/* Minimalist & Professional Design System for Mehmet Güngör */

:root {
    --bg: #ffffff;
    --bg-alt: #f9fafb;
    --border: #e5e7eb;
    
    --text: #111827;
    --text-muted: #4b5563;
    --text-light: #9ca3af;
    
    --accent: #1d4ed8;
    --accent-hover: #1e40af;
    --accent-bg: rgba(29, 78, 216, 0.05);

    --font-sans: 'Inter', -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, sans-serif;
    --font-serif: 'Newsreader', 'Georgia', serif;
    --font-mono: 'Fira Code', monospace;
    
    --radius: 6px;
    --max-width: 820px;
    --transition: all 0.2s ease;
}

body.dark-mode {
    --bg: #0f172a;
    --bg-alt: #1e293b;
    --border: #334155;
    
    --text: #f8fafc;
    --text-muted: #94a3b8;
    --text-light: #64748b;
    
    --accent: #60a5fa;
    --accent-hover: #93c5fd;
    --accent-bg: rgba(96, 165, 250, 0.1);
}

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

html {
    scroll-behavior: smooth;
}

body {
    background-color: var(--bg);
    color: var(--text);
    font-family: var(--font-sans);
    line-height: 1.7;
    font-size: 1.05rem;
    -webkit-font-smoothing: antialiased;
    transition: background-color 0.2s ease, color 0.2s ease;
}

.container {
    max-width: var(--max-width);
    margin: 0 auto;
    padding: 0 1.5rem;
}

/* Header */
header {
    border-bottom: 1px solid var(--border);
    background: var(--bg);
    position: sticky;
    top: 0;
    z-index: 100;
}

.nav-wrapper {
    display: flex;
    justify-content: space-between;
    align-items: center;
    height: 64px;
}

.logo {
    font-weight: 700;
    font-size: 1.15rem;
    color: var(--text);
    text-decoration: none;
    letter-spacing: -0.3px;
}

.nav-links {
    display: flex;
    align-items: center;
    gap: 1.5rem;
}

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

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

.nav-links a.active {
    color: var(--accent);
    font-weight: 600;
}

.theme-toggle {
    background: none;
    border: none;
    color: var(--text-muted);
    cursor: pointer;
    padding: 0.4rem;
    display: flex;
    align-items: center;
    border-radius: var(--radius);
}

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

.theme-toggle svg {
    width: 18px;
    height: 18px;
    fill: currentColor;
}

.sun-icon { display: none; }
.moon-icon { display: block; }
body.dark-mode .sun-icon { display: block; }
body.dark-mode .moon-icon { display: none; }

/* Sections */
section {
    padding: 3rem 0;
    border-bottom: 1px solid var(--border);
}

section:last-of-type {
    border-bottom: none;
}

/* Hero Section */
.hero {
    padding: 4rem 0 3rem 0;
}

.hero h1 {
    font-size: 2.25rem;
    font-weight: 800;
    letter-spacing: -0.5px;
    line-height: 1.25;
    margin-bottom: 0.5rem;
}

.hero .subtitle {
    font-size: 1.15rem;
    color: var(--accent);
    font-weight: 600;
    margin-bottom: 1.25rem;
}

.hero p {
    color: var(--text-muted);
    font-size: 1.05rem;
    margin-bottom: 1.5rem;
    max-width: 720px;
}

.link-group {
    display: flex;
    flex-wrap: wrap;
    gap: 1rem;
    align-items: center;
}

.link-item {
    color: var(--accent);
    text-decoration: none;
    font-weight: 600;
    font-size: 0.95rem;
    display: inline-flex;
    align-items: center;
    gap: 0.3rem;
}

.link-item:hover {
    text-decoration: underline;
}

.link-sep {
    color: var(--text-light);
}

/* Section Titles */
.section-title {
    font-size: 1.35rem;
    font-weight: 700;
    letter-spacing: -0.3px;
    margin-bottom: 1.5rem;
    color: var(--text);
}

/* Research List */
.research-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(240px, 1fr));
    gap: 1.25rem;
}

.research-card {
    background: var(--bg-alt);
    border: 1px solid var(--border);
    border-radius: var(--radius);
    padding: 1.25rem;
}

.research-card h3 {
    font-size: 1.05rem;
    font-weight: 700;
    margin-bottom: 0.5rem;
}

.research-card p {
    font-size: 0.95rem;
    color: var(--text-muted);
}

/* Publications List */
.pub-list {
    display: flex;
    flex-direction: column;
    gap: 1.5rem;
}

.pub-item {
    display: flex;
    flex-direction: column;
    gap: 0.3rem;
}

.pub-title-row {
    display: flex;
    justify-content: space-between;
    align-items: baseline;
    gap: 1rem;
}

.pub-title {
    font-weight: 700;
    font-size: 1.05rem;
    color: var(--text);
    text-decoration: none;
}

.pub-title:hover {
    color: var(--accent);
}

.pub-authors {
    font-size: 0.95rem;
    color: var(--text-muted);
}

.pub-venue {
    font-size: 0.9rem;
    color: var(--text-light);
    font-style: italic;
}

.pub-links {
    display: flex;
    gap: 0.75rem;
    font-size: 0.85rem;
    margin-top: 0.2rem;
}

.pub-link {
    color: var(--accent);
    text-decoration: none;
    font-weight: 600;
}

.pub-link:hover {
    text-decoration: underline;
}

.pub-cite-count {
    font-size: 0.8rem;
    color: var(--text-muted);
    background: var(--bg-alt);
    border: 1px solid var(--border);
    padding: 0.1rem 0.5rem;
    border-radius: 99px;
    font-weight: 500;
}

/* Blog Notice Box */
.blog-notice {
    background: var(--bg-alt);
    border: 1px solid var(--border);
    border-left: 3px solid var(--accent);
    border-radius: var(--radius);
    padding: 1.25rem 1.5rem;
    display: flex;
    justify-content: space-between;
    align-items: center;
    gap: 1rem;
}

.blog-notice p {
    font-size: 0.98rem;
    color: var(--text-muted);
}

.blog-notice strong {
    color: var(--text);
}

/* Contact List */
.contact-list {
    list-style: none;
    display: flex;
    flex-direction: column;
    gap: 0.75rem;
}

.contact-list li {
    display: flex;
    align-items: center;
    gap: 0.75rem;
    font-size: 0.98rem;
}

.contact-list a {
    color: var(--accent);
    text-decoration: none;
}

.contact-list a:hover {
    text-decoration: underline;
}

/* Footer */
footer {
    padding: 2.5rem 0;
    color: var(--text-light);
    font-size: 0.9rem;
    border-top: 1px solid var(--border);
    text-align: center;
}

@media (max-width: 640px) {
    .hero h1 { font-size: 1.85rem; }
    .blog-notice { flex-direction: column; align-items: flex-start; }
    .nav-links { gap: 1rem; }
}