/* ================================================================
    SEVAL TUZ - KURUMSAL LANDING PAGE STYLESHEET
    Tasarım Dili: Modern, Endüstriyel Soft, Temiz, Premium
    Framework: YOK (Saf CSS)
    ================================================================
*/

/* -----------------------------------------------------------
   1. RESET VE TEMEL AYARLAR
----------------------------------------------------------- */
:root {
    /* Renk Paleti */
    --primary-color: #0056b3; /* Seval Tuz Kurumsal Mavi */
    --primary-dark: #003d82;
    --primary-light: #e6f0fa;
    --accent-color: #f8f9fa;
    --text-dark: #2c3e50;
    --text-light: #6c757d;
    --white: #ffffff;
    --border-color: #e9ecef;
    --success-color: #28a745;
    
    /* Tipografi */
    --font-main: 'Segoe UI', Roboto, Helvetica, Arial, sans-serif;
    
    /* Ölçüler ve Aralıklar */
    --container-width: 1200px;
    --header-height: 80px;
    --header-scroll-height: 60px;
    --section-spacing: 100px;
    --border-radius: 12px;
    --border-radius-lg: 20px;
    
    /* Efektler */
    --shadow-sm: 0 2px 8px rgba(0,0,0,0.05);
    --shadow-md: 0 8px 24px rgba(0,0,0,0.08);
    --shadow-lg: 0 16px 40px rgba(0,0,0,0.12);
    --transition-fast: 0.3s ease;
    --transition-slow: 0.6s cubic-bezier(0.25, 0.8, 0.25, 1);
}

*, *::before, *::after {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}

html {
    scroll-behavior: smooth;
    font-size: 16px;
}

body {
    font-family: var(--font-main);
    color: var(--text-dark);
    background-color: var(--white);
    line-height: 1.6;
    overflow-x: hidden;
    -webkit-font-smoothing: antialiased;
}

/* -----------------------------------------------------------
   2. YARDIMCI SINIFLAR (UTILITIES)
----------------------------------------------------------- */
.container {
    width: 90%;
    max-width: var(--container-width);
    margin: 0 auto;
    padding: 0 20px;
}

.section-padding {
    padding: var(--section-spacing) 0;
}

.text-center {
    text-align: center;
}

.bg-light {
    background-color: #fcfcfc;
}

.bg-accent {
    background-color: var(--primary-light);
}

.mb-5 {
    margin-bottom: 3rem;
}

/* Buton Stilleri */
.btn {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    padding: 12px 32px;
    border-radius: 50px; /* Tam yuvarlak */
    font-weight: 600;
    text-decoration: none;
    transition: all var(--transition-fast);
    cursor: pointer;
    font-size: 0.95rem;
    letter-spacing: 0.5px;
}

.btn-primary {
    background-color: var(--primary-color);
    color: var(--white);
    border: 2px solid var(--primary-color);
    box-shadow: 0 4px 15px rgba(0, 86, 179, 0.3);
}

.btn-primary:hover {
    background-color: var(--primary-dark);
    border-color: var(--primary-dark);
    transform: translateY(-2px);
    box-shadow: 0 8px 20px rgba(0, 86, 179, 0.4);
}

.btn-outline {
    background-color: transparent;
    color: var(--white);
    border: 2px solid var(--white);
    margin-left: 15px;
}

.btn-outline:hover {
    background-color: var(--white);
    color: var(--primary-dark);
    transform: translateY(-2px);
}

.btn-full {
    width: 100%;
    border-radius: var(--border-radius);
}

/* Section Başlıkları */
.section-header {
    margin-bottom: 60px;
    max-width: 700px;
    margin-left: auto;
    margin-right: auto;
}

.section-title {
    font-size: 2.5rem;
    font-weight: 800;
    color: var(--text-dark);
    margin-bottom: 15px;
    position: relative;
    display: inline-block;
}

.section-subtitle {
    color: var(--text-light);
    font-size: 1.1rem;
}

/* -----------------------------------------------------------
   3. HEADER VE NAVİGASYON (MODERN TRANSPARENT)
----------------------------------------------------------- */
#main-header {
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    height: 100px; /* Başlangıç yüksekliği artırıldı */
    background-color: transparent; /* Şeffaf Başlangıç */
    z-index: 1000;
    transition: all 0.4s ease; /* Yumuşak geçiş */
    border-bottom: 1px solid rgba(255, 255, 255, 0.1); /* Çok hafif çizgi */
}

/* --- SCROLLED STATE (Aşağı inince) --- */
#main-header.scrolled {
    height: 80px; /* Küçülme */
    background-color: rgba(255, 255, 255, 0.98); /* Beyaz arka plan */
    backdrop-filter: blur(10px);
    box-shadow: 0 5px 20px rgba(0, 0, 0, 0.05);
    border-bottom: none;
}

.header-container {
    display: grid;
    /* Grid yapısı: Sol Menü - Logo - Sağ Menü */
    grid-template-columns: 1fr auto 1fr;
    align-items: center;
    height: 100%;
    max-width: 1400px; /* Menülerin çok ayrılmaması için limit */
    margin: 0 auto;
    padding: 0 40px;
}

/* --- LOGO AYARLARI --- */
/* --- LOGO AYARLARI --- */
.logo-container {
    display: flex;
    justify-content: center;
    align-items: center;
}

.main-logo-img {
    height: 80px;
    transition: all 0.4s ease; /* 'height' yerine 'all' yaptık ki renk de yumuşak değişsin */
    display: block;
    
    /* SİHİRLİ DOKUNUŞ BURADA: */
    /* Logoyu tamamen beyaza çevirir (Siyah yap -> Tersine çevir = Beyaz) */
    filter: brightness(0) invert(1); 
    opacity: 0.9; /* Hafif bir yumuşaklık için */
}

/* --- SCROLLED STATE (Aşağı inince) --- */
#main-header.scrolled .main-logo-img {
    height: 60px; /* Küçülme */
    
    /* Filtreyi kaldırıyoruz, orijinal lacivert rengine dönüyor */
    filter: none; 
    opacity: 1;
}

/* --- MENÜ YERLEŞİMİ (ORTAYA YAKINLAŞTIRMA) --- */
.nav-left {
    justify-self: end; /* Kendi alanının sonuna (sağa/ortaya) yasla */
    margin-right: 40px; /* Logodan biraz boşluk */
}

.nav-right {
    justify-self: start; /* Kendi alanının başına (sola/ortaya) yasla */
    margin-left: 40px; /* Logodan biraz boşluk */
}

.nav-list {
    list-style: none;
    display: flex;
    gap: 40px; /* Linkler arası boşluk */
}

/* --- MENÜ LINKLERİ VE TİPOGRAFİ --- */
.nav-link {
    text-decoration: none;
    color: #ffffff; /* Başlangıçta BEYAZ yazı (Hero üstünde) */
    font-weight: 600;
    font-size: 0.9rem;
    letter-spacing: 1px; /* Modern, geniş harfler */
    text-transform: uppercase; /* Premium his için büyük harf */
    transition: color 0.3s ease;
    position: relative;
    padding: 5px 0;
    text-shadow: 0 2px 4px rgba(0,0,0,0.3); /* Okunabilirlik için gölge */
}

/* Link Alt Çizgi Efekti */
.nav-link::after {
    content: '';
    position: absolute;
    bottom: 0;
    left: 0;
    width: 0;
    height: 2px;
    background-color: #ffffff; /* Beyaz çizgi */
    transition: width 0.3s ease;
}

.nav-link:hover::after {
    width: 100%;
}

/* --- SCROLLED STATE RENK DEĞİŞİMLERİ --- */
/* Header beyaz olunca linkler koyu olsun */
#main-header.scrolled .nav-link {
    color: var(--text-dark); /* Koyu gri/lacivert */
    text-shadow: none;
}

#main-header.scrolled .nav-link:hover {
    color: var(--primary-color); /* Hover rengi mavi */
}

#main-header.scrolled .nav-link::after {
    background-color: var(--primary-color); /* Çizgi maviye döner */
}

/* İletişim Butonu Özel Stil */
.nav-link.btn-contact {
    /* Normal link gibi görünsün ama belki border eklenebilir, 
       şimdilik sadelik için diğerleriyle aynı bıraktım */
}
/* -----------------------------------------------------------
   4. HERO SECTION
----------------------------------------------------------- */
.hero-section {
    position: relative;
    height: 100vh;
    min-height: 600px;
    display: flex;
    align-items: center;
    justify-content: center;
    overflow: hidden;
    text-align: center;
    color: var(--white);
}

.hero-bg-wrapper {
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    z-index: -1;
}

.hero-bg {
    width: 100%;
    height: 100%;
    background-size: cover;
    background-position: center;
    background-repeat: no-repeat;
    /* Hafif zoom efekti için */
    animation: zoomEffect 20s infinite alternate; 
}

.hero-overlay {
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    /* Modern degrade overlay */
    background: linear-gradient(135deg, rgba(0, 40, 85, 0.8) 0%, rgba(0, 86, 179, 0.6) 100%);
}

.hero-content {
    position: relative;
    z-index: 2;
    max-width: 800px;
}

.hero-subtitle {
    display: block;
    font-size: 0.9rem;
    letter-spacing: 3px;
    text-transform: uppercase;
    margin-bottom: 20px;
    font-weight: 600;
    opacity: 0.9;
}

.hero-title {
    font-size: 4rem;
    line-height: 1.1;
    font-weight: 800;
    margin-bottom: 25px;
}

.highlight-text {
    /* Massive Dynamic tarzı yumuşak text efekti */
    background: -webkit-linear-gradient(left, #fff, #b4d2f0);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
}

.hero-desc {
    font-size: 1.2rem;
    margin-bottom: 40px;
    opacity: 0.9;
    max-width: 600px;
    margin-left: auto;
    margin-right: auto;
}

/* Scroll Indicator Animasyonu */
.scroll-indicator {
    position: absolute;
    bottom: 30px;
    left: 50%;
    transform: translateX(-50%);
    opacity: 0.7;
}

.mouse {
    width: 26px;
    height: 40px;
    border: 2px solid #fff;
    border-radius: 20px;
    position: relative;
}

.wheel {
    width: 4px;
    height: 8px;
    background: #fff;
    position: absolute;
    top: 6px;
    left: 50%;
    transform: translateX(-50%);
    border-radius: 2px;
    animation: scrollWheel 2s infinite;
}

/* -----------------------------------------------------------
   5. DEĞERLER KARTLARI
----------------------------------------------------------- */
.values-grid {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: 30px;
}

.value-card {
    background: var(--white);
    padding: 40px 30px;
    border-radius: var(--border-radius-lg);
    box-shadow: var(--shadow-sm);
    text-align: center;
    transition: transform var(--transition-slow), box-shadow var(--transition-slow);
    border: 1px solid var(--border-color);
}

.value-card:hover {
    transform: translateY(-10px);
    box-shadow: var(--shadow-lg);
}

.value-card .icon-wrapper {
    width: 80px;
    height: 80px;
    background-color: var(--primary-light);
    color: var(--primary-color);
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    margin: 0 auto 25px;
    transition: transform var(--transition-fast);
}

.value-card:hover .icon-wrapper {
    transform: scale(1.1) rotate(5deg);
    background-color: var(--primary-color);
    color: var(--white);
}

.value-card h3 {
    font-size: 1.4rem;
    margin-bottom: 15px;
    color: var(--text-dark);
}

.value-card p {
    color: var(--text-light);
    font-size: 0.95rem;
}

/* -----------------------------------------------------------
   6. ÜRÜNLER (GRID VE FILTRELEME)
----------------------------------------------------------- */
.filter-container {
    display: flex;
    justify-content: center;
    gap: 15px;
    flex-wrap: wrap;
}

.filter-btn {
    background: none;
    border: none;
    padding: 10px 20px;
    font-size: 1rem;
    color: var(--text-light);
    cursor: pointer;
    border-radius: 30px;
    transition: all var(--transition-fast);
    font-weight: 500;
}

.filter-btn.active, .filter-btn:hover {
    background-color: var(--primary-color);
    color: var(--white);
    box-shadow: 0 4px 12px rgba(0, 86, 179, 0.2);
}

.products-grid {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(280px, 1fr));
    gap: 30px;
    min-height: 400px; /* Boş kalırsa layout çökmesin */
}

.product-card {
    background-color: var(--white);
    border-radius: var(--border-radius);
    overflow: hidden;
    box-shadow: var(--shadow-sm);
    transition: all var(--transition-fast);
    position: relative;
    /* Kartın görünürlüğü JS ile kontrol edilecek ama default açık */
    display: flex;
    flex-direction: column;
}

.product-card:hover {
    box-shadow: var(--shadow-md);
    transform: translateY(-5px);
}

.product-image {
    position: relative;
    height: 250px; /* Sabit yükseklik */
    background-color: #f0f0f0;
    overflow: hidden;
}

.product-image img {
    width: 100%;
    height: 100%;
    object-fit: cover;
    transition: transform 0.8s ease;
}

.product-card:hover .product-image img {
    transform: scale(1.08);
}

.product-overlay {
    position: absolute;
    top: 15px;
    left: 15px;
    z-index: 10;
}

.badge {
    background-color: rgba(255, 255, 255, 0.9);
    padding: 5px 12px;
    border-radius: 20px;
    font-size: 0.75rem;
    font-weight: 700;
    color: var(--primary-dark);
    box-shadow: 0 2px 5px rgba(0,0,0,0.1);
    text-transform: uppercase;
    letter-spacing: 0.5px;
}

.product-info {
    padding: 20px;
    flex-grow: 1;
    display: flex;
    flex-direction: column;
}

.product-info h3 {
    font-size: 1.1rem;
    margin-bottom: 5px;
    color: var(--text-dark);
}

.product-info .weight {
    font-size: 0.85rem;
    color: var(--primary-color);
    font-weight: 600;
    margin-bottom: 10px;
    display: block;
}

.product-info p {
    font-size: 0.9rem;
    color: var(--text-light);
    line-height: 1.5;
    margin-top: auto; /* Yazıyı alta itmez, düzenli tutar */
}

/* Filtreleme Animasyon Sınıfları */
.hide {
    display: none; /* Layouttan kaldırır */
}

.show-anim {
    animation: fadeInScale 0.5s ease forwards;
}

/* -----------------------------------------------------------
   7. SERTİFİKALAR
----------------------------------------------------------- */
.certificates-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(150px, 1fr));
    gap: 20px;
    text-align: center;
}

.cert-item {
    display: flex;
    flex-direction: column;
    align-items: center;
    justify-content: center;
    padding: 25px 15px;
    background-color: var(--white);
    border: 1px solid var(--border-color);
    border-radius: var(--border-radius);
    text-decoration: none;
    color: var(--text-dark);
    transition: all var(--transition-fast);
}

.cert-item:hover {
    border-color: var(--primary-color);
    background-color: var(--primary-light);
    transform: translateY(-5px);
}

.cert-icon {
    margin-bottom: 15px;
    color: var(--text-light);
    transition: color var(--transition-fast);
}

.cert-item:hover .cert-icon {
    color: var(--primary-color);
}

.cert-item span {
    font-weight: 700;
    font-size: 0.9rem;
    margin-bottom: 5px;
    display: block;
}

.cert-item small {
    color: var(--text-light);
    font-size: 0.75rem;
}

/* -----------------------------------------------------------
   8. İLETİŞİM FORMU
----------------------------------------------------------- */
.contact-container {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 50px;
    align-items: center;
}

.contact-info {
    padding-right: 20px;
}

.contact-title {
    font-size: 2rem;
    margin-bottom: 20px;
    color: var(--text-dark);
}

.contact-list {
    list-style: none;
    margin-top: 30px;
}

.contact-list li {
    display: flex;
    align-items: center;
    margin-bottom: 20px;
    font-size: 1rem;
    color: var(--text-dark);
}

.contact-icon {
    width: 40px;
    height: 40px;
    border-radius: 50%;
    background-color: var(--white);
    display: flex;
    align-items: center;
    justify-content: center;
    margin-right: 15px;
    color: var(--primary-color);
    box-shadow: var(--shadow-sm);
}

.contact-form-wrapper {
    background-color: var(--white);
    padding: 40px;
    border-radius: var(--border-radius-lg);
    box-shadow: var(--shadow-md);
}

.form-group {
    margin-bottom: 20px;
}

.form-group label {
    display: block;
    margin-bottom: 8px;
    font-weight: 600;
    font-size: 0.9rem;
    color: var(--text-dark);
}

.form-group input,
.form-group textarea {
    width: 100%;
    padding: 12px 15px;
    border: 1px solid var(--border-color);
    border-radius: 8px;
    font-family: var(--font-main);
    font-size: 1rem;
    transition: border-color var(--transition-fast);
    background-color: #fcfcfc;
}

.form-group input:focus,
.form-group textarea:focus {
    outline: none;
    border-color: var(--primary-color);
    background-color: var(--white);
    box-shadow: 0 0 0 3px rgba(0, 86, 179, 0.1);
}

.submit-btn {
    background-color: var(--primary-dark);
    border-color: var(--primary-dark);
    gap: 10px; /* İkon ile yazı arası */
    font-size: 1rem;
    color: white;
}

.form-status {
    margin-top: 15px;
    font-size: 0.9rem;
    font-weight: 600;
    text-align: center;
}

.form-status.success {
    color: var(--success-color);
}

.form-status.error {
    color: #dc3545;
}

/* -----------------------------------------------------------
   9. FOOTER
----------------------------------------------------------- */
#main-footer {
    background-color: var(--white);
    border-top: 1px solid var(--border-color);
    padding-top: 60px;
    padding-bottom: 30px;
}

.footer-content {
    display: flex;
    flex-direction: column;
    align-items: center;
    text-align: center;
    gap: 30px;
}

.footer-logo {
    height: 80px;
    margin-bottom: 15px;
}

.footer-brand p {
    color: var(--text-light);
    max-width: 400px;
    margin: 0 auto;
    font-size: 0.9rem;
}

.footer-social {
    display: flex;
    gap: 20px;
}

.social-link {
    display: flex;
    align-items: center;
    justify-content: center;
    width: 44px;
    height: 44px;
    border-radius: 50%;
    background-color: var(--accent-color);
    color: var(--text-dark);
    transition: all var(--transition-fast);
}

.social-link:hover {
    background-color: var(--primary-color);
    color: var(--white);
    transform: rotate(360deg);
}

.footer-bottom {
    margin-top: 20px;
    padding-top: 20px;
    border-top: 1px solid var(--border-color);
    width: 100%;
    display: flex;
    flex-direction: column;
    align-items: center;
    gap: 10px;
}

.footer-bottom p {
    font-size: 0.8rem;
    color: #aaa;
}

/* -----------------------------------------------------------
   10. ANİMASYON KEYFRAMES
----------------------------------------------------------- */
@keyframes zoomEffect {
    0% { transform: scale(1); }
    100% { transform: scale(1.1); }
}

@keyframes scrollWheel {
    0% { top: 6px; opacity: 1; }
    100% { top: 18px; opacity: 0; }
}

@keyframes fadeInUp {
    from {
        opacity: 0;
        transform: translate3d(0, 40px, 0);
    }
    to {
        opacity: 1;
        transform: translate3d(0, 0, 0);
    }
}

@keyframes fadeInScale {
    from {
        opacity: 0;
        transform: scale(0.9);
    }
    to {
        opacity: 1;
        transform: scale(1);
    }
}

/* Helper Classes for JS Animation */
.fade-in-up {
    opacity: 0;
    animation-name: fadeInUp;
    animation-duration: 0.8s;
    animation-fill-mode: forwards;
}

.delay-100 { animation-delay: 0.1s; }
.delay-200 { animation-delay: 0.2s; }
.delay-300 { animation-delay: 0.3s; }

/* Scroll Trigger Class (Başlangıçta gizli, JS ile aktifleşir) */
.scroll-trigger {
    opacity: 0;
    transform: translateY(30px);
    transition: opacity 0.8s ease-out, transform 0.8s ease-out;
}

.scroll-trigger.active {
    opacity: 1;
    transform: translateY(0);
}

/* -----------------------------------------------------------
   11. RESPONSIVE TASARIM (MEDIA QUERIES)
----------------------------------------------------------- */

/* Tablet ve Küçük Laptoplar */
@media (max-width: 992px) {
    .section-title {
        font-size: 2rem;
    }
    
    .hero-title {
        font-size: 3rem;
    }

    .values-grid {
        grid-template-columns: repeat(2, 1fr); /* 3'ten 2'ye düşür */
    }

    .contact-container {
        grid-template-columns: 1fr; /* Alt alta al */
        text-align: center;
    }

    .contact-info {
        padding-right: 0;
        margin-bottom: 30px;
    }

    .contact-list li {
        justify-content: center;
    }

    .contact-icon {
        margin-right: 10px;
    }
}

/* Mobil Telefonlar */
@media (max-width: 768px) {
    /* Header Düzenlemesi - Mobilde menüler gizlenir, sadece logo kalır */
    .nav-left, .nav-right {
        display: none;
    }

    .logo-container {
        justify-content: center;
        width: 100%;
    }

    .hero-title {
        font-size: 2.2rem;
    }

    .values-grid {
        grid-template-columns: 1fr; /* Tek kolon */
    }

    .certificates-grid {
        grid-template-columns: repeat(2, 1fr);
    }

    /* Mobilde paddingleri daralt */
    .section-padding {
        padding: 60px 0;
    }
    
    .contact-form-wrapper {
        padding: 25px;
    }
}

/* Çok Küçük Ekranlar */
@media (max-width: 480px) {
    .hero-title {
        font-size: 1.8rem;
    }

    .certificates-grid {
        grid-template-columns: 1fr;
    }

    .filter-btn {
        width: 100%; /* Butonlar alt alta sıralanır */
        margin-bottom: 5px;
    }
}