:root {
    --background-color: #f8f9fa;
    --card-background: #ffffff;
    --primary-text-color: #212529;
    --secondary-text-color: #6c757d;
    --accent-color: #007bff;
    --border-color: #dee2e6;
    --shadow-color: rgba(0, 0, 0, 0.1);
}

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

html {
    scroll-behavior: smooth;
}

body {
    font-family: 'Poppins', sans-serif;
    background-color: var(--background-color);
    color: var(--primary-text-color);
    line-height: 1.7;
}

header {
    text-align: center;
    padding: 3rem 1rem 1rem 1rem;
    background-color: var(--card-background);
}

header h1 {
    color: var(--accent-color);
    margin-bottom: 0.5rem;
}

header p {
    max-width: 600px;
    margin: 0 auto 2rem auto;
    color: var(--secondary-text-color);
}

.header-image {
    width: 100%;
    max-width: 1200px; /* Görselin çok genişlemesini önler */
    height: 350px;
    object-fit: cover; /* Resmin orantısını korur */
    border-radius: 8px;
    margin: 0 auto;
    display: block;
}

nav {
    position: sticky;
    top: 0;
    background-color: var(--card-background);
    padding: 1rem;
    text-align: center;
    z-index: 1000;
    border-bottom: 1px solid var(--border-color);
    box-shadow: 0 2px 4px var(--shadow-color);
}

nav ul {
    list-style: none;
    display: flex;
    justify-content: center;
    flex-wrap: wrap;
    gap: 1.5rem;
}

nav a {
    text-decoration: none;
    color: var(--primary-text-color);
    font-weight: 600;
    transition: color 0.3s ease;
}

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

main {
    max-width: 900px;
    margin: 2rem auto;
    padding: 0 1rem;
}

section {
    background-color: var(--card-background);
    margin-bottom: 2rem;
    padding: 2rem;
    border-radius: 8px;
    border: 1px solid var(--border-color);
    box-shadow: 0 4px 8px var(--shadow-color);
}

section h2, section h3 {
    color: var(--accent-color);
    margin-bottom: 1rem;
    padding-bottom: 0.5rem;
    border-bottom: 1px solid var(--border-color);
}

.image-container {
    margin: 3rem 0;
    text-align: center;
}

.section-image {
    max-width: 100%;
    height: auto;
    border-radius: 8px;
    box-shadow: 0 6px 12px var(--shadow-color);
}


table {
    width: 100%;
    border-collapse: collapse;
    margin-top: 1rem;
}

th, td {
    padding: 12px 15px;
    border: 1px solid var(--border-color);
    text-align: left;
}

thead {
    background-color: #e9ecef;
}

th {
    font-weight: 600;
}

tbody tr:nth-child(even) {
    background-color: #f8f9fa;
}

footer {
    text-align: center;
    padding: 2rem;
    margin-top: 2rem;
    background-color: #e9ecef;
    border-top: 1px solid var(--border-color);
}

footer a {
    color: var(--accent-color);
    text-decoration: none;
    font-size: 1.1rem;
}

footer p {
    margin-top: 0.5rem;
    color: var(--secondary-text-color);
    font-size: 0.9rem;
}

#backToTopBtn {
    display: none;
    position: fixed;
    bottom: 20px;
    right: 20px;
    z-index: 1001;
    border: none;
    outline: none;
    background-color: var(--accent-color);
    color: white;
    cursor: pointer;
    padding: 15px;
    border-radius: 50%;
    font-size: 18px;
    width: 50px;
    height: 50px;
    box-shadow: 0 2px 5px var(--shadow-color);
    transition: background-color 0.3s, opacity 0.3s;
}

#backToTopBtn:hover {
    background-color: #0056b3;
}