/* =============================================
   CSS CUSTOM PROPERTIES
   ============================================= */
:root {
    /* Colors - Technical precision palette */
    --color-primary: #0A0E27;
    --color-secondary: #1A1F3A;
    --color-accent: #FF6B35;
    --color-accent-alt: #F7931E;
    --color-text: #0A0E27;
    --color-text-light: #5A6674;
    --color-background: #FFFFFF;
    --color-background-alt: #F8F9FA;
    --color-border: #E1E4E8;
    
    /* Typography */
    --font-display: 'DM Sans', -apple-system, BlinkMacSystemFont, 'Segoe UI', system-ui, sans-serif;
    --font-body: 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', system-ui, sans-serif;
    --font-mono: 'JetBrains Mono', 'Courier New', monospace;
    
    /* Spacing */
    --spacing-unit: 8px;
    --container-max: 1200px;
    --container-padding: 24px;
    
    /* Transitions */
    --transition-smooth: cubic-bezier(0.4, 0.0, 0.2, 1);
    --transition-bounce: cubic-bezier(0.68, -0.55, 0.265, 1.55);
}

/* =============================================
   RESET & BASE STYLES
   ============================================= */
* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}

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

body {
    font-family: var(--font-body);
    color: var(--color-text);
    background-color: var(--color-background);
    line-height: 1.6;
    -webkit-font-smoothing: antialiased;
    -moz-osx-font-smoothing: grayscale;
}

img {
    max-width: 100%;
    height: auto;
    display: block;
}

a {
    color: inherit;
    text-decoration: none;
}

button {
    font-family: inherit;
    cursor: pointer;
    border: none;
    background: none;
}

/* =============================================
   UTILITY CLASSES
   ============================================= */
.container {
    max-width: var(--container-max);
    margin: 0 auto;
    padding: 0 var(--container-padding);
}

/* =============================================
   NAVIGATION
   ============================================= */
.main-nav {
    position: fixed;
    top: 0;
    left: 0;
    right: 0;
    background: rgba(255, 255, 255, 0.95);
    backdrop-filter: blur(10px);
    z-index: 1000;
    border-bottom: 1px solid var(--color-border);
    transition: transform 0.3s var(--transition-smooth);
}

.nav-container {
    max-width: var(--container-max);
    margin: 0 auto;
    padding: calc(var(--spacing-unit) * 3) var(--container-padding);
    display: flex;
    justify-content: space-between;
    align-items: center;
}

.logo {
    font-family: var(--font-display);
    font-size: 1.25rem;
    font-weight: 700;
    letter-spacing: -0.02em;
}

.nav-menu {
    display: flex;
    gap: calc(var(--spacing-unit) * 5);
    list-style: none;
}

.nav-link {
    font-size: 0.9375rem;
    font-weight: 500;
    position: relative;
    transition: color 0.2s ease;
}

.nav-link:hover {
    color: var(--color-accent);
}

.nav-link::after {
    content: '';
    position: absolute;
    bottom: -4px;
    left: 0;
    width: 0;
    height: 2px;
    background: var(--color-accent);
    transition: width 0.3s var(--transition-smooth);
}

.nav-link:hover::after,
.nav-link.active::after {
    width: 100%;
}

/* Mobile Navigation Toggle */
.nav-toggle {
    display: none;
    flex-direction: column;
    gap: 5px;
    padding: 8px;
}

.nav-toggle span {
    width: 24px;
    height: 2px;
    background: var(--color-text);
    transition: all 0.3s ease;
}

/* =============================================
   HERO SECTION
   ============================================= */
.hero {
    min-height: 90vh;
    display: flex;
    flex-direction: column;
    justify-content: center;
    align-items: center;
    text-align: center;
    padding: calc(var(--spacing-unit) * 15) var(--container-padding) calc(var(--spacing-unit) * 10);
    position: relative;
    margin-top: 80px;
}

.hero-content {
    max-width: 900px;
    animation: fadeInUp 0.8s var(--transition-smooth);
}

.hero-title {
    font-family: var(--font-display);
    font-size: clamp(2.5rem, 6vw, 4.5rem);
    font-weight: 700;
    line-height: 1.1;
    letter-spacing: -0.03em;
    margin-bottom: calc(var(--spacing-unit) * 3);
}

.highlight {
    color: var(--color-accent);
    display: block;
}

.hero-subtitle {
    font-size: clamp(1rem, 2vw, 1.25rem);
    color: var(--color-text-light);
    line-height: 1.7;
    max-width: 700px;
    margin: 0 auto;
}

.scroll-indicator {
    position: absolute;
    bottom: 40px;
    left: 50%;
    transform: translateX(-50%);
    display: flex;
    flex-direction: column;
    align-items: center;
    gap: 12px;
    opacity: 0.6;
    animation: fadeIn 1s 0.5s both;
}

.scroll-indicator span {
    font-size: 0.8125rem;
    text-transform: uppercase;
    letter-spacing: 0.1em;
    font-weight: 500;
}

.scroll-line {
    width: 1px;
    height: 60px;
    background: linear-gradient(to bottom, var(--color-text), transparent);
    animation: scrollPulse 2s infinite;
}

/* =============================================
   PROJECTS SECTION
   ============================================= */
.projects {
    padding: calc(var(--spacing-unit) * 15) 0;
}

.section-header {
    margin-bottom: calc(var(--spacing-unit) * 8);
}

.section-header h2 {
    font-family: var(--font-display);
    font-size: clamp(2rem, 4vw, 3rem);
    font-weight: 700;
    letter-spacing: -0.02em;
    margin-bottom: calc(var(--spacing-unit) * 4);
}

.filter-controls {
    display: flex;
    gap: calc(var(--spacing-unit) * 2);
    flex-wrap: wrap;
}

.filter-btn {
    padding: calc(var(--spacing-unit) * 1.5) calc(var(--spacing-unit) * 3);
    font-size: 0.9375rem;
    font-weight: 500;
    border: 1px solid var(--color-border);
    border-radius: 6px;
    transition: all 0.2s ease;
}

.filter-btn:hover {
    border-color: var(--color-accent);
    color: var(--color-accent);
}

.filter-btn.active {
    background: var(--color-accent);
    color: white;
    border-color: var(--color-accent);
}

/* Projects Grid */
.projects-grid {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(320px, 1fr));
    gap: calc(var(--spacing-unit) * 4);
}

.project-card {
    position: relative;
    opacity: 0;
    animation: fadeInUp 0.6s var(--transition-smooth) forwards;
}

.project-card:nth-child(1) { animation-delay: 0.1s; }
.project-card:nth-child(2) { animation-delay: 0.2s; }
.project-card:nth-child(3) { animation-delay: 0.3s; }
.project-card:nth-child(4) { animation-delay: 0.4s; }
.project-card:nth-child(5) { animation-delay: 0.5s; }
.project-card:nth-child(6) { animation-delay: 0.6s; }

.project-link {
    display: block;
}

.project-image {
    position: relative;
    overflow: hidden;
    border-radius: 8px;
    aspect-ratio: 4/3;
    background: var(--color-background-alt);
}

.project-image img {
    width: 100%;
    height: 100%;
    object-fit: cover;
    transition: transform 0.6s var(--transition-smooth);
}

.project-overlay {
    position: absolute;
    inset: 0;
    background: rgba(10, 14, 39, 0.85);
    display: flex;
    align-items: center;
    justify-content: center;
    opacity: 0;
    transition: opacity 0.3s ease;
}

.view-project {
    color: white;
    font-weight: 600;
    font-size: 1.125rem;
    transform: translateY(10px);
    transition: transform 0.3s var(--transition-smooth);
}

.project-card:hover .project-image img {
    transform: scale(1.05);
}

.project-card:hover .project-overlay {
    opacity: 1;
}

.project-card:hover .view-project {
    transform: translateY(0);
}

.project-info {
    padding: calc(var(--spacing-unit) * 3) 0;
}

.project-title {
    font-family: var(--font-display);
    font-size: 1.375rem;
    font-weight: 600;
    margin-bottom: calc(var(--spacing-unit) * 1);
}

.project-category {
    color: var(--color-text-light);
    font-size: 0.9375rem;
}

/* =============================================
   PROCESS SECTION
   ============================================= */
.process {
    padding: calc(var(--spacing-unit) * 15) 0;
    background: var(--color-background-alt);
}

.section-title {
    font-family: var(--font-display);
    font-size: clamp(2rem, 4vw, 3rem);
    font-weight: 700;
    letter-spacing: -0.02em;
    text-align: center;
    margin-bottom: calc(var(--spacing-unit) * 10);
}

.process-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
    gap: calc(var(--spacing-unit) * 6);
}

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

.step-number {
    font-family: var(--font-display);
    font-size: 3rem;
    font-weight: 700;
    color: var(--color-accent);
    margin-bottom: calc(var(--spacing-unit) * 2);
    opacity: 0.2;
}

.process-step h3 {
    font-family: var(--font-display);
    font-size: 1.5rem;
    font-weight: 600;
    margin-bottom: calc(var(--spacing-unit) * 2);
}

.process-step p {
    color: var(--color-text-light);
    line-height: 1.7;
}

/* =============================================
   FOOTER
   ============================================= */
.footer {
    padding: calc(var(--spacing-unit) * 10) 0 calc(var(--spacing-unit) * 4);
    background: var(--color-primary);
    color: white;
}

.footer-content {
    display: flex;
    justify-content: space-between;
    align-items: flex-start;
    margin-bottom: calc(var(--spacing-unit) * 6);
}

.footer-left h3 {
    font-family: var(--font-display);
    font-size: 1.5rem;
    font-weight: 700;
    margin-bottom: calc(var(--spacing-unit) * 1);
}

.footer-left p {
    opacity: 0.7;
}

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

.footer-link {
    display: block;
    font-size: 1.125rem;
    margin-bottom: calc(var(--spacing-unit) * 2);
    transition: color 0.2s ease;
}

.footer-link:hover {
    color: var(--color-accent);
}

.social-links {
    display: flex;
    gap: calc(var(--spacing-unit) * 3);
}

.social-link {
    opacity: 0.7;
    transition: all 0.2s ease;
}

.social-link:hover {
    opacity: 1;
    color: var(--color-accent);
}

.footer-bottom {
    padding-top: calc(var(--spacing-unit) * 4);
    border-top: 1px solid rgba(255, 255, 255, 0.1);
    text-align: center;
    opacity: 0.5;
    font-size: 0.875rem;
}

/* =============================================
   ANIMATIONS
   ============================================= */
@keyframes fadeIn {
    from {
        opacity: 0;
    }
    to {
        opacity: 0.6;
    }
}

@keyframes fadeInUp {
    from {
        opacity: 0;
        transform: translateY(30px);
    }
    to {
        opacity: 1;
        transform: translateY(0);
    }
}

@keyframes scrollPulse {
    0%, 100% {
        transform: translateY(0);
        opacity: 1;
    }
    50% {
        transform: translateY(10px);
        opacity: 0.5;
    }
}

/* =============================================
   RESPONSIVE DESIGN
   ============================================= */
@media (max-width: 768px) {
    .nav-menu {
        position: fixed;
        top: 80px;
        left: 0;
        right: 0;
        background: white;
        flex-direction: column;
        padding: calc(var(--spacing-unit) * 3);
        gap: calc(var(--spacing-unit) * 3);
        border-bottom: 1px solid var(--color-border);
        transform: translateY(-100%);
        opacity: 0;
        transition: all 0.3s var(--transition-smooth);
    }
    
    .nav-menu.active {
        transform: translateY(0);
        opacity: 1;
    }
    
    .nav-toggle {
        display: flex;
    }
    
    .nav-toggle.active span:nth-child(1) {
        transform: rotate(45deg) translate(5px, 5px);
    }
    
    .nav-toggle.active span:nth-child(2) {
        opacity: 0;
    }
    
    .nav-toggle.active span:nth-child(3) {
        transform: rotate(-45deg) translate(7px, -6px);
    }
    
    .projects-grid {
        grid-template-columns: 1fr;
    }
    
    .footer-content {
        flex-direction: column;
        gap: calc(var(--spacing-unit) * 6);
    }
    
    .footer-right {
        text-align: left;
    }
    
    .social-links {
        justify-content: flex-start;
    }
}

@media (max-width: 480px) {
    :root {
        --container-padding: 16px;
    }
    
    .hero {
        min-height: 80vh;
    }
    
    .process-grid {
        grid-template-columns: 1fr;
    }
}