/* ==========================================================================
   1. Design System Tokens & Base Settings
   ========================================================================== */
:root {
    /* Fonts */
    --font-heading: 'Quicksand', 'M PLUS Rounded 1c', -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, sans-serif;
    --font-body: 'Quicksand', 'M PLUS Rounded 1c', -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, sans-serif;

    /* Transition Speeds */
    --transition-fast: 0.2s cubic-bezier(0.4, 0, 0.2, 1);
    --transition-normal: 0.4s cubic-bezier(0.4, 0, 0.2, 1);
    --transition-slow: 0.6s cubic-bezier(0.4, 0, 0.2, 1);
    
    /* Layout Constants */
    --header-height: 80px;
    --max-width: 1200px;
}

/* Bilingual text styling */
.en-text {
    display: block;
    font-size: 0.88em;
    opacity: 0.75;
    margin-top: 0.4rem;
    font-weight: 400;
    line-height: 1.5;
}


/* Dark Mode Tokens (Default) */
[data-theme="dark"] {
    --bg-color: #070913;
    --bg-grid: rgba(255, 255, 255, 0.02);
    --text-primary: #f1f5f9;
    --text-secondary: #94a3b8;
    
    --primary-color: #00d2ff;
    --primary-glow: rgba(0, 210, 255, 0.3);
    --secondary-color: #d946ef;
    --secondary-glow: rgba(217, 70, 239, 0.3);
    --accent-color: #3b82f6;

    --card-bg: rgba(15, 23, 42, 0.65);
    --card-border: rgba(255, 255, 255, 0.06);
    --card-hover-border: rgba(0, 210, 255, 0.4);
    
    --glass-bg: rgba(7, 9, 19, 0.75);
    --glass-border: rgba(255, 255, 255, 0.08);
    
    --input-bg: rgba(15, 23, 42, 0.8);
    --input-border: rgba(255, 255, 255, 0.1);
    
    --shadow-sm: 0 2px 8px rgba(0, 0, 0, 0.5);
    --shadow-md: 0 8px 30px rgba(0, 0, 0, 0.6);
    
    --orb-1-color: rgba(0, 210, 255, 0.15);
    --orb-2-color: rgba(217, 70, 239, 0.15);
}

/* Light Mode Tokens */
[data-theme="light"] {
    --bg-color: #f8fafc;
    --bg-grid: rgba(15, 23, 42, 0.02);
    --text-primary: #0f172a;
    --text-secondary: #475569;
    
    --primary-color: #0284c7;
    --primary-glow: rgba(2, 132, 199, 0.15);
    --secondary-color: #c026d3;
    --secondary-glow: rgba(192, 38, 211, 0.15);
    --accent-color: #2563eb;

    --card-bg: rgba(255, 255, 255, 0.8);
    --card-border: rgba(15, 23, 42, 0.06);
    --card-hover-border: rgba(2, 132, 199, 0.4);
    
    --glass-bg: rgba(255, 255, 255, 0.8);
    --glass-border: rgba(15, 23, 42, 0.08);
    
    --input-bg: #ffffff;
    --input-border: rgba(15, 23, 42, 0.15);
    
    --shadow-sm: 0 2px 8px rgba(15, 23, 42, 0.05);
    --shadow-md: 0 8px 30px rgba(15, 23, 42, 0.08);
    
    --orb-1-color: rgba(14, 165, 233, 0.08);
    --orb-2-color: rgba(232, 121, 249, 0.08);
}

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

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

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

/* Background grid pattern */
body::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    background-image: 
        linear-gradient(var(--bg-grid) 1px, transparent 1px),
        linear-gradient(90deg, var(--bg-grid) 1px, transparent 1px);
    background-size: 40px 40px;
    z-index: -2;
    pointer-events: none;
}

/* ==========================================================================
   2. Layout & Reusable UI Elements
   ========================================================================== */
.container {
    width: 100%;
    max-width: var(--max-width);
    margin: 0 auto;
    padding: 0 2rem;
}

.section-padding {
    padding: 8rem 0;
}

/* Glow Orbs */
.glow-container {
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    overflow: hidden;
    z-index: -1;
    pointer-events: none;
}

.glow-orb {
    position: absolute;
    border-radius: 50%;
    filter: blur(120px);
    opacity: 0.8;
    animation: floatOrb 20s infinite alternate ease-in-out;
}

.orb-1 {
    width: 500px;
    height: 500px;
    background: var(--orb-1-color);
    top: -100px;
    right: -100px;
}

.orb-2 {
    width: 600px;
    height: 600px;
    background: var(--orb-2-color);
    top: 600px;
    left: -150px;
    animation-delay: -5s;
}

@keyframes floatOrb {
    0% { transform: translate(0, 0) scale(1); }
    100% { transform: translate(60px, 40px) scale(1.1); }
}

/* Headings */
h1, h2, h3, h4, h5, h6 {
    font-family: var(--font-heading);
    font-weight: 700;
    letter-spacing: -0.02em;
    line-height: 1.2;
}

.section-header {
    text-align: center;
    margin-bottom: 5rem;
}

.section-subtitle {
    font-size: 0.9rem;
    text-transform: uppercase;
    letter-spacing: 0.2em;
    color: var(--primary-color);
    font-weight: 600;
    display: inline-block;
    margin-bottom: 0.75rem;
}

.section-title {
    font-size: 2.5rem;
    font-weight: 800;
}

/* Gradient Text */
.text-gradient {
    background: linear-gradient(135deg, var(--primary-color) 0%, var(--secondary-color) 100%);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
}

/* Cards (Glassmorphism) */
.card-blur {
    background: var(--card-bg);
    border: 1px solid var(--card-border);
    backdrop-filter: blur(16px);
    -webkit-backdrop-filter: blur(16px);
    border-radius: 16px;
    padding: 2.5rem;
    box-shadow: var(--shadow-sm);
    transition: transform var(--transition-normal), 
                border-color var(--transition-normal), 
                box-shadow var(--transition-normal);
}

/* Buttons */
.btn {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    padding: 0.85rem 2rem;
    border-radius: 50px;
    font-family: var(--font-heading);
    font-weight: 600;
    font-size: 0.95rem;
    text-decoration: none;
    cursor: pointer;
    transition: transform var(--transition-fast), 
                box-shadow var(--transition-fast), 
                background-color var(--transition-fast), 
                color var(--transition-fast);
}

.btn-primary {
    background-color: var(--primary-color);
    color: #070913;
    border: none;
    box-shadow: 0 4px 20px var(--primary-glow);
}

.btn-primary:hover {
    transform: translateY(-2px);
    box-shadow: 0 6px 25px var(--primary-glow);
}

.btn-secondary {
    background-color: transparent;
    color: var(--text-primary);
    border: 1.5px solid var(--card-border);
}

.btn-secondary:hover {
    background-color: var(--card-border);
    transform: translateY(-2px);
}

.btn-block {
    display: flex;
    width: 100%;
}

/* ==========================================================================
   3. Header & Navigation
   ========================================================================== */
.header {
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    height: var(--header-height);
    background: var(--glass-bg);
    border-bottom: 1px solid var(--glass-border);
    backdrop-filter: blur(12px);
    -webkit-backdrop-filter: blur(12px);
    z-index: 1000;
    display: flex;
    align-items: center;
    transition: background-color var(--transition-normal), border-color var(--transition-normal);
}

.nav-container {
    width: 100%;
    max-width: var(--max-width);
    margin: 0 auto;
    padding: 0 2rem;
    display: flex;
    align-items: center;
    justify-content: space-between;
}

.logo {
    display: flex;
    align-items: center;
    gap: 0.75rem;
    text-decoration: none;
}

.logo-img {
    width: 44px;
    height: 44px;
    border-radius: 8px;
    object-fit: cover;
    flex-shrink: 0;
}

.logo-text {
    font-family: var(--font-heading);
    font-weight: 800;
    font-size: 1.45rem;
    color: var(--text-primary);
    line-height: 1.2;
}

.nav-menu {
    display: flex;
    align-items: center;
    gap: 2.5rem;
}

.nav-link {
    color: var(--text-secondary);
    text-decoration: none;
    font-weight: 500;
    font-size: 0.95rem;
    position: relative;
    padding: 0.5rem 0;
    transition: color var(--transition-fast);
}

.nav-link:hover, .nav-link.active {
    color: var(--text-primary);
}

/* Underline slide effect */
.nav-link::after {
    content: '';
    position: absolute;
    bottom: 0;
    left: 0;
    width: 100%;
    height: 2px;
    background-color: var(--primary-color);
    transform: scaleX(0);
    transform-origin: right;
    transition: transform var(--transition-fast);
}

.nav-link:hover::after, .nav-link.active::after {
    transform: scaleX(1);
    transform-origin: left;
}

.nav-actions {
    display: flex;
    align-items: center;
    gap: 1.5rem;
}

/* Theme Toggle */
.theme-toggle-btn {
    background: none;
    border: 1px solid var(--card-border);
    border-radius: 50%;
    width: 44px;
    height: 44px;
    display: flex;
    align-items: center;
    justify-content: center;
    cursor: pointer;
    color: var(--text-primary);
    transition: background-color var(--transition-fast);
}

.theme-toggle-btn:hover {
    background-color: var(--card-border);
}

.theme-toggle-btn svg {
    width: 20px;
    height: 20px;
}

/* Show/hide icons based on theme */
[data-theme="dark"] .sun-icon { display: block; }
[data-theme="dark"] .moon-icon { display: none; }
[data-theme="light"] .sun-icon { display: none; }
[data-theme="light"] .moon-icon { display: block; }

/* Mobile Menu Toggle */
.mobile-menu-btn {
    display: none;
    flex-direction: column;
    justify-content: space-between;
    width: 24px;
    height: 18px;
    background: none;
    border: none;
    cursor: pointer;
    z-index: 1001;
}

.mobile-menu-btn span {
    display: block;
    width: 100%;
    height: 2px;
    background-color: var(--text-primary);
    transition: transform var(--transition-fast), opacity var(--transition-fast);
}

/* Mobile active state (hamburger to cross) */
.mobile-menu-btn.active span:nth-child(1) {
    transform: translateY(8px) rotate(45deg);
}

.mobile-menu-btn.active span:nth-child(2) {
    opacity: 0;
}

.mobile-menu-btn.active span:nth-child(3) {
    transform: translateY(-8px) rotate(-45deg);
}

/* ==========================================================================
   4. Hero Section
   ========================================================================== */
.hero-section {
    position: relative;
    height: 100vh;
    display: flex;
    align-items: center;
    padding-top: var(--header-height);
}

.hero-content {
    max-width: 800px;
}

.hero-badge {
    display: inline-block;
    padding: 0.5rem 1rem;
    border-radius: 50px;
    background-color: var(--card-border);
    border: 1px solid var(--card-border);
    font-size: 0.8rem;
    font-weight: 600;
    text-transform: uppercase;
    letter-spacing: 0.15em;
    color: var(--primary-color);
    margin-bottom: 2rem;
}

.hero-title {
    font-size: clamp(3rem, 6vw, 5rem);
    font-weight: 800;
    margin-bottom: 1.5rem;
    line-height: 1.1;
}

.hero-title-small {
    font-size: clamp(1.8rem, 4.6vw, 3.8rem);
    white-space: nowrap;
}

@media (max-width: 576px) {
    .hero-title-small {
        font-size: 6.5vw;
        white-space: normal;
    }
}

.hero-description {
    font-size: clamp(1.1rem, 2vw, 1.25rem);
    color: var(--text-secondary);
    margin-bottom: 3rem;
    max-width: 650px;
    line-height: 1.7;
}

.hero-actions {
    display: flex;
    gap: 1.5rem;
}

/* Scroll Down Indicator */
.scroll-down {
    position: absolute;
    bottom: 2.5rem;
    left: 50%;
    transform: translateX(-50%);
    cursor: pointer;
    opacity: 0.7;
    transition: opacity var(--transition-fast);
}

.scroll-down:hover {
    opacity: 1;
}

.mouse {
    width: 26px;
    height: 44px;
    border: 2px solid var(--text-primary);
    border-radius: 20px;
    display: flex;
    justify-content: center;
    padding-top: 8px;
}

.wheel {
    width: 4px;
    height: 8px;
    background-color: var(--primary-color);
    border-radius: 2px;
    animation: scrollMouse 1.5s infinite;
}

@keyframes scrollMouse {
    0% { transform: translateY(0); opacity: 1; }
    100% { transform: translateY(12px); opacity: 0; }
}

/* ==========================================================================
   5. About Section
   ========================================================================== */
.about-grid {
    display: grid;
    grid-template-columns: 1.2fr 0.8fr;
    gap: 3rem;
    align-items: start;
}

.about-info h3 {
    font-size: 1.8rem;
    margin-bottom: 1.5rem;
}

.about-info p {
    color: var(--text-secondary);
    margin-bottom: 1.5rem;
}

/* Timeline */
.experience-timeline {
    margin-top: 3.5rem;
    border-left: 2px solid var(--card-border);
    padding-left: 2rem;
    position: relative;
}

.timeline-item {
    position: relative;
    margin-bottom: 2.5rem;
}

.timeline-item:last-child {
    margin-bottom: 0;
}

.timeline-dot {
    position: absolute;
    left: calc(-2rem - 6px);
    top: 6px;
    width: 10px;
    height: 10px;
    border-radius: 50%;
    background-color: var(--primary-color);
    box-shadow: 0 0 10px var(--primary-glow);
}

.timeline-date {
    font-size: 0.85rem;
    color: var(--primary-color);
    font-weight: 600;
    margin-bottom: 0.25rem;
}

.timeline-title {
    font-size: 1.15rem;
    margin-bottom: 0.5rem;
}

.timeline-desc {
    font-size: 0.95rem;
    color: var(--text-secondary);
}

/* Skills Categories */
.skills-card h3 {
    font-size: 1.5rem;
    margin-bottom: 2rem;
}

.skill-category {
    margin-bottom: 2rem;
}

.skill-category:last-child {
    margin-bottom: 0;
}

.skill-category h4 {
    font-size: 1rem;
    color: var(--text-primary);
    margin-bottom: 1rem;
    font-weight: 600;
}

.skill-tags {
    display: flex;
    flex-wrap: wrap;
    gap: 0.75rem;
}

.skill-tag {
    background-color: var(--card-border);
    border: 1px solid var(--card-border);
    color: var(--text-secondary);
    padding: 0.4rem 1rem;
    border-radius: 50px;
    font-size: 0.85rem;
    font-weight: 500;
    transition: background-color var(--transition-fast), 
                color var(--transition-fast), 
                border-color var(--transition-fast);
}

.skill-tag:hover {
    background-color: var(--primary-glow);
    border-color: var(--primary-color);
    color: var(--primary-color);
}

/* ==========================================================================
   6. Projects Section
   ========================================================================== */
.projects-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(350px, 1fr));
    gap: 2.5rem;
}

.project-card {
    background-color: var(--card-bg);
    border: 1px solid var(--card-border);
    border-radius: 16px;
    overflow: hidden;
    transition: transform var(--transition-normal), 
                border-color var(--transition-normal), 
                box-shadow var(--transition-normal);
}

.project-card:hover {
    transform: translateY(-6px);
    border-color: var(--card-hover-border);
    box-shadow: 0 10px 30px rgba(0, 210, 255, 0.05);
}

.project-image-wrapper {
    position: relative;
    width: 100%;
    padding-bottom: 60%; /* Aspect ratio 5:3 */
    overflow: hidden;
}

.project-image {
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    object-fit: cover;
    transition: transform var(--transition-slow);
}

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

.project-overlay {
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    background-color: rgba(7, 9, 19, 0.4);
    opacity: 0;
    display: flex;
    align-items: center;
    justify-content: center;
    transition: opacity var(--transition-normal);
}

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

.project-link {
    background-color: var(--bg-color);
    color: var(--text-primary);
    width: 50px;
    height: 50px;
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    text-decoration: none;
    transform: scale(0.8);
    transition: transform var(--transition-normal), background-color var(--transition-fast);
}

.project-card:hover .project-link {
    transform: scale(1);
}

.project-link:hover {
    background-color: var(--primary-color);
    color: #070913;
}

.project-link svg {
    width: 22px;
    height: 22px;
}

.project-info {
    padding: 2rem;
}

.project-category {
    font-size: 0.75rem;
    font-weight: 600;
    color: var(--primary-color);
    text-transform: uppercase;
    letter-spacing: 0.15em;
    display: block;
    margin-bottom: 0.75rem;
}

.project-title {
    font-size: 1.4rem;
    margin-bottom: 1rem;
}

.project-desc {
    font-size: 0.95rem;
    color: var(--text-secondary);
    margin-bottom: 1.5rem;
    line-height: 1.6;
}

.project-tags {
    display: flex;
    flex-wrap: wrap;
    gap: 0.5rem;
}

.project-tag-small {
    background-color: var(--card-border);
    color: var(--text-primary);
    padding: 0.25rem 0.75rem;
    border-radius: 4px;
    font-size: 0.75rem;
    font-weight: 500;
    display: inline-flex;
    align-items: center;
    gap: 0.35rem;
}

.project-tag-small span {
    line-height: 1;
}

.tag-icon {
    width: 12px;
    height: 12px;
    stroke-width: 2.5px;
    flex-shrink: 0;
}

.tag-icon-img {
    width: 14px;
    height: 14px;
    object-fit: contain;
    border-radius: 3px;
    flex-shrink: 0;
}

/* ==========================================================================
   7. Contact Section
   ========================================================================== */
.contact-grid {
    display: grid;
    grid-template-columns: 0.8fr 1.2fr;
    gap: 3rem;
    align-items: start;
}

.contact-card h3 {
    font-size: 1.8rem;
    margin-bottom: 1rem;
}

.contact-card p {
    color: var(--text-secondary);
    margin-bottom: 3rem;
}

.contact-methods {
    display: flex;
    flex-direction: column;
    gap: 2rem;
}

.contact-method-item {
    display: flex;
    align-items: center;
    gap: 1.25rem;
}

.icon-wrapper {
    width: 50px;
    height: 50px;
    background-color: var(--card-border);
    border: 1px solid var(--card-border);
    border-radius: 12px;
    display: flex;
    align-items: center;
    justify-content: center;
    color: var(--primary-color);
    flex-shrink: 0;
}

.icon-wrapper svg {
    width: 22px;
    height: 22px;
}

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

.method-label {
    font-size: 0.8rem;
    text-transform: uppercase;
    letter-spacing: 0.1em;
    color: var(--text-secondary);
}

.method-value {
    font-size: 1.05rem;
    font-weight: 600;
    color: var(--text-primary);
    text-decoration: none;
    transition: color var(--transition-fast);
}

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

/* Form Styles */
.contact-form {
    display: flex;
    flex-direction: column;
    gap: 1.75rem;
}

.form-group {
    display: flex;
    flex-direction: column;
    gap: 0.5rem;
}

.form-group label {
    font-size: 0.85rem;
    font-weight: 600;
    color: var(--text-primary);
}

.form-group input,
.form-group textarea {
    background-color: var(--input-bg);
    border: 1px solid var(--input-border);
    color: var(--text-primary);
    padding: 0.95rem 1.25rem;
    border-radius: 8px;
    font-family: var(--font-body);
    font-size: 0.95rem;
    transition: border-color var(--transition-fast), box-shadow var(--transition-fast);
}

.form-group input:focus,
.form-group textarea:focus {
    outline: none;
    border-color: var(--primary-color);
    box-shadow: 0 0 0 4px var(--primary-glow);
}

/* ==========================================================================
   8. Footer
   ========================================================================== */
.footer {
    border-top: 1px solid var(--card-border);
    padding: 3rem 0;
    background-color: var(--bg-color);
}

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

.footer-content p {
    color: var(--text-secondary);
    font-size: 0.9rem;
}

.social-links {
    display: flex;
    gap: 1.5rem;
}

.social-links a {
    color: var(--text-secondary);
    transition: color var(--transition-fast), transform var(--transition-fast);
}

.social-links a:hover {
    color: var(--primary-color);
    transform: translateY(-2px);
}

.social-links a svg {
    width: 22px;
    height: 22px;
}

/* ==========================================================================
   9. Scroll & Animation Effects
   ========================================================================== */
.animate-fade-in {
    opacity: 0;
    animation: fadeIn 1s forwards ease-out;
}

.animate-slide-up {
    opacity: 0;
    transform: translateY(30px);
    animation: slideUp 1s forwards ease-out;
}

.animate-slide-up-delayed {
    opacity: 0;
    transform: translateY(30px);
    animation: slideUp 1s forwards ease-out;
    animation-delay: 0.3s;
}

/* JS Scroll Reveal classes */
.reveal {
    opacity: 0;
    transition: opacity var(--transition-slow), transform var(--transition-slow);
}

.reveal-up {
    opacity: 0;
    transform: translateY(50px);
    transition: opacity 1s cubic-bezier(0.2, 0.8, 0.2, 1), 
                transform 1s cubic-bezier(0.2, 0.8, 0.2, 1);
}

.reveal-left {
    opacity: 0;
    transform: translateX(-50px);
    transition: opacity 1.2s cubic-bezier(0.2, 0.8, 0.2, 1), 
                transform 1.2s cubic-bezier(0.2, 0.8, 0.2, 1);
}

.reveal-right {
    opacity: 0;
    transform: translateX(50px);
    transition: opacity 1.2s cubic-bezier(0.2, 0.8, 0.2, 1), 
                transform 1.2s cubic-bezier(0.2, 0.8, 0.2, 1);
}

.active-reveal {
    opacity: 1;
    transform: translate(0, 0);
}

@keyframes fadeIn {
    to { opacity: 1; }
}

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

/* ==========================================================================
   10. Responsive Media Queries
   ========================================================================== */
@media (max-width: 992px) {
    .section-padding {
        padding: 5rem 0;
    }
    
    .about-grid, .contact-grid {
        grid-template-columns: 1fr;
        gap: 4rem;
    }
    
    .skills-container {
        order: -1;
    }
}

@media (max-width: 768px) {
    /* Mobile Navigation */
    .mobile-menu-btn {
        display: flex;
    }
    
    .nav-menu {
        position: fixed;
        top: var(--header-height);
        left: 0;
        width: 100%;
        height: calc(100vh - var(--header-height));
        background-color: var(--bg-color);
        flex-direction: column;
        justify-content: center;
        gap: 3rem;
        padding: 2rem;
        transform: translateX(100%);
        transition: transform var(--transition-normal);
        border-top: 1px solid var(--card-border);
    }
    
    .nav-menu.active {
        transform: translateX(0);
    }
    
    .nav-link {
        font-size: 1.5rem;
    }
    
    /* Hero section adjust */
    .hero-actions {
        flex-direction: column;
        gap: 1rem;
    }
    
    .btn {
        width: 100%;
    }
    
    .footer-content {
        flex-direction: column;
        gap: 2rem;
        text-align: center;
    }
}