/* 1. TEMA DEĞİŞKENLERİ (Gece/Gündüz Modu İçin) */
:root {
    --bg-color: #f8f9fa;
    --text-color: #212529;
    --card-bg: #fff;
    --border-color: #eaeaea;
}

[data-theme="dark"] {
    --bg-color: #121212;
    --text-color: #e0e0e0;
    --card-bg: #1e1e1e;
    --border-color: #333;
}

/* 2. GENEL AYARLAR */
* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}

body {
    font-family: 'Inter', sans-serif;
    background-color: var(--bg-color);
    color: var(--text-color);
    line-height: 1.6;
    transition: background-color 0.3s, color 0.3s;
}

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

/* 3. ÜST MENÜ */
.navbar {
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding-bottom: 2rem;
    border-bottom: 1px solid var(--border-color);
}

.logo {
    font-weight: 600;
    font-size: 1.5rem;
    letter-spacing: -1px;
}

.nav-links {
    list-style: none;
    display: flex;
    gap: 2rem;
    align-items: center;
}

.nav-links a {
    text-decoration: none;
    color: var(--text-color);
    font-weight: 400;
    transition: opacity 0.3s ease;
}

.nav-links a:hover {
    opacity: 0.6;
}

/* 4. HAKKIMDA  */
.hero-section {
    margin: 5rem 0;
}

.hero-section h2 {
    font-size: 2.8rem;
    margin-bottom: 1rem;
    letter-spacing: -1px;
}

.hero-section p {
    font-size: 1.15rem;
    color: var(--text-color);
    opacity: 0.8;
    margin-bottom: 2.5rem;
    max-width: 600px;
}

/* BUTON KAPSAYICISI (Yan yana düzenli dursunlar diye) */
.about-buttons {
    display: flex;
    gap: 25px; /* Butonlar arası boşluk */
    align-items: center;
    flex-wrap: wrap; /* Mobilde alt alta inmesi için */
}

/* TIPA TIP AYNI OLAN ORİJİNAL BUTON TASARIMI */
.btn {
    display: inline-block;
    padding: 0.8rem 1.8rem;
    background-color: var(--text-color);
    color: var(--bg-color);
    text-decoration: none;
    border-radius: 4px;
    font-weight: 600;
    transition: transform 0.2s ease, opacity 0.3s ease;
}

.btn:hover {
    transform: translateY(-2px);
    opacity: 0.8;
}

/* 5. PROJELER */
.projects-section {
    margin-top: 4rem;
}

.projects-section h2 {
    font-size: 1.8rem;
    margin-bottom: 2rem;
}

.project-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
    gap: 2rem;
}
/* Sabitlenmiş projelerin başlığına eklenecek minimalist detay */
.project-card.featured h3::before {
    content: '✦'; /* Minimalist 4 köşeli yıldız */
    display: inline-block;
    margin-right: 8px;
    font-size: 1rem;
    opacity: 0.5; /* Rengi biraz soluklaştırarak zarif durmasını sağladık */
    transform: translateY(-1px); /* Hizalamayı kusursuzlaştırmak için */
}
.project-card {
    background-color: var(--card-bg);
    padding: 2.5rem 2rem;
    border: 1px solid var(--border-color);
    border-radius: 6px;
    transition: transform 0.3s ease, box-shadow 0.3s ease;
}

.project-card:hover {
    transform: translateY(-5px);
    box-shadow: 0 10px 30px rgba(0,0,0,0.08);
}

.project-card h3 {
    margin-bottom: 0.8rem;
    font-size: 1.3rem;
}

.project-card p {
    color: var(--text-color);
    opacity: 0.8;
    margin-bottom: 1.5rem;
    font-size: 0.95rem;
}

.github-link {
    color: var(--text-color);
    font-weight: 600;
    text-decoration: none;
    border-bottom: 2px solid transparent;
    transition: border-color 0.3s ease;
    font-size: 0.9rem;
}

.github-link:hover {
    border-color: var(--text-color);
}

/* 6. İLETİŞİM */
.contact-section {
    margin: 8rem 0 4rem 0;
    text-align: left; 
}

.contact-section h2 {
    font-size: 1.8rem;
    margin-bottom: 1rem;
}

.contact-section p {
    color: var(--text-color);
    opacity: 0.8;
    margin-bottom: 2.5rem;
    max-width: 600px;
    font-size: 1.05rem;
}

/* Gündüz Modunda Siyah Mail Linki */
.contact-link {
    font-size: 1.2rem;
    color: #000;
    text-decoration: none;
    font-weight: 700;
    border-bottom: 2px solid #000;
    padding-bottom: 5px;
    transition: opacity 0.3s ease;
}

.contact-link:hover {
    opacity: 0.6;
}

/* Gece Modunda Beyaz Mail Linki */
[data-theme="dark"] .contact-link {
    color: #fff;
    border-bottom: 2px solid #fff;
}

/* 7. MOBİL  */
@media (max-width: 768px) {
   
    html, body {
        overflow-x: hidden; 
    }

    header, main, footer {
        padding: 1.5rem 1rem; 
    }

    .navbar {
        flex-direction: column;
        gap: 1rem;
    }

    .nav-links {
        flex-wrap: wrap; 
        justify-content: center; 
        gap: 1rem; 
        width: 100%;
    }

    .hero-section {
        margin: 3rem 0; 
    }

    .hero-section h2 {
        font-size: 2rem;
    }

    .project-grid {
        grid-template-columns: 1fr; 
        gap: 1.5rem;
    }

    .project-card {
        padding: 1.5rem; 
    }
}

/* 8. TEMA DEĞİŞTİRME ANAHTARI (TOGGLE SWITCH) */
.theme-switch {
    display: inline-block;
    position: relative;
    width: 46px;
    height: 24px;
    cursor: pointer;
}

.theme-switch input {
    opacity: 0;
    width: 0;
    height: 0;
}

.slider {
    position: absolute;
    cursor: pointer;
    top: 0; left: 0; right: 0; bottom: 0;
    background-color: transparent;
    border: 2px solid var(--text-color);
    border-radius: 24px;
    transition: 0.3s;
}

.slider:before {
    position: absolute;
    content: "";
    height: 14px;
    width: 14px;
    left: 3px;
    bottom: 3px;
    background-color: var(--text-color);
    border-radius: 50%;
    transition: 0.3s;
}

input:checked + .slider:before {
    transform: translateX(22px);
    /* Gündüz topunu Gece Hilaline çeviren CSS sihri */
    background-color: transparent;
    box-shadow: inset -4px -4px 0 0 var(--text-color);
}