/* --- Global Variables & Theme Setup --- */
:root {
    --bg-color: #f8fafc;
    --card-bg: #ffffff;
    --text-color: #1e293b;
    --text-muted: #64748b;
    --accent-color: #2563eb;
    --accent-light: #dbeafe;
    --border-color: #e2e8f0;
    --nav-bg: rgba(255, 255, 255, 0.85);
    --shadow: 0 4px 6px -1px rgba(0, 0, 0, 0.05), 0 2px 4px -1px rgba(0, 0, 0, 0.03);
    --transition: all 0.3s cubic-bezier(0.4, 0, 0.2, 1);
}

[data-theme="dark"] {
    --bg-color: #0f172a;
    --card-bg: #1e293b;
    --text-color: #f1f5f9;
    --text-muted: #94a3b8;
    --accent-color: #3b82f6;
    --accent-light: #1e3a8a;
    --border-color: #334155;
    --nav-bg: rgba(15, 23, 42, 0.85);
    --shadow: 0 4px 6px -1px rgba(0, 0, 0, 0.3), 0 2px 4px -1px rgba(0, 0, 0, 0.2);
}

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

html {
    scroll-behavior: smooth;
}

body {
    font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, Helvetica, Arial, sans-serif;
    background-color: var(--bg-color);
    color: var(--text-color);
    line-height: 1.6;
    transition: var(--transition);
}

.container {
    max-width: 1100px;
    margin: 0 auto;
    padding: 0 2rem;
}

/* --- Navigation --- */
header {
    position: sticky;
    top: 0;
    z-index: 1000;
    background-color: var(--nav-bg);
    backdrop-filter: blur(12px);
    border-bottom: 1px solid var(--border-color);
    transition: var(--transition);
}

.navbar {
    display: flex;
    justify-content: space-between;
    align-items: center;
    max-width: 1100px;
    margin: 0 auto;
    padding: 1rem 2rem;
}

.nav-brand {
    font-size: 1.5rem;
    font-weight: 800;
    color: var(--accent-color);
}

.nav-links {
    display: flex;
    list-style: none;
    gap: 2rem;
}

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

.nav-links a:hover, .nav-links a.active {
    color: var(--accent-color);
}

.theme-toggle {
    cursor: pointer;
    font-size: 1.2rem;
    color: var(--text-muted);
    transition: var(--transition);
}

.theme-toggle:hover {
    color: var(--accent-color);
}

/* --- Section Formatting --- */
.section {
    padding: 5rem 0 2rem 0;
}

.section-title {
    font-size: 2rem;
    margin-bottom: 2rem;
    position: relative;
    display: inline-block;
}

.section-title::after {
    content: '';
    position: absolute;
    left: 0;
    bottom: -6px;
    width: 40px;
    height: 4px;
    background-color: var(--accent-color);
    border-radius: 2px;
}

/* --- Hero Section --- */
.hero-section {
    padding: 7rem 0 4rem 0;
}

.hero-grid {
    display: grid;
    grid-template-columns: 250px 1fr;
    gap: 3rem;
    align-items: center;
}

.hero-image-wrapper {
    width: 220px;
    height: 220px;
    border-radius: 50%;
    overflow: hidden;
    box-shadow: var(--shadow);
    border: 4px solid var(--card-bg);
}

.hero-img {
    width: 100%;
    height: 150%;
    object-fit: cover;
}

.hero-content h1 {
    font-size: 3rem;
    line-height: 1.1;
    margin-bottom: 0.5rem;
}

.tagline {
    font-size: 1.25rem;
    color: var(--accent-color);
    font-weight: 600;
    margin-bottom: 1.5rem;
}

.bio {
    color: var(--text-muted);
    margin-bottom: 1.5rem;
    text-align: justify;
}

.contact-info {
    display: flex;
    flex-wrap: wrap;
    gap: 1.5rem;
    font-size: 0.9rem;
    color: var(--text-muted);
    margin-bottom: 1.5rem;
}

.contact-info a {
    color: inherit;
    text-decoration: none;
}

.contact-info i {
    color: var(--accent-color);
}

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

.social-links a {
    font-size: 1.5rem;
    color: var(--text-muted);
    transition: var(--transition);
}

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

/* --- Work Experience Timeline --- */
.timeline {
    position: relative;
    border-left: 2px solid var(--border-color);
    padding-left: 2rem;
    margin-left: 0.5rem;
}

.timeline-item {
    position: relative;
    margin-bottom: 2rem;
}

.timeline-dot {
    position: absolute;
    left: calc(-2rem - 7px);
    top: 6px;
    width: 12px;
    height: 12px;
    border-radius: 50%;
    background-color: var(--accent-color);
    box-shadow: 0 0 0 4px var(--bg-color);
}

.timeline-header {
    margin-bottom: 1rem;
}

.timeline-header h3 {
    font-size: 1.3rem;
}

.company {
    display: block;
    font-weight: 600;
    color: var(--accent-color);
}

.duration {
    font-size: 0.85rem;
    color: var(--text-muted);
}

.timeline-body {
    padding-left: 1.2rem;
    color: var(--text-muted);
}

.timeline-body li {
    margin-bottom: 0.5rem;
}

/* --- Skills Block --- */
.skills-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(220px, 1fr));
    gap: 1.5rem;
}

.skills-category {
    background-color: var(--card-bg);
    padding: 1.5rem;
    border-radius: 8px;
    border: 1px solid var(--border-color);
    box-shadow: var(--shadow);
}

.skills-category h3 {
    font-size: 1.1rem;
    margin-bottom: 1rem;
    display: flex;
    align-items: center;
    gap: 0.5rem;
}

.skills-category i {
    color: var(--accent-color);
}

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

.tag {
    background-color: var(--bg-color);
    border: 1px solid var(--border-color);
    padding: 0.25rem 0.75rem;
    border-radius: 20px;
    font-size: 0.85rem;
    font-weight: 500;
}

/* --- Projects Section --- */
.filter-buttons {
    display: flex;
    gap: 1rem;
    margin-bottom: 2rem;
}

.filter-btn {
    background-color: var(--card-bg);
    border: 1px solid var(--border-color);
    color: var(--text-color);
    padding: 0.5rem 1.25rem;
    border-radius: 6px;
    cursor: pointer;
    font-weight: 500;
    transition: var(--transition);
}

.filter-btn.active, .filter-btn:hover {
    background-color: var(--accent-color);
    color: white;
    border-color: var(--accent-color);
}

.projects-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
    gap: 1.5rem;
}

.project-card {
    background-color: var(--card-bg);
    border: 1px solid var(--border-color);
    padding: 2rem;
    border-radius: 8px;
    box-shadow: var(--shadow);
    transition: var(--transition);
    display: flex;
    flex-direction: column;
}

.project-card.hide {
    display: none;
}

.project-card:hover {
    transform: translateY(-5px);
    box-shadow: 0 10px 15px -3px rgba(0, 0, 0, 0.1);
}

.project-icon {
    font-size: 2rem;
    color: var(--accent-color);
    margin-bottom: 1rem;
}

.project-card h3 {
    margin-bottom: 0.75rem;
}

.project-card p {
    color: var(--text-muted);
    font-size: 0.95rem;
    margin-bottom: 1rem;
    flex-grow: 1;
}

.project-card ul {
    padding-left: 1rem;
    font-size: 0.85rem;
    color: var(--text-muted);
    margin-bottom: 1.5rem;
}

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

.project-tags span {
    background-color: var(--accent-light);
    color: var(--accent-color);
    padding: 0.2rem 0.6rem;
    border-radius: 4px;
    font-size: 0.8rem;
    font-weight: 600;
}

[data-theme="dark"] .project-tags span {
    background-color: #1e3a8a;
    color: #60a5fa;
}

/* --- Education & Layout Mix --- */
.dual-grid {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 4rem;
}

.edu-card {
    background-color: var(--card-bg);
    border-left: 4px solid var(--accent-color);
    padding: 1rem 1.5rem;
    margin-bottom: 1.25rem;
    box-shadow: var(--shadow);
    border-radius: 0 8px 8px 0;
}

.institution {
    font-weight: 500;
}

.year {
    font-size: 0.85rem;
    color: var(--text-muted);
}

.subsection-title {
    margin: 2rem 0 1rem 0;
}

.lang-tag {
    background-color: var(--card-bg);
}

.cert-list {
    list-style: none;
}

.cert-list li {
    display: flex;
    align-items: flex-start;
    gap: 1rem;
    margin-bottom: 1.5rem;
}

.cert-icon {
    color: var(--accent-color);
    font-size: 1.2rem;
    margin-top: 0.2rem;
}

/* --- Footer --- */
footer {
    text-align: center;
    padding: 3rem 0;
    margin-top: 4rem;
    border-top: 1px solid var(--border-color);
    color: var(--text-muted);
    font-size: 0.9rem;
}

/* --- Responsive Adaptations --- */
@media (max-width: 768px) {
    .hero-grid {
        grid-template-columns: 1fr;
        text-align: center;
    }
    .hero-image-wrapper {
        margin: 0 auto;
    }
    .contact-info {
        justify-content: center;
    }
    .social-links {
        justify-content: center;
    }
    .nav-links {
        display: none; /* Can be paired with a hamburger toggle in script.js */
    }
    .dual-grid {
        grid-template-columns: 1fr;
        gap: 2rem;
    }
}