document.addEventListener("DOMContentLoaded", function() {
    const styleId = 'eltek-custom-style';
    let themeInterval;

    function applyTheme() {
        const isAuthPage = window.location.pathname === '/' || 
                           window.location.pathname.includes('sign-in') || 
                           window.location.pathname.includes('sign-up');

        if (isAuthPage) {
            if (!document.getElementById(styleId)) {
                const style = document.createElement('style');
                style.id = styleId;
                style.innerHTML = `
                    /* 1. ARKA PLAN: Sadece body'ye veriyoruz, böylece z-index sorunu yaratmıyor */
                    body {
                        background-image: url('/eltek-assets/Login_Screen_Background.png') !important;
                        background-size: cover !important;
                        background-position: center !important;
                        background-repeat: no-repeat !important;
                        background-attachment: fixed !important;
                        background-color: #0f172a !important; 
                    }
                    
                    /* 2. BEYAZ KATMANLARI ŞEFFAFLAŞTIR: Arka planın önünü kapatan tüm perdeleri kaldırıyoruz */
                    #__next, #__next > div, main, [class*="layout_auth"], [class*="bg-"] {
                        background: transparent !important;
                        background-color: transparent !important;
                    }
                    
                    /* 3. Form Dışı Yazıları Beyaz Yap */
                    main, [class*="layout_auth"] {
                        color: #ffffff !important;
                    }
                    /* Linkleri ELTEK Yeşili Yap */
                    main a, [class*="layout_auth"] a {
                        color: #95bd22 !important; 
                        text-decoration: none !important;
                        font-weight: bold !important;
                    }
                    main a:hover, [class*="layout_auth"] a:hover {
                        text-decoration: underline !important;
                    }
                    
                    /* 4. GİRİŞ KUTUSU */
                    form {
                        background: rgba(20, 30, 45, 0.85) !important;
                        backdrop-filter: blur(12px) !important;
                        border-radius: 12px !important;
                        padding: 2.5rem !important;
                        box-shadow: 0 10px 40px rgba(0, 0, 0, 0.8) !important;
                        border: 1px solid rgba(255, 255, 255, 0.1) !important;
                        width: 100% !important;
                        box-sizing: border-box !important;
                    }

                    form h1, form h2, form h3, form p, form span, form label, form div {
                        color: #ffffff !important;
                    }
                    
                    /* 5. EMAIL VE ŞİFRE INPUTLARI */
                    form input {
                        background-color: rgba(0, 0, 0, 0.4) !important; 
                        color: #ffffff !important; 
                        border: 1px solid rgba(255, 255, 255, 0.3) !important;
                        padding: 12px !important;
                        border-radius: 6px !important;
                    }
                    form input:focus {
                        border-color: #95bd22 !important; 
                        background-color: rgba(0, 0, 0, 0.6) !important;
                        outline: none !important;
                    }
                `;
                document.head.appendChild(style);
            }

            if (!themeInterval) {
                themeInterval = setInterval(() => {
                    // Sayfa açıldıktan sonra beyaz renk gelirse ez
                    document.querySelectorAll('#__next, #__next > div, main, [class*="layout_auth"]').forEach(el => {
                        if (el.style.backgroundColor && el.style.backgroundColor !== 'transparent') {
                            el.style.setProperty('background-color', 'transparent', 'important');
                        }
                    });

                    // LOGO DEĞİŞİMİ
                    const logoLinks = document.querySelectorAll('a[href="/"]');
                    logoLinks.forEach(link => {
                        const svgLogo = link.querySelector('svg');
                        if (svgLogo) svgLogo.style.display = 'none'; 
                        
                        if (!link.querySelector('.eltek-logo')) {
                            const img = document.createElement('img');
                            img.src = '/eltek-assets/ELTEK_Logo.png';
                            img.className = 'eltek-logo';
                            img.style.height = '80px'; 
                            img.style.width = 'auto';
                            img.style.display = 'block';
                            img.style.margin = '0 auto'; 
                            link.appendChild(img);
                        }
                    });

                    // METİNLER VE GÜVENLİ GİZLEME (Sorunu çözen kısım burası!)
                    document.querySelectorAll('h1, h2, h3, p, span, div').forEach(el => {
                        if (el.childNodes.length === 1 && el.childNodes[0].nodeType === 3) {
                            let text = el.innerText.trim();
                            
                            // ELTEK Rengi
                            if (text === 'Work in all dimensions.') {
                                el.innerText = 'ELTEK';
                                el.style.textAlign = 'center';
                                el.style.display = 'block'; 
                                el.style.width = '100%';
                                el.style.setProperty('color', '#95bd22', 'important'); 
                            }
                            
                            // PLANE'i İki Satıra Bölme
                            if (text === 'Welcome back to Plane.') {
                                el.innerHTML = 'PLANE<br><span style="font-size: 0.8em; opacity: 0.9;">Project Management Tool</span>';
                                el.style.textAlign = 'center';
                                el.style.display = 'block';
                                el.style.width = '100%';
                            }
                            
                            // KUTUYU YOK ETMEK YERİNE SADECE İÇİNDEKİ YAZIYI SİL (Çökmeyi önler)
                            if (text.includes('Join 10,000+ teams')) {
                                el.innerHTML = ''; 
                            }
                        }
                    });
                    
                    // Marka logolarını güvenle gizle
                    document.querySelectorAll('img').forEach(img => {
                        let src = (img.src || '').toLowerCase();
                        let alt = (img.alt || '').toLowerCase();
                        if(src.includes('sony') || src.includes('dolby') || src.includes('zerodha') || src.includes('accenture') || 
                           alt.includes('sony') || alt.includes('dolby') || alt.includes('zerodha') || alt.includes('accenture')) {
                            img.style.opacity = '0'; // Kutuyu silmek yerine sadece görünmez yapıyoruz (Güvenli)
                        }
                    });

                }, 200);
            }
        } else {
            // SİSTEMİN İÇİNDEYİZ -> TÜM TEMAYI SİL
            const customStyle = document.getElementById(styleId);
            if (customStyle) customStyle.remove();

            if (themeInterval) {
                clearInterval(themeInterval);
                themeInterval = null;
            }
            
            document.body.style.backgroundImage = '';
            document.body.style.backgroundColor = '';
            document.querySelectorAll('#__next, #__next > div').forEach(el => {
                el.style.backgroundColor = '';
            });
        }
    }

    applyTheme();

    const originalPushState = history.pushState;
    const originalReplaceState = history.replaceState;

    history.pushState = function() {
        originalPushState.apply(this, arguments);
        setTimeout(applyTheme, 50);
    };
    history.replaceState = function() {
        originalReplaceState.apply(this, arguments);
        setTimeout(applyTheme, 50);
    };
    window.addEventListener('popstate', applyTheme);
});