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

html {
    scroll-behavior: smooth;
}

body {
    font-family: 'Inter', sans-serif;
    background: #ffffff;
    color: #222;
    line-height: 1.7;
}

/* =======================================
   NAVBAR
======================================= */
.navbar {
    width: 100%;
    background: #ffffff;
    padding: 18px 0;
    display: flex;
    justify-content: center;
    position: sticky;
    top: 0;
    z-index: 999;
    transition: box-shadow 0.3s ease;
}

.navbar.scrolled {
    box-shadow: 0 3px 10px rgba(0,0,0,0.15);
}

.nav-links {
    display: flex;
    gap: 32px;        /* Home - About - Research ... aralığı artırıldı */
    list-style: none;
}

.nav-links a {
    text-decoration: none;
    color: #222;
    font-size: 1.15rem;    /* Başlıklar büyütüldü */
    font-weight: 600;
    position: relative;
    padding-bottom: 4px;
    transition: color 0.25s ease;
}

/* MAVİ hover effect */
.nav-links a:hover {
    color: #0066cc;
}

/* MAVİ underline animation */
.nav-links a::after {
    content: "";
    position: absolute;
    bottom: -3px;
    left: 0;
    width: 0%;
    height: 2px;
    background: #0066cc;
    transition: width 0.3s ease;
}

.nav-links a:hover::after {
    width: 100%;
}

/* ACTIVE PAGE (About, Research, Publications...) */
.nav-links a.active {
    color: #0066cc;
}

.nav-links a.active::after {
    width: 100%;
}

/* =======================================
   HERO
======================================= */
.hero {
    height: 550px;
    width: 100%;
    background-image: url('image3.jpg');
    background-size: cover;
    background-position: center;
    position: relative;
    opacity: 0;
    animation: fadeIn 1.2s ease forwards;
}

/* Soft overlay */
.hero::before {
    content: "";
    position: absolute;
    top: 0; left: 0;
    width: 100%; height: 100%;
    background: linear-gradient(
        rgba(0,0,0,0.35),
        rgba(0,0,0,0.10)
    );
    z-index: 1;
}

.hero-content {
    position: absolute;
    top: 58%;
    left: 50%;
    transform: translate(-50%, -50%);
    text-align: center;
    color: white;
    z-index: 2;
}

/* Title + subtitles */
.hero-content h1 {
    font-size: clamp(2.8rem, 4vw, 3.9rem);
    font-weight: 800;
    letter-spacing: 3px;
    text-shadow: 0 5px 12px rgba(0,0,0,0.5);
}

.hero-content h3 {
    margin-top: 14px;
    font-size: 1.3rem;
}

.hero-content h4 {
    margin-top: 8px;
    font-size: 1.15rem;
    opacity: 0.95;
}

/* =======================================
   SECTION
======================================= */
.section {
    max-width: 950px;
    margin: 80px auto;
    padding: 0 20px;
}

.section h2 {
    font-size: 2rem;
    color: #003366;
    margin-bottom: 18px;
}

.btn {
    display: inline-block;
    margin-top: 25px;
    background: #003366;
    color: white;
    padding: 12px 22px;
    border-radius: 6px;
    text-decoration: none;
    font-weight: 600;
    transition: background 0.25s ease;
}

.btn:hover {
    background: #001f44;
}

/* =======================================
   FOOTER
======================================= */
footer {
    margin-top: 60px;
    text-align: center;
    padding: 25px 0;
    border-top: 1px solid #eee;
    background: #f9f9f9;
}

/* =======================================
   ANIMATIONS
======================================= */
@keyframes fadeIn {
    from { opacity: 0; }
    to   { opacity: 1; }
}

/* =======================================
   RESPONSIVE NAVBAR TEXT (ANTI-OVERFLOW)
======================================= */
@media (max-width: 1400px) {
    .nav-links a {
        font-size: 0.95rem;
    }
}

@media (max-width: 1200px) {
    .nav-links a {
        font-size: 0.88rem;
        gap: 22px;
    }
}

@media (max-width: 1000px) {
    .nav-links {
        gap: 18px;
    }
    .nav-links a {
        font-size: 0.80rem;
    }
}

/* =======================================
   HAMBURGER MENU (MOBILE)
======================================= */

.hamburger {
    display: none;
    font-size: 2rem;
    cursor: pointer;
    padding: 0 20px;
}

.mobile-menu {
    display: none;
    flex-direction: column;
    background: #ffffff;
    padding: 15px 0;
    width: 100%;
    border-bottom: 1px solid #ddd;
}

.mobile-menu a {
    padding: 12px 25px;
    text-decoration: none;
    color: #222;
    font-size: 1.05rem;
}

.mobile-menu a:hover {
    background: #f5f5f5;
}

/* Show hamburger + hide normal menu on mobile */
@media (max-width: 900px) {
    .nav-links {
        display: none;
    }
    .hamburger {
        display: block;
    }
}

/* ============================
   PAGE-SPECIFIC HERO IMAGES
============================ */

/* Home */
.hero.home {
    background-image: url('image3.jpg');
}

/* About */
.hero.about {
    background-image: url('image1.jpg');
}

/* Research */
.hero.research {
    background-image: url('image2.jpg');
}

/* Projects */
.hero.projects {
    background-image: url('image4.jpg');
}

/* Publications */
.hero.publications {
    background-image: url('image5.jpg');
}

/* News (tekrar image1 kullanıyoruz) */
.hero.news {
    background-image: url('image1.jpg');
}

/* Literature Highlights */
.hero.literature {
    background-image: url('image2.jpg');
}

/* Books & Movies */
.hero.books {
    background-image: url('image4.jpg');
}

/* People */
.hero.people {
    background-image: url('image5.jpg');
}

/* Contact */
.hero.contact {
    background-image: url('image2.jpg');
}

.profile-btn {
    display: inline-block;
    margin-top: 12px;
    padding: 8px 14px;
    background: #0077b5; /* LinkedIn blue */
    color: white;
    border-radius: 6px;
    text-decoration: none;
    font-weight: 600;
    transition: background 0.2s ease;
}

.profile-btn:hover {
    background: #005582;
}
/* =======================================
   JUSTIFY TEXT FOR ALL PARAGRAPHS
======================================= */
p {
    text-align: justify;
    text-justify: inter-word;
}

/* ================================
   MODERN TIMELINE DESIGN
================================ */

.timeline {
    position: relative;
    margin: 50px auto;
    max-width: 760px;
    padding-left: 25px;
    border-left: 3px solid #003366; /* main theme color */
}

.timeline-item {
    position: relative;
    margin-bottom: 45px;
}

.timeline-dot {
    position: absolute;
    left: -11px;
    top: 5px;
    width: 18px;
    height: 18px;
    background: #003366;
    border-radius: 50%;
    border: 3px solid #fff;
    box-shadow: 0 0 0 3px #003366;
}

.timeline-content {
    padding-left: 15px;
}

.timeline-content h3 {
    font-size: 1.35rem;
    color: #003366;
    margin-bottom: 6px;
    font-weight: 700;
}

.timeline-content p {
    margin: 0;
    color: #444;
    line-height: 1.6;
    opacity: 0.9;
}

/* Mobile Optimization */
@media (max-width: 600px) {
    .timeline {
        padding-left: 20px;
    }
    .timeline-content h3 {
        font-size: 1.2rem;
    }
}


/* YEAR HEADINGS */
.year-heading {
    margin-top: 50px;
    color: #003366;
    font-size: 1.8rem;
    font-weight: 700;
}


/* ===========================
   ACCORDION (PROJECTS PAGE)
=========================== */

.accordion {
    margin-top: 30px;
    border-radius: 8px;
}

.accordion-item {
    border: 1px solid #ddd;
    margin-bottom: 12px;
    border-radius: 6px;
    overflow: hidden;
    background: #fff;
}

.accordion-header {
    width: 100%;
    text-align: left;
    padding: 18px 16px;
    font-size: 1.15rem;
    font-weight: 600;
    background: #f5f5f5;
    color: #003366;
    border: none;
    cursor: pointer;
    outline: none;
    transition: background 0.3s ease;
}

.accordion-header:hover {
    background: #e8eef7;
}

.accordion-content {
    display: none;
    padding: 20px;
    font-size: 1rem;
    line-height: 1.7;
    color: #333;
    background: #fff;
}

.accordion-item.active .accordion-content {
    display: block;
}
.accordion-header {
    border: none;
    outline: none;
    background: #f5f5f5;
}