:root {
    --bg-color: #fcfcfc;
    --text-primary: #111827;
    --text-secondary: #4b5563;
    --text-tertiary: #9ca3af;
    --border-color: #e5e7eb;
    --accent-color: #2563eb;
    --surface-bg: #ffffff;

    --font-sans: 'Inter', -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, Helvetica, Arial, sans-serif;
    --font-serif: 'Merriweather', Georgia, "Times New Roman", serif;
}

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

html {
    scroll-behavior: smooth;
    font-size: 16px;
}

body {
    background-color: var(--bg-color);
    color: var(--text-primary);
    font-family: var(--font-sans);
    line-height: 1.7;
    -webkit-font-smoothing: antialiased;
    -moz-osx-font-smoothing: grayscale;
}

/* Layout */
.layout-wrapper {
    max-width: 1100px;
    margin: 0 auto;
    display: flex;
    flex-wrap: wrap;
    min-height: 100vh;
}

/* Sidebar */
.sidebar {
    width: 320px;
    padding: 4rem 2rem 2rem 2rem;
    position: sticky;
    top: 0;
    height: 100vh;
    border-right: 1px solid var(--border-color);
    display: flex;
    flex-direction: column;
}

.profile-container {
    margin-bottom: 3rem;
}

.profile-img {
    width: 120px;
    height: 120px;
    border-radius: 50%;
    object-fit: cover;
    margin-bottom: 1.5rem;
    border: 1px solid var(--border-color);
}

.name {
    font-family: var(--font-serif);
    font-size: 1.5rem;
    font-weight: 700;
    margin-bottom: 0.2rem;
    color: var(--text-primary);
}

.title {
    font-size: 0.95rem;
    color: var(--text-secondary);
    margin-bottom: 1.5rem;
    font-weight: 400;
}

.contact-info {
    display: flex;
    flex-direction: column;
    gap: 0.8rem;
}

.contact-info a {
    display: inline-flex;
    align-items: center;
    gap: 0.8rem;
    color: var(--text-secondary);
    text-decoration: none;
    font-size: 0.9rem;
    transition: color 0.2s;
}

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

.contact-info i {
    width: 16px;
    color: var(--text-tertiary);
}

.sidebar-nav ul {
    list-style: none;
    display: flex;
    flex-direction: column;
    gap: 1rem;
}

.sidebar-nav a {
    text-decoration: none;
    color: var(--text-secondary);
    font-size: 0.95rem;
    font-weight: 500;
    transition: all 0.2s;
    position: relative;
    padding-left: 1rem;
    display: block;
}

.sidebar-nav a::before {
    content: '';
    position: absolute;
    left: 0;
    top: 50%;
    transform: translateY(-50%);
    width: 2px;
    height: 0;
    background-color: var(--accent-color);
    transition: height 0.2s;
}

.sidebar-nav a:hover,
.sidebar-nav a.active {
    color: var(--text-primary);
}

.sidebar-nav a:hover::before,
.sidebar-nav a.active::before {
    height: 100%;
}

/* Main Content */
.content {
    flex: 1;
    padding: 4rem;
    max-width: 100%;
    overflow-x: hidden;
}

.blog-section {
    margin-bottom: 5rem;
}

.section-title {
    font-family: var(--font-serif);
    font-size: 2rem;
    font-weight: 700;
    margin-bottom: 2rem;
    color: var(--text-primary);
    border-bottom: 2px solid var(--border-color);
    padding-bottom: 0.5rem;
    display: inline-block;
}

/* Typography & Prose */
.prose {
    font-family: var(--font-serif);
    font-size: 1.1rem;
    color: var(--text-secondary);
    max-width: 650px;
}

.prose p {
    margin-bottom: 1.5rem;
}

/* Expertise / Areas Grid */
.expertise-grid {
    display: flex;
    flex-direction: column;
    gap: 0.8rem;
    max-width: 800px;
}

.expertise-item {
    display: flex;
    align-items: center;
    gap: 1rem;
    background-color: #f9fafb;
    padding: 0.6rem 1.2rem;
    border-radius: 8px;
    border: 1px solid var(--border-color);
    transition: all 0.2s ease;
}

.expertise-item:hover {
    border-color: var(--accent-color);
    transform: translateY(-2px);
    box-shadow: 0 4px 12px rgba(0, 0, 0, 0.05);
}

.expertise-item i {
    color: var(--accent-color);
    font-size: 1.1rem;
}

.expertise-item .tse-icon {
    width: 22px;
    height: 22px;
    object-fit: cover;
    border-radius: 50%;
}

.expertise-item span {
    font-weight: 500;
    font-size: 1rem;
    color: var(--text-primary);
    line-height: 1.4;
}

/* Timeline (CV style) */
.timeline {
    position: relative;
    max-width: 700px;
}

.timeline-item {
    display: flex;
    align-items: flex-start;
    margin-bottom: 3rem;
    position: relative;
}

.timeline-meta {
    display: none;
    /* Tarih alanını tamamen gizliyoruz */
}

.timeline-meta .date {
    font-size: 0.85rem;
    color: var(--text-tertiary);
    font-weight: 500;
    text-transform: uppercase;
    letter-spacing: 0.05em;
}

/* Sertifika kurum logoları eklentileri */
.cert-logo {
    width: 60px;
    height: 60px;
    object-fit: contain;
    border-radius: 6px;
    background-color: #fff;
    padding: 4px;
    border: 1px solid var(--border-color);
    margin-right: 20px;
    flex-shrink: 0;
}

.timeline-content {
    flex: 1;
    /* border-left ve padding-left kaldırılarak tam sola yaslandı */
    position: relative;
    padding-top: 5px;
    /* Logo üst hizası ile eşitlemek için */
}

.timeline-content h3 {
    font-size: 1.2rem;
    margin-bottom: 0.2rem;
    font-weight: 600;
}

.timeline-content .company {
    display: block;
    font-size: 0.95rem;
    color: var(--accent-color);
    margin-bottom: 1rem;
    font-weight: 500;
}

.timeline-content p {
    color: var(--text-secondary);
    font-size: 0.95rem;
}

/* Articles / Projects Grid */
.articles-grid {
    display: grid;
    grid-template-columns: 1fr;
    gap: 2.5rem;
    max-width: 700px;
}

.blog-card {
    padding-bottom: 2rem;
    border-bottom: 1px solid var(--border-color);
}

.blog-card:last-child {
    border-bottom: none;
}

.article-meta {
    margin-bottom: 0.8rem;
    display: flex;
    gap: 1rem;
    align-items: center;
}

.article-meta .tag {
    font-size: 0.75rem;
    background-color: #f3f4f6;
    color: var(--text-secondary);
    padding: 0.2rem 0.6rem;
    border-radius: 4px;
    text-transform: uppercase;
    font-weight: 600;
}

.article-meta .date {
    font-size: 0.85rem;
    color: var(--text-tertiary);
}

.blog-card h3 {
    font-family: var(--font-serif);
    font-size: 1.4rem;
    margin-bottom: 0.8rem;
    line-height: 1.4;
}

.blog-card p {
    color: var(--text-secondary);
    margin-bottom: 1.2rem;
    font-size: 0.95rem;
}

.read-more {
    color: var(--accent-color);
    text-decoration: none;
    font-weight: 500;
    font-size: 0.9rem;
    transition: transform 0.2s;
    display: inline-block;
}

.read-more:hover {
    transform: translateX(4px);
}

/* References / Marquee */
.references-section {
    margin: 4rem 0 5rem 0;
    max-width: 800px;
}

.marquee-wrapper {
    overflow: hidden;
    white-space: nowrap;
    position: relative;
    width: 100%;
    display: flex;
    background-color: #ffffff;
    border-radius: 12px;
    padding: 2rem 0;
    border: 1px solid var(--border-color);
}

.marquee-content {
    display: inline-flex;
    align-items: center;
    animation: scroll 25s linear infinite;
}

.marquee-wrapper:hover .marquee-content {
    animation-play-state: paused;
}

.ref-item {
    width: 400px;
    min-width: 400px;
    display: flex;
    flex-direction: column;
    justify-content: center;
    align-items: center;
    gap: 1rem;
    transition: all 0.3s;
}

.ref-item:hover {
    transform: scale(1.05);
}

.ref-item img {
    height: 120px;
    max-width: 90%;
    object-fit: contain;
}

.ref-item span {
    display: block;
    width: 100%;
    text-align: center;
    font-size: 1.1rem;
    font-weight: 600;
    color: var(--text-secondary);
    font-family: var(--font-sans);
    margin-top: 0.5rem;
}

@keyframes scroll {
    0% {
        transform: translateX(0);
    }

    100% {
        transform: translateX(-50%);
    }
}

.ref-item:hover {
    transform: scale(1.05);
}

.ref-item img {
    height: 60px;
    max-width: 80%;
    object-fit: contain;
}

/* Responsive */
@media (max-width: 900px) {
    .layout-wrapper {
        flex-direction: column;
    }

    .sidebar {
        width: 100%;
        height: auto;
        position: relative;
        border-right: none;
        border-bottom: 1px solid var(--border-color);
        padding: 3rem 2rem;
        align-items: center;
        text-align: center;
    }

    .contact-info {
        align-items: center;
    }

    .sidebar-nav ul {
        flex-direction: row;
        justify-content: center;
        flex-wrap: wrap;
    }

    .sidebar-nav a::before {
        bottom: -5px;
        top: auto;
        left: 50%;
        transform: translateX(-50%);
        width: 0;
        height: 2px;
        transition: width 0.2s;
    }

    .sidebar-nav a:hover::before,
    .sidebar-nav a.active::before {
        width: 20px;
        height: 2px;
    }

    .sidebar-nav a {
        padding-left: 0;
    }

    .content {
        padding: 3rem 2rem;
        border-top: none;
    }

    .timeline-item {
        flex-direction: column;
        gap: 0.5rem;
    }

    .timeline-meta {
        display: none;
    }

    .timeline-content {
        padding-left: 0;
        margin-left: 0;
    }
}