/* Base variables - Light Theme (Default) */
:root {
    --bg-color: #ffffff;
    --surface-color: #f8f9fa;
    --surface-hover: #e9ecef;
    --text-color: #1a1a1a;
    --text-muted: #6c757d;
    --border-color: #dee2e6;
    
    --primary-color: #0d6efd;
    --primary-hover: #0b5ed7;
    --secondary-color: #6c757d;
    
    --font-family: 'Inter', -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, "Helvetica Neue", Arial, sans-serif;
    --transition-speed: 0.2s;
}

/* Dark Theme */
:root[data-theme="dark"] {
    --bg-color: #121212;
    --surface-color: #1e1e1e;
    --surface-hover: #2d2d2d;
    --text-color: #e0e0e0;
    --text-muted: #a0a0a0;
    --border-color: #333333;
    
    --primary-color: #3b82f6;
    --primary-hover: #60a5fa;
}

/* Reset & Basics */
* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}

body {
    font-family: var(--font-family);
    background-color: var(--bg-color);
    color: var(--text-color);
    line-height: 1.6;
    transition: background-color var(--transition-speed), color var(--transition-speed);
}

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

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

.container {
    width: 100%;
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 20px;
}

/* Typography */
h1, h2, h3, h4, h5, h6 {
    margin-bottom: 1rem;
    font-weight: 700;
    line-height: 1.2;
}

/* Buttons */
.btn {
    display: inline-block;
    padding: 10px 20px;
    border-radius: 4px;
    font-weight: 600;
    text-align: center;
    cursor: pointer;
    border: none;
    transition: background-color var(--transition-speed), transform 0.1s;
}

.btn-primary {
    background-color: var(--primary-color);
    color: #ffffff;
}

.btn-primary:hover {
    background-color: var(--primary-hover);
    color: #ffffff;
}

.btn-sm {
    padding: 8px 16px;
    font-size: 0.875rem;
}

/* Header */
.site-header {
    background-color: var(--surface-color);
    border-bottom: 1px solid var(--border-color);
    position: sticky;
    top: 0;
    z-index: 100;
}

.header-inner {
    display: flex;
    justify-content: space-between;
    align-items: center;
    height: 70px;
}

.brand-logo {
    font-size: 1.25rem;
    font-weight: 800;
    color: var(--text-color);
}

.brand-logo .accent {
    color: var(--primary-color);
}

.main-nav {
    display: flex;
    align-items: center;
    gap: 30px;
}

.nav-links {
    list-style: none;
    display: flex;
    gap: 20px;
}

.nav-links a {
    color: var(--text-color);
    font-weight: 500;
}

.nav-links a:hover {
    color: var(--primary-color);
}

.nav-actions {
    display: flex;
    align-items: center;
    gap: 15px;
}

.theme-toggle {
    background: none;
    border: none;
    cursor: pointer;
    color: var(--text-color);
    display: flex;
    align-items: center;
    justify-content: center;
    padding: 8px;
    border-radius: 50%;
    transition: background-color var(--transition-speed);
}

.theme-toggle:hover {
    background-color: var(--surface-hover);
}

:root[data-theme="dark"] .icon-moon { display: none; }
:root[data-theme="light"] .icon-sun { display: none; }

.mobile-menu-toggle {
    display: none;
    background: none;
    border: none;
    cursor: pointer;
    flex-direction: column;
    gap: 5px;
    padding: 5px;
}

.mobile-menu-toggle span {
    display: block;
    width: 25px;
    height: 2px;
    background-color: var(--text-color);
    transition: 0.3s;
}

/* Main Content */
.main-content {
    min-height: calc(100vh - 70px - 200px); /* Approx calc */
}

/* Footer */
.site-footer {
    background-color: var(--surface-color);
    border-top: 1px solid var(--border-color);
    padding: 60px 0 20px;
    margin-top: 60px;
}

.footer-grid {
    display: grid;
    grid-template-columns: 2fr 1fr 1fr 1fr;
    gap: 40px;
    margin-bottom: 40px;
}

.footer-brand .footer-desc {
    color: var(--text-muted);
    margin-top: 15px;
}

.footer-links h4, .footer-contact h4 {
    margin-bottom: 20px;
    font-size: 1.1rem;
}

.footer-links ul, .footer-contact ul {
    list-style: none;
}

.footer-links li, .footer-contact li {
    margin-bottom: 10px;
}

.footer-links a, .footer-contact a {
    color: var(--text-muted);
}

.footer-links a:hover, .footer-contact a:hover {
    color: var(--primary-color);
}

.footer-bottom {
    text-align: center;
    padding-top: 20px;
    border-top: 1px solid var(--border-color);
    color: var(--text-muted);
    font-size: 0.875rem;
}

/* Mobile Responsive */
@media (max-width: 768px) {
    .mobile-menu-toggle {
        display: flex;
    }

    .main-nav {
        display: none;
        position: absolute;
        top: 70px;
        left: 0;
        right: 0;
        background-color: var(--surface-color);
        flex-direction: column;
        padding: 20px;
        border-bottom: 1px solid var(--border-color);
    }

    .main-nav.active {
        display: flex;
    }

    .nav-links {
        flex-direction: column;
        width: 100%;
        text-align: center;
        gap: 15px;
        margin-bottom: 20px;
    }

    .nav-actions {
        flex-direction: column;
        width: 100%;
    }

    .footer-grid {
        grid-template-columns: 1fr;
        gap: 30px;
    }
}

/* Phase 2: Homepage Styles */
/* Utilities */
.section-alternate {
    background-color: var(--surface-color);
}
.text-center { text-align: center; }
.mx-auto { margin-left: auto; margin-right: auto; }
.mt-20 { margin-top: 20px; }
.btn-secondary {
    background-color: var(--surface-color);
    color: var(--text-color);
    border: 1px solid var(--border-color);
}
.btn-secondary:hover {
    background-color: var(--surface-hover);
}
.btn-outline {
    background-color: transparent;
    color: var(--primary-color);
    border: 1px solid var(--primary-color);
}
.btn-outline:hover {
    background-color: var(--primary-color);
    color: #ffffff;
}

/* Common Section Styles */
section {
    padding: 80px 0;
}
.eyebrow {
    display: block;
    font-size: 0.875rem;
    font-weight: 700;
    color: var(--primary-color);
    text-transform: uppercase;
    letter-spacing: 0.05em;
    margin-bottom: 10px;
}
.section-header {
    margin-bottom: 40px;
}
.section-header h2 {
    font-size: 2.5rem;
    margin-bottom: 20px;
}

/* Hero Section */
.hero-section {
    padding: 100px 0;
}
.hero-container {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 40px;
    align-items: center;
}
.hero-content h1 {
    font-size: 3.5rem;
    margin-bottom: 20px;
}
.hero-content .supporting-text {
    font-size: 1.25rem;
    color: var(--text-muted);
    margin-bottom: 30px;
    max-width: 90%;
}
.hero-actions {
    display: flex;
    gap: 15px;
}

/* Hero Visual - Geometric */
.hero-visual {
    position: relative;
    width: 100%;
    height: 400px;
    display: flex;
    justify-content: center;
    align-items: center;
}
.geometric-shape {
    position: absolute;
    border: 1px solid var(--border-color);
    border-radius: 50%;
}
.shape-1 {
    width: 300px;
    height: 300px;
    border-color: var(--primary-color);
    opacity: 0.2;
}
.shape-2 {
    width: 200px;
    height: 200px;
    background-color: var(--surface-color);
}
.geometric-grid {
    position: absolute;
    width: 100%;
    height: 100%;
    background-image: radial-gradient(var(--border-color) 1px, transparent 1px);
    background-size: 20px 20px;
    opacity: 0.5;
    z-index: -1;
}

/* Editorial Sections */
.editorial-header {
    margin-bottom: 30px;
}
.editorial-header h2 {
    font-size: 2.5rem;
    max-width: 800px;
}
.editorial-body {
    max-width: 800px;
    font-size: 1.125rem;
    color: var(--text-muted);
}
.feature-list {
    list-style: none;
    margin-bottom: 20px;
}
.feature-list li {
    padding-left: 20px;
    position: relative;
    margin-bottom: 15px;
}
.feature-list li::before {
    content: "→";
    position: absolute;
    left: 0;
    color: var(--primary-color);
    font-weight: bold;
}

/* Programs Grid */
.programs-grid {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(300px, 1fr));
    gap: 30px;
}
.program-tile {
    display: flex;
    flex-direction: column;
    background-color: var(--bg-color);
    border: 1px solid var(--border-color);
    border-radius: 8px;
    padding: 30px;
    color: var(--text-color);
    transition: transform 0.2s, box-shadow 0.2s, border-color 0.2s;
}
.program-tile:hover, .program-tile:focus-within {
    transform: translateY(-5px);
    box-shadow: 0 10px 20px rgba(0,0,0,0.05);
    border-color: var(--primary-color);
}
:root[data-theme="dark"] .program-tile:hover {
    box-shadow: 0 10px 20px rgba(0,0,0,0.2);
}
.tile-category {
    font-size: 0.75rem;
    text-transform: uppercase;
    font-weight: 700;
    color: var(--text-muted);
    margin-bottom: 10px;
}
.tile-title {
    font-size: 1.5rem;
    margin-bottom: 15px;
}
.tile-positioning {
    color: var(--text-muted);
    margin-bottom: 20px;
    flex-grow: 1;
}
.tile-footer {
    display: flex;
    justify-content: space-between;
    align-items: center;
    border-top: 1px solid var(--border-color);
    padding-top: 15px;
    font-size: 0.875rem;
}
.tile-audience {
    color: var(--text-muted);
}
.tile-cta {
    color: var(--primary-color);
    font-weight: 600;
}

/* Approach Section */
.approach-grid {
    display: flex;
    justify-content: space-between;
    align-items: flex-start;
    gap: 20px;
}
.approach-step {
    flex: 1;
    text-align: center;
}
.step-number {
    display: inline-block;
    width: 60px;
    height: 60px;
    line-height: 60px;
    border-radius: 50%;
    background-color: var(--surface-color);
    color: var(--primary-color);
    font-weight: 700;
    font-size: 1.25rem;
    margin-bottom: 20px;
}
.step-connector {
    display: flex;
    align-items: center;
    justify-content: center;
    height: 60px;
    color: var(--border-color);
    font-size: 1.5rem;
}

/* Why Section */
.why-grid {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 40px;
}
.why-item {
    display: flex;
    gap: 20px;
}
.why-number {
    font-size: 3rem;
    font-weight: 800;
    color: var(--border-color);
    line-height: 1;
}
.why-content h3 {
    margin-bottom: 10px;
}
.why-content p {
    color: var(--text-muted);
}

/* Audiences Section */
.audiences-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
    gap: 30px;
}
.audience-card {
    background-color: var(--surface-color);
    padding: 40px 30px;
    border-radius: 8px;
    position: relative;
    overflow: hidden;
}
.audience-number {
    position: absolute;
    top: 20px;
    right: 20px;
    font-size: 4rem;
    font-weight: 800;
    color: var(--border-color);
    opacity: 0.3;
    line-height: 1;
    z-index: 0;
}
.audience-card h3, .audience-card p, .audience-card .btn {
    position: relative;
    z-index: 1;
}
.audience-positioning {
    margin-bottom: 15px;
    font-weight: 500;
}
.audience-focus {
    color: var(--text-muted);
    font-size: 0.875rem;
    margin-bottom: 25px;
}

/* Contact CTA Section */
.contact-cta-section .supporting-text {
    max-width: 600px;
    margin-bottom: 30px;
    font-size: 1.125rem;
    color: var(--text-muted);
}
.cta-secondary {
    margin-top: 20px;
    font-size: 0.875rem;
    color: var(--text-muted);
}

/* Mobile Responsive - Homepage */
@media (max-width: 768px) {
    .hero-container {
        grid-template-columns: 1fr;
    }
    .hero-content h1 {
        font-size: 2.5rem;
    }
    .hero-visual {
        height: 250px;
    }
    
    .approach-grid {
        flex-direction: column;
    }
    .step-connector {
        transform: rotate(90deg);
        height: 40px;
        width: 100%;
    }
    
    .why-grid {
        grid-template-columns: 1fr;
    }
}

/* Phase 3: Programs Catalogue Styles */

.programs-hero {
    padding: 80px 0;
}
.programs-hero h1 {
    font-size: 3rem;
}
.programs-hero .supporting-text {
    font-size: 1.25rem;
    max-width: 800px;
}

/* Engineering & Architecture Section */
.engineering-section {
    padding: 80px 0;
    background-color: var(--bg-color);
}
.engineering-card {
    display: flex;
    justify-content: space-between;
    align-items: center;
    background-color: var(--surface-color);
    border: 1px solid var(--border-color);
    border-radius: 8px;
    padding: 40px;
    gap: 30px;
    transition: transform 0.2s, box-shadow 0.2s, border-color 0.2s;
}
.engineering-card:hover {
    transform: translateY(-5px);
    box-shadow: 0 10px 20px rgba(0,0,0,0.05);
    border-color: var(--primary-color);
}
:root[data-theme="dark"] .engineering-card:hover {
    box-shadow: 0 10px 20px rgba(0,0,0,0.2);
}
.engineering-content {
    flex: 2;
}
.engineering-action {
    flex: 1;
    text-align: right;
}

/* Career Cross-Nav */
.career-cross-nav {
    padding: 60px 0;
}

/* Mobile Responsive - Programs */
@media (max-width: 768px) {
    .engineering-card {
        flex-direction: column;
        align-items: flex-start;
        text-align: left;
    }
    .engineering-action {
        text-align: left;
        width: 100%;
        margin-top: 20px;
    }
}

/* Phase 4: Program Detail Styles */

.breadcrumb-section {
    padding: 20px 0;
    border-bottom: 1px solid var(--border-color);
}
.breadcrumb-section a {
    color: var(--text-muted);
    font-size: 0.875rem;
}
.breadcrumb-section a:hover {
    color: var(--primary-color);
}

.program-hero {
    padding: 60px 0 80px;
}
.program-hero h1 {
    font-size: 3rem;
    margin-bottom: 15px;
}

/* Overview Layout */
.overview-grid {
    display: grid;
    grid-template-columns: 2fr 1fr;
    gap: 60px;
}
.overview-sidebar {
    background-color: var(--bg-color);
    border: 1px solid var(--border-color);
    border-radius: 8px;
    padding: 30px;
    height: fit-content;
}
.sidebar-block {
    margin-bottom: 30px;
}
.sidebar-block:last-child {
    margin-bottom: 0;
}
.sidebar-block h3 {
    font-size: 1.125rem;
    margin-bottom: 10px;
    color: var(--primary-color);
}
.details-block .detail-item {
    margin-bottom: 15px;
    padding-bottom: 15px;
    border-bottom: 1px solid var(--border-color);
}
.details-block .detail-item:last-child {
    margin-bottom: 0;
    padding-bottom: 0;
    border-bottom: none;
}

/* Learning Outcomes */
.learning-outcomes {
    padding: 80px 0;
}

/* Curriculum List */
.curriculum-list {
    display: grid;
    gap: 20px;
}
.curriculum-item {
    background-color: var(--bg-color);
    border: 1px solid var(--border-color);
    border-radius: 8px;
    padding: 25px 30px;
}
.curriculum-item h3 {
    margin-bottom: 10px;
    font-size: 1.25rem;
}
.curriculum-item p {
    color: var(--text-muted);
}

/* Two Column Grid */
.two-col-grid {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 40px;
}

/* FAQ Section */
.faq-list {
    display: grid;
    gap: 20px;
}
.faq-item {
    background-color: var(--bg-color);
    border: 1px solid var(--border-color);
    border-radius: 8px;
    padding: 30px;
}
.faq-item h3 {
    margin-bottom: 15px;
    font-size: 1.125rem;
}
.faq-item p {
    color: var(--text-muted);
}

/* Mobile Responsive - Program Detail */
@media (max-width: 768px) {
    .overview-grid {
        grid-template-columns: 1fr;
        gap: 40px;
    }
    .two-col-grid {
        grid-template-columns: 1fr;
    }
}