/* style.css */
:root {
    --ana-renk: #0f172a; /* Gece Mavisi */
    --ikinci-renk: #1e293b; /* Koyu Gri/Lacivert */
    --metin-renk: #f8fafc; /* Açık Gri/Beyaz */
    --vurgu-renk: #3b82f6; /* Elektrik Mavisi */
    --hover-renk: #2563eb;
    --celik-gri: #64748b;
    --acik-gri: #f1f5f9;
}

* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
    font-family: 'Segoe UI', Tahoma, Geneva, Verdana, sans-serif;
}

body {
    background-color: var(--acik-gri);
    color: #333;
    line-height: 1.6;
    display: flex;
    flex-direction: column;
    min-height: 100vh;
}

/* --- HEADER --- */
header {
    background-color: var(--ana-renk);
    padding: 20px 5%;
    display: flex;
    justify-content: space-between;
    align-items: center;
    position: sticky;
    top: 0;
    z-index: 100;
    box-shadow: 0 2px 10px rgba(0,0,0,0.1);
}

.logo {
    color: var(--metin-renk);
    font-size: 24px;
    font-weight: bold;
    text-decoration: none;
}
.logo span { color: var(--vurgu-renk); }

nav ul {
    list-style: none;
    display: flex;
    gap: 25px;
}
nav ul li a {
    color: var(--metin-renk);
    text-decoration: none;
    font-size: 16px;
    transition: color 0.3s;
}
nav ul li a:hover, nav ul li a.aktif { color: var(--vurgu-renk); }

/* --- ORTAK BUTONLAR & FORMLAR --- */
.btn-primary {
    background-color: var(--vurgu-renk);
    color: white;
    padding: 15px 30px;
    border: none;
    border-radius: 5px;
    font-size: 16px;
    font-weight: bold;
    cursor: pointer;
    text-decoration: none;
    transition: background 0.3s;
}
.btn-primary:hover { background-color: var(--hover-renk); }

/* --- SAYFA BAŞLIKLARI --- */
.sayfa-baslik {
    background-color: var(--ikinci-renk);
    color: white;
    text-align: center;
    padding: 60px 20px;
    border-bottom: 4px solid var(--vurgu-renk);
}

/* --- İÇERİK KONTEYNERLERİ --- */
.kapsayici {
    max-width: 1200px;
    margin: 50px auto;
    padding: 0 5%;
    flex: 1;
}

/* --- FOOTER --- */
footer {
    background-color: var(--ana-renk);
    color: #cbd5e1;
    text-align: center;
    padding: 30px 5%;
    margin-top: auto;
    border-top: 1px solid #334155;
}

/* Mobil Uyumluluk */
@media (max-width: 768px) {
    header { flex-direction: column; gap: 15px; }
}