/* Google Fonts Import */
@import url('https://fonts.googleapis.com/css2?family=Poppins:wght@300;400;600;700&display=swap');

/* --- CSS Variables for Theming --- */
:root {
    --primary-color: #0077cc;
    --primary-hover: #005fa3;
    --secondary-color: #e9ecef;
    --secondary-hover: #d3d9df;
    --background-color: #f8f9fa;
    --card-bg-color: #ffffff;
    --text-color: #495057;
    --heading-color: #212529;
    --border-color: #dee2e6;
    --shadow: 0 4px 12px rgba(0, 0, 0, 0.08);
}

body.dark-mode {
    --primary-color: #0088ff;
    --primary-hover: #33a0ff;
    --secondary-color: #343a40;
    --secondary-hover: #495057;
    --background-color: #121212;
    --card-bg-color: #1e1e1e;
    --text-color: #adb5bd;
    --heading-color: #e9ecef;
    --border-color: #343a40;
    --shadow: 0 4px 12px rgba(0, 0, 0, 0.2);
}

/* --- General & Base Styles --- */
* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
    scroll-behavior: smooth;
}

body {
    font-family: 'Poppins', sans-serif;
    background-color: var(--background-color);
    color: var(--text-color);
    line-height: 1.7;
    transition: background-color 0.3s, color 0.3s;
}

main {
    padding-top: 70px; /* Offset for fixed navbar */
}

.content-section {
    max-width: 960px;
    margin: 0 auto;
    padding: 5rem 2rem;
}

.section-title {
    text-align: center;
    font-size: 2.5rem;
    font-weight: 700;
    color: var(--heading-color);
    margin-bottom: 3rem;
    position: relative;
}

.section-title::after {
    content: '';
    width: 80px;
    height: 4px;
    background-color: var(--primary-color);
    border-radius: 2px;
    position: absolute;
    bottom: -10px;
    left: 50%;
    transform: translateX(-50%);
}

/* --- Navigation Bar --- */
.navbar {
    width: 100%;
    background-color: var(--card-bg-color);
    border-bottom: 1px solid var(--border-color);
    position: fixed;
    top: 0;
    left: 0;
    z-index: 1000;
    box-shadow: 0 2px 5px rgba(0,0,0,0.05);
    transition: background-color 0.3s, border-bottom 0.3s;
}

.nav-container {
    max-width: 1100px;
    margin: 0 auto;
    display: flex;
    justify-content: space-between;
    align-items: center;
    height: 70px;
    padding: 0 2rem;
}

.nav-logo {
    font-size: 1.5rem;
    font-weight: 700;
    color: var(--primary-color);
    text-decoration: none;
}

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

.nav-item a {
    color: var(--heading-color);
    text-decoration: none;
    font-weight: 600;
    transition: color 0.3s;
}

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

#theme-toggle {
    background: none;
    border: 1px solid var(--border-color);
    color: var(--text-color);
    width: 40px;
    height: 40px;
    border-radius: 50%;
    cursor: pointer;
    font-size: 1.1rem;
    transition: all 0.3s;
}
#theme-toggle:hover {
    color: var(--primary-color);
    border-color: var(--primary-color);
}

/* --- Hero Section --- */
.hero-section {
    display: flex;
    align-items: center;
    justify-content: center;
    text-align: center;
    min-height: 100vh;
    padding: 0 2rem;
    background-color: var(--card-bg-color);
}

.hero-content h1 {
    font-size: 4rem;
    font-weight: 700;
    color: var(--heading-color);
    margin-bottom: 0.5rem;
}

.hero-content .subtitle {
    font-size: 1.5rem;
    color: var(--primary-color);
    font-weight: 600;
    margin-bottom: 1rem;
}

.hero-content .description {
    font-size: 1.1rem;
    max-width: 600px;
    margin: 0 auto 2rem;
}

.hero-buttons {
    display: flex;
    justify-content: center;
    gap: 1rem;
}

.btn {
    padding: 12px 28px;
    border-radius: 50px;
    text-decoration: none;
    font-weight: 600;
    transition: all 0.3s ease;
    border: 2px solid transparent;
}

.btn-primary {
    background-color: var(--primary-color);
    color: #fff;
}
.btn-primary:hover {
    background-color: var(--primary-hover);
    transform: translateY(-3px);
}

.btn-secondary {
    background-color: transparent;
    color: var(--primary-color);
    border-color: var(--primary-color);
}
.btn-secondary:hover {
    background-color: var(--primary-color);
    color: #fff;
    transform: translateY(-3px);
}

/* --- Experience Timeline --- */
.timeline {
    position: relative;
    max-width: 700px;
    margin: 0 auto;
}
.timeline::after {
    content: '';
    position: absolute;
    width: 4px;
    background-color: var(--primary-color);
    top: 0;
    bottom: 0;
    left: 50%;
    margin-left: -2px;
    border-radius: 2px;
}
.timeline-item {
    padding: 10px 40px;
    position: relative;
    width: 50%;
}
.timeline-item:nth-child(odd) {
    left: 0;
}
.timeline-item:nth-child(even) {
    left: 50%;
}
.timeline-dot {
    content: '';
    position: absolute;
    width: 16px;
    height: 16px;
    background-color: var(--card-bg-color);
    border: 4px solid var(--primary-color);
    top: 24px;
    border-radius: 50%;
    z-index: 1;
}
.timeline-item:nth-child(odd) .timeline-dot {
    right: -8px;
}
.timeline-item:nth-child(even) .timeline-dot {
    left: -8px;
}
.timeline-date {
    font-weight: 600;
    color: var(--primary-color);
}
.timeline-content {
    padding: 20px;
    background-color: var(--card-bg-color);
    border-radius: 8px;
    box-shadow: var(--shadow);
}
.timeline-content h3 {
    font-weight: 700;
    color: var(--heading-color);
}
.timeline-content .company {
    font-weight: 600;
    font-style: italic;
    margin-bottom: 0.5rem;
}
.timeline-content ul {
    list-style-type: none;
    padding-left: 0;
}
.timeline-content ul li::before {
    content: '✓';
    color: var(--primary-color);
    margin-right: 8px;
}

/* --- Cards Grid (Skills & Certs) --- */
.card-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
    gap: 1.5rem;
}

.skill-card, .cert-card {
    background-color: var(--card-bg-color);
    padding: 2rem;
    border-radius: 8px;
    box-shadow: var(--shadow);
    text-align: center;
    transition: transform 0.3s, box-shadow 0.3s;
}
.skill-card:hover, .cert-card:hover {
    transform: translateY(-5px);
    box-shadow: 0 8px 20px rgba(0, 0, 0, 0.12);
}
.skill-card i, .cert-icon i {
    font-size: 2.5rem;
    color: var(--primary-color);
    margin-bottom: 1rem;
}
.skill-card h3, .cert-card h3 {
    color: var(--heading-color);
    margin-bottom: 0.5rem;
}

.cert-card { text-decoration: none; color: var(--text-color); display: block; }
.cert-card .view-credential {
    display: inline-block;
    margin-top: 1rem;
    font-weight: 600;
    color: var(--primary-color);
}
.view-credential i { font-size: 0.9em; margin-left: 5px; }


/* --- Contact Section --- */
#contact { text-align: center; }
.contact-text { max-width: 500px; margin: 0 auto 2rem; }
.contact-buttons { display: flex; justify-content: center; gap: 1rem; }

/* --- Footer --- */
footer { text-align: center; padding: 2rem; background-color: var(--card-bg-color); border-top: 1px solid var(--border-color); }

/* --- Responsive Design --- */
@media (max-width: 768px) {
    .nav-menu { display: none; } /* Simplified for example; requires JS for hamburger menu */
    .hero-content h1 { font-size: 2.5rem; }
    .hero-content .subtitle { font-size: 1.2rem; }
    
    .timeline::after { left: 20px; }
    .timeline-item { width: 100%; padding-left: 60px; padding-right: 15px; }
    .timeline-item:nth-child(even) { left: 0; }
    .timeline-dot { left: 12px; }
    .timeline-item:nth-child(odd) .timeline-dot, .timeline-item:nth-child(even) .timeline-dot { right: auto; left: 12px; }
}