/* ===================================
   SAI-IPL Global Styles
   Minimalist & Clean Design System
   =================================== */

/* Google Fonts */
@import url('https://fonts.googleapis.com/css2?family=Open+Sans:wght@300;400;600;700&display=swap');

/* ===================================
   CSS Custom Properties
   =================================== */
:root {
    /* Colors - Professional Engineering Palette */
    --color-primary: #dc2626;
    /* Brand Red */
    --color-primary-light: #ef4444;
    /* Bright Red */
    --color-primary-dark: #991b1b;
    /* Dark Red */
    --color-secondary: #059669;
    /* Professional Green */
    --color-accent: #f59e0b;
    /* Amber/Gold */

    /* Neutrals */
    --color-white: #ffffff;
    --color-gray-50: #f9fafb;
    --color-gray-100: #f3f4f6;
    --color-gray-200: #e5e7eb;
    --color-gray-300: #d1d5db;
    --color-gray-400: #9ca3af;
    --color-gray-500: #6b7280;
    --color-gray-600: #4b5563;
    --color-gray-700: #374151;
    --color-gray-800: #1f2937;
    --color-gray-900: #111827;

    /* Typography */
    --font-primary: 'Open Sans', 'Helvetica Neue', Helvetica, Arial, sans-serif;
    --font-fallback: -apple-system, BlinkMacSystemFont, 'Segoe UI', sans-serif;

    /* Font Sizes */
    --text-xs: 0.75rem;
    /* 12px */
    --text-sm: 0.875rem;
    /* 14px */
    --text-base: 1rem;
    /* 16px */
    --text-lg: 1.125rem;
    /* 18px */
    --text-xl: 1.25rem;
    /* 20px */
    --text-2xl: 1.5rem;
    /* 24px */
    --text-3xl: 1.875rem;
    /* 30px */
    --text-4xl: 2.25rem;
    /* 36px */
    --text-5xl: 3rem;
    /* 48px */
    --text-6xl: 3.75rem;
    /* 60px */

    /* Spacing */
    --space-1: 0.25rem;
    /* 4px */
    --space-2: 0.5rem;
    /* 8px */
    --space-3: 0.75rem;
    /* 12px */
    --space-4: 1rem;
    /* 16px */
    --space-5: 1.25rem;
    /* 20px */
    --space-6: 1.5rem;
    /* 24px */
    --space-8: 2rem;
    /* 32px */
    --space-10: 2.5rem;
    /* 40px */
    --space-12: 3rem;
    /* 48px */
    --space-16: 4rem;
    /* 64px */
    --space-20: 5rem;
    /* 80px */
    --space-24: 6rem;
    /* 96px */

    /* Shadows */
    --shadow-sm: 0 1px 2px 0 rgba(0, 0, 0, 0.05);
    --shadow: 0 1px 3px 0 rgba(0, 0, 0, 0.1), 0 1px 2px 0 rgba(0, 0, 0, 0.06);
    --shadow-md: 0 4px 6px -1px rgba(0, 0, 0, 0.1), 0 2px 4px -1px rgba(0, 0, 0, 0.06);
    --shadow-lg: 0 10px 15px -3px rgba(0, 0, 0, 0.1), 0 4px 6px -2px rgba(0, 0, 0, 0.05);
    --shadow-xl: 0 20px 25px -5px rgba(0, 0, 0, 0.1), 0 10px 10px -5px rgba(0, 0, 0, 0.04);

    /* Border Radius */
    --radius-sm: 0.25rem;
    /* 4px */
    --radius: 0.5rem;
    /* 8px */
    --radius-lg: 0.75rem;
    /* 12px */
    --radius-xl: 1rem;
    /* 16px */

    /* Transitions */
    --transition-fast: 150ms ease-in-out;
    --transition-base: 250ms ease-in-out;
    --transition-slow: 350ms ease-in-out;
}

/* ===================================
   Reset & Base Styles
   =================================== */
* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}

html {
    scroll-behavior: smooth;
    font-size: 16px;
}

body {
    font-family: var(--font-primary);
    font-size: var(--text-base);
    line-height: 1.6;
    color: var(--color-gray-800);
    background-color: var(--color-white);
    -webkit-font-smoothing: antialiased;
    -moz-osx-font-smoothing: grayscale;
}

/* ===================================
   Typography
   =================================== */
h1,
h2,
h3,
h4,
h5,
h6 {
    font-weight: 700;
    line-height: 1.2;
    color: var(--color-gray-900);
    margin-bottom: var(--space-4);
}

h1 {
    font-size: var(--text-5xl);
}

h2 {
    font-size: var(--text-4xl);
}

h3 {
    font-size: var(--text-3xl);
}

h4 {
    font-size: var(--text-2xl);
}

h5 {
    font-size: var(--text-xl);
}

h6 {
    font-size: var(--text-lg);
}

p {
    margin-bottom: var(--space-4);
    color: var(--color-gray-700);
}

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

a:hover {
    color: var(--color-primary-light);
}

/* ===================================
   Layout Components
   =================================== */
.container {
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 var(--space-6);
}

.section {
    padding: var(--space-20) 0;
}

.section-alt {
    background-color: var(--color-gray-50);
}

/* ===================================
   Navigation
   =================================== */
.navbar {
    position: fixed;
    top: 0;
    left: 0;
    right: 0;
    background-color: var(--color-white);
    box-shadow: var(--shadow-md);
    z-index: 1000;
    transition: all var(--transition-base);
}

.navbar .container {
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding-top: var(--space-4);
    padding-bottom: var(--space-4);
}

.navbar-brand {
    font-size: var(--text-2xl);
    font-weight: 700;
    color: var(--color-primary);
}

.navbar-brand span {
    color: var(--color-secondary);
}

.navbar-menu {
    display: flex;
    list-style: none;
    gap: var(--space-8);
    align-items: center;
}

.navbar-menu a {
    color: var(--color-gray-700);
    font-weight: 600;
    font-size: var(--text-sm);
    text-transform: uppercase;
    letter-spacing: 0.5px;
    padding: var(--space-2) var(--space-3);
    border-radius: var(--radius-sm);
    transition: all var(--transition-fast);
}

.navbar-menu a:hover,
.navbar-menu a.active {
    color: var(--color-primary);
    background-color: var(--color-gray-50);
}

.navbar-toggle {
    display: none;
    background: none;
    border: none;
    font-size: var(--text-2xl);
    color: var(--color-gray-700);
    cursor: pointer;
}

/* ===================================
   Hero Section
   =================================== */
.hero {
    position: relative;
    min-height: 100vh;
    display: flex;
    align-items: center;
    justify-content: center;
    background: linear-gradient(135deg, var(--color-primary) 0%, var(--color-primary-dark) 100%);
    color: var(--color-white);
    text-align: center;
    overflow: hidden;
    margin-top: 72px;
}

.hero::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    background-image: url('images/hero-engineering.jpg');
    background-size: cover;
    background-position: center;
    opacity: 0.15;
    z-index: 0;
}

.hero-content {
    position: relative;
    z-index: 1;
    max-width: 900px;
    padding: var(--space-8);
}

.hero h1 {
    color: var(--color-white);
    font-size: var(--text-6xl);
    margin-bottom: var(--space-6);
    font-weight: 700;
}

.hero p {
    color: rgba(255, 255, 255, 0.9);
    font-size: var(--text-xl);
    margin-bottom: var(--space-8);
}

/* ===================================
   Buttons
   =================================== */
.btn {
    display: inline-block;
    padding: var(--space-4) var(--space-8);
    font-size: var(--text-base);
    font-weight: 600;
    text-align: center;
    border-radius: var(--radius);
    cursor: pointer;
    transition: all var(--transition-base);
    border: 2px solid transparent;
    text-transform: uppercase;
    letter-spacing: 0.5px;
}

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

.btn-primary:hover {
    background-color: #047857;
    transform: translateY(-2px);
    box-shadow: var(--shadow-lg);
}

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

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

/* ===================================
   Cards
   =================================== */
.card {
    background-color: var(--color-white);
    border-radius: var(--radius-lg);
    padding: var(--space-8);
    box-shadow: var(--shadow);
    transition: all var(--transition-base);
    height: 100%;
}

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

.card-icon {
    width: 60px;
    height: 60px;
    background: linear-gradient(135deg, var(--color-primary), var(--color-primary-light));
    border-radius: var(--radius);
    display: flex;
    align-items: center;
    justify-content: center;
    margin-bottom: var(--space-6);
    font-size: var(--text-3xl);
    color: var(--color-white);
}

.card h3 {
    color: var(--color-gray-900);
    margin-bottom: var(--space-4);
}

.card p {
    color: var(--color-gray-600);
    font-size: var(--text-sm);
}

/* ===================================
   Icon Styles (Aria-labeled)
   =================================== */
.list-icon {
    display: inline-block;
    margin-right: var(--space-2);
    font-style: normal;
}

.checkmark {
    display: inline-block;
    margin-right: var(--space-2);
    color: var(--color-secondary);
    font-weight: bold;
    font-style: normal;
}

/* ===================================
   Grid System
   =================================== */
.grid {
    display: grid;
    gap: var(--space-8);
}

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

.grid-3 {
    grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
}

.grid-4 {
    grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
}

/* ===================================
   Forms
   =================================== */
.form-group {
    margin-bottom: var(--space-6);
}

.form-label {
    display: block;
    margin-bottom: var(--space-2);
    font-weight: 600;
    color: var(--color-gray-700);
    font-size: var(--text-sm);
}

.form-input,
.form-textarea,
.form-select {
    width: 100%;
    padding: var(--space-4);
    border: 2px solid var(--color-gray-300);
    border-radius: var(--radius);
    font-family: var(--font-primary);
    font-size: var(--text-base);
    transition: all var(--transition-fast);
}

.form-input:focus,
.form-textarea:focus,
.form-select:focus {
    outline: none;
    border-color: var(--color-primary);
    box-shadow: 0 0 0 3px rgba(30, 58, 138, 0.1);
}

.form-textarea {
    resize: vertical;
    min-height: 150px;
}

/* ===================================
   Footer
   =================================== */
.footer {
    background-color: var(--color-gray-900);
    color: var(--color-gray-300);
    padding: var(--space-16) 0 var(--space-8);
}

.footer-content {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
    gap: var(--space-12);
    margin-bottom: var(--space-12);
}

.footer h4 {
    color: var(--color-white);
    margin-bottom: var(--space-4);
    font-size: var(--text-lg);
}

.footer p,
.footer a {
    color: var(--color-gray-400);
    font-size: var(--text-sm);
}

.footer a:hover {
    color: var(--color-white);
}

.footer-bottom {
    border-top: 1px solid var(--color-gray-800);
    padding-top: var(--space-6);
    text-align: center;
    color: var(--color-gray-500);
    font-size: var(--text-sm);
}

/* ===================================
   Utility Classes
   =================================== */
.text-center {
    text-align: center;
}

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

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

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

.mt-8 {
    margin-top: var(--space-8);
}

.mb-4 {
    margin-bottom: var(--space-4);
}

.mb-8 {
    margin-bottom: var(--space-8);
}

.mb-12 {
    margin-bottom: var(--space-12);
}

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

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

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

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

.bg-gray-50 {
    background-color: var(--color-gray-50);
}

/* ===================================
   Responsive Design
   =================================== */
@media (max-width: 768px) {
    :root {
        --text-5xl: 2.5rem;
        --text-4xl: 2rem;
        --text-3xl: 1.5rem;
    }

    .navbar-menu {
        display: none;
        position: absolute;
        top: 100%;
        left: 0;
        right: 0;
        background-color: var(--color-white);
        flex-direction: column;
        padding: var(--space-6);
        box-shadow: var(--shadow-lg);
    }

    .navbar-menu.active {
        display: flex;
    }

    .navbar-toggle {
        display: block;
    }

    .hero {
        min-height: 80vh;
        margin-top: 64px;
    }

    .hero h1 {
        font-size: var(--text-4xl);
    }

    .section {
        padding: var(--space-12) 0;
    }
}

/* ===================================
   Animations
   =================================== */
@keyframes fadeInUp {
    from {
        opacity: 0;
        transform: translateY(30px);
    }

    to {
        opacity: 1;
        transform: translateY(0);
    }
}

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

@keyframes slideInLeft {
    from {
        opacity: 0;
        transform: translateX(-30px);
    }

    to {
        opacity: 1;
        transform: translateX(0);
    }
}

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