:root {
    --primary-color: #2563eb;
    --text-color: #1f2937;
    --bg-color: #ffffff;
    --bg-secondary: #f3f4f6;
    --card-bg: #ffffff;
    --border-color: #e5e7eb;
    --heading-font: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, "Helvetica Neue", Arial, sans-serif;
    --body-font: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, "Helvetica Neue", Arial, sans-serif;
}

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

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

a {
    color: var(--primary-color);
    text-decoration: none;
    transition: color 0.2s;
}

a:hover {
    color: #1d4ed8;
    text-decoration: underline;
}

/* Typography */
h1, h2, h3, h4, h5, h6 {
    font-family: var(--heading-font);
    font-weight: 700;
    line-height: 1.2;
    margin-bottom: 1rem;
    color: #111827;
}

h1 { font-size: 3rem; }
h2 { font-size: 2.25rem; border-bottom: 2px solid var(--border-color); padding-bottom: 0.5rem; margin-top: 3rem; }
h3 { font-size: 1.5rem; margin-top: 1.5rem; }

/* Layout */
.container {
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 1.5rem;
}

/* Header */
header {
    background: rgba(255, 255, 255, 0.7);
    backdrop-filter: blur(20px);
    -webkit-backdrop-filter: blur(20px);
    padding: 1rem 2rem;
    position: fixed;
    top: 1.5rem;
    left: 50%;
    transform: translateX(-50%);
    width: 90%;
    max-width: 1000px;
    z-index: 1000;
    box-shadow: 0 10px 40px rgba(0, 0, 0, 0.08);
    border: 1px solid rgba(255, 255, 255, 0.5);
    border-radius: 100px;
}

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

.logo {
    font-weight: 800;
    font-size: 1.25rem;
    background: linear-gradient(135deg, #2563eb, #1d4ed8);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    text-decoration: none;
    letter-spacing: -0.02em;
}

nav ul {
    display: flex;
    list-style: none;
    gap: 1.5rem;
    align-items: center;
}

nav a {
    color: #1f2937;
    font-weight: 600;
    font-size: 0.9rem;
    transition: color 0.2s;
}

nav a:hover {
    color: var(--primary-color);
    text-decoration: none;
}

/* Hero Section */
.hero {
    padding: 12rem 0 8rem;
    text-align: center;
    background: linear-gradient(135deg, #3b82f6 0%, #2563eb 100%);
    color: white;
    border-radius: 2.5rem;
    margin: 0.75rem;
    box-shadow: 0 20px 40px -10px rgba(37, 99, 235, 0.2);
}

.hero h1 {
    font-size: 3.5rem;
    margin-bottom: 1.5rem;
    color: white;
    letter-spacing: -0.02em;
}

.hero p {
    font-size: 1.35rem;
    color: rgba(255, 255, 255, 0.95);
    max-width: 700px;
    margin: 0 auto 2.5rem;
    font-weight: 400;
}

.social-links {
    margin-top: 2rem;
    display: flex;
    gap: 1rem;
    justify-content: center;
}

.btn {
    display: inline-block;
    padding: 0.75rem 2rem;
    background-color: var(--primary-color);
    color: white;
    border-radius: 3rem;
    font-weight: 600;
    text-decoration: none;
    transition: all 0.2s ease;
}

.btn:hover {
    background-color: #1d4ed8;
    color: white;
    text-decoration: none;
    transform: translateY(-2px);
    box-shadow: 0 4px 12px rgba(37, 99, 235, 0.3);
}

/* Hero specific buttons */
.hero .btn-outline {
    background-color: rgba(255, 255, 255, 0.1);
    border: 1px solid rgba(255, 255, 255, 0.3);
    color: white;
    backdrop-filter: blur(5px);
    border-radius: 3rem;
    padding: 0.75rem 1.5rem;
}

.hero .btn-outline:hover {
    background-color: white;
    color: var(--primary-color);
    border-color: white;
    transform: translateY(-2px);
    box-shadow: 0 4px 15px rgba(0, 0, 0, 0.1);
}

/* Default outline button for other sections */
.btn-outline {
    display: inline-block;
    padding: 0.75rem 1.5rem;
    background-color: transparent;
    border: 2px solid var(--border-color);
    color: #4b5563;
    border-radius: 3rem;
    font-weight: 600;
    text-decoration: none;
    transition: all 0.2s ease;
}

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

/* Sections */
section {
    padding: 4rem 0;
}

.section-intro {
    text-align: center;
    margin-bottom: 3rem;
}

/* Grid Layout */
.project-grid {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(350px, 1fr));
    gap: 2rem;
}

.project-card {
    background: var(--card-bg);
    border: 1px solid var(--border-color);
    border-radius: 0.5rem;
    overflow: hidden;
    transition: transform 0.2s, box-shadow 0.2s;
    display: flex;
    flex-direction: column;
}

.project-card:hover {
    transform: translateY(-4px);
    box-shadow: 0 10px 15px -3px rgba(0, 0, 0, 0.1);
}

.project-image {
    width: 100%;
    height: 200px;
    object-fit: cover;
    border-bottom: 1px solid var(--border-color);
}

.project-content {
    padding: 1.5rem;
    flex-grow: 1;
    display: flex;
    flex-direction: column;
}

.project-tags {
    margin-bottom: 0.5rem;
    font-size: 0.875rem;
    color: #6b7280;
    text-transform: uppercase;
    letter-spacing: 0.05em;
    font-weight: 600;
}

.project-content p {
    color: #4b5563;
    margin-bottom: 1.5rem;
    font-size: 0.95rem;
    flex-grow: 1;
}

.project-links {
    margin-top: auto;
    display: flex;
    gap: 1rem;
    flex-wrap: wrap;
}

.project-links a {
    font-size: 0.9rem;
    font-weight: 600;
}

/* Timeline for Professional Experience */
.timeline {
    position: relative;
    max-width: 800px;
    margin: 0 auto;
}

.timeline-item {
    padding: 2rem;
    border-left: 2px solid var(--border-color);
    position: relative;
    margin-left: 1rem;
}

.timeline-item::before {
    content: '';
    position: absolute;
    left: -0.6rem;
    top: 2.5rem;
    width: 1rem;
    height: 1rem;
    background: var(--primary-color);
    border-radius: 50%;
    border: 2px solid white;
}

.timeline-date {
    font-size: 0.875rem;
    color: #6b7280;
    margin-bottom: 0.5rem;
    font-weight: 600;
}

.timeline-title {
    font-size: 1.25rem;
    font-weight: 700;
    margin-bottom: 0.25rem;
}

.timeline-subtitle {
    font-size: 1rem;
    color: #4b5563;
    margin-bottom: 1rem;
    font-style: italic;
}

/* Footer */
footer {
    background-color: var(--bg-secondary);
    padding: 4rem 0;
    margin-top: 4rem;
    text-align: center;
    border-top: 1px solid var(--border-color);
}

@media (max-width: 768px) {
    header {
        width: 94%;
        padding: 0.75rem 1rem;
        border-radius: 2rem;
        top: 1rem;
    }

    .header-content {
        flex-direction: column;
        gap: 0.75rem;
    }

    .logo {
        font-size: 1.2rem;
    }

    nav {
        width: 100%;
        overflow-x: auto;
        -webkit-overflow-scrolling: touch;
        /* Hide scrollbar */
        scrollbar-width: none;
        -ms-overflow-style: none;
    }

    nav::-webkit-scrollbar {
        display: none;
    }

    nav ul {
        gap: 0.5rem;
        justify-content: space-between;
        padding: 0 0.25rem;
        width: 100%;
    }

    nav a {
        font-size: 0.85rem;
        white-space: nowrap;
    }
    
    /* Adjust resume button on mobile */
    nav .btn-outline {
        padding: 0.4rem 1rem !important;
        font-size: 0.8rem !important;
    }

    h1 { font-size: 2rem; }
    .hero { 
        padding-top: 11rem; /* More space for the taller header */
        margin: 0.5rem;
        border-radius: 2rem;
    }
    .project-grid { grid-template-columns: 1fr; }
}