:root {
    --bg-color: #f1f5f9;
    --card-bg: #ffffff;
    --text-main: #1e293b;
    --text-muted: #64748b;
    --border-color: #e2e8f0;
    --primary: #4f46e5;
    --primary-hover: #4338ca;
    --accent: #06b6d4;
    --danger: #ef4444;
    --success: #10b981;
    --shadow: 0 10px 15px -3px rgba(0, 0, 0, 0.05), 0 4px 6px -4px rgba(0, 0, 0, 0.05);
    --radius: 12px;
}

[data-theme="dark"] {
    --bg-color: #0b0f19;
    --card-bg: #111827;
    --text-main: #f3f4f6;
    --text-muted: #9ca3af;
    --border-color: #1f2937;
    --primary: #6366f1;
    --primary-hover: #4f46e5;
    --accent: #22d3ee;
    --shadow: 0 10px 15px -3px rgba(0, 0, 0, 0.3);
}

* { box-sizing: border-box; margin: 0; padding: 0; font-family: 'Inter', 'Segoe UI', system-ui, sans-serif; }
body { background-color: var(--bg-color); color: var(--text-main); transition: background 0.3s ease, color 0.3s ease; min-height: 100vh; line-height: 1.5; overflow-x: hidden; }

/* Modern Üst Menü (Responsive Navbar) */
header { background: var(--card-bg); border-bottom: 1px solid var(--border-color); padding: 0 25px; height: 75px; display: flex; justify-content: space-between; align-items: center; position: sticky; top: 0; z-index: 1000; box-shadow: 0 4px 6px -1px rgba(0,0,0,0.02); }
.logo h3 a { color: var(--text-main); text-decoration: none; font-weight: 800; font-size: 20px; letter-spacing: -0.5px; background: linear-gradient(135deg, var(--primary), var(--accent)); -webkit-background-clip: text; -webkit-text-fill-color: transparent; }

nav { display: flex; align-items: center; gap: 6px; }
nav a { color: var(--text-muted); text-decoration: none; padding: 8px 12px; border-radius: 8px; font-weight: 600; font-size: 14px; transition: all 0.2s; white-space: nowrap; }
nav a:hover { color: var(--primary); background: rgba(79, 70, 229, 0.05); }

/* Mobil Hamburger Butonu (Varsayılan gizli) */
.menu-toggle { display: none; background: none; border: none; font-size: 24px; cursor: pointer; color: var(--text-main); padding: 5px; }

/* İçerik Düzeni ve Esnek Konteyner */
.container { max-width: 1100px; margin: 30px auto; padding: 0 15px; width: 100%; }
.card { background: var(--card-bg); border: 1px solid var(--border-color); border-radius: var(--radius); padding: 22px; margin-bottom: 20px; box-shadow: var(--shadow); width: 100%; overflow: hidden; }

/* Butonlar ve Form Elemanları (Esnek) */
button, .btn { background: var(--primary); color: white; border: none; padding: 10px 18px; border-radius: 8px; cursor: pointer; font-weight: 600; font-size: 14px; text-decoration: none; display: inline-flex; align-items: center; justify-content: center; gap: 8px; transition: background 0.2s, transform 0.1s; white-space: nowrap; }
button:hover, .btn:hover { background: var(--primary-hover); transform: translateY(-1px); }
.btn-danger { background: var(--danger); }
.btn-success { background: var(--success); }

input, textarea, select { width: 100%; padding: 12px 14px; margin: 6px 0 15px 0; border: 1px solid var(--border-color); border-radius: 8px; background: var(--bg-color); color: var(--text-main); font-size: 14px; outline: none; transition: border-color 0.2s; }
input:focus, textarea:focus, select:focus { border-color: var(--primary); box-shadow: 0 0 0 3px rgba(79, 70, 229, 0.15); }

.flex-row { display: flex; gap: 20px; width: 100%; }
.flex-col { flex: 1; }
.badge { background: rgba(79, 70, 229, 0.1); color: var(--primary); padding: 4px 10px; border-radius: 20px; font-size: 12px; font-weight: 700; display: inline-block; }

/* Bildirim Menüsü (Dropdown) */
.notification-wrapper { position: relative; display: inline-block; }
.notification-badge { background: var(--danger); color: white; border-radius: 50%; padding: 2px 6px; font-size: 10px; position: absolute; top: 2px; right: 2px; font-weight: bold; }
.dropdown-menu { display: none; position: absolute; right: 0; top: 45px; background: var(--card-bg); border: 1px solid var(--border-color); width: 280px; box-shadow: 0 20px 25px -5px rgba(0, 0, 0, 0.1); border-radius: var(--radius); z-index: 1000; padding: 15px; max-height: 350px; overflow-y: auto; }
.notification-wrapper:hover .dropdown-menu { display: block; }
.notif-item { padding: 8px 0; border-bottom: 1px solid var(--border-color); font-size: 13px; }
.notif-item:last-child { border-bottom: none; }

/* Haber ve Blog Siteleri Yatay Liste Tasarımı */
.news-list-container { display: flex; flex-direction: column; gap: 15px; margin-top: 15px; }
.news-item-card { display: flex; gap: 18px; background: var(--card-bg); border: 1px solid var(--border-color); border-radius: var(--radius); overflow: hidden; box-shadow: var(--shadow); transition: transform 0.2s; }
.news-item-card:hover { transform: translateY(-2px); }
.news-item-img { width: 220px; min-width: 220px; height: 150px; object-fit: cover; }
.news-item-body { padding: 15px 18px 15px 0; flex: 1; display: flex; flex-direction: column; justify-content: space-between; }
.news-item-title { font-size: 17px; font-weight: 700; margin: 6px 0; line-height: 1.35; }
.news-item-title a { color: var(--text-main); text-decoration: none; }
.news-item-title a:hover { color: var(--primary); }
.news-item-excerpt { font-size: 13.5px; color: var(--text-muted); line-height: 1.45; margin-bottom: 8px; }
.news-item-meta { font-size: 12px; color: var(--text-muted); display: flex; align-items: center; gap: 12px; flex-wrap: wrap; }

/* =========================================================
   MOBİL VE TABLET UYUMLULUK (RESPONSIVE BREAKPOINTS)
   ========================================================= */
@media (max-width: 900px) {
    header { padding: 0 15px; height: 65px; }
    .menu-toggle { display: block; }
    
    /* Mobil Menü Açılır / Kapanır Yapı */
    nav { 
        display: none; 
        flex-direction: column; 
        position: absolute; 
        top: 65px; 
        left: 0; 
        width: 100%; 
        background: var(--card-bg); 
        border-bottom: 1px solid var(--border-color); 
        padding: 15px 20px; 
        box-shadow: 0 10px 15px -3px rgba(0,0,0,0.1); 
        align-items: flex-start;
        gap: 12px;
    }
    nav.active { display: flex; }
    nav a { width: 100%; padding: 10px; border-radius: 6px; }
    
    .flex-row { flex-direction: column; gap: 15px; }
    
    /* Haber Kartları Mobilde Dikey Olur */
    .news-item-card { flex-direction: column; }
    .news-item-img { width: 100%; height: 180px; min-width: unset; }
    .news-item-body { padding: 15px; }
}

@media (max-width: 480px) {
    .container { padding: 0 10px; margin: 15px auto; }
    .card { padding: 15px; }
    .logo h3 a { font-size: 18px; }
}

/* Akış Medya Standart Boyutlandırma (Maksimum 350px Yükseklik) */
.feed-media-wrapper { 
    margin-top: 12px; 
    border-radius: var(--radius); 
    overflow: hidden; 
    max-height: 350px; 
    background: #000; 
    display: flex; 
    justify-content: center; 
    align-items: center; 
    cursor: pointer; 
    border: 1px solid var(--border-color); 
}
.feed-media-wrapper img, .feed-media-wrapper video { 
    width: 100%; 
    height: 350px; 
    object-fit: cover; 
    transition: transform 0.2s; 
}
.feed-media-wrapper img:hover { 
    transform: scale(1.02); 
}

/* Sosyal Medya Tarzı Tam Ekran Önizleme (Lightbox Modal) */
.lightbox-modal { 
    display: none; 
    position: fixed; 
    z-index: 9999; 
    top: 0; 
    left: 0; 
    width: 100%; 
    height: 100%; 
    background: rgba(0, 0, 0, 0.85); 
    backdrop-filter: blur(5px); 
    justify-content: center; 
    align-items: center; 
    padding: 20px; 
}
.lightbox-modal.active { 
    display: flex; 
}
.lightbox-content { 
    max-width: 90%; 
    max-height: 90%; 
    border-radius: 8px; 
    box-shadow: 0 25px 50px -12px rgba(0, 0, 0, 0.5); 
    object-fit: contain; 
}
.lightbox-close { 
    position: absolute; 
    top: 20px; 
    right: 30px; 
    color: #fff; 
    font-size: 36px; 
    font-weight: bold; 
    cursor: pointer; 
    background: rgba(0, 0, 0, 0.5); 
    width: 45px; 
    height: 45px; 
    border-radius: 50%; 
    display: flex; 
    align-items: center; 
    justify-content: center; 
    transition: background 0.2s; 
}
.lightbox-close:hover { 
    background: rgba(255, 255, 255, 0.2); 
}
/* Mobil Cihazlar İçin Medya Boyutlandırma ve Lightbox Optimizasyonu */
@media (max-width: 768px) {
    .feed-media-wrapper {
        max-height: 280px; /* Mobilde dikey alanı çok kaplamaması için biraz daha kompakt */
    }
    .feed-media-wrapper img, .feed-media-wrapper video {
        height: 280px;
    }
    
    /* Mobilde Lightbox Kapatma Butonu ve Görsel Konumu */
    .lightbox-close {
        top: 10px;
        right: 15px;
        width: 40px;
        height: 40px;
        font-size: 30px;
    }
    .lightbox-content {
        max-width: 95%;
        max-height: 85vh;
    }
}