/* Light Theme Variables */
:root {
    --bg-main: #ffffff;
    --bg-card: #ffffff;
    --bg-card-hover: #f9fafb;
    --border-color: #e5e7eb;
    --text-primary: #111827;
    --text-muted: #6b7280;
    --accent-color: #000000;
    --accent-glow: rgba(0, 0, 0, 0.1);
    --success-green: #10b981;
    --font-heading: 'Poppins', sans-serif;
}

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

html {
    scroll-behavior: smooth;
}

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

/* Core Container Constraint layout */
.section-container {
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 24px;
}

/* Top Navigation */
.top-nav {
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: 24px;
    background-color: var(--bg-main);
    position: sticky;
    top: 0;
    z-index: 1000;
}

.logo {
    font-weight: 600;
    font-size: 1.25rem;
    color: var(--text-primary);
}

.nav-links {
    list-style: none;
    display: flex;
    gap: 32px;
    align-items: center;
}

.nav-links a {
    text-decoration: none;
    color: var(--text-muted);
    font-size: 0.95rem;
    font-weight: 500;
    transition: color 0.2s;
}

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

.theme-toggle {
    background: none;
    border: none;
    font-size: 1.2rem;
    color: var(--text-muted);
    cursor: pointer;
    transition: color 0.2s;
}
.theme-toggle:hover {
    color: var(--text-primary);
}

/* Base Fade and Transition Classes for Observer */
.section {
    padding: 100px 0;
    opacity: 0;
    transform: translateY(25px);
    transition: opacity 0.8s cubic-bezier(0.25, 1, 0.5, 1), transform 0.8s cubic-bezier(0.25, 1, 0.5, 1);
}

.section.visible {
    opacity: 1;
    transform: translateY(0);
}

/* Hero Section */
.hero {
    display: flex;
    align-items: center;
    justify-content: space-between;
    min-height: calc(100vh - 80px);
    padding-bottom: 50px;
}

.hero-content {
    flex: 1;
    max-width: 600px;
}

.status-badge-top {
    display: inline-flex;
    align-items: center;
    gap: 8px;
    background-color: #f3f4f6;
    color: var(--text-primary);
    font-size: 0.85rem;
    font-weight: 600;
    padding: 6px 16px;
    border-radius: 20px;
    margin-bottom: 24px;
    border: 1px solid var(--border-color);
}

.status-badge-top i {
    color: var(--text-muted);
}

.hero h1 {
    font-size: 4.5rem;
    line-height: 1.1;
    color: var(--text-primary);
    margin-bottom: 24px;
    font-weight: 500;
    letter-spacing: -0.02em;
}

.hero-subtitle {
    font-size: 1.25rem;
    color: var(--text-muted);
    margin-bottom: 16px;
    line-height: 1.5;
}
.hero-subtitle strong {
    color: var(--text-primary);
    font-weight: 600;
}

.hero-description {
    font-size: 1.1rem;
    color: var(--text-muted);
    margin-bottom: 40px;
    line-height: 1.6;
}

.hero-actions {
    display: flex;
    gap: 16px;
    margin-bottom: 40px;
}

/* Universal Button Design */
.btn {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    gap: 8px;
    padding: 14px 28px;
    font-size: 1rem;
    font-weight: 500;
    border-radius: 8px;
    cursor: pointer;
    transition: all 0.2s ease;
    text-decoration: none;
}

.btn-primary {
    background-color: var(--accent-color);
    color: #fff;
    border: 1px solid var(--accent-color);
}

.btn-primary:hover {
    background-color: #333;
    border-color: #333;
}

.btn-outline {
    background-color: transparent;
    color: var(--text-primary);
    border: 1px solid var(--border-color);
}

.btn-outline:hover {
    border-color: var(--text-muted);
    background-color: #f9fafb;
}

.btn-secondary {
    background-color: #f3f4f6;
    color: var(--text-primary);
    border: 1px solid var(--border-color);
}

.btn-secondary:hover {
    background-color: #e5e7eb;
}

/* Socials */
.hero-socials {
    display: flex;
    gap: 20px;
}

.hero-socials a {
    display: flex;
    align-items: center;
    justify-content: center;
    width: 44px;
    height: 44px;
    border-radius: 50%;
    border: 1px solid var(--border-color);
    color: var(--text-primary);
    font-size: 1.1rem;
    transition: all 0.2s ease;
    text-decoration: none;
}

.hero-socials a:hover {
    background-color: #f3f4f6;
    border-color: var(--text-muted);
}

/* Hero Image Right Side */
.hero-image-container {
    position: relative;
    flex: 1;
    display: flex;
    justify-content: center;
    align-items: center;
}

.image-wrapper {
    width: 450px;
    height: 450px;
    border-radius: 50%;
    background: radial-gradient(circle, #f3f4f6 0%, transparent 70%);
    display: flex;
    align-items: center;
    justify-content: center;
}

.hero-profile-img {
    width: 380px;
    height: 380px;
    border-radius: 50%;
    object-fit: cover;
    box-shadow: 0 20px 40px rgba(0,0,0,0.08);
}

.status-badge-bottom {
    position: absolute;
    bottom: 20px;
    right: 50px;
    background-color: #ffffff;
    border: 1px solid var(--border-color);
    padding: 10px 20px;
    border-radius: 30px;
    display: flex;
    align-items: center;
    gap: 10px;
    font-weight: 500;
    font-size: 0.95rem;
    box-shadow: 0 4px 12px rgba(0,0,0,0.05);
}

.status-dot {
    width: 10px;
    height: 10px;
    background-color: var(--success-green);
    border-radius: 50%;
    display: inline-block;
}

/* General Typography & Others */
h2 {
    font-size: 2rem;
    color: var(--text-primary);
    margin-bottom: 35px;
    position: relative;
    display: inline-block;
    font-weight: 600;
}

h3 {
    color: var(--text-primary);
    font-weight: 600;
}

.about-content p {
    font-size: 1.05rem;
    margin-bottom: 20px;
    color: var(--text-muted);
    max-width: 800px;
}

/* Projects Matrix Architecture */
.group-title {
    font-size: 1.2rem;
    margin-top: 40px;
    margin-bottom: 20px;
    color: var(--text-muted);
    display: flex;
    align-items: center;
    gap: 10px;
}

.projects-grid {
    display: grid;
    gap: 24px;
}

.major-grid {
    grid-template-columns: 1fr;
}

.minor-grid {
    grid-template-columns: repeat(auto-fit, minmax(320px, 1fr));
}

.project-card {
    background-color: var(--bg-card);
    border: 1px solid var(--border-color);
    border-radius: 12px;
    padding: 24px;
    position: relative;
    transition: transform 0.2s ease, border-color 0.2s ease, box-shadow 0.2s ease;
    display: flex;
    flex-direction: column;
}

.project-card:hover {
    transform: translateY(-4px);
    border-color: var(--text-muted);
    box-shadow: 0 8px 24px rgba(0, 0, 0, 0.05);
}

.project-thumb {
    width: 100%;
    height: 160px;
    object-fit: cover;
    border-radius: 6px;
    border: 1px solid var(--border-color);
    margin-bottom: 16px;
}

.project-card h4 {
    font-size: 1.3rem;
    color: var(--text-primary);
    margin-bottom: 10px;
    display: flex;
    align-items: center;
    justify-content: space-between;
}

.status-tag {
    font-size: 0.75rem;
    background-color: #f3f4f6;
    color: var(--text-primary);
    padding: 3px 8px;
    border-radius: 12px;
    border: 1px solid var(--border-color);
}

.project-card p, .project-card .project-bullets {
    color: var(--text-muted);
    font-size: 0.92rem;
    margin-bottom: 20px;
    flex-grow: 1;
}

.project-card .project-bullets {
    padding-left: 20px;
}

.project-card .project-bullets li {
    margin-bottom: 8px;
}

.project-card .project-bullets li strong {
    color: var(--text-primary);
}

.project-card.featured {
    border-left: 3px solid var(--text-primary);
}

.project-badge {
    position: absolute;
    top: 12px;
    right: 12px;
    background-color: var(--success-green);
    color: #fff;
    font-size: 0.75rem;
    font-weight: 600;
    padding: 4px 10px;
    border-radius: 4px;
}

.project-tags {
    display: flex;
    flex-wrap: wrap;
    gap: 8px;
    margin-top: 16px;
    margin-bottom: 20px;
}

.project-tags span {
    font-size: 0.78rem;
    font-family: monospace;
    background-color: #f3f4f6;
    color: #4b5563;
    padding: 4px 10px;
    border-radius: 4px;
    border: 1px solid var(--border-color);
}

.project-links {
    margin-top: auto;
}

/* Experience */
.code-bg {
    background-color: #f9fafb;
}

.experience-card {
    background-color: var(--bg-card);
    border: 1px solid var(--border-color);
    border-radius: 12px;
    padding: 30px;
}

.exp-header {
    display: flex;
    justify-content: space-between;
    align-items: flex-start;
    flex-wrap: wrap;
    gap: 10px;
    margin-bottom: 5px;
}

.exp-date {
    color: var(--text-muted);
    font-family: monospace;
    font-size: 0.9rem;
}

.exp-company {
    color: var(--text-muted);
    font-weight: 600;
    font-size: 0.95rem;
    margin-bottom: 20px;
}

.exp-bullets {
    list-style: none;
}

.exp-bullets li {
    position: relative;
    padding-left: 20px;
    margin-bottom: 12px;
    font-size: 0.95rem;
    color: var(--text-primary);
}

.exp-bullets li::before {
    content: '›';
    position: absolute;
    left: 0;
    top: -2px;
    color: var(--text-muted);
    font-size: 1.4rem;
}

/* Skills */
.skills-categories {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(220px, 1fr));
    gap: 20px;
}

.skill-category {
    background-color: var(--bg-card);
    border: 1px solid var(--border-color);
    border-radius: 12px;
    padding: 24px;
}

.skill-category h3 {
    font-size: 1rem;
    margin-bottom: 16px;
    border-bottom: 1px solid var(--border-color);
    padding-bottom: 8px;
    display: flex;
    align-items: center;
    gap: 8px;
    color: var(--text-primary);
}

.skills-list {
    display: flex;
    flex-wrap: wrap;
    gap: 8px;
}

.skills-list span {
    font-size: 0.85rem;
    background-color: #f3f4f6;
    color: var(--text-primary);
    padding: 6px 12px;
    border-radius: 6px;
    border: 1px solid var(--border-color);
    transition: all 0.2s ease;
}

/* Contact */
.contact-section {
    text-align: center;
    background-color: #f9fafb;
}

.contact-prompt {
    color: var(--text-muted);
    margin-bottom: 30px;
    font-size: 1.1rem;
}

.contact-grid {
    display: flex;
    justify-content: center;
    flex-wrap: wrap;
    gap: 16px;
}

.contact-tile {
    display: inline-flex;
    align-items: center;
    gap: 10px;
    background-color: var(--bg-card);
    border: 1px solid var(--border-color);
    padding: 14px 24px;
    border-radius: 12px;
    color: var(--text-primary);
    font-weight: 600;
    transition: all 0.2s ease;
    text-decoration: none;
}

.contact-tile:hover {
    border-color: var(--text-muted);
    box-shadow: 0 4px 12px rgba(0, 0, 0, 0.05);
    transform: translateY(-2px);
}

/* Mobile Media Queries */
@media (max-width: 992px) {
    .hero {
        flex-direction: column;
        text-align: center;
        padding-top: 40px;
    }
    
    .hero-content {
        display: flex;
        flex-direction: column;
        align-items: center;
    }
    
    .hero-image-container {
        margin-top: 60px;
    }
    
    .image-wrapper {
        width: 350px;
        height: 350px;
    }
    
    .hero-profile-img {
        width: 300px;
        height: 300px;
    }
    
    .status-badge-bottom {
        right: 0;
        bottom: 0;
    }
}

@media (max-width: 768px) {
    .nav-links {
        display: none;
    }
    .hero h1 {
        font-size: 3rem;
    }
    .exp-header {
        flex-direction: column;
    }
    .minor-grid {
        grid-template-columns: 1fr;
    }
}

/* Dark Theme Overrides */
body.dark-mode {
    --bg-main: #0d1117;
    --bg-card: #161b22;
    --bg-card-hover: #21262d;
    --border-color: #30363d;
    --text-primary: #c9d1d9;
    --text-muted: #8b949e;
    --accent-color: #a371f7;
    --accent-glow: rgba(163, 113, 247, 0.25);
    --success-green: #238636;
}

body.dark-mode .code-bg,
body.dark-mode .contact-section {
    background-color: #090d13;
}

body.dark-mode .status-badge-top,
body.dark-mode .status-badge-bottom,
body.dark-mode .project-tags span,
body.dark-mode .skills-list span,
body.dark-mode .btn-secondary,
body.dark-mode .hero-socials a:hover,
body.dark-mode .btn-outline:hover {
    background-color: #21262d;
    color: var(--text-primary);
}

body.dark-mode .image-wrapper {
    background: radial-gradient(circle, #21262d 0%, transparent 70%);
}