/* 
  Sarp Coskun - Premium Dark Theme 
  Typography: Outfit (Headings), Inter (Body)
*/

:root {
    /* Colors */
    --bg-dark: #0a0a0a;
    --bg-card: #141414;
    --bg-card-hover: #1a1a1a;
    
    --text-primary: #ffffff;
    --text-secondary: #a1a1aa;
    
    --accent-color: #3b82f6; /* Subtle blue for accents */
    --accent-hover: #60a5fa;
    --border-color: rgba(255, 255, 255, 0.08);
    
    /* Spacing & Layout */
    --max-width: 1100px;
    --section-padding: 100px 0;
    
    /* Typography */
    --font-heading: 'Outfit', sans-serif;
    --font-body: 'Inter', sans-serif;
    
    /* Transitions */
    --transition-fast: 0.2s ease;
    --transition-normal: 0.4s ease;
}

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

html {
    scroll-behavior: smooth;
    scroll-padding-top: 88px;
    font-size: 16px;
    color-scheme: dark;
}

body {
    background-color: var(--bg-dark);
    color: var(--text-primary);
    font-family: var(--font-body);
    line-height: 1.6;
    overflow-x: hidden;
}

.skip-link {
    position: absolute;
    left: 16px;
    top: -48px;
    z-index: 3000;
    padding: 10px 16px;
    background: var(--text-primary);
    color: var(--bg-dark);
    border-radius: 8px;
    font-weight: 600;
}

.skip-link:focus {
    top: 16px;
}

:focus-visible {
    outline: 2px solid var(--accent-color);
    outline-offset: 3px;
}

a {
    text-decoration: none;
    color: inherit;
    transition: color var(--transition-fast);
}

img {
    max-width: 100%;
    display: block;
}

/* Typography Base */
h1, h2, h3, h4, h5, h6 {
    font-family: var(--font-heading);
    font-weight: 700;
    line-height: 1.2;
}

.text-center { text-align: center; }

/* Buttons */
.btn {
    display: inline-block;
    padding: 14px 28px;
    border-radius: 8px;
    font-weight: 500;
    font-family: var(--font-body);
    cursor: pointer;
    transition: all var(--transition-fast);
    border: none;
    font-size: 1rem;
}

.btn-primary {
    background-color: var(--text-primary);
    color: var(--bg-dark);
}

.btn-primary:hover {
    background-color: #e4e4e7;
    transform: translateY(-2px);
}

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

.btn-secondary:hover {
    background-color: rgba(255, 255, 255, 0.05);
    border-color: rgba(255, 255, 255, 0.2);
    transform: translateY(-2px);
}

/* Cards */
.card {
    background-color: var(--bg-card);
    border: 1px solid var(--border-color);
    border-radius: 16px;
    padding: 32px;
    transition: all var(--transition-normal);
}

.card:hover {
    background-color: var(--bg-card-hover);
    border-color: rgba(255, 255, 255, 0.15);
    transform: translateY(-5px);
    box-shadow: 0 10px 30px rgba(0, 0, 0, 0.5);
}

/* Container */
.section-container, .nav-container, .hero-container, .footer-container {
    max-width: var(--max-width);
    margin: 0 auto;
    padding: 0 24px;
}

/* Navbar */
.navbar {
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    padding: 20px 0;
    background-color: rgba(10, 10, 10, 0.85);
    backdrop-filter: blur(12px);
    -webkit-backdrop-filter: blur(12px);
    z-index: 1000;
    border-bottom: 1px solid transparent;
    transition: all var(--transition-fast);
}

.navbar.scrolled {
    padding: 15px 0;
    border-bottom: 1px solid var(--border-color);
}

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

.logo {
    font-family: var(--font-heading);
    font-weight: 800;
    font-size: 1.25rem;
    letter-spacing: 1px;
}

.nav-links {
    display: flex;
    align-items: center;
    gap: 32px;
}

.nav-links a {
    font-size: 0.9rem;
    font-weight: 500;
    color: var(--text-secondary);
}

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

.nav-cta {
    color: var(--text-primary) !important;
    border: 1px solid var(--border-color);
    padding: 8px 16px;
    border-radius: 6px;
}

.nav-cta:hover {
    background-color: rgba(255, 255, 255, 0.05);
}

.mobile-menu-btn {
    display: none;
    flex-direction: column;
    justify-content: center;
    align-items: center;
    gap: 5px;
    width: 44px;
    height: 44px;
    background: none;
    border: none;
    padding: 0;
    cursor: pointer;
    color: var(--text-primary);
}

.mobile-menu-btn span {
    display: block;
    width: 22px;
    height: 2px;
    background-color: var(--text-primary);
    border-radius: 1px;
}

/* Mobile Menu */
.mobile-menu {
    position: fixed;
    top: 0;
    right: -100%;
    width: 100%;
    height: 100vh;
    background-color: var(--bg-dark);
    z-index: 2000;
    display: flex;
    flex-direction: column;
    justify-content: center;
    align-items: center;
    gap: 32px;
    transition: right var(--transition-normal);
}

.mobile-menu.active {
    right: 0;
}

.mobile-menu a {
    font-family: var(--font-heading);
    font-size: 2rem;
    font-weight: 600;
}

.mobile-menu-close {
    position: absolute;
    top: 24px;
    right: 24px;
    width: 44px;
    height: 44px;
    background: none;
    border: none;
    padding: 0;
    color: var(--text-primary);
    cursor: pointer;
    font-size: 2.4rem;
    line-height: 1;
}

/* Hero Section */
.hero {
    padding-top: 180px;
    padding-bottom: 100px;
    min-height: 100vh;
    display: flex;
    align-items: center;
}

.hero-container {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 60px;
    align-items: center;
}

.hero-title {
    font-size: clamp(3rem, 5vw, 4.5rem);
    letter-spacing: -1px;
    margin-bottom: 16px;
}

.hero-subtitle {
    font-size: clamp(1.2rem, 2vw, 1.5rem);
    color: var(--text-secondary);
    font-weight: 400;
    margin-bottom: 24px;
}

.hero-description {
    font-size: 1.25rem;
    line-height: 1.65;
    color: var(--text-secondary);
    max-width: 520px;
    margin-bottom: 40px;
}

.hero-description .highlight-text {
    color: #bfdbfe;
    font-weight: 600;
}

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

.hero-image-wrapper {
    position: relative;
    border-radius: 24px;
    overflow: hidden;
}

.hero-image-wrapper::after {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    box-shadow: inset 0 0 80px 40px var(--bg-dark);
    pointer-events: none;
    z-index: 3;
    border-radius: 24px;
}

.hero-image {
    width: 100%;
    height: auto;
    border-radius: 24px;
    position: relative;
    z-index: 2;
    object-fit: cover;
    object-position: 72% 50%;
}

.glow-effect {
    position: absolute;
    top: 50%;
    left: 50%;
    width: 120%;
    height: 120%;
    background: radial-gradient(circle, rgba(255,255,255,0.1) 0%, rgba(0,0,0,0) 70%);
    transform: translate(-50%, -50%);
    z-index: 1;
}

/* About Section */
.about-section {
    padding: var(--section-padding);
    background-color: var(--bg-card);
    border-top: 1px solid var(--border-color);
    border-bottom: 1px solid var(--border-color);
}

.about-grid {
    display: grid;
    grid-template-columns: 2fr 3fr;
    gap: 60px;
    align-items: start;
}

.about-image-wrapper {
    border-radius: 16px;
    overflow: hidden;
}

.about-image {
    width: 100%;
    aspect-ratio: 1/1;
    object-fit: cover;
    object-position: 78% 28%;
    filter: grayscale(20%);
}

.section-title {
    font-size: 2.5rem;
    margin-bottom: 32px;
}

.section-subtitle {
    color: var(--text-secondary);
    font-size: 1.1rem;
    margin-top: -20px;
    margin-bottom: 40px;
}

.section-subtitle a {
    color: var(--text-primary);
    text-decoration: underline;
    text-underline-offset: 3px;
}

.section-subtitle a:hover {
    color: var(--accent-hover);
}

.about-text p {
    margin-bottom: 20px;
    color: var(--text-secondary);
    font-size: 1.05rem;
}

.about-text strong {
    color: var(--text-primary);
}

.about-text a {
    color: var(--text-primary);
    text-decoration: underline;
    text-underline-offset: 3px;
}

.about-text a:hover {
    color: var(--accent-hover);
}

.skills-container {
    display: flex;
    flex-wrap: wrap;
    gap: 12px;
    margin-top: 32px;
}

.skill-tag {
    padding: 8px 16px;
    background-color: rgba(255, 255, 255, 0.05);
    border: 1px solid var(--border-color);
    border-radius: 40px;
    font-size: 0.9rem;
    color: var(--text-primary);
}

/* Work Section (Timeline) */
.work-section {
    padding: var(--section-padding);
}

.timeline {
    position: relative;
    max-width: 820px;
    margin: 60px auto 0;
}

.timeline::before {
    content: '';
    position: absolute;
    top: 0;
    left: 24px;
    height: 100%;
    width: 1px;
    background-color: var(--border-color);
}

.timeline-item {
    position: relative;
    padding-left: 70px;
    margin-bottom: 40px;
}

.timeline-item:last-child {
    margin-bottom: 0;
}

.timeline-dot {
    position: absolute;
    left: 20px;
    top: 32px;
    width: 9px;
    height: 9px;
    border-radius: 50%;
    background-color: var(--accent-color);
    box-shadow: 0 0 0 8px var(--bg-dark), 0 0 12px var(--accent-color);
}

.timeline-date {
    font-family: var(--font-heading);
    color: var(--text-secondary);
    font-size: 0.9rem;
    margin-bottom: 8px;
    letter-spacing: 0.5px;
    text-transform: uppercase;
}

.timeline-role {
    font-size: 1.4rem;
    margin-bottom: 4px;
    color: var(--text-primary);
}

.timeline-company {
    color: var(--accent-hover);
    font-weight: 500;
    font-size: 1.05rem;
    margin-bottom: 16px;
}

.timeline-list {
    list-style: none;
    padding: 0;
    margin: 0;
    display: flex;
    flex-direction: column;
    gap: 12px;
}

.timeline-list li {
    position: relative;
    padding-left: 20px;
    font-size: 0.98rem;
    color: var(--text-secondary);
    line-height: 1.6;
}

.timeline-list li::before {
    content: '';
    position: absolute;
    left: 0;
    top: 10px;
    width: 6px;
    height: 6px;
    border-radius: 50%;
    background-color: var(--accent-color);
}

.timeline-list strong {
    color: var(--text-primary);
    font-weight: 600;
}

/* Courses Section */
.courses-section {
    padding: var(--section-padding);
    background-color: var(--bg-card);
    border-top: 1px solid var(--border-color);
}

.course-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(min(100%, 350px), 1fr));
    gap: 32px;
    margin-top: 50px;
}

.course-icon {
    margin-bottom: 20px;
    color: var(--text-primary);
}

.course-icon svg {
    width: 2.4rem;
    height: 2.4rem;
    display: block;
}

.course-title {
    font-size: 1.4rem;
    margin-bottom: 12px;
}

.course-desc {
    color: var(--text-secondary);
    font-size: 1rem;
}

/* Newsletter Section */
.newsletter-section {
    padding: var(--section-padding);
}

.newsletter-box {
    text-align: center;
    max-width: 800px;
    margin: 0 auto;
    padding: 60px 40px;
}

.newsletter-title {
    font-size: 2.5rem;
    margin-bottom: 16px;
}

.newsletter-desc {
    color: var(--text-secondary);
    margin-bottom: 40px;
    font-size: 1.1rem;
}

.social-follow-links {
    display: flex;
    gap: 16px;
    justify-content: center;
    flex-wrap: wrap;
}

.social-follow-btn {
    display: inline-flex;
    align-items: center;
    gap: 10px;
    padding: 14px 28px;
    border-radius: 10px;
    border: 1px solid var(--border-color);
    background-color: rgba(255, 255, 255, 0.05);
    color: var(--text-primary);
    font-family: var(--font-body);
    font-size: 1rem;
    font-weight: 500;
    transition: all var(--transition-fast);
}

.social-follow-btn .social-icon {
    width: 1.25rem;
    height: 1.25rem;
    display: block;
    flex-shrink: 0;
}

.social-follow-btn:hover {
    transform: translateY(-3px);
    box-shadow: 0 8px 24px rgba(0, 0, 0, 0.4);
}

.social-follow-btn.linkedin:hover {
    background-color: #0a66c2;
    border-color: #0a66c2;
}

.social-follow-btn.x-twitter:hover {
    background-color: #000;
    border-color: rgba(255, 255, 255, 0.25);
}

.social-follow-btn.youtube:hover {
    background-color: #ff0000;
    border-color: #ff0000;
}

/* Footer */
.footer {
    padding: 60px 0;
    border-top: 1px solid var(--border-color);
    text-align: center;
}

.footer-logo {
    font-family: var(--font-heading);
    font-weight: 800;
    font-size: 1.25rem;
    letter-spacing: 1px;
    margin-bottom: 24px;
}

.footer-socials {
    display: flex;
    justify-content: center;
    gap: 24px;
    margin-bottom: 24px;
}

.footer-socials a {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    width: 2rem;
    height: 2rem;
    color: var(--text-secondary);
}

.footer-socials svg {
    width: 1.5rem;
    height: 1.5rem;
    display: block;
}

.footer-socials a:hover {
    color: var(--text-primary);
    transform: translateY(-2px);
}

.footer-copyright {
    color: #71717a;
    font-size: 0.9rem;
}

/* Animations: only hide content when JS is available */
html.js .fade-up {
    opacity: 0;
    transform: translateY(30px);
    transition: opacity 0.8s ease, transform 0.8s ease;
}

html.js .fade-up.visible {
    opacity: 1;
    transform: translateY(0);
}

.delay-1 { transition-delay: 0.2s; }
.delay-2 { transition-delay: 0.4s; }

@media (prefers-reduced-motion: reduce) {
    html {
        scroll-behavior: auto;
    }

    html.js .fade-up,
    .card,
    .btn,
    .social-follow-btn {
        transition: none;
        transform: none;
    }

    html.js .fade-up {
        opacity: 1;
    }
}

/* Responsive Design */
@media (max-width: 900px) {
    .hero-container {
        grid-template-columns: 1fr;
        text-align: center;
        gap: 40px;
    }
    
    .hero-actions {
        justify-content: center;
    }
    
    .hero-description {
        margin: 0 auto 40px;
    }
    
    .hero-image {
        max-width: 500px;
        margin: 0 auto;
    }
    
    .about-grid {
        grid-template-columns: 1fr;
    }
    
    .about-image-wrapper {
        max-width: 500px;
        margin: 0 auto;
    }
}

@media (max-width: 768px) {
    html.js .nav-links {
        display: none;
    }
    
    html.js .mobile-menu-btn {
        display: flex;
    }

    .hero {
        padding-top: 120px;
        padding-bottom: 64px;
        min-height: auto;
    }

    .hero-actions {
        flex-wrap: wrap;
    }
    
    .hero-title {
        font-size: 2.5rem;
    }
    
    .section-title {
        font-size: 2rem;
    }
    
    .timeline::before {
        left: 0;
    }
    
    .timeline-item {
        padding-left: 30px;
    }
    
    .timeline-dot {
        left: -4px;
    }
    
    .social-follow-links {
        flex-direction: column;
        align-items: center;
    }

    .social-follow-btn {
        width: 100%;
        max-width: 280px;
        justify-content: center;
    }
}

/* Writing / posts */
.post-page {
    padding: 140px 0 80px;
}

.post-wrap,
.writing-wrap {
    max-width: 760px;
    margin: 0 auto;
    padding: 0 24px;
}

.writing-wrap {
    max-width: 860px;
}

.post-kicker,
.writing-kicker {
    display: inline-block;
    color: var(--text-secondary);
    font-size: 0.9rem;
    letter-spacing: 0.04em;
    text-transform: uppercase;
    margin-bottom: 16px;
}

.post-kicker a,
.writing-kicker a {
    color: var(--accent-hover);
}

.post-title {
    font-size: clamp(2rem, 4vw, 2.8rem);
    margin-bottom: 12px;
}

.post-date {
    color: var(--text-secondary);
    margin-bottom: 40px;
}

.post-body {
    color: var(--text-secondary);
    font-size: 1.05rem;
    line-height: 1.75;
}

.post-body p,
.post-body div,
.post-body li {
    margin-bottom: 12px;
}

.post-body a {
    color: var(--accent-hover);
    text-decoration: underline;
    text-underline-offset: 3px;
}

.post-body img {
    max-width: 100%;
    height: auto;
    border-radius: 8px;
    margin: 16px 0;
}

.post-body blockquote {
    border-left: 2px solid var(--accent-color);
    padding: 8px 0 8px 20px;
    margin: 20px 0;
    color: var(--text-primary);
}

.post-body pre,
.post-body code {
    font-family: Menlo, Monaco, Consolas, monospace;
    font-size: 0.92em;
}

.post-body table {
    width: 100%;
    border-collapse: collapse;
    margin: 24px 0;
    font-size: 0.95rem;
}

.post-body th,
.post-body td {
    border: 1px solid var(--border-color);
    padding: 10px 12px;
    vertical-align: top;
}

.post-body th {
    color: var(--text-primary);
    background: var(--bg-card);
}

.post-body ul,
.post-body ol {
    padding-left: 22px;
    margin: 12px 0 20px;
}

.post-comments {
    margin-top: 56px;
    padding-top: 32px;
    border-top: 1px solid var(--border-color);
}

.post-comments h2 {
    font-size: 1.4rem;
    margin-bottom: 24px;
}

.comment {
    background: var(--bg-card);
    border: 1px solid var(--border-color);
    border-radius: 12px;
    padding: 20px 24px;
    margin-bottom: 12px;
}

.comment-meta {
    color: var(--text-secondary);
    font-size: 0.85rem;
    margin-bottom: 8px;
}

.comment-author {
    color: var(--text-primary);
    font-weight: 600;
}

.writing-title {
    font-size: clamp(2rem, 4vw, 2.8rem);
    margin-bottom: 12px;
}

.writing-intro {
    color: var(--text-secondary);
    margin-bottom: 48px;
}

.writing-year {
    font-size: 1.4rem;
    margin: 36px 0 12px;
}

.writing-list {
    list-style: none;
    padding: 0;
}

.writing-list li {
    border-bottom: 1px solid var(--border-color);
}

.writing-list a {
    display: flex;
    gap: 16px;
    padding: 14px 0;
    color: var(--text-primary);
}

.writing-list a:hover {
    color: var(--accent-hover);
}

.writing-list time {
    flex: 0 0 150px;
    color: var(--text-secondary);
    font-size: 0.9rem;
}

@media (max-width: 768px) {
    .writing-list a {
        flex-direction: column;
        gap: 4px;
    }

    .writing-list time {
        flex: none;
    }
}