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

:root {
    /* Color Palette */
    --primary-color: #2c3e50;
    --secondary-color: #3498db;
    --accent-color: #e74c3c;
    --text-color: #333333;
    --text-light: #666666;
    --bg-color: #ffffff;
    --bg-light: #f8f9fa;
    --bg-dark: #1a1a1a;
    --border-color: #e0e0e0;
    --success-color: #27ae60;
    --error-color: #e74c3c;
    
    /* Typography */
    --font-primary: 'Segoe UI', Tahoma, Geneva, Verdana, sans-serif;
    --font-size-base: 16px;
    --font-size-small: 14px;
    --font-size-large: 18px;
    --font-size-h1: 2.5rem;
    --font-size-h2: 2rem;
    --font-size-h3: 1.5rem;
    --font-size-h4: 1.25rem;
    
    /* Spacing */
    --spacing-xs: 0.5rem;
    --spacing-sm: 1rem;
    --spacing-md: 1.5rem;
    --spacing-lg: 2rem;
    --spacing-xl: 3rem;
    
    /* Transitions */
    --transition: all 0.3s ease;
}

html {
    scroll-behavior: smooth;
}

body {
    font-family: var(--font-primary);
    font-size: var(--font-size-base);
    line-height: 1.6;
    color: var(--text-color);
    background-color: var(--bg-color);
}

/* ========================================
   Typography
   ======================================== */
h1, h2, h3, h4, h5, h6 {
    font-weight: 600;
    line-height: 1.2;
    margin-bottom: var(--spacing-sm);
    color: var(--primary-color);
}

h1 {
    font-size: var(--font-size-h1);
}

h2 {
    font-size: var(--font-size-h2);
}

h3 {
    font-size: var(--font-size-h3);
}

h4 {
    font-size: var(--font-size-h4);
}

p {
    margin-bottom: var(--spacing-sm);
    color: var(--text-light);
}

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

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

/* ========================================
   Container & Layout
   ======================================== */
.container {
    width: 100%;
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 var(--spacing-md);
}

/* ========================================
   Header & Navigation
   ======================================== */
header {
    background-color: var(--bg-color);
    box-shadow: 0 2px 5px rgba(0, 0, 0, 0.1);
    position: sticky;
    top: 0;
    z-index: 1000;
}

header .container {
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: var(--spacing-sm) var(--spacing-md);
}

.logo h1 {
    margin: 0;
    font-size: 1.5rem;
    color: var(--primary-color);
}

nav {
    position: relative;
}

.nav-menu {
    display: flex;
    list-style: none;
    gap: var(--spacing-md);
}

.nav-menu a {
    color: var(--text-color);
    font-weight: 500;
    padding: var(--spacing-xs) var(--spacing-sm);
    border-radius: 4px;
    transition: var(--transition);
}

.nav-menu a:hover,
.nav-menu a.active {
    color: var(--secondary-color);
    background-color: var(--bg-light);
}

/* Hamburger Menu */
.hamburger {
    display: none;
    flex-direction: column;
    background: none;
    border: none;
    cursor: pointer;
    padding: var(--spacing-xs);
    gap: 4px;
}

.hamburger span {
    width: 25px;
    height: 3px;
    background-color: var(--primary-color);
    transition: var(--transition);
    border-radius: 2px;
}

/* ========================================
   Main Content
   ======================================== */
main {
    min-height: calc(100vh - 200px);
}

/* Page Header */
.page-header {
    background: linear-gradient(135deg, var(--primary-color) 0%, var(--secondary-color) 100%);
    color: white;
    padding: var(--spacing-xl) 0;
    text-align: center;
}

.page-header h2 {
    color: white;
    margin-bottom: var(--spacing-sm);
}

.page-subtitle {
    color: rgba(255, 255, 255, 0.9);
    font-size: var(--font-size-large);
}

/* Hero Section */
.hero {
    background: linear-gradient(135deg, var(--bg-light) 0%, var(--bg-color) 100%);
    padding: var(--spacing-xl) 0;
    text-align: center;
}

.hero-content {
    max-width: 800px;
    margin: 0 auto;
}

.hero h2 {
    font-size: 2.5rem;
    margin-bottom: var(--spacing-md);
}

.intro-text {
    font-size: var(--font-size-large);
    margin-bottom: var(--spacing-lg);
    color: var(--text-color);
}

/* Buttons */
.btn {
    display: inline-block;
    padding: 12px 24px;
    border: none;
    border-radius: 5px;
    font-size: var(--font-size-base);
    font-weight: 500;
    text-align: center;
    cursor: pointer;
    transition: var(--transition);
    text-decoration: none;
}

.btn-primary {
    background-color: var(--secondary-color);
    color: white;
}

.btn-primary:hover {
    background-color: #2980b9;
    transform: translateY(-2px);
    box-shadow: 0 4px 8px rgba(0, 0, 0, 0.2);
}

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

.btn-secondary:hover {
    background-color: var(--secondary-color);
    color: white;
}

.btn-small {
    padding: 8px 16px;
    font-size: var(--font-size-small);
}

.cta-buttons {
    display: flex;
    gap: var(--spacing-md);
    justify-content: center;
    flex-wrap: wrap;
}

/* Featured Section */
.featured,
.quick-links {
    padding: var(--spacing-xl) 0;
}

.featured h2,
.quick-links h2 {
    text-align: center;
    margin-bottom: var(--spacing-lg);
}

.featured-grid,
.links-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
    gap: var(--spacing-md);
}

.featured-card,
.link-card {
    background-color: var(--bg-light);
    padding: var(--spacing-md);
    border-radius: 8px;
    transition: var(--transition);
    border: 1px solid var(--border-color);
}

.link-card {
    display: block;
    color: inherit;
}

.featured-card:hover,
.link-card:hover {
    transform: translateY(-5px);
    box-shadow: 0 5px 15px rgba(0, 0, 0, 0.1);
}

.featured-card h3,
.link-card h3 {
    margin-bottom: var(--spacing-sm);
}

/* ========================================
   About Page
   ======================================== */
.about-content {
    padding: var(--spacing-xl) 0;
}

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

.image-placeholder {
    width: 100%;
    aspect-ratio: 1;
    background: linear-gradient(135deg, var(--bg-light) 0%, var(--border-color) 100%);
    border-radius: 8px;
    display: flex;
    align-items: center;
    justify-content: center;
    color: var(--text-light);
    font-size: var(--font-size-large);
}

.about-image {
    width: 100%;
}

.profile-photo {
    width: 100%;
    height: auto;
    object-fit: contain;
    border-radius: 8px;
    display: block;
}

.about-text h3 {
    margin-bottom: var(--spacing-md);
}

.education,
.interests {
    padding: var(--spacing-lg) 0;
}

.education h3,
.interests h3 {
    margin-bottom: var(--spacing-lg);
    text-align: center;
}

.education-timeline {
    max-width: 800px;
    margin: 0 auto;
}

.education-item {
    background-color: var(--bg-light);
    padding: var(--spacing-md);
    border-radius: 8px;
    margin-bottom: var(--spacing-md);
    border-left: 4px solid var(--secondary-color);
}

.institution {
    font-weight: 600;
    color: var(--primary-color);
}

.dates {
    color: var(--text-light);
    font-size: var(--font-size-small);
    margin: var(--spacing-xs) 0;
}

.interests-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
    gap: var(--spacing-md);
}

.interest-card {
    background-color: var(--bg-light);
    padding: var(--spacing-md);
    border-radius: 8px;
    text-align: center;
    transition: var(--transition);
}

.interest-card:hover {
    transform: translateY(-5px);
    box-shadow: 0 5px 15px rgba(0, 0, 0, 0.1);
}

/* ========================================
   Projects Page
   ======================================== */
.projects-carousel {
    padding: var(--spacing-xl) 0;
    background-color: var(--bg-light);
}

.carousel-container {
    position: relative;
    max-width: 1000px;
    margin: 0 auto;
}

.carousel-wrapper {
    overflow: hidden;
    border-radius: 8px;
}

.carousel-track {
    display: flex;
    transition: transform 0.5s ease;
}

.project-slide {
    min-width: 100%;
    display: none;
    background-color: white;
    border-radius: 8px;
    overflow: hidden;
    box-shadow: 0 4px 15px rgba(0, 0, 0, 0.1);
}

.project-slide.active {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: var(--spacing-lg);
}

.project-image {
    overflow: hidden;
    width: 100%;
    aspect-ratio: 4/3;
}

.project-image .image-placeholder {
    width: 100%;
    aspect-ratio: 4/3;
    background: linear-gradient(135deg, var(--bg-light) 0%, var(--border-color) 100%);
    display: flex;
    align-items: center;
    justify-content: center;
    color: var(--text-light);
}

.project-image img,
.project-image-img {
    width: 100%;
    height: 100%;
    object-fit: cover;
    display: block;
}

.project-info {
    padding: var(--spacing-lg);
    display: flex;
    flex-direction: column;
    justify-content: center;
}

.project-description {
    margin: var(--spacing-md) 0;
}

.project-tech {
    display: flex;
    flex-wrap: wrap;
    gap: var(--spacing-xs);
    margin: var(--spacing-md) 0;
}

.tech-tag {
    background-color: var(--bg-light);
    padding: 4px 12px;
    border-radius: 20px;
    font-size: var(--font-size-small);
    color: var(--primary-color);
    border: 1px solid var(--border-color);
}

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

.carousel-btn {
    position: absolute;
    top: 50%;
    transform: translateY(-50%);
    background-color: var(--primary-color);
    color: white;
    border: none;
    width: 40px;
    height: 40px;
    border-radius: 50%;
    font-size: 1.5rem;
    cursor: pointer;
    transition: var(--transition);
    z-index: 10;
}

.carousel-btn:hover {
    background-color: var(--secondary-color);
}

.carousel-btn.prev {
    left: -50px;
}

.carousel-btn.next {
    right: -50px;
}

.carousel-dots {
    display: flex;
    justify-content: center;
    gap: var(--spacing-xs);
    margin-top: var(--spacing-md);
}

.dot {
    width: 12px;
    height: 12px;
    border-radius: 50%;
    border: none;
    background-color: var(--border-color);
    cursor: pointer;
    transition: var(--transition);
}

.dot.active {
    background-color: var(--secondary-color);
}

.projects-grid {
    padding: var(--spacing-xl) 0;
}

.projects-grid h3 {
    text-align: center;
    margin-bottom: var(--spacing-lg);
}

.projects-list {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
    gap: var(--spacing-lg);
}

.project-card {
    background-color: var(--bg-light);
    border-radius: 8px;
    overflow: hidden;
    transition: var(--transition);
    border: 1px solid var(--border-color);
}

.project-card:hover {
    transform: translateY(-5px);
    box-shadow: 0 5px 15px rgba(0, 0, 0, 0.1);
}

.project-card-image {
    overflow: hidden;
}

.image-placeholder-small {
    width: 100%;
    aspect-ratio: 16/9;
    background: linear-gradient(135deg, var(--bg-light) 0%, var(--border-color) 100%);
    display: flex;
    align-items: center;
    justify-content: center;
    color: var(--text-light);
}

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

.project-card-tech {
    display: flex;
    flex-wrap: wrap;
    gap: var(--spacing-xs);
    margin-top: var(--spacing-sm);
}

.tech-tag-small {
    background-color: white;
    padding: 3px 10px;
    border-radius: 15px;
    font-size: 12px;
    color: var(--primary-color);
    border: 1px solid var(--border-color);
}

/* ========================================
   Skills Page
   ======================================== */
.skills-content {
    padding: var(--spacing-xl) 0;
}

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

.skills-category h3 {
    margin-bottom: var(--spacing-lg);
    text-align: center;
    border-bottom: 2px solid var(--border-color);
    padding-bottom: var(--spacing-sm);
}

.skills-grid {
    max-width: 800px;
    margin: 0 auto;
}

.skill-item {
    margin-bottom: var(--spacing-md);
}

.skill-header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    margin-bottom: var(--spacing-xs);
}

.skill-header h4 {
    margin: 0;
    color: var(--primary-color);
}

.skill-level {
    font-size: var(--font-size-small);
    color: var(--text-light);
    font-style: italic;
}

.skill-bar {
    width: 100%;
    height: 10px;
    background-color: var(--bg-light);
    border-radius: 5px;
    overflow: hidden;
}

.skill-progress {
    height: 100%;
    background: linear-gradient(90deg, var(--secondary-color) 0%, #2980b9 100%);
    border-radius: 5px;
    transition: width 1s ease;
}

.skills-tags {
    display: flex;
    flex-wrap: wrap;
    gap: var(--spacing-sm);
    justify-content: center;
}

.skill-tag {
    background-color: var(--bg-light);
    padding: 8px 16px;
    border-radius: 20px;
    font-size: var(--font-size-base);
    color: var(--primary-color);
    border: 1px solid var(--border-color);
    transition: var(--transition);
}

.skill-tag:hover {
    background-color: var(--secondary-color);
    color: white;
    border-color: var(--secondary-color);
    transform: translateY(-2px);
}

.soft-skill {
    background-color: #fff5e6;
    border-color: #ffd699;
}

.soft-skill:hover {
    background-color: #ffd699;
}

/* ========================================
   Contact Page
   ======================================== */
.contact-content {
    padding: var(--spacing-xl) 0;
}

.contact-grid {
    display: grid;
    grid-template-columns: 1fr 1.5fr;
    gap: var(--spacing-xl);
}

.contact-info h3 {
    margin-bottom: var(--spacing-md);
}

.contact-details {
    margin: var(--spacing-lg) 0;
}

.contact-item {
    margin-bottom: var(--spacing-md);
}

.contact-item h4 {
    color: var(--secondary-color);
    margin-bottom: var(--spacing-xs);
    font-size: 1.1rem;
}

.social-links {
    margin-top: var(--spacing-lg);
}

.social-icons {
    display: flex;
    gap: var(--spacing-md);
    margin-top: var(--spacing-sm);
}

.social-icons a {
    padding: 8px 16px;
    background-color: var(--bg-light);
    border-radius: 5px;
    transition: var(--transition);
}

.social-icons a:hover {
    background-color: var(--secondary-color);
    color: white;
}

/* Contact Form */
.contact-form {
    background-color: var(--bg-light);
    padding: var(--spacing-lg);
    border-radius: 8px;
}

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

.form-group label {
    display: block;
    margin-bottom: var(--spacing-xs);
    font-weight: 500;
    color: var(--primary-color);
}

.required {
    color: var(--error-color);
}

.form-group input,
.form-group textarea {
    width: 100%;
    padding: 10px;
    border: 1px solid var(--border-color);
    border-radius: 5px;
    font-family: inherit;
    font-size: var(--font-size-base);
    transition: var(--transition);
}

.form-group input:focus,
.form-group textarea:focus {
    outline: none;
    border-color: var(--secondary-color);
    box-shadow: 0 0 0 3px rgba(52, 152, 219, 0.1);
}

.form-group textarea {
    resize: vertical;
}

.error-message {
    display: block;
    color: var(--error-color);
    font-size: var(--font-size-small);
    margin-top: var(--spacing-xs);
    min-height: 20px;
}

.form-group input.error,
.form-group textarea.error {
    border-color: var(--error-color);
}

.form-success {
    margin-top: var(--spacing-md);
    padding: var(--spacing-sm);
    background-color: #d4edda;
    color: var(--success-color);
    border-radius: 5px;
    display: none;
}

.form-success.show {
    display: block;
}

/* ========================================
   Footer
   ======================================== */
footer {
    background-color: var(--primary-color);
    color: white;
    padding: var(--spacing-lg) 0;
    margin-top: var(--spacing-xl);
}

footer .container {
    display: flex;
    justify-content: space-between;
    align-items: center;
    flex-wrap: wrap;
    gap: var(--spacing-md);
}

footer p {
    color: rgba(255, 255, 255, 0.8);
    margin: 0;
}

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

.footer-links a {
    color: rgba(255, 255, 255, 0.8);
    transition: var(--transition);
}

.footer-links a:hover {
    color: white;
}

/* ========================================
   Responsive Design - Media Queries
   ======================================== */

/* Tablet (768px - 1024px) */
@media screen and (max-width: 1024px) {
    .carousel-btn.prev {
        left: -30px;
    }
    
    .carousel-btn.next {
        right: -30px;
    }
    
    .project-slide.active {
        grid-template-columns: 1fr;
    }
}

/* Mobile (below 768px) */
@media screen and (max-width: 768px) {
    :root {
        --font-size-h1: 2rem;
        --font-size-h2: 1.75rem;
        --font-size-h3: 1.25rem;
    }
    
    /* Navigation */
    .hamburger {
        display: flex;
    }
    
    .nav-menu {
        position: absolute;
        top: 100%;
        right: 0;
        flex-direction: column;
        background-color: white;
        width: 200px;
        box-shadow: 0 5px 15px rgba(0, 0, 0, 0.2);
        border-radius: 5px;
        padding: var(--spacing-sm);
        display: none;
        gap: var(--spacing-xs);
    }
    
    .nav-menu.active {
        display: flex;
    }
    
    .nav-menu a {
        padding: var(--spacing-sm);
        display: block;
        width: 100%;
    }
    
    /* Hero */
    .hero h2 {
        font-size: 2rem;
    }
    
    .intro-text {
        font-size: var(--font-size-base);
    }
    
    .cta-buttons {
        flex-direction: column;
    }
    
    .btn {
        width: 100%;
    }
    
    /* About */
    .about-grid {
        grid-template-columns: 1fr;
    }
    
    /* Projects */
    .carousel-btn {
        width: 35px;
        height: 35px;
        font-size: 1.2rem;
    }
    
    .carousel-btn.prev {
        left: 10px;
    }
    
    .carousel-btn.next {
        right: 10px;
    }
    
    /* Contact */
    .contact-grid {
        grid-template-columns: 1fr;
    }
    
    /* Footer */
    footer .container {
        flex-direction: column;
        text-align: center;
    }
    
    /* General */
    .featured-grid,
    .links-grid,
    .projects-list,
    .interests-grid {
        grid-template-columns: 1fr;
    }
    
    .container {
        padding: 0 var(--spacing-sm);
    }
}

/* Small Mobile (below 480px) */
@media screen and (max-width: 480px) {
    .logo h1 {
        font-size: 1.25rem;
    }
    
    .hero h2 {
        font-size: 1.75rem;
    }
    
    .page-header {
        padding: var(--spacing-lg) 0;
    }
    
    .carousel-btn {
        width: 30px;
        height: 30px;
        font-size: 1rem;
    }
}

/* Accessibility: Focus States */
*:focus-visible {
    outline: 2px solid var(--secondary-color);
    outline-offset: 2px;
}

/* Skip to main content link (for screen readers) */
.skip-link {
    position: absolute;
    top: -40px;
    left: 0;
    background: var(--primary-color);
    color: white;
    padding: 8px;
    z-index: 100;
}

.skip-link:focus {
    top: 0;
}