        width: 100%;
    }
}

/* Login form specific styles */
.form-container {
    max-width: 400px;
    margin: 2rem auto;
    padding: 2rem;
    background-color: var(--nissan-light);
    border-radius: var(--border-radius);
    box-shadow: var(--shadow);
}

.form-container .message {
    margin-bottom: 1rem;
}

.form-container input[type="password"] {
    margin-bottom: 1rem;
}

.btn-delete {
    background-color: #dc3545;
    color: white;
    padding: 0.5rem 1rem;
    margin-top: 1rem;
    font-size: 0.9rem;
    width: 100%;
}

.btn-delete:hover {
    background-color: #c82333;
}

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

    .header h1 {
        font-size: 1.5rem;
    }

    .form-container {
        padding: 1rem;
        margin: 1rem;
    }

    .upgrades-grid {
        grid-template-columns: 1fr;
    }

    .btn {
        width: 100%;
        margin: 0.5rem 0;
    }
}

@media (max-width: 480px) {
    .header h1 {
        font-size: 1.25rem;
    }

    .section-title {
        font-size: 1.5rem;
    }
}