/**
 * HVAC & Electrical Solutions Website
 * Main Stylesheet
 * 
 * Design System: Technical Elegance with Industrial Confidence
 */

/* ============================================
   CSS Variables & Root Styles
   ============================================ */

:root {
    /* Colors */
    --primary-navy: #1a2332;
    --accent-green: #22c55e;
    --dark-green: #16a34a;
    --steel-gray: #64748b;
    --white: #ffffff;
    --light-gray: #f1f5f9;
    --light-green: #c8e6c9;
    --light-green-2: #a5d6a7;
    --bg-green: #e8f5e9;
    --border-gray: #e2e8f0;
    --dark-overlay: rgba(0, 0, 0, 0.4);
    
    /* Typography */
    --font-display: 'Poppins', sans-serif;
    --font-body: 'Inter', sans-serif;
    
    /* Spacing */
    --spacing-xs: 8px;
    --spacing-sm: 16px;
    --spacing-md: 24px;
    --spacing-lg: 32px;
    --spacing-xl: 48px;
    --spacing-2xl: 80px;
    
    /* Border Radius */
    --radius-sm: 4px;
    --radius-md: 8px;
    --radius-lg: 12px;
    
    /* Shadows */
    --shadow-sm: 0 1px 3px rgba(0, 0, 0, 0.1);
    --shadow-md: 0 4px 6px rgba(0, 0, 0, 0.1);
    --shadow-lg: 0 10px 15px rgba(0, 0, 0, 0.1);
    
    /* Transitions */
    --transition: all 0.3s ease;
}

/* ============================================
   Global Styles
   ============================================ */

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

html {
    scroll-behavior: smooth;
}

body {
    font-family: var(--font-body);
    color: var(--primary-navy);
    background-color: var(--white);
    line-height: 1.6;
}

/* ============================================
   Typography
   ============================================ */

h1, h2, h3, h4, h5, h6 {
    font-family: var(--font-display);
    font-weight: 700;
    line-height: 1.2;
    margin-bottom: var(--spacing-md);
}

h1 {
    font-size: 48px;
}

h2 {
    font-size: 36px;
}

h3 {
    font-size: 24px;
}

p {
    margin-bottom: var(--spacing-md);
    color: var(--steel-gray);
}

a {
    color: var(--accent-green);
    text-decoration: none;
    transition: var(--transition);
}

a:hover {
    color: #16a34a;
}

/* ============================================
   Container & Layout
   ============================================ */

.container {
    max-width: 1280px;
    margin: 0 auto;
    padding: 0 var(--spacing-lg);
}

.section {
    padding: var(--spacing-2xl) 0;
}

.section-header {
    text-align: center;
    margin-bottom: var(--spacing-2xl);
}

.accent-line {
    width: 60px;
    height: 4px;
    background-color: var(--accent-green);
    margin: 0 auto var(--spacing-md);
}

.section-title {
    font-size: 40px;
    color: var(--primary-navy);
    margin-bottom: var(--spacing-md);
}

.section-subtitle {
    font-size: 18px;
    color: var(--steel-gray);
}

/* ============================================
   Buttons
   ============================================ */

.btn {
    display: inline-block;
    padding: 12px 24px;
    border-radius: var(--radius-md);
    font-weight: 600;
    text-align: center;
    cursor: pointer;
    transition: var(--transition);
    border: none;
    font-family: var(--font-body);
    font-size: 16px;
    text-decoration: none;
}

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

.btn-primary:hover {
    background-color: #16a34a;
    transform: translateY(-2px);
    box-shadow: var(--shadow-lg);
}

.btn-outline {
    background-color: transparent;
    color: var(--white);
    border: 2px solid var(--white);
}

.btn-outline:hover {
    background-color: rgba(255, 255, 255, 0.1);
}

.btn-secondary {
    background-color: transparent;
    color: var(--accent-green);
    border: 2px solid var(--accent-green);
}

.btn-secondary:hover {
    background-color: var(--accent-green);
    color: var(--white);
}

/* ============================================
   Cards
   ============================================ */

.card {
    background-color: var(--white);
    border: 1px solid var(--border-gray);
    border-radius: var(--radius-md);
    padding: var(--spacing-md);
    box-shadow: var(--shadow-sm);
    transition: var(--transition);
}

.card:hover {
    box-shadow: var(--shadow-lg);
    transform: translateY(-4px);
}

.card-image {
    width: 100%;
    height: 200px;
    object-fit: cover;
    border-radius: var(--radius-md);
    margin-bottom: var(--spacing-md);
}

.card-title {
    font-size: 20px;
    color: var(--primary-navy);
    margin-bottom: var(--spacing-sm);
}

.card-text {
    font-size: 14px;
    color: var(--steel-gray);
    margin-bottom: var(--spacing-md);
}

/* ============================================
   Grid Layouts
   ============================================ */

.grid {
    display: grid;
    gap: var(--spacing-lg);
}

.grid-2 {
    grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
}

.grid-3 {
    grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
}

.grid-5 {
    grid-template-columns: repeat(auto-fit, minmax(150px, 1fr));
}

/* ============================================
   Responsive Design
   ============================================ */

@media (max-width: 768px) {
    h1 {
        font-size: 32px;
    }
    
    h2 {
        font-size: 28px;
    }
    
    h3 {
        font-size: 20px;
    }
    
    .container {
        padding: 0 var(--spacing-md);
    }
    
    .section {
        padding: var(--spacing-xl) 0;
    }
    
    .grid-2,
    .grid-3,
    .grid-5 {
        grid-template-columns: 1fr;
    }
}

/* ============================================
   Utility Classes
   ============================================ */

.text-center {
    text-align: center;
}

.text-white {
    color: var(--white);
}

.bg-light {
    background-color: var(--light-green);
}

.bg-light-gray {
    background-color: var(--light-gray);
}

.bg-dark {
    background-color: var(--primary-navy);
}

.bg-green-light {
    background-color: var(--light-green);
}

.mb-1 { margin-bottom: var(--spacing-xs); }
.mb-2 { margin-bottom: var(--spacing-sm); }
.mb-3 { margin-bottom: var(--spacing-md); }
.mb-4 { margin-bottom: var(--spacing-lg); }
.mb-5 { margin-bottom: var(--spacing-xl); }

.mt-1 { margin-top: var(--spacing-xs); }
.mt-2 { margin-top: var(--spacing-sm); }
.mt-3 { margin-top: var(--spacing-md); }
.mt-4 { margin-top: var(--spacing-lg); }
.mt-5 { margin-top: var(--spacing-xl); }

.p-2 { padding: var(--spacing-sm); }
.p-3 { padding: var(--spacing-md); }
.p-4 { padding: var(--spacing-lg); }

.flex {
    display: flex;
}

.flex-center {
    display: flex;
    align-items: center;
    justify-content: center;
}

.flex-between {
    display: flex;
    align-items: center;
    justify-content: space-between;
}

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

.gap-1 { gap: var(--spacing-xs); }
.gap-2 { gap: var(--spacing-sm); }
.gap-3 { gap: var(--spacing-md); }
.gap-4 { gap: var(--spacing-lg); }

.w-full {
    width: 100%;
}

.h-auto {
    height: auto;
}

.rounded {
    border-radius: var(--radius-md);
}

.shadow {
    box-shadow: var(--shadow-md);
}

.hidden {
    display: none;
}

.visible {
    display: block;
}

/* ============================================
   Animations
   ============================================ */

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

.fade-in {
    animation: fadeIn 0.6s ease-out;
}

@keyframes slideInLeft {
    from {
        opacity: 0;
        transform: translateX(-20px);
    }
    to {
        opacity: 1;
        transform: translateX(0);
    }
}

.slide-in-left {
    animation: slideInLeft 0.6s ease-out;
}

@keyframes slideInRight {
    from {
        opacity: 0;
        transform: translateX(20px);
    }
    to {
        opacity: 1;
        transform: translateX(0);
    }
}

.slide-in-right {
    animation: slideInRight 0.6s ease-out;
}