/* --- RESET & VARIABLES --- */
:root {
    --primary: #1B4D3E; 
    --secondary: #D4AF37; 
    --dark: #2C3E50; 
    --light: #F4F7F6; 
    --white: #ffffff;
    --font-heading: 'Playfair Display', serif; 
    --font-body: 'Lato', sans-serif; 
}

* { margin: 0; padding: 0; box-sizing: border-box; }
html { scroll-behavior: smooth; }
body { font-family: var(--font-body); color: var(--dark); line-height: 1.7; background-color: var(--white); }
.container { max-width: 1200px; margin: 0 auto; padding: 0 20px; }
a { text-decoration: none; color: inherit; transition: 0.3s; }
ul { list-style: none; }

/* --- NAVBAR & DROPDOWN --- */
.navbar {
    background: rgba(255, 255, 255, 0.98);
    padding: 1rem 0;
    position: fixed;
    width: 100%;
    top: 0;
    z-index: 1000;
    box-shadow: 0 2px 10px rgba(0,0,0,0.05);
}
.navbar .container { display: flex; justify-content: space-between; align-items: center; }
.logo { font-family: var(--font-heading); font-size: 1.5rem; font-weight: 700; color: var(--primary); letter-spacing: 1px; }
.logo span { font-size: 0.9rem; color: var(--secondary); }
.nav-links { display: flex; gap: 25px; align-items: center; }
.nav-links a { font-size: 0.9rem; font-weight: 600; text-transform: uppercase; letter-spacing: 0.5px; color: var(--dark); }
.nav-links a:hover, .nav-links a.active { color: var(--primary); }

/* Dropdown Stili */
.dropdown { position: relative; display: inline-block; }
.dropdown-content {
    display: none;
    position: absolute;
    background-color: #fff;
    min-width: 200px;
    box-shadow: 0px 8px 16px 0px rgba(0,0,0,0.1);
    z-index: 1;
    border-top: 3px solid var(--secondary);
    padding: 10px 0;
    border-radius: 0 0 5px 5px;
}
.dropdown-content a {
    color: var(--dark);
    padding: 10px 20px;
    text-decoration: none;
    display: block;
    text-transform: none; 
    font-size: 0.9rem;
}
.dropdown-content a:hover { background-color: #f1f1f1; color: var(--primary); }
.dropdown:hover .dropdown-content { display: block; }

.btn-nav { border: 1px solid var(--primary); padding: 6px 18px; border-radius: 2px; }
.btn-nav:hover { background: var(--primary); color: var(--white); }
.hamburger { display: none; }

/* --- HERO SECTION --- */
.hero {
    height: 60vh; 
    min-height: 450px; 
    background-image: url('https://images.unsplash.com/photo-1448375240586-dfd8f3f0d8db?q=80&w=1920');
    background-size: cover;
    background-position: center;
    position: relative;
    display: flex;
    align-items: center;
    color: var(--white);
    margin-top: 60px; 
    overflow: hidden;
}
.overlay { position: absolute; top: 0; left: 0; width: 100%; height: 100%; background: linear-gradient(rgba(27, 77, 62, 0.9), rgba(0, 0, 0, 0.6)); z-index: 1; }
.hero-content { position: relative; z-index: 3; max-width: 800px; padding-top: 10px; text-align: center; margin: 0 auto; } 

.hero-decor {
    position: absolute;
    z-index: 2;
    color: rgba(255, 255, 255, 0.05); 
    font-size: 25rem; 
    pointer-events: none;
}
.left-decor { left: -50px; top: 50%; transform: translateY(-50%); }
.right-decor { right: -50px; top: 50%; transform: translateY(-50%); }

.eyebrow { text-transform: uppercase; letter-spacing: 3px; font-size: 0.9rem; color: var(--secondary); margin-bottom: 0.5rem; font-weight: 700; }
.hero h1 { font-family: var(--font-heading); font-size: 3rem; line-height: 1.2; margin-bottom: 1rem; }
.tagline { font-size: 1.1rem; margin-bottom: 1.5rem; color: rgba(255,255,255,0.9); font-weight: 300; max-width: 700px; margin-left: auto; margin-right: auto; }

/* --- BUTTONS --- */
.btn { display: inline-block; padding: 10px 25px; font-weight: 600; text-transform: uppercase; font-size: 0.8rem; letter-spacing: 1px; transition: all 0.3s ease; }
.btn-primary { background: var(--secondary); color: #000; }
.btn-primary:hover { background: #fff; }
.btn-outline { border: 1px solid rgba(255,255,255,0.5); color: var(--white); margin-left: 15px; }
.btn-outline:hover { border-color: var(--white); background: rgba(255,255,255,0.1); }

/* --- SECTIONS --- */
.section { padding: 80px 0; }
.section-header { text-align: center; margin-bottom: 60px; }
.section-header h2 { font-family: var(--font-heading); font-size: 2.5rem; color: var(--primary); }
.line { width: 60px; height: 3px; background: var(--secondary); margin: 15px auto 0; }

/* Grid & Cards */
.grid-3 { display: grid; grid-template-columns: repeat(auto-fit, minmax(300px, 1fr)); gap: 30px; }
.card { background: var(--white); padding: 40px 30px; border: 1px solid #eee; transition: 0.3s; text-align: center; }
.card:hover { transform: translateY(-5px); box-shadow: 0 15px 30px rgba(0,0,0,0.05); border-top: 3px solid var(--primary); }
.card .icon { font-size: 2.5rem; color: var(--primary); margin-bottom: 20px; }
.card h3 { font-family: var(--font-heading); margin-bottom: 15px; font-size: 1.5rem; }

/* About Section & Photo */
.bg-light { background-color: var(--light); }
.split-layout { display: flex; align-items: center; gap: 60px; }
.about-text { flex: 1.2; }
.about-image { flex: 0.8; text-align: center; }

.profile-photo {
    width: 100%;
    max-width: 400px;
    border-radius: 10px;
    box-shadow: 20px 20px 0px rgba(27, 77, 62, 0.1);
    filter: grayscale(10%);
    transition: 0.3s;
}
.profile-photo:hover { filter: grayscale(0%); transform: scale(1.01); }

.lead { font-size: 1.2rem; color: var(--primary); margin-bottom: 1.2rem; font-weight: 600; }
.social-icons-big { margin-top: 25px; display: flex; gap: 15px; flex-wrap: wrap; }
.social-icons-big a {
    display: flex; align-items: center; justify-content: center;
    width: 45px; height: 45px;
    background: var(--white);
    border: 1px solid #ddd;
    color: var(--dark);
    border-radius: 50%;
    font-size: 1.2rem;
    transition: 0.3s;
}
.social-icons-big a:hover { background: var(--primary); color: var(--white); border-color: var(--primary); }

/* --- CONTACT FOOTER --- */
footer { background: var(--primary); color: var(--white); padding: 60px 0 20px; }

.contact-layout {
    display: flex;
    justify-content: space-between;
    gap: 50px;
    align-items: center;
    padding-bottom: 40px;
    border-bottom: 1px solid rgba(255,255,255,0.1);
    margin-bottom: 20px;
}

.contact-info { flex: 1; }
.contact-info h3 { font-family: var(--font-heading); font-size: 2rem; margin-bottom: 5px; }
.contact-info .role { font-size: 1.1rem; color: var(--secondary); margin-bottom: 25px; }

.info-item { display: flex; align-items: flex-start; margin-bottom: 15px; }
.info-item i { font-size: 1.2rem; color: var(--secondary); margin-right: 15px; margin-top: 5px; width: 20px; }
.info-item span { color: rgba(255,255,255,0.8); font-size: 1rem; }

.contact-map { flex: 1; width: 100%; }
.footer-bottom { text-align: center; font-size: 0.8rem; color: rgba(255,255,255,0.4); }

/* --- PUBLICATIONS (Makaleler) --- */
.pub-card {
    background: #fff;
    padding: 25px;
    border: 1px solid #eee;
    border-left: 4px solid var(--secondary);
    transition: 0.3s;
    height: 100%;
    display: flex;
    flex-direction: column;
    justify-content: space-between;
}
.pub-card:hover { transform: translateY(-3px); box-shadow: 0 10px 20px rgba(0,0,0,0.08); }
.pub-year {
    font-size: 0.85rem;
    color: #888;
    font-weight: 700;
    margin-bottom: 10px;
    display: inline-block;
    background: #f4f4f4;
    padding: 2px 8px;
    border-radius: 4px;
}
.pub-title {
    font-family: var(--font-heading);
    font-size: 1.1rem;
    color: var(--primary);
    margin-bottom: 10px;
    line-height: 1.4;
}
.pub-journal { font-style: italic; font-size: 0.9rem; color: #555; margin-bottom: 15px; }
.btn-doi {
    display: inline-block;
    font-size: 0.8rem;
    color: var(--primary);
    border: 1px solid var(--primary);
    padding: 5px 15px;
    border-radius: 20px;
    transition: 0.3s;
    text-align: center;
    width: fit-content;
}
.btn-doi:hover { background: var(--primary); color: #fff; }

/* --- PROJECTS (Projeler) --- */
.project-card {
    background: #fff;
    border-radius: 8px;
    overflow: hidden;
    box-shadow: 0 5px 15px rgba(0,0,0,0.05);
    margin-bottom: 30px;
    border: 1px solid #eee;
}
.project-header {
    background: var(--primary);
    color: #fff;
    padding: 15px 25px;
    display: flex;
    justify-content: space-between;
    align-items: center;
}
.project-body { padding: 25px; }
.project-role {
    color: var(--secondary);
    font-weight: 700;
    font-size: 0.9rem;
    text-transform: uppercase;
    margin-bottom: 10px;
    display: block;
}

/* --- TEACHING (Dersler) --- */
.course-card {
    display: flex;
    gap: 20px;
    background: #fff;
    padding: 25px;
    margin-bottom: 20px;
    border-radius: 8px;
    border: 1px solid #eee;
    align-items: flex-start;
}
.course-icon {
    font-size: 2rem;
    color: var(--secondary);
    background: rgba(27, 77, 62, 0.05);
    width: 60px;
    height: 60px;
    display: flex;
    align-items: center;
    justify-content: center;
    border-radius: 50%;
    flex-shrink: 0;
}
.course-info h3 { color: var(--primary); font-family: var(--font-heading); margin-bottom: 5px; }
.course-meta { font-size: 0.85rem; color: #666; margin-bottom: 10px; font-weight: 600; }
.course-desc { font-size: 0.95rem; color: #444; }

@media (max-width: 768px) {
    .nav-links { display: none; }
    .hamburger { display: block; font-size: 1.5rem; cursor: pointer; }
    .hero { height: auto; padding: 80px 0; }
    .hero-decor { display: none; }
    .hero h1 { font-size: 2.2rem; }
    .split-layout, .contact-layout { flex-direction: column; }
    .profile-photo { max-width: 300px; margin-top: 30px; }
    .contact-map { width: 100%; margin-top: 20px; }
    .course-card { flex-direction: column; }
}