/* =========================================
   1. DEĞİŞKENLER & TEMEL AYARLAR
   ========================================= */
:root {
    --primary-text-color: #ffffff;

    --cta-background-color: rgba(255, 255, 255, 0.1);
    --cta-hover-background-color: rgba(255, 255, 255, 0.25);
    /* Gölge daha doğal ve yumuşak hale getirildi */
    --text-shadow: 0 4px 8px rgba(0, 0, 0, 0.01);
    --safe-bottom: env(safe-area-inset-bottom, 20px);
}

*, *::before, *::after { 
    box-sizing: border-box; 
}

body {
    margin: 0;
    padding: 0;
    font-family: 'Inter', -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, Helvetica, Arial, sans-serif;
    color: var(--primary-text-color);
    background-color: #5BA3E6;
    /* Masaüstü (Varsayılan) Arka Plan Ayarları - Gradient Karartma Eklendi */
    background-image: 
        linear-gradient(to bottom, rgba(45, 90, 175, 1) 0%, transparent 70%),
        url('website-background-desktop.jpg');
    background-size: 100% 100%, cover;
    background-position: center top, center center;
    background-repeat: no-repeat, no-repeat;
    background-attachment: fixed;
    
    overflow: hidden;
    -webkit-font-smoothing: antialiased;
    -moz-osx-font-smoothing: grayscale;
}

/* =========================================
   2. HEADER & LOGO
   ========================================= */
.header {
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    /* Çentik olan cihazlar için güvenli alan boşluğu */
    padding: max(3rem, env(safe-area-inset-top)) 6rem 3rem 6rem;
    display: flex;
    justify-content: space-between;
    align-items: center;
    z-index: 100;
}

.logo {
   pointer-events: none;
    width: 240px;
    max-width: 80vw;
    height: auto;
 /*    filter: invert(0); */
    display: block;
}
/* =========================================
   3. ANA İÇERİK (TYPOGRAPHY & LAYOUT)
   ========================================= */
.main-content {
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 100dvh;
    display: flex;
    align-items: center;
    justify-content: flex-start;
    padding: 0 2rem 0 6rem;
    z-index: 10;
}

.text-container {
    max-width: 65%;
    display: flex;
    flex-direction: column;
    gap: 1.5rem;
    text-shadow: var(--text-shadow);
}

.main-headline {
    font-size: clamp(2rem, 4vw, 3.8rem);
    font-weight: 700;
    line-height: 1.1;
    margin: 0;
    letter-spacing: -0.02em;
    transition: opacity 0.2s ease;
}

.sub-headline {
    font-size: clamp(1.1rem, 1.5vw, 1.4rem);
    font-weight: 400;
    line-height: 1.6;
    margin: 0;
    max-width: 90%;
    opacity: 0.95;
    transition: opacity 0.2s ease;
}

/* =========================================
   4. BUTONLAR
   ========================================= */
.btn {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    text-decoration: none;
    color: var(--primary-text-color);
    border: 1px solid rgba(255, 255, 255, 0.8);
    border-radius: 50px;
    background-color: var(--cta-background-color);
    backdrop-filter: blur(10px);
    -webkit-backdrop-filter: blur(10px);
    font-weight: 500;
    cursor: pointer;
    transition: all 0.3s ease;
    outline: none;
}

.btn:hover, .btn:focus-visible {
    background-color: var(--cta-hover-background-color);
}

.cta-button {
    align-self: flex-start;
    padding: 1.1rem 2.5rem;
    font-size: 1.1rem;
    margin-top: 0.5rem;
    transition: all 0.3s ease, opacity 0.2s ease;
}

.lang-toggle {
    padding: 0.5rem 1.2rem;
    font-size: 0.9rem;
    background: rgba(0, 0, 0, 0.2);
    border: 1px solid rgba(255, 255, 255, 0.4);
    /* iOS soluklaştırma sorununa karşı eklendi */
    color: #ffffff !important; 
    -webkit-text-fill-color: #ffffff;
    opacity: 1;
}

/* =========================================
   5. FOOTER
   ========================================= */
.footer {
    position: fixed;
    bottom: 0;
    left: 0;
    width: 100%;
    padding: 2rem 6rem;
    display: flex;
    justify-content: space-between;
    background: linear-gradient(to top, rgba(0, 0, 0, 0.7) -50%, transparent 100%);
    z-index: 100;
}

.footer a {
    color: var(--primary-text-color);
    text-decoration: none;
    font-size: 1.1rem;
    font-weight: 500;
    border-bottom: 1px solid var(--primary-text-color);
    padding-bottom: 3px;
    transition: opacity 0.3s ease;
}

.footer a:hover, .footer a:focus-visible {
    opacity: 0.7;
}

/* =========================================
   6. RESPONSIVE TASARIM (TABLET & MOBİL)
   ========================================= */

/* Tablet & Küçük Masaüstü */
@media (max-width: 1024px) {
    .header { 
        padding: max(2rem, env(safe-area-inset-top)) 2rem 2rem 2rem; 
    }
    .footer { padding: 2rem; }
    .main-content { padding: 0 2rem; }
    .text-container { max-width: 100%; }
}

/* Mobil Görünüm (Dikey - Portrait) */
@media (max-width: 768px) {
    body {
        /* iOS fixed bug'ını çözmek ve gradient eklemek için güncellendi */
        background-attachment: scroll; 
        background-color: rgba(45, 90, 175, 1);
        background-image: 
            linear-gradient(to bottom, rgba(45, 90, 175, 1) 0%, transparent 70%),
            url('website-background-p1.jpg');
        
        background-position: center top, center bottom;
        background-size: 100% 100%, cover;
        overflow-y: auto;
        overflow-x: hidden;
    }
    
    .header {
        /* Çentik alanı için güvenli boşluk */
        padding: max(1.5rem, env(safe-area-inset-top)) 1.5rem 1.5rem 1.5rem;
        justify-content: center;
    }
    
    .logo { width: 170px; }
    
    .lang-toggle {
        position: absolute;
        right: 1.5rem;
        /* Çentiğe göre buton hizalamasını güvenli alana kaydırmak için */
        top: max(50%, calc(env(safe-area-inset-top) + 20px));
        transform: translateY(-50%);
    }

    .main-content {
        position: relative;
        height: auto;
        min-height: 100dvh;
        padding: 120px 1.5rem 240px 1.5rem; 
        justify-content: center;
    }

    .text-container {
        align-items: center;
        text-align: center;
        gap: 1.2rem;
    }

    .sub-headline { max-width: 100%; }
    
    .cta-button {
        align-self: center;
        width: 100%;
        max-width: 320px;
        padding: 1.2rem;
        margin-top: 1rem;
    }
    
    .footer {
        padding: 1.5rem;
        padding-bottom: calc(1rem + var(--safe-bottom));
        justify-content: space-around;
        background: linear-gradient(to top, rgba(0, 0, 0, 0.85) 0%, transparent 100%);
    }
    
    .footer a { font-size: 1rem; }
}

/* Mobil Görünüm (Yatay - Landscape Ekran Döndürme Durumu) */
@media (max-height: 500px) and (orientation: landscape) {
    .header { padding: max(1rem, env(safe-area-inset-top)) 2rem 1rem 2rem; }
    .logo { width: 150px; }
    .lang-toggle { right: 2rem; top: 50%; }
    
    .main-content {
        padding: 70px 2rem 60px 2rem;
        min-height: 100dvh;
    }
    
    .text-container {
        flex-direction: row;
        align-items: center;
        text-align: left;
        gap: 2rem;
    }
    
    .sub-headline { display: none; }
    
    .cta-button {
        margin: 0;
        padding: 0.8rem 1.5rem;
        width: auto;
    }
    
    .footer { padding: 1rem 2rem; }
}