:root {
    /* Color Palette - Modern Dark Tech Theme */
    --bg-body: #0f172a;       /* Slate 900 */
    --bg-card: #1e293b;       /* Slate 800 */
    --bg-card-hover: #334155; /* Slate 700 */
    --primary: #38bdf8;       /* Sky 400 */
    --secondary: #818cf8;     /* Indigo 400 */
    --accent: #2dd4bf;        /* Teal 400 */
    --text-main: #f1f5f9;     /* Slate 100 */
    --text-muted: #94a3b8;    /* Slate 400 */
    --border: #334155;
    
    --spacing-sm: 0.5rem;
    --spacing-md: 1rem;
    --spacing-lg: 2rem;
    --spacing-xl: 4rem;
    
    --radius: 12px;
    --shadow: 0 4px 6px -1px rgba(0, 0, 0, 0.1), 0 2px 4px -1px rgba(0, 0, 0, 0.06);
    --transition: all 0.3s ease;
}

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

html {
    scroll-behavior: smooth;
}

body {
    font-family: 'Prompt', sans-serif;
    background-color: var(--bg-body);
    color: var(--text-main);
    line-height: 1.6;
    overflow-x: hidden;
}

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

ul {
    list-style: none;
}

/* Container Utility */
.container {
    max-width: 1100px;
    margin: 0 auto;
    padding: 0 var(--spacing-lg);
}

section {
    padding: var(--spacing-xl) 0;
}

/* Typography */
h1, h2, h3, h4 {
    font-weight: 700;
    color: var(--text-main);
    line-height: 1.2;
}

h1 { font-size: 2.5rem; }
h2 { font-size: 2rem; margin-bottom: var(--spacing-lg); position: relative; display: inline-block; }
h2::after {
    content: '';
    display: block;
    width: 60%;
    height: 4px;
    background: linear-gradient(90deg, var(--primary), var(--secondary));
    margin-top: var(--spacing-sm);
    border-radius: 2px;
}
h3 { font-size: 1.25rem; color: var(--primary); margin-bottom: var(--spacing-sm); }

.text-english { font-family: 'Prompt', sans-serif; color: var(--text-muted); font-weight: 300; }
.highlight { color: var(--primary); }

/* Navigation */
nav {
    position: fixed;
    top: 0;
    width: 100%;
    background-color: rgba(15, 23, 42, 0.9);
    backdrop-filter: blur(10px);
    border-bottom: 1px solid var(--border);
    z-index: 1000;
    padding: 1rem 0;
}

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

.logo {
    font-size: 1.25rem;
    font-weight: 700;
    color: var(--primary);
}

.nav-links {
    display: flex;
    gap: var(--spacing-lg);
}

.nav-links a {
    font-size: 0.9rem;
    color: var(--text-muted);
}

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

/* Mobile Nav Button (Hidden on Desktop) */
.menu-toggle { display: none; font-size: 1.5rem; cursor: pointer; }

/* Hero Section */
.hero {
    min-height: 100vh;
    display: flex;
    align-items: center;
    justify-content: center;
    text-align: center;
    background: radial-gradient(circle at top right, #1e293b 0%, #0f172a 60%);
    padding-top: 60px;
}

.hero-content {
    max-width: 800px;
    animation: fadeIn 1s ease-out;
}

.quote-box {
    font-style: italic;
    color: var(--text-muted);
    margin: var(--spacing-lg) 0;
    padding: 0 var(--spacing-md);
    border-left: 3px solid var(--secondary);
    background: rgba(255,255,255,0.03);
    border-radius: 0 var(--radius) var(--radius) 0;
}

.profile-pic {
    width: 150px;
    height: 150px;
    border-radius: 50%;
    object-fit: cover;
    border: 3px solid var(--primary);
    margin-bottom: var(--spacing-md);
    box-shadow: 0 0 20px rgba(56, 189, 248, 0.3);
    cursor: pointer;
    transition: var(--transition);
}

.profile-pic:hover {
    transform: scale(1.05);
}

.contact-info {
    display: flex;
    justify-content: center;
    gap: var(--spacing-lg);
    flex-wrap: wrap;
    margin-top: var(--spacing-lg);
}

.contact-item {
    display: flex;
    align-items: center;
    gap: 0.5rem;
    color: var(--text-main);
    background: var(--bg-card);
    padding: 0.5rem 1rem;
    border-radius: 50px;
    border: 1px solid var(--border);
    font-size: 0.9rem;
}

.contact-item i { color: var(--primary); }

/* Video Placeholder */
.video-wrapper {
    width: 100%;
    max-width: 700px;
    margin: 0 auto var(--spacing-lg) auto;
    aspect-ratio: 16/9;
    background: #000;
    border-radius: var(--radius);
    display: flex;
    align-items: center;
    justify-content: center;
    flex-direction: column;
    color: var(--text-muted);
    border: 2px dashed var(--border);
    position: relative;
    overflow: hidden;
}

.play-btn {
    font-size: 3rem;
    color: var(--primary);
    cursor: pointer;
    transition: transform 0.2s;
}

.play-btn:hover { transform: scale(1.1); }

/* Section Titles */
.section-header {
    text-align: center;
    margin-bottom: var(--spacing-xl);
}

/* Cards (Education, Experience) */
.card {
    background: var(--bg-card);
    border-radius: var(--radius);
    padding: var(--spacing-lg);
    margin-bottom: var(--spacing-lg);
    border: 1px solid var(--border);
    transition: var(--transition);
}

.card:hover {
    transform: translateY(-5px);
    border-color: var(--primary);
    box-shadow: var(--shadow);
}

.card-header {
    display: flex;
    justify-content: space-between;
    align-items: flex-start;
    margin-bottom: var(--spacing-md);
    flex-wrap: wrap;
    gap: var(--spacing-sm);
}

.card-date {
    background: rgba(56, 189, 248, 0.1);
    color: var(--primary);
    padding: 0.25rem 0.75rem;
    border-radius: 20px;
    font-size: 0.85rem;
    font-weight: 600;
}

.card-body ul {
    padding-left: 1.5rem;
}

.card-body li {
    margin-bottom: 0.5rem;
    position: relative;
    list-style-type: disc;
    color: var(--text-muted);
}

.card-body li span {
    color: var(--text-main);
}

/* Experience Details */
.exp-subsection {
    margin-top: var(--spacing-md);
    padding-left: var(--spacing-md);
    border-left: 2px solid var(--border);
}

.exp-title {
    font-size: 1rem;
    color: var(--accent);
    margin-top: 1rem;
    font-weight: 600;
}

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

.skill-tag {
    background: var(--bg-card);
    padding: var(--spacing-md);
    border-radius: var(--radius);
    text-align: center;
    border: 1px solid var(--border);
    font-size: 0.9rem;
    transition: var(--transition);
    cursor: pointer;
}

.skill-tag:hover {
    background: var(--bg-card-hover);
    color: var(--primary);
    border-color: var(--primary);
    transform: translateY(-3px);
}

.skill-tag i {
    display: block;
    font-size: 1.5rem;
    margin-bottom: var(--spacing-sm);
    color: var(--secondary);
}

/* Certificates List */
.cert-list {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(300px, 1fr));
    gap: var(--spacing-md);
}

.cert-item {
    display: flex;
    align-items: center;
    gap: var(--spacing-md);
    background: var(--bg-card);
    padding: var(--spacing-md);
    border-radius: var(--radius);
    border-left: 4px solid var(--accent);
    cursor: pointer;
    transition: var(--transition);
}

.cert-item:hover {
    background: var(--bg-card-hover);
    transform: translateX(5px);
}

.cert-item i {
    color: var(--accent);
    font-size: 1.2rem;
}

/* Achievements */
.achievement-item {
    display: flex;
    justify-content: space-between;
    align-items: center;
    background: linear-gradient(90deg, rgba(56,189,248,0.1) 0%, rgba(30,41,59,0) 100%);
    padding: var(--spacing-md);
    margin-bottom: var(--spacing-sm);
    border-radius: var(--radius);
    border: 1px solid rgba(56,189,248,0.2);
    cursor: pointer;
    transition: var(--transition);
}

.achievement-item:hover {
    background: linear-gradient(90deg, rgba(56,189,248,0.2) 0%, rgba(30,41,59,0.1) 100%);
    transform: translateX(5px);
}

.achievement-medal { color: #fbbf24; margin-right: var(--spacing-sm); }

/* Footer */
footer {
    text-align: center;
    padding: var(--spacing-xl) 0;
    border-top: 1px solid var(--border);
    color: var(--text-muted);
    margin-top: var(--spacing-xl);
}

/* Image Preview Overlay */
.image-preview {
    position: fixed;
    top: 0;
    right: 0;
    width: 60%;
    height: 100vh;
    background: rgba(15, 23, 42, 0.95);
    backdrop-filter: blur(10px);
    z-index: 2000;
    padding: var(--spacing-lg);
    display: flex;
    flex-direction: column;
    align-items: center;
    justify-content: center;
    transform: translateX(100%);
    transition: transform 0.4s cubic-bezier(0.4, 0, 0.2, 1);
    border-left: 1px solid var(--border);
    box-shadow: -10px 0 30px rgba(0, 0, 0, 0.3);
}

.image-preview.active {
    transform: translateX(0);
}

.image-preview-close {
    position: absolute;
    top: var(--spacing-lg);
    right: var(--spacing-lg);
    font-size: 1.5rem;
    color: var(--text-muted);
    cursor: pointer;
    transition: var(--transition);
    z-index: 2001;
    background: rgba(0, 0, 0, 0.5);
    width: 40px;
    height: 40px;
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
}

.image-preview-close:hover {
    color: var(--primary);
    background: rgba(56, 189, 248, 0.1);
}

#previewImage {
    max-width: 100%;
    max-height: 80vh;
    object-fit: contain;
    border-radius: var(--radius);
    box-shadow: 0 10px 30px rgba(0, 0, 0, 0.5);
    animation: fadeIn 0.3s ease-out;
}

.image-title {
    margin-top: var(--spacing-md);
    text-align: center;
    color: var(--primary);
    font-weight: 600;
    font-size: 1.1rem;
    padding: 0 var(--spacing-md);
}

/* Cursor styles for clickable elements */
[data-image] {
    cursor: zoom-in;
    position: relative;
}

[data-image]::after {
    content: '👁️';
    position: absolute;
    top: 5px;
    right: 5px;
    font-size: 0.8rem;
    opacity: 0;
    transition: opacity 0.3s ease;
}

[data-image]:hover::after {
    opacity: 1;
}

/* Responsive Design */
@media (max-width: 768px) {
    h1 { font-size: 2rem; }
    .nav-links { display: none; } /* Simplified for mobile, ideally needs JS toggle */
    .menu-toggle { display: block; }
    
    .card-header { flex-direction: column; }
    .skills-grid { grid-template-columns: repeat(2, 1fr); }
    
    /* Image Preview for Mobile */
    .image-preview {
        width: 100%;
        right: 0;
        padding: var(--spacing-md);
    }
    
    .image-title {
        font-size: 1rem;
    }
}

@media (max-width: 480px) {
    .skills-grid {
        grid-template-columns: 1fr;
    }
    
    .cert-list {
        grid-template-columns: 1fr;
    }
}

@keyframes fadeIn {
    from { opacity: 0; transform: translateY(20px); }
    to { opacity: 1; transform: translateY(0); }
}