/* GENEL VE RESET */
body {
    font-family: 'Segoe UI', Tahoma, Geneva, Verdana, sans-serif;
    margin: 0;
    display: flex;
    flex-direction: column;
    min-height: 100vh;
    background-color: #f4f7f6;
    color: #333;
}

.main-container {
    display: flex;
    width: 100%;
    flex-grow: 1;
    /* HEADER boyutu kadar düşürüldü */
    height: calc(100vh - 74px);
    overflow: hidden;
}

* {
    box-sizing: border-box;
}

/* HEADER DÜZENLEMELERİ (Önceki sayfanın tasarımı korundu) */
.header {
    background-color: #fff;
    padding: 10px 40px;
    display: flex;
    justify-content: center;
    border-bottom: 2px solid #f39c12;
    box-shadow: 0 2px 4px rgba(0,0,0,0.05);
    flex-shrink: 0;
    height: 74px;
}

.header-content {
    width: 100%;
    max-width: 1400px;
    display: flex;
    justify-content: space-between;
    align-items: center;
}

.icon-svg {
    width: 22px;
    height: 22px;
    fill: currentColor;
    margin-right: 8px;
    flex-shrink: 0;
}

.logo {
    display: flex;
    align-items: center;
}

    .logo .icon-svg {
        color: #2c3e50;
        width: 30px;
        height: 30px;
        margin-right: 10px;
    }

    .logo span {
        font-size: 1.5em;
        color: #2c3e50;
        font-weight: bold;
    }

.nav-links {
    display: flex;
    align-items: center;
    list-style: none;
    padding: 0;
    margin: 0 50px;
}

    .nav-links li {
        margin: 0 15px;
    }

    .nav-links a {
        text-decoration: none;
        color: #333;
        font-size: 0.95em;
        transition: color 0.3s;
        display: flex;
        align-items: center;
        padding: 5px 0;
    }

        .nav-links a .icon-svg {
            color: #7f8c8d;
        }

        .nav-links a:hover {
            color: #f39c12;
        }

.social-menu a {
    margin-left: 10px;
    display: inline-block;
    line-height: 0;
}

    .social-menu a .icon-img {
        width: 24px;
        height: 24px;
        vertical-align: middle;
        border-radius: 4px;
        transition: opacity 0.3s;
    }

    .social-menu a:hover {
        opacity: 0.8;
    }

/* SIDEBAR VE İÇERİK STİLLERİ */
.sidebar {
    width: 340px; /* Biraz genişletildi */
    background-color: #2c3e50;
    color: #ecf0f1;
    padding: 20px;
    box-shadow: 2px 0 5px rgba(0,0,0,0.1);
    flex-shrink: 0;
    position: sticky;
    top: 0;
    overflow-y: auto;
    height: 100%;
}

    .sidebar h2 {
        color: #fff;
        text-align: center;
        margin-bottom: 20px;
        font-size: 1.6em;
        border-bottom: 2px solid #f39c12;
        padding-bottom: 10px;
    }

/* Grup Başlıkları (Seviyeler - Eskiden Accordion Trigger idi) */
.group-title {
    padding: 12px 15px;
    margin: 15px -20px 0 -20px;
    font-weight: bold;
    font-size: 1.0em;
    display: flex;
    justify-content: flex-start; /* Simgeler solda olsun */
    align-items: center;
    color: #fff;
    cursor: default; /* Artık tıklanabilir değil */
    transition: background-color 0.3s;
}

    .group-title i.fas {
        margin-right: 10px;
        font-size: 1.1em;
        /* Chevron simgesi kaldırıldı veya gizlendi */
        display: none;
    }

/* Seviye Renkleri */
.level-1 {
    background-color: #3498db; /* Temel (Mavi) */
}

.level-2 {
    background-color: #f39c12; /* Orta (Turuncu) */
    color: #333;
}

    .level-2 i {
        color: #333;
    }

.level-3 {
    background-color: #e74c3c; /* İleri (Kırmızı) */
}

.level-4 {
    background-color: #27ae60; /* Uygulama (Yeşil) */
}

.level-5 {
    background-color: #8e44ad; /* Ekstra Konular (Mor) */
}

/* Alt Menü İçeriği - Sabit Açık Yapı */
.submenu {
    padding: 0 0 0 0;
    margin-bottom: 5px;
    background-color: #34495e; /* Alt menü koyu arkaplan */
    /* Accordion için kullanılan stiller kaldırıldı: max-height: 0, overflow: hidden, transition */
}

    /* Alt Menü Alt Başlıkları */
    .submenu h4 {
        color: #bdc3c7;
        padding: 10px 15px 5px 30px;
        margin: 0;
        font-size: 0.85em;
        font-weight: bold;
        text-transform: uppercase;
    }

.menu-item {
    padding: 8px 15px 8px 30px;
    cursor: pointer;
    transition: all 0.3s ease;
    display: flex;
    align-items: flex-start;
    font-size: 0.9em;
    margin-bottom: 1px;
    border-left: 3px solid transparent;
}

    .menu-item:hover {
        background-color: #46627f;
        border-left: 3px solid #f39c12;
    }

    .menu-item.active {
        background-color: #f39c12;
        color: #333;
        font-weight: bold;
        border-left: 3px solid #c0392b;
    }

/* Bölüm Numarası */
.section-number {
    background-color: #c0392b;
    padding: 2px 6px;
    border-radius: 3px;
    margin-right: 10px;
    font-weight: bold;
    font-size: 0.85em;
    flex-shrink: 0;
    color: #fff;
}

.menu-item.active .section-number {
    background-color: #2c3e50;
    color: #fff;
}

/* İçerik Stilleri */
.content-area {
    flex-grow: 1;
    padding: 40px;
    overflow-y: auto;
}

    .content-area h1 {
        color: #2c3e50;
        border-bottom: 2px solid #bdc3c7;
        padding-bottom: 10px;
        margin-bottom: 30px;
    }

#topic-title {
    font-size: 1.5em;
    color: #f39c12;
    margin-bottom: 20px;
    font-weight: bold;
}

.content-section {
    background-color: #fff;
    padding: 25px;
    border-radius: 8px;
    box-shadow: 0 4px 10px rgba(0, 0, 0, 0.05);
    margin-bottom: 20px;
}

    .content-section h3 {
        color: #34495e;
        margin-top: 0;
        border-left: 4px solid #3498db;
        padding-left: 15px;
        margin-bottom: 20px;
    }

    /* Alt Başlıklar */
    .content-section h4 {
        color: #555;
        margin-top: 25px;
        font-weight: 600;
        border-bottom: 1px dashed #eee;
        padding-bottom: 5px;
    }

    .content-section p {
        line-height: 1.7;
        margin-bottom: 15px;
    }

    .content-section ul, .content-section ol {
        line-height: 1.6;
        padding-left: 25px;
        margin-bottom: 15px;
    }

    .content-section li {
        margin-bottom: 6px;
    }

    .content-section code {
        background-color: #ecf0f1;
        padding: 15px;
        display: block;
        white-space: pre-wrap;
        margin: 15px 0;
        border-radius: 5px;
        font-size: 0.9em;
        overflow-x: auto;
        color: #c0392b;
    }