:root {
    /* Dark theme (default) - matching api-manager */
    --bg-primary: #1a1a1a;
    --bg-secondary: #2d2d2d;
    --bg-tertiary: #1a1a1a;
    --bg-container: #2d2d2d;
    --bg-input: #1a1a1a;
    --text-primary: #e8e8e8;
    --text-secondary: #999;
    --text-tertiary: #ccc;
    --border-color: #444;
    --border-secondary: #333;
    --accent-color: #C8102E;
    --accent-hover: #a00d25;
    --success-color: #28a745;
    --danger-color: #dc3545;
    --warning-color: #ffc107;
    --shadow-color: rgba(0, 0, 0, 0.3);
    --shadow-hover: rgba(0, 0, 0, 0.4);
    --card-shadow: 0 4px 12px rgba(0, 0, 0, 0.3);
    --hover-bg: rgba(255, 255, 255, 0.05);
    --grid-color: rgba(200, 16, 46, 0.03);
    
    /* Layout */
    --topnav-height: 64px;
    --content-max-width: 1400px;
    
    /* Spacing */
    --spacing-xs: 4px;
    --spacing-sm: 8px;
    --spacing-md: 16px;
    --spacing-lg: 24px;
    --spacing-xl: 32px;
    
    /* Border radius */
    --radius-sm: 2px;
    --radius-md: 2px;
    --radius-lg: 2px;
}

body.light-mode {
    /* Light theme */
    --bg-primary: #f5f5f5;
    --bg-secondary: #ffffff;
    --bg-tertiary: #fafafa;
    --bg-container: #ffffff;
    --bg-input: #ffffff;
    --text-primary: #1a1a1a;
    --text-secondary: #666;
    --text-tertiary: #333;
    --border-color: #ddd;
    --border-secondary: #e8e8e8;
    --accent-color: #C8102E;
    --accent-hover: #a00d25;
    --shadow-color: rgba(0, 0, 0, 0.1);
    --shadow-hover: rgba(0, 0, 0, 0.15);
    --card-shadow: 0 2px 8px rgba(0, 0, 0, 0.1);
    --hover-bg: rgba(0, 0, 0, 0.05);
}

/* ============================================
   GLOBAL STYLES
   ============================================ */
* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}

body {
    font-family: 'Helvetica Neue', Arial, sans-serif;
    background: linear-gradient(135deg, var(--bg-primary) 0%, var(--bg-secondary) 100%);
    color: var(--text-primary);
    line-height: 1.6;
    min-height: 100vh;
    transition: background 0.3s, color 0.3s;
}

body::before {
    content: '';
    position: fixed;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    background:
        repeating-linear-gradient(90deg, transparent, transparent 2px, var(--grid-color) 2px, var(--grid-color) 4px),
        repeating-linear-gradient(0deg, transparent, transparent 2px, var(--grid-color) 2px, var(--grid-color) 4px);
    pointer-events: none;
    z-index: 0;
}

/* ============================================
   TOP NAVIGATION
   ============================================ */
.topnav {
    position: fixed;
    top: 0;
    left: 0;
    right: 0;
    height: var(--topnav-height);
    background-color: var(--bg-secondary);
    color: var(--text-primary);
    display: flex;
    align-items: center;
    justify-content: space-between;
    padding: 0 var(--spacing-xl);
    box-shadow: var(--card-shadow);
    z-index: 1000;
    border-bottom: 1px solid var(--border-color);
}

.nav-left {
    display: flex;
    align-items: center;
    gap: var(--spacing-md);
}

.app-title {
    font-size: 24px;
    font-weight: 700;
    color: var(--text-primary);
    text-transform: uppercase;
    letter-spacing: 2px;
}

.nav-right {
    display: flex;
    align-items: center;
    gap: var(--spacing-md);
}

.service-badge {
    background-color: var(--bg-tertiary);
    color: var(--text-secondary);
    padding: var(--spacing-xs) var(--spacing-md);
    border-radius: var(--radius-sm);
    font-size: 13px;
    font-weight: 600;
    text-transform: uppercase;
    letter-spacing: 1px;
    border: 1px solid var(--border-color);
}

.theme-toggle {
    padding: 12px;
    background: var(--bg-tertiary);
    border: 1px solid var(--border-color);
    border-radius: var(--radius-sm);
    cursor: pointer;
    font-size: 20px;
    transition: all 0.3s;
    display: flex;
    align-items: center;
    justify-content: center;
    width: 48px;
    height: 48px;
}

.theme-toggle:hover {
    border-color: var(--accent-color);
    background: var(--hover-bg);
}

/* ============================================
   MAIN CONTENT
   ============================================ */
.main-content {
    margin-top: var(--topnav-height);
    padding: var(--spacing-xl);
    max-width: var(--content-max-width);
    margin-left: auto;
    margin-right: auto;
    position: relative;
    z-index: 1;
}

.page-header {
    margin-bottom: var(--spacing-xl);
}

.header-content h2 {
    font-size: 32px;
    font-weight: 700;
    color: var(--text-primary);
    margin-bottom: var(--spacing-xs);
}

.subtitle {
    font-size: 16px;
    color: var(--text-secondary);
}

/* ============================================
   BUILDER CONTAINER
   ============================================ */
.builder-container {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: var(--spacing-lg);
}

@media (max-width: 1024px) {
    .builder-container {
        grid-template-columns: 1fr;
    }
}

.form-section,
.results-section {
    background-color: var(--bg-secondary);
    border-radius: var(--radius-sm);
    padding: var(--spacing-xl);
    box-shadow: var(--card-shadow);
    border: 1px solid var(--border-color);
    border-top: 3px solid var(--accent-color);
    transition: transform 0.3s, box-shadow 0.3s;
}

.form-section:hover,
.results-section:hover {
    transform: translateY(-2px);
    box-shadow: 0 6px 20px var(--shadow-hover);
}

.section-title {
    font-size: 20px;
    font-weight: 700;
    color: var(--text-primary);
    margin-bottom: var(--spacing-lg);
    padding-bottom: var(--spacing-md);
    border-bottom: 2px solid var(--border-color);
    text-transform: uppercase;
    letter-spacing: 1px;
}

.mt-4 {
    margin-top: var(--spacing-xl);
}

/* ============================================
   FORM STYLES
   ============================================ */
.form-row {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(200px, 1fr));
    gap: var(--spacing-md);
    margin-bottom: var(--spacing-lg);
}

.form-group {
    display: flex;
    flex-direction: column;
}

.form-group label {
    font-size: 12px;
    font-weight: 600;
    color: var(--text-secondary);
    margin-bottom: var(--spacing-sm);
    text-transform: uppercase;
    letter-spacing: 0.5px;
}

.form-control {
    padding: 14px 16px;
    font-size: 14px;
    border: 2px solid var(--border-color);
    border-radius: var(--radius-sm);
    background-color: var(--bg-input);
    color: var(--text-primary);
    transition: all 0.3s ease;
    font-family: inherit;
}

.form-control:hover {
    border-color: var(--text-secondary);
}

.form-control:focus {
    outline: none;
    border-color: var(--accent-color);
    box-shadow: 0 0 0 4px rgba(200, 16, 46, 0.15);
}

.form-control:disabled,
.form-control[readonly] {
    background-color: var(--bg-tertiary);
    cursor: not-allowed;
}

/* ============================================
   BUTTONS
   ============================================ */
.form-actions {
    display: flex;
    gap: var(--spacing-md);
    margin-top: var(--spacing-xl);
}

.btn {
    padding: 14px 24px;
    font-size: 14px;
    font-weight: 700;
    border: none;
    border-radius: var(--radius-sm);
    cursor: pointer;
    transition: all 0.3s ease;
    text-transform: uppercase;
    letter-spacing: 1px;
    box-shadow: 0 4px 12px rgba(200, 16, 46, 0.3);
}

.btn-primary {
    background-color: var(--accent-color);
    color: white;
}

.btn-primary:hover {
    background-color: var(--accent-hover);
    box-shadow: 0 6px 16px rgba(200, 16, 46, 0.4);
    transform: translateY(-1px);
}

.btn-secondary {
    background-color: var(--bg-tertiary);
    color: var(--text-primary);
    border: 1px solid var(--border-color);
}

.btn-secondary:hover {
    background-color: var(--hover-bg);
    border-color: var(--accent-color);
}

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

/* ============================================
   RESULTS SECTION
   ============================================ */
.cost-breakdown {
    display: flex;
    flex-direction: column;
    gap: var(--spacing-md);
}

.cost-item {
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: var(--spacing-md);
    background-color: var(--bg-tertiary);
    border-radius: var(--radius-sm);
    border: 1px solid var(--border-color);
    transition: all 0.2s ease;
}

.cost-item:hover {
    background-color: var(--hover-bg);
    border-color: var(--accent-color);
}

.cost-label {
    font-size: 12px;
    font-weight: 600;
    color: var(--text-secondary);
    text-transform: uppercase;
    letter-spacing: 0.5px;
}

.cost-value {
    font-size: 18px;
    font-weight: 700;
    color: var(--accent-color);
}

.cost-divider {
    height: 2px;
    background-color: var(--border-color);
    margin: var(--spacing-sm) 0;
}

.cost-total {
    background-color: var(--accent-color);
    color: white;
    border: none;
}

.cost-total .cost-label,
.cost-total .cost-value {
    color: white;
}

.cost-grand-total {
    background-color: var(--accent-color);
    color: white;
    font-size: 18px;
    padding: var(--spacing-lg);
    box-shadow: 0 4px 12px rgba(200, 16, 46, 0.4);
}

.cost-grand-total .cost-label,
.cost-grand-total .cost-value {
    color: white;
    font-size: 20px;
    font-weight: 700;
}

/* ============================================
   ANIMATIONS
   ============================================ */
@keyframes fadeIn {
    from {
        opacity: 0;
        transform: translateY(10px);
    }
    to {
        opacity: 1;
        transform: translateY(0);
    }
}

.results-section {
    animation: fadeIn 0.3s ease;
}