/* Genel Stiller */
:root {
    --heading-font: 'Montserrat', sans-serif;
    --body-font: 'Open Sans', sans-serif;
    --nav-height: 70px; 
    
    /* Light Theme (Varsayılan) */
    --primary-color-light: #2c3e50; /* Midnight Blue */
    --secondary-color-light: #1abc9c; /* Turquoise */
    --dark-color-light: #34495e;    /* Wet Asphalt */
    --light-color-light: #ecf0f1;   /* Clouds */
    --background-color-light: #ffffff; /* White */
    --text-color-light: #34495e;
    --card-bg-light: #ffffff;
    --card-shadow-light: rgba(0,0,0,0.08);
    --header-bg-initial-light: rgba(52, 73, 94, 0.9);
    --header-bg-scrolled-light: #34495e;
    --hero-overlay-start-light: rgba(44, 62, 80, 0.85);
    --hero-overlay-end-light: rgba(26, 188, 156, 0.85);
    --footer-bg-light: #34495e;
    --footer-text-light: #bdc3c7;
    --placeholder-img-bg-light: #ccc;


    /* Dark Theme */
    --primary-color-dark: #3498db;  /* Brighter Blue for Dark Mode */
    --secondary-color-dark: #1dd2af; /* Brighter Turquoise */
    --dark-color-dark: #2c3e50;     /* Darker Background for elements */
    --light-color-dark: #3b5266;    /* Lighter shade for cards/sections on dark bg */
    --background-color-dark: #1f2937; /* Very Dark Blue/Gray */
    --text-color-dark: #e5e7eb;     /* Light Gray for text */
    --card-bg-dark: #2c3e50; 
    --card-shadow-dark: rgba(0,0,0,0.25);
    --header-bg-initial-dark: rgba(31, 41, 55, 0.9); /* Darker initial header */
    --header-bg-scrolled-dark: #1f2937; /* Darker scrolled header */
    --hero-overlay-start-dark: rgba(31, 41, 55, 0.85);
    --hero-overlay-end-dark: rgba(29, 210, 175, 0.75);
    --footer-bg-dark: #111827; /* Even Darker Footer */
    --footer-text-dark: #9ca3af;
    --placeholder-img-bg-dark: #555;
}

html[data-theme="light"] {
    --primary-color: var(--primary-color-light);
    --secondary-color: var(--secondary-color-light);
    --dark-color: var(--dark-color-light);
    --light-color: var(--light-color-light);
    --background-color: var(--background-color-light);
    --text-color: var(--text-color-light);
    --card-bg: var(--card-bg-light);
    --card-shadow: var(--card-shadow-light);
    --header-bg-initial: var(--header-bg-initial-light);
    --header-bg-scrolled: var(--header-bg-scrolled-light);
    --hero-overlay-start: var(--hero-overlay-start-light);
    --hero-overlay-end: var(--hero-overlay-end-light);
    --footer-bg: var(--footer-bg-light);
    --footer-text: var(--footer-text-light);
    --placeholder-img-bg: var(--placeholder-img-bg-light);
}

html[data-theme="dark"] {
    --primary-color: var(--primary-color-dark);
    --secondary-color: var(--secondary-color-dark);
    --dark-color: var(--dark-color-dark);
    --light-color: var(--light-color-dark);
    --background-color: var(--background-color-dark);
    --text-color: var(--text-color-dark);
    --card-bg: var(--card-bg-dark);
    --card-shadow: var(--card-shadow-dark);
    --header-bg-initial: var(--header-bg-initial-dark);
    --header-bg-scrolled: var(--header-bg-scrolled-dark);
    --hero-overlay-start: var(--hero-overlay-start-dark);
    --hero-overlay-end: var(--hero-overlay-end-dark);
    --footer-bg: var(--footer-bg-dark);
    --footer-text: var(--footer-text-dark);
    --placeholder-img-bg: var(--placeholder-img-bg-dark);
}


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

body {
    font-family: var(--body-font);
    line-height: 1.7;
    color: var(--text-color);
    background-color: var(--background-color);
    transition: background-color 0.3s ease, color 0.3s ease;
}

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

.container {
    width: 90%;
    max-width: 1100px;
    margin: auto;
    overflow: hidden; 
    padding: 0 20px;
}

h1, h2, h3, h4, h5, h6 {
    font-family: var(--heading-font);
    color: var(--primary-color);
    margin-bottom: 1rem;
    font-weight: 700;
    transition: color 0.3s ease;
}

h1 { font-size: 2.8rem; line-height: 1.2; }
h2 { font-size: 2.2rem; margin-bottom: 2.5rem; text-align: center; }
h3 { font-size: 1.5rem; }

p {
    margin-bottom: 1rem;
    font-weight: 400;
}

a {
    text-decoration: none;
    color: var(--secondary-color);
    transition: color 0.3s ease;
}

a:hover {
    color: var(--primary-color);
}

img {
    max-width: 100%;
    height: auto;
    display: block;
    border-radius: 4px; 
}

ul {
    list-style: none;
}

section {
    padding: 80px 0;
    transition: background-color 0.3s ease;
}

/* Header & Navigasyon */
header {
    background: var(--header-bg-initial);
    color: #fff;
    padding: 0; 
    position: sticky;
    top: 0;
    z-index: 1000;
    height: var(--nav-height);
    transition: background-color 0.3s ease, box-shadow 0.3s ease;
}

header.header-scrolled {
    background: var(--header-bg-scrolled);
    box-shadow: 0 2px 10px var(--card-shadow);
}

header .header-container { 
    display: flex;
    justify-content: space-between;
    align-items: center;
    height: 100%;
}

header .logo {
    font-size: 1.8rem;
    font-weight: bold;
    color: #fff;
    font-family: var(--heading-font);
}

header .logo .logo-serdal {
    font-weight: normal; 
}

header .logo .logo-web {
    color: var(--secondary-color);
    font-weight: 700; 
}


header .logo:hover .logo-serdal {
    color: var(--light-color);
}
header .logo:hover .logo-web {
    color: #fff;
}


header .main-nav ul {
    display: flex;
}

header .main-nav ul li {
    margin-left: 25px;
}

header .main-nav ul li a {
    color: #fff;
    padding: 8px 12px;
    font-weight: 600;
    font-size: 0.95rem;
    border-radius: 4px;
    transition: background-color 0.3s ease, color 0.3s ease;
}

header .main-nav ul li a:hover,
header .main-nav ul li a.active {
    background-color: var(--secondary-color);
    color: #fff;
}

.header-controls {
    display: flex;
    align-items: center;
    gap: 15px; /* Butonlar arası boşluk */
}

/* Theme Toggle Button */
.theme-toggle {
    background: none;
    border: none;
    color: #fff;
    font-size: 1.3rem; /* Hamburger ile aynı veya biraz küçük */
    cursor: pointer;
    padding: 5px;
    display: flex;
    align-items: center;
    justify-content: center;
    transition: color 0.3s ease;
}

.theme-toggle:hover {
    color: var(--secondary-color);
}


/* Hamburger Menu */
.hamburger-menu {
    display: none; 
    background: none;
    border: none;
    color: #fff;
    font-size: 1.8rem;
    cursor: pointer;
    padding: 5px;
}

/* Hero Bölümü */
.hero-section {
    color: #fff;
    height: calc(100vh - var(--nav-height));
    min-height: 500px;
    display: flex;
    justify-content: center;
    align-items: center;
    text-align: center;
    padding: 0 20px; 
    position: relative; 
    overflow: hidden; 
    background-color: var(--primary-color); 
}

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

.hero-video-background video {
    width: 100%;
    height: 100%;
    object-fit: cover; 
}

.hero-overlay {
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    background: linear-gradient(to right, var(--hero-overlay-start), var(--hero-overlay-end));
    z-index: 2; 
}

.hero-content {
    position: relative; 
    z-index: 3;
}

.hero-content h1 {
    font-size: 3.2rem;
    margin-bottom: 1.5rem;
    color: #fff; /* Hero başlığı her zaman beyaz */
    font-weight: 700;
    min-height: 100px; 
}

.hero-content h1 .cursor {
    display: inline-block;
    background-color: var(--secondary-color);
    width: 3px;
    animation: blink 1s infinite;
    margin-left: 2px;
    position: relative;
    top: -2px; 
}

@keyframes blink {
    0%, 100% { opacity: 1; }
    50% { opacity: 0; }
}

.hero-content p {
    font-size: 1.2rem;
    margin-bottom: 2.5rem;
    max-width: 650px;
    margin-left: auto;
    margin-right: auto;
    line-height: 1.8;
    color: #fff; /* Hero paragrafı her zaman beyaz */
}

.cta-button {
    display: inline-block;
    background: var(--secondary-color);
    color: #fff;
    padding: 15px 35px;
    border-radius: 50px; 
    font-size: 1.1rem;
    font-weight: 600;
    transition: background-color 0.3s ease, transform 0.3s ease, box-shadow 0.3s ease;
    border: none;
    box-shadow: 0 4px 10px rgba(26, 188, 156, 0.4); /* Bu gölge temadan bağımsız olabilir veya değişken kullanılabilir */
}

html[data-theme="dark"] .cta-button {
    box-shadow: 0 4px 10px rgba(29, 210, 175, 0.3);
}


.cta-button:hover {
    background: var(--primary-color);
    color: #fff;
    transform: translateY(-3px);
}
html[data-theme="light"] .cta-button:hover {
    box-shadow: 0 6px 12px rgba(44, 62, 80, 0.3);
}
html[data-theme="dark"] .cta-button:hover {
    box-shadow: 0 6px 12px rgba(52, 152, 219, 0.3);
}


/* Hizmetler Bölümü */
.services-section {
    background: var(--light-color);
}

.service-cards {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(300px, 1fr)); 
    gap: 30px;
    text-align: center;
}

.service-card {
    background: var(--card-bg);
    padding: 35px 25px;
    border-radius: 8px;
    box-shadow: 0 5px 15px var(--card-shadow);
    transition: transform 0.3s ease, box-shadow 0.3s ease, background-color 0.3s ease;
}

.service-card:hover {
    transform: translateY(-8px);
    box-shadow: 0 10px 20px var(--card-shadow);
}

.service-card i {
    font-size: 2.8rem;
    color: var(--secondary-color);
    margin-bottom: 1.5rem;
}
.service-card h3 {
    color: var(--primary-color);
}

/* Müşteri Yorumları Bölümü - Slider */
.testimonials-section {
    background-color: var(--background-color);
}

.testimonial-slider-viewport {
    width: 100%;
    overflow: hidden;
    position: relative;
    margin-bottom: 30px;
}

.testimonials-container { 
    display: flex;
    transition: transform 0.5s ease-in-out;
}

.testimonial-card {
    background: var(--card-bg); /* light-color yerine card-bg */
    padding: 30px; 
    border-radius: 8px;
    box-shadow: 0 6px 18px var(--card-shadow); 
    border-left: 5px solid var(--secondary-color);
    flex: 0 0 100%; 
    min-width: 100%; 
    box-sizing: border-box; 
    display: flex;
    flex-direction: column;
    align-items: center; 
    text-align: center; 
    transition: background-color 0.3s ease, border-color 0.3s ease;
}

.testimonial-avatar {
    width: 80px;
    height: 80px;
    border-radius: 50%;
    background-color: var(--secondary-color); 
    margin-bottom: 20px;
    display: flex;
    justify-content: center;
    align-items: center;
    color: white;
    font-size: 1.5rem; 
    font-weight: bold;
    transition: background-color 0.3s ease;
}
.testimonial-avatar::before { 
    font-family: "Font Awesome 6 Free";
    font-weight: 900;
    content: "\f007"; 
}


.testimonial-card p {
    font-style: italic;
    margin-bottom: 15px;
    color: var(--text-color);
    font-size: 1rem; 
    line-height: 1.7;
    max-width: 90%; 
}

.testimonial-card .author {
    font-weight: bold;
    color: var(--primary-color);
    text-align: center; 
    font-size: 0.95rem;
    margin-top: auto; 
}
.testimonial-card .author::before {
    content: "— ";
}

.testimonial-navigation {
    text-align: center;
    margin-top: 30px;
}

.testimonial-nav-btn {
    background-color: var(--secondary-color);
    color: white;
    border: none;
    padding: 12px 25px; 
    margin: 0 10px;
    border-radius: 5px;
    cursor: pointer;
    font-size: 1rem;
    font-weight: 600;
    transition: background-color 0.3s ease;
}

.testimonial-nav-btn:hover {
    background-color: var(--primary-color);
}

.testimonial-nav-btn:disabled {
    background-color: #ccc; /* Bu da değişken olabilir */
    cursor: not-allowed;
}

html[data-theme="dark"] .testimonial-nav-btn:disabled {
    background-color: #555;
    color: #888;
}

.testimonial-nav-btn i {
    margin-right: 8px;
}
.testimonial-nav-btn:last-of-type i { 
    margin-left: 8px;
    margin-right: 0;
}


/* Hakkımda Bölümü */
.about-section {
    background: var(--light-color);
}
.about-content {
    display: flex;
    flex-wrap: wrap;
    align-items: center;
    gap: 50px;
}

.about-text {
    flex: 2; 
    min-width: 300px;
}
.about-text strong {
    color: var(--secondary-color);
    font-weight: 700;
}

.about-image {
    flex: 1;
    min-width: 280px;
    max-width: 350px; 
    margin: 0 auto;
}

.about-image img {
    border-radius: 12px; 
    width: 100%;
    box-shadow: 0 10px 25px var(--card-shadow);
    border: 5px solid var(--secondary-color);
    background-color: var(--placeholder-img-bg); /* Placeholder için arka plan */
    transition: border-color 0.3s ease, background-color 0.3s ease;
}

/* İletişim Bölümü */
.contact-section {
    text-align: center;
    background-color: var(--background-color);
}

.contact-info p {
    font-size: 1.1rem;
    margin-bottom: 1rem;
    display: flex; 
    align-items: center;
    justify-content: center;
}

.contact-info i {
    margin-right: 12px;
    color: var(--secondary-color);
    font-size: 1.3rem; 
    width: 20px; 
    text-align: center;
}

.contact-info a {
    transition: color 0.3s ease;
}
.contact-info a:hover {
    color: var(--primary-color);
}

.map-container {
    margin-top: 40px; /* Üstteki içerikle arasına boşluk bırakır */
    border-radius: 8px;
    overflow: hidden; /* iframe'in köşelerini yuvarlak yapmak için */
    box-shadow: 0 8px 20px var(--card-shadow);
}

.map-container iframe {
    display: block; /* iframe altındaki gereksiz boşluğu kaldırır */
    width: 100%;
    height: 450px; /* Yüksekliği isteğe göre ayarlanabilir */
    border: none; /* iframe kenarlığını kaldırır */
}


/* Footer */
footer {
    background: var(--footer-bg);
    color: var(--footer-text); 
    text-align: center;
    padding: 3rem 0;
    transition: background-color 0.3s ease, color 0.3s ease;
}

footer .container {
    display: flex;
    flex-direction: column;
    align-items: center;
}

footer p {
    margin-bottom: 1rem;
    font-size: 0.9rem;
}

.social-links a {
    color: var(--footer-text);
    margin: 0 12px;
    font-size: 1.6rem;
    transition: color 0.3s ease, transform 0.3s ease;
}

.social-links a:hover {
    color: var(--secondary-color);
    transform: translateY(-3px);
}

/* Duyarlılık (Responsive) */
@media (max-width: 768px) {
    html {
      font-size: 15px; 
    }

    header .main-nav {
        display: none; 
        flex-direction: column;
        width: 100%;
        background-color: var(--header-bg-scrolled); /* Mobil menü arka planı için */
        position: absolute;
        top: var(--nav-height); 
        left: 0;
        padding: 10px 0;
        box-shadow: 0 5px 10px var(--card-shadow);
        z-index: 999; 
    }

    header .main-nav.active { 
        display: flex;
    }

    header .main-nav ul {
        flex-direction: column;
        width: 100%;
    }

    header .main-nav ul li {
        margin: 10px 0;
        text-align: center;
    }
    header .main-nav ul li a {
        padding: 12px 20px;
        display: block; 
    }
    header .main-nav ul li a.active,
    header .main-nav ul li a:hover {
         background-color: var(--secondary-color);
         color: #fff;
    }

    .hamburger-menu {
        display: block; 
    }
    
    .hero-content h1 {
        font-size: 2.5rem;
        min-height: 80px; 
    }

    .hero-content p {
        font-size: 1.1rem;
    }

    .about-content {
        flex-direction: column;
        text-align: center;
    }
    .about-text {
        flex: 1; 
    }

    .about-image img {
        margin-top: 20px;
        max-width: 280px;
    }
    
    .testimonial-card {
        padding: 25px; 
    }
    .testimonial-card p {
        font-size: 0.95rem;
    }
    .testimonial-avatar {
        width: 70px;
        height: 70px;
        font-size: 1.3rem;
    }

    .map-container {
        height: 350px;
    }
    .map-container iframe {
        height: 350px;
    }


    section {
        padding: 60px 0;
    }
     h2 { font-size: 2rem; margin-bottom: 2rem; }
}

@media (max-width: 480px) {
    html {
      font-size: 14px;
    }
    .hero-content h1 {
        font-size: 2rem;
        min-height: 70px;
    }
    .hero-content p {
        font-size: 1rem;
    }
    .cta-button {
        padding: 12px 25px;
        font-size: 1rem;
    }

    .service-cards {
        grid-template-columns: 1fr;
        gap: 20px;
    }
     h1 { font-size: 2rem; }
     h2 { font-size: 1.8rem; }

    .testimonial-nav-btn {
        padding: 10px 15px;
        font-size: 0.9rem;
    }
    .testimonial-card {
        padding: 20px;
    }
    .map-container {
        height: 300px;
    }
    .map-container iframe {
        height: 300px;
    }
}