/* ============================================
   DESIGN SYSTEM - CSS CUSTOM PROPERTIES
   ============================================ */

@import url('https://fonts.googleapis.com/css2?family=Inter:wght@300;400;500;600;700;800&family=Fira+Code:wght@400;500&display=swap');

:root {
    /* Color Palette - Dark Theme */
    --color-bg-primary: #0a0e27;
    --color-bg-secondary: #151932;
    --color-bg-tertiary: #1e2442;
    --color-bg-elevated: #252b4a;

    /* Accent Colors */
    --color-accent-primary: #6366f1;
    --color-accent-secondary: #8b5cf6;
    --color-accent-tertiary: #ec4899;
    --color-accent-success: #10b981;
    --color-accent-warning: #f59e0b;

    /* Gradient Colors */
    --gradient-primary: linear-gradient(135deg, #6366f1 0%, #8b5cf6 50%, #ec4899 100%);
    --gradient-secondary: linear-gradient(135deg, #0ea5e9 0%, #6366f1 100%);
    --gradient-accent: linear-gradient(135deg, #f59e0b 0%, #ec4899 100%);

    /* Text Colors */
    --color-text-primary: #f1f5f9;
    --color-text-secondary: #cbd5e1;
    --color-text-tertiary: #94a3b8;
    --color-text-muted: #64748b;

    /* Typography */
    --font-primary: 'Inter', -apple-system, BlinkMacSystemFont, sans-serif;
    --font-code: 'Fira Code', monospace;

    /* Spacing */
    --spacing-xs: 0.5rem;
    --spacing-sm: 1rem;
    --spacing-md: 1.5rem;
    --spacing-lg: 2rem;
    --spacing-xl: 3rem;
    --spacing-2xl: 4rem;
    --spacing-3xl: 6rem;

    /* Border Radius */
    --radius-sm: 0.375rem;
    --radius-md: 0.5rem;
    --radius-lg: 0.75rem;
    --radius-xl: 1rem;
    --radius-2xl: 1.5rem;
    --radius-full: 9999px;

    /* Shadows */
    --shadow-sm: 0 1px 2px 0 rgba(0, 0, 0, 0.3);
    --shadow-md: 0 4px 6px -1px rgba(0, 0, 0, 0.4);
    --shadow-lg: 0 10px 15px -3px rgba(0, 0, 0, 0.5);
    --shadow-xl: 0 20px 25px -5px rgba(0, 0, 0, 0.6);
    --shadow-glow: 0 0 20px rgba(99, 102, 241, 0.4);

    /* Transitions */
    --transition-fast: 150ms cubic-bezier(0.4, 0, 0.2, 1);
    --transition-base: 300ms cubic-bezier(0.4, 0, 0.2, 1);
    --transition-slow: 500ms cubic-bezier(0.4, 0, 0.2, 1);

    /* Z-index */
    --z-base: 1;
    --z-dropdown: 10;
    --z-sticky: 100;
    --z-fixed: 1000;
    --z-modal: 10000;
}

/* ============================================
   RESET & BASE STYLES
   ============================================ */

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

html {
    scroll-behavior: smooth;
    overflow-x: hidden;
}

body {
    font-family: var(--font-primary);
    background-color: var(--color-bg-primary);
    color: var(--color-text-primary);
    line-height: 1.6;
    overflow-x: hidden;
    position: relative;
}

/* Animated background */
body::before {
    content: '';
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    background:
        radial-gradient(circle at 20% 50%, rgba(99, 102, 241, 0.1) 0%, transparent 50%),
        radial-gradient(circle at 80% 80%, rgba(139, 92, 246, 0.1) 0%, transparent 50%),
        radial-gradient(circle at 40% 20%, rgba(236, 72, 153, 0.05) 0%, transparent 50%);
    z-index: -1;
    animation: backgroundShift 20s ease-in-out infinite;
}

@keyframes backgroundShift {

    0%,
    100% {
        opacity: 1;
    }

    50% {
        opacity: 0.7;
    }
}

/* ============================================
   NAVIGATION
   ============================================ */

header {
    position: fixed;
    top: 0;
    left: 0;
    right: 0;
    z-index: var(--z-fixed);
    padding: var(--spacing-md) 0;
    backdrop-filter: blur(12px);
    background: rgba(10, 14, 39, 0.8);
    border-bottom: 1px solid rgba(99, 102, 241, 0.1);
    transition: all var(--transition-base);
}

header.scrolled {
    padding: var(--spacing-sm) 0;
    background: rgba(10, 14, 39, 0.95);
    box-shadow: var(--shadow-lg);
}

nav {
    max-width: 1400px;
    margin: 0 auto;
    padding: 0 var(--spacing-lg);
    display: flex;
    justify-content: space-between;
    align-items: center;
}

.logo {
    font-size: 1.5rem;
    font-weight: 800;
    background: var(--gradient-primary);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
    letter-spacing: -0.02em;
    transition: transform var(--transition-base);
}

.logo:hover {
    transform: scale(1.05);
}

nav ul {
    display: flex;
    list-style: none;
    gap: var(--spacing-lg);
    align-items: center;
}

nav a {
    color: var(--color-text-secondary);
    text-decoration: none;
    font-weight: 500;
    font-size: 0.95rem;
    position: relative;
    padding: var(--spacing-xs) var(--spacing-sm);
    transition: color var(--transition-base);
}

nav a::after {
    content: '';
    position: absolute;
    bottom: 0;
    left: 50%;
    transform: translateX(-50%) scaleX(0);
    width: 80%;
    height: 2px;
    background: var(--gradient-primary);
    transition: transform var(--transition-base);
}

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

nav a:hover::after,
nav a.active::after {
    transform: translateX(-50%) scaleX(1);
}

.mobile-menu-btn {
    display: none;
    background: none;
    border: none;
    color: var(--color-text-primary);
    font-size: 1.5rem;
    cursor: pointer;
    padding: var(--spacing-xs);
    transition: transform var(--transition-base);
}

.mobile-menu-btn:hover {
    transform: rotate(90deg);
}

/* ============================================
   SECTIONS & LAYOUT
   ============================================ */

section {
    min-height: 100vh;
    padding: var(--spacing-3xl) var(--spacing-lg);
    display: flex;
    align-items: center;
    justify-content: center;
}

.container {
    max-width: 1400px;
    width: 100%;
    margin: 0 auto;
}

.section-title {
    font-size: clamp(2.5rem, 5vw, 3.5rem);
    font-weight: 800;
    margin-bottom: var(--spacing-xl);
    text-align: center;
    letter-spacing: -0.02em;
}

.section-title .gradient-text {
    background: var(--gradient-primary);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
}

.section-subtitle {
    text-align: center;
    color: var(--color-text-tertiary);
    font-size: 1.125rem;
    margin-bottom: var(--spacing-2xl);
    max-width: 600px;
    margin-left: auto;
    margin-right: auto;
}

/* ============================================
   HOME / HERO SECTION
   ============================================ */

#home {
    position: relative;
    overflow: hidden;
}

.hero-content {
    text-align: center;
    position: relative;
    z-index: 2;
}

.hero-greeting {
    font-size: 1.25rem;
    color: var(--color-accent-primary);
    font-weight: 600;
    margin-bottom: var(--spacing-sm);
    opacity: 0;
    animation: fadeInUp 0.6s ease-out 0.2s forwards;
}

.hero-title {
    font-size: clamp(3rem, 8vw, 5rem);
    font-weight: 900;
    margin-bottom: var(--spacing-md);
    line-height: 1.1;
    letter-spacing: -0.03em;
    opacity: 0;
    animation: fadeInUp 0.6s ease-out 0.4s forwards;
}

.hero-subtitle {
    font-size: clamp(1.5rem, 4vw, 2.5rem);
    color: var(--color-text-secondary);
    margin-bottom: var(--spacing-lg);
    opacity: 0;
    animation: fadeInUp 0.6s ease-out 0.6s forwards;
}

.hero-description {
    font-size: 1.125rem;
    color: var(--color-text-tertiary);
    max-width: 700px;
    margin: 0 auto var(--spacing-xl);
    line-height: 1.8;
    opacity: 0;
    animation: fadeInUp 0.6s ease-out 0.8s forwards;
}

.hero-cta {
    display: flex;
    gap: var(--spacing-md);
    justify-content: center;
    flex-wrap: wrap;
    opacity: 0;
    animation: fadeInUp 0.6s ease-out 1s forwards;
}

/* ============================================
   BUTTONS
   ============================================ */

.btn {
    padding: var(--spacing-md) var(--spacing-xl);
    border-radius: var(--radius-full);
    font-weight: 600;
    font-size: 1rem;
    text-decoration: none;
    display: inline-flex;
    align-items: center;
    gap: var(--spacing-xs);
    cursor: pointer;
    border: none;
    transition: all var(--transition-base);
    position: relative;
    overflow: hidden;
}

.btn::before {
    content: '';
    position: absolute;
    top: 50%;
    left: 50%;
    width: 0;
    height: 0;
    border-radius: 50%;
    background: rgba(255, 255, 255, 0.1);
    transform: translate(-50%, -50%);
    transition: width 0.6s, height 0.6s;
}

.btn:hover::before {
    width: 300px;
    height: 300px;
}

.btn-primary {
    background: var(--gradient-primary);
    color: white;
    box-shadow: var(--shadow-glow);
}

.btn-primary:hover {
    transform: translateY(-2px);
    box-shadow: 0 0 30px rgba(99, 102, 241, 0.6);
}

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

.btn-secondary:hover {
    background: rgba(99, 102, 241, 0.1);
    transform: translateY(-2px);
}

/* ============================================
   CARDS
   ============================================ */

.card {
    background: var(--color-bg-secondary);
    border-radius: var(--radius-xl);
    padding: var(--spacing-xl);
    border: 1px solid rgba(99, 102, 241, 0.1);
    transition: all var(--transition-base);
    position: relative;
    overflow: hidden;
}

.card::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    height: 3px;
    background: var(--gradient-primary);
    transform: scaleX(0);
    transition: transform var(--transition-base);
}

.card:hover {
    transform: translateY(-8px);
    box-shadow: var(--shadow-xl);
    border-color: rgba(99, 102, 241, 0.3);
}

.card:hover::before {
    transform: scaleX(1);
}

/* ============================================
   GRID LAYOUTS
   ============================================ */

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

.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));
}

/* ============================================
   EXPERIENCE SECTION
   ============================================ */

.timeline {
    position: relative;
    padding-left: var(--spacing-xl);
}

.timeline::before {
    content: '';
    position: absolute;
    left: 0;
    top: 0;
    bottom: 0;
    width: 2px;
    background: var(--gradient-primary);
}

.timeline-item {
    position: relative;
    padding-bottom: var(--spacing-xl);
    padding-left: var(--spacing-xl);
}

.timeline-item::before {
    content: '';
    position: absolute;
    left: -26px;
    top: 0;
    width: 12px;
    height: 12px;
    border-radius: 50%;
    background: var(--color-accent-primary);
    border: 3px solid var(--color-bg-primary);
    box-shadow: var(--shadow-glow);
}

.timeline-date {
    color: var(--color-accent-primary);
    font-weight: 600;
    font-size: 0.875rem;
    margin-bottom: var(--spacing-xs);
}

.timeline-title {
    font-size: 1.5rem;
    font-weight: 700;
    margin-bottom: var(--spacing-xs);
}

.timeline-company {
    color: var(--color-text-secondary);
    font-size: 1.125rem;
    margin-bottom: var(--spacing-sm);
}

.timeline-description {
    color: var(--color-text-tertiary);
    line-height: 1.8;
}

/* ============================================
   PROJECTS SECTION
   ============================================ */

.project-card {
    background: var(--color-bg-secondary);
    border-radius: var(--radius-xl);
    overflow: hidden;
    border: 1px solid rgba(99, 102, 241, 0.1);
    transition: all var(--transition-base);
}

.project-card:hover {
    transform: translateY(-8px);
    box-shadow: var(--shadow-xl);
    border-color: rgba(99, 102, 241, 0.3);
}

.project-image {
    width: 100%;
    height: 200px;
    background: var(--gradient-secondary);
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 3rem;
    position: relative;
    overflow: hidden;
}

.project-image::after {
    content: '';
    position: absolute;
    inset: 0;
    background: rgba(0, 0, 0, 0.3);
    opacity: 0;
    transition: opacity var(--transition-base);
}

.project-card:hover .project-image::after {
    opacity: 1;
}

.project-content {
    padding: var(--spacing-lg);
}

.project-title {
    font-size: 1.5rem;
    font-weight: 700;
    margin-bottom: var(--spacing-sm);
}

.project-description {
    color: var(--color-text-tertiary);
    margin-bottom: var(--spacing-md);
    line-height: 1.8;
}

.project-tags {
    display: flex;
    flex-wrap: wrap;
    gap: var(--spacing-xs);
    margin-bottom: var(--spacing-md);
}

.tag {
    padding: var(--spacing-xs) var(--spacing-sm);
    background: rgba(99, 102, 241, 0.1);
    border: 1px solid rgba(99, 102, 241, 0.2);
    border-radius: var(--radius-full);
    font-size: 0.875rem;
    color: var(--color-accent-primary);
    font-weight: 500;
}

.project-links {
    display: flex;
    gap: var(--spacing-sm);
}

.project-link {
    padding: var(--spacing-sm) var(--spacing-md);
    background: rgba(99, 102, 241, 0.1);
    color: var(--color-text-primary);
    text-decoration: none;
    border-radius: var(--radius-md);
    font-weight: 500;
    font-size: 0.875rem;
    transition: all var(--transition-base);
}

.project-link:hover {
    background: var(--color-accent-primary);
    transform: translateY(-2px);
}

/* ============================================
   SKILLS SECTION
   ============================================ */

.skills-category {
    margin-bottom: var(--spacing-2xl);
}

.skills-category-title {
    font-size: 1.5rem;
    font-weight: 700;
    margin-bottom: var(--spacing-lg);
    display: flex;
    align-items: center;
    gap: var(--spacing-sm);
}

.skills-category-title::before {
    content: '';
    width: 4px;
    height: 24px;
    background: var(--gradient-primary);
    border-radius: var(--radius-full);
}

.skills-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(140px, 1fr));
    gap: var(--spacing-md);
}

.skill-item {
    background: var(--color-bg-secondary);
    padding: var(--spacing-lg);
    border-radius: var(--radius-lg);
    text-align: center;
    border: 1px solid rgba(99, 102, 241, 0.1);
    transition: all var(--transition-base);
    cursor: pointer;
}

.skill-item:hover {
    transform: translateY(-4px);
    border-color: rgba(99, 102, 241, 0.3);
    box-shadow: var(--shadow-lg);
}

.skill-icon {
    font-size: 2.5rem;
    margin-bottom: var(--spacing-sm);
    display: block;
    color: var(--color-accent-primary);
    font-style: normal;
    line-height: 1.2;
}

.skill-icon-svg {
    width: 2.5rem;
    height: 2.5rem;
    margin: 0 auto var(--spacing-sm);
}

.skill-name {
    font-weight: 600;
    color: var(--color-text-primary);
    margin-bottom: var(--spacing-xs);
}

.skill-level {
    font-size: 0.875rem;
    color: var(--color-text-tertiary);
}

/* ============================================
   CONTACT SECTION
   ============================================ */

.contact-container {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: var(--spacing-2xl);
    align-items: start;
}

.contact-info {
    display: flex;
    flex-direction: column;
    gap: var(--spacing-lg);
}

.contact-info-item {
    display: flex;
    align-items: center;
    gap: var(--spacing-md);
    padding: var(--spacing-lg);
    background: var(--color-bg-secondary);
    border-radius: var(--radius-lg);
    border: 1px solid rgba(99, 102, 241, 0.1);
    transition: all var(--transition-base);
}

.contact-info-item:hover {
    border-color: rgba(99, 102, 241, 0.3);
    transform: translateX(8px);
}

.contact-icon {
    width: 48px;
    height: 48px;
    background: var(--gradient-primary);
    border-radius: var(--radius-md);
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 1.5rem;
    flex-shrink: 0;
}

.contact-details h3 {
    font-size: 1.125rem;
    font-weight: 600;
    margin-bottom: var(--spacing-xs);
}

.contact-details p {
    color: var(--color-text-tertiary);
}

.contact-form {
    background: var(--color-bg-secondary);
    padding: var(--spacing-xl);
    border-radius: var(--radius-xl);
    border: 1px solid rgba(99, 102, 241, 0.1);
}

.form-group {
    margin-bottom: var(--spacing-lg);
}

.form-group label {
    display: block;
    margin-bottom: var(--spacing-xs);
    font-weight: 600;
    color: var(--color-text-secondary);
}

.form-group input,
.form-group textarea {
    width: 100%;
    padding: var(--spacing-md);
    background: var(--color-bg-tertiary);
    border: 1px solid rgba(99, 102, 241, 0.1);
    border-radius: var(--radius-md);
    color: var(--color-text-primary);
    font-family: var(--font-primary);
    font-size: 1rem;
    transition: all var(--transition-base);
}

.form-group input:focus,
.form-group textarea:focus {
    outline: none;
    border-color: var(--color-accent-primary);
    box-shadow: 0 0 0 3px rgba(99, 102, 241, 0.1);
}

.form-group textarea {
    resize: none;
    min-height: 150px;
}

/* ============================================
   FOOTER
   ============================================ */

footer {
    background: var(--color-bg-secondary);
    padding: var(--spacing-2xl) var(--spacing-lg);
    border-top: 1px solid rgba(99, 102, 241, 0.1);
}

.footer-content {
    max-width: 1400px;
    margin: 0 auto;
    display: flex;
    justify-content: space-between;
    align-items: center;
    flex-wrap: wrap;
    gap: var(--spacing-lg);
}

.social-links {
    display: flex;
    gap: var(--spacing-md);
}

.social-link {
    width: 40px;
    height: 40px;
    background: var(--color-bg-tertiary);
    border-radius: var(--radius-md);
    display: flex;
    align-items: center;
    justify-content: center;
    color: var(--color-text-primary);
    text-decoration: none;
    transition: all var(--transition-base);
}

.social-link:hover {
    background: var(--color-accent-primary);
    transform: translateY(-4px);
}

/* ============================================
   ANIMATIONS
   ============================================ */

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

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

.fade-in {
    opacity: 0;
    animation: fadeInUp 0.6s ease-out forwards;
}

/* ============================================
   RESPONSIVE DESIGN
   ============================================ */

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

@media (max-width: 768px) {
    section {
        padding: var(--spacing-2xl) var(--spacing-md);
    }

    #home {
        padding-top: 120px;
    }

    nav ul {
        position: fixed;
        top: 0;
        right: -100%;
        width: 70%;
        height: 100vh;
        background: var(--color-bg-secondary);
        flex-direction: column;
        padding: var(--spacing-3xl) var(--spacing-lg);
        transition: right var(--transition-base);
        box-shadow: var(--shadow-xl);
    }

    nav ul.active {
        right: 0;
    }

    .mobile-menu-btn {
        display: block;
    }

    .hero-cta {
        flex-direction: column;
    }

    .timeline {
        padding-left: var(--spacing-md);
    }

    .timeline-item {
        padding-left: var(--spacing-md);
    }

    .grid-2,
    .grid-3,
    .grid-4 {
        grid-template-columns: 1fr;
    }

    .skills-grid {
        grid-template-columns: repeat(auto-fit, minmax(120px, 1fr));
    }
}

@media (max-width: 480px) {
    :root {
        --spacing-xl: 2rem;
        --spacing-2xl: 3rem;
        --spacing-3xl: 4rem;
    }

    .hero-title {
        font-size: 2.5rem;
    }

    .section-title {
        font-size: 2rem;
    }

    .btn {
        width: 100%;
        justify-content: center;
    }
}

/* ============================================
   UTILITY CLASSES
   ============================================ */

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

.text-gradient {
    background: var(--gradient-primary);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
}

.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);
}

.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);
}