:root {
    --color-text-primary: #1A1A1A;
    --color-background-primary: #FFFFFF;
    --color-background-secondary: #F5F5F7;
    --color-accent-primary: #00BCD4;
    --color-accent-secondary: #FF3B30;
    --color-header-background: #F5F5F7;
    --color-header-text: #1A1A1A;
    --color-footer-background: #1A1A1A;
    --color-footer-text: #A1A1A6;
    --color-modal-background: rgba(0,0,0,0.8);
    --color-modal-content-background: #FFFFFF;
    --color-shadow: rgba(0,0,0,0.1);
    --logo-filter: none;
}

[data-theme="dark"] {
    --color-text-primary: #FFFFFF;
    --color-background-primary: #1A1A1A;
    --color-background-secondary: #2C2C2E;
    --color-header-background: #1A1A1A;
    --color-header-text: #FFFFFF;
    --color-footer-text: #8E8E93;
    --color-modal-content-background: #2C2C2E;
    --color-shadow: rgba(255,255,255,0.2);
    --logo-filter: brightness(0) invert(1);
}

body {
    font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, Helvetica, Arial, sans-serif, "Apple Color Emoji", "Segoe UI Emoji", "Segoe UI Symbol";
    margin: 0;
    padding: 0;
    box-sizing: border-box;
    background-color: var(--color-background-primary);
    color: var(--color-text-primary);
    line-height: 1.6;
    transition: background-color 0.3s ease, color 0.3s ease;
}

.container {
    width: 90%;
    max-width: 1024px; /* Apple.com'a benzer daha dar bir içerik alanı */
    margin: 0 auto;
    padding: 20px 0;
}

/* Header */
header {
    background-color: var(--color-header-background);
    color: var(--color-header-text);
    padding: 3px 0; /* Further reduced vertical padding */
    position: fixed;
    width: 100%;
    top: 0;
    left: 0;
    z-index: 1000;
    box-shadow: 0 2px 5px var(--color-shadow);
}

header .container {
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: 5px 5px; /* Reduced vertical padding for header's container */
}

.logo-link {
    padding-top: 8px; /* Small buffer above the logo */
    text-decoration: none;
}

.logo {
    /* padding-top is now on .logo-link */
}

.logo img {
    height: 60px; /* Further reduced logo height */
    filter: none; /* Default dark logo for light mode */
    transition: filter 0.3s ease;
}

[data-theme="dark"] .logo img {
    filter: brightness(0) invert(1); /* Invert to white for dark mode */
}

nav.main-nav {
    display: flex;
}

nav.main-nav ul {
    list-style: none;
    margin: 0;
    padding: 0;
    display: flex;
}

nav.main-nav ul li {
    margin-left: 30px;
}

nav.main-nav ul li a {
    color: var(--color-header-text);
    text-decoration: none;
    font-weight: 600;
    font-size: 1em;
    transition: color 0.3s ease;
}

nav.main-nav ul li a:hover {
    color: var(--color-accent-primary); /* Vurgu rengi */
}

.language-selector.main-lang-selector {
    display: block;
}

.language-selector select {
    background-color: var(--color-header-background);
    color: var(--color-header-text);
    border: 1px solid var(--color-footer-text);
    padding: 6px 10px;
    border-radius: 5px;
    font-size: 0.9em;
    cursor: pointer;
    appearance: none;
    -webkit-appearance: none;
    -moz-appearance: none;
    background-repeat: no-repeat;
    background-position: right 8px top 50%;
    background-size: 10px auto;
    transition: background-color 0.3s ease, color 0.3s ease, border-color 0.3s ease;
    background-image: url('data:image/svg+xml;charset=US-ASCII,%3Csvg%20xmlns%3D%22http%3A%2F%2Fwww.w3.org%2F2000%2Fsvg%22%20width%3D%22292.4%22%20height%3D%22292.4%22%3E%3Cpath%20fill%3D%22%231A1A1A%22%20d%3D%22M287%2069.4a17.6%2017.6%200%200%200-13-5.4H18.4c-6.5%200-12.3%203.2-16.1%208.1-3.8%204.9-4.6%2011-2.4%2017.4l133.7%20163.5c3.8%204.9%209.6%208.1%2016.1%208.1s12.3-3.2%2016.1-8.1L289.4%2094.7c2.2-6.4%201.4-12.5-2.4-17.4z%22%2F%3E%3C%2Fsvg%3E');
}

[data-theme="dark"] .language-selector select {
    background-image: url('data:image/svg+xml;charset=US-ASCII,%3Csvg%20xmlns%3D%22http%3A%2F%2Fwww.w3.org%2F2000%2Fsvg%22%20width%3D%22292.4%22%20height%3D%22292.4%22%3E%3Cpath%20fill%3D%22%23FFFFFF%22%20d%3D%22M287%2069.4a17.6%2017.6%200%200%200-13-5.4H18.4c-6.5%200-12.3%203.2-16.1%208.1-3.8%204.9-4.6%2011-2.4%2017.4l133.7%20163.5c3.8%204.9%209.6%208.1%2016.1%208.1s12.3-3.2%2016.1-8.1L289.4%2094.7c2.2-6.4%201.4-12.5-2.4-17.4z%22%2F%3E%3C%2Fsvg%3E');
}

.language-selector select:focus {
    outline: none;
    border-color: var(--color-accent-primary);
}

.menu-toggle {
    display: none; /* Hide on desktop */
    font-size: 1.8em;
    cursor: pointer;
    color: var(--color-header-text);
}

/* Theme Toggle Switch */
.theme-switch-wrapper {
    display: flex;
    align-items: center;
    margin-left: 15px;
}

.theme-switch {
    display: inline-block;
    height: 18px;
    position: relative;
    width: 34px;
}

.theme-switch input {
    display:none;
}

.slider {
    background-color: #ccc;
    bottom: 0;
    cursor: pointer;
    left: 0;
    position: absolute;
    right: 0;
    top: 0;
    transition: .4s;
    border-radius: 18px;
}

.slider:before {
    background-color: white;
    bottom: 4px;
    content: "";
    height: 10px;
    left: 4px;
    position: absolute;
    transition: .4s;
    width: 10px;
    border-radius: 50%;
}

input:checked + .slider {
    background-color: var(--color-accent-primary);
}

input:checked + .slider:before {
    transform: translateX(16px);
}

.theme-switch-wrapper .fa-sun, .theme-switch-wrapper .fa-moon {
    color: var(--color-header-text);
    margin: 0 6px;
    font-size: 0.9em;
}

.mobile-menu {
    display: none; /* Hidden by default */
}

/* Hero Section */
.hero-section {
    background: var(--color-background-primary);
    color: var(--color-text-primary);
    text-align: center;
    padding: 140px 0; /* Adjusted for less space on desktop */
    display: flex;
    flex-direction: column; /* İçerikleri dikey hizalamak için */
    align-items: center;
    justify-content: center;
    min-height: 90vh; /* Tam ekran yüksekliği */
    margin-top: 0; /* Header yüksekliği kadar boşluk kaldırıldı, padding ile ayarlanacak */
    overflow: hidden; /* Animasyonlar için */
    position: relative;
}

.hero-section::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    background: linear-gradient(45deg, var(--color-accent-secondary), var(--color-accent-primary));
    opacity: 0.2;
    animation: gradientAnimation 15s ease infinite;
    z-index: 0;
}

.hero-section .container {
    position: relative;
    z-index: 1;
}

.hero-animated-logo {
    margin-bottom: 10px; /* Logo ile metin arasındaki boşluk azaltıldı */
    opacity: 0;
    animation: logoFadeInBlur 12s infinite alternate; /* Animasyon süresi artırıldı */
}

.hero-animated-logo img {
    height: 280px; /* Animasyonlu logo boyutu */
    filter: var(--logo-filter);
    transition: filter 0.3s ease;
}

@keyframes logoFadeInBlur {
    0% {
        opacity: 0;
        filter: var(--logo-filter) blur(10px);
        transform: translateY(-50px) scale(0.5);
    }
    10% {
        opacity: 1;
        filter: var(--logo-filter) blur(0px);
        transform: translateY(0) scale(1.2);
    }
    20% {
        opacity: 1;
        filter: var(--logo-filter) blur(0px);
        transform: translateY(0) scale(1.2);
    }
    25% {
        opacity: 0.5;
        filter: var(--logo-filter) blur(5px);
        transform: translateY(-5px) scale(1.15);
    }
    30% {
        opacity: 1;
        filter: var(--logo-filter) blur(0px);
        transform: translateY(0) scale(1.2);
    }
    80% {
        opacity: 1;
        filter: var(--logo-filter) blur(0px);
        transform: translateY(0) scale(1.2);
    }
    100% {
        opacity: 0;
        filter: var(--logo-filter) blur(10px);
        transform: translateY(50px) scale(0.5);
    }
}

.hero-section h1,
.hero-section p,
.hero-section .btn {
    opacity: 0; /* Re-enabled for testing IntersectionObserver */
    transform: translateY(30px); /* Re-enabled for testing IntersectionObserver */
    transition: opacity 0.8s ease-out, transform 0.8s ease-out;
}

.hero-section.is-visible h1 {
    opacity: 1;
    transform: translateY(0);
    transition-delay: 0.1s;
}

.hero-section.is-visible p {
    opacity: 1;
    transform: translateY(0);
    transition-delay: 0.3s;
}

.hero-section.is-visible .btn {
    opacity: 1;
    transform: translateY(0);
    transition-delay: 0.5s;
}

.hero-section h1 {
    font-size: 3.5em;
    margin-bottom: 20px;
    font-weight: 700;
    letter-spacing: -0.02em;
}

.hero-section p {
    font-size: 1.3em;
    margin-bottom: 40px;
    font-weight: 400;
    opacity: 0.8;
}

.btn {
    background-color: var(--color-accent-primary); /* Vurgu rengi */
    color: var(--color-white);
    padding: 12px 25px;
    text-decoration: none;
    border-radius: 50px;
    font-weight: 600;
    transition: background-color 0.3s ease, transform 0.2s ease;
    display: inline-block;
}

.btn:hover {
    background-color: #0097a7; /* Darker turquoise, consider making this a variable if needed */
    transform: translateY(-2px);
}

/* Section Stilleri */
.section {
    padding: 100px 0;
    text-align: center;
    background-color: var(--color-background-primary);
    position: relative; /* Animasyonlar için */
    overflow: hidden; /* Animasyonlar için */
    transition: background-color 0.3s ease;
}

.section:nth-of-type(even) {
    background-color: var(--color-background-secondary);
}

.section h2,
.section p,
.section .btn {
    opacity: 0;
    transform: translateY(30px);
    transition: opacity 0.8s ease-out, transform 0.8s ease-out;
}

.section.is-visible h2 {
    opacity: 1;
    transform: translateY(0);
    transition-delay: 0.1s;
}

.section.is-visible p {
    opacity: 1;
    transform: translateY(0);
    transition-delay: 0.3s;
}

.section.is-visible .btn {
    opacity: 1;
    transform: translateY(0);
    transition-delay: 0.5s;
}

.section h2 {
    font-size: 2.8em;
    margin-bottom: 50px;
    color: var(--color-text-primary);
    font-weight: 700;
    letter-spacing: -0.01em;
}

.section p {
    font-size: 1.1em;
    max-width: 800px;
    margin: 0 auto 20px auto;
    color: var(--color-text-secondary); /* Using a secondary text color for paragraphs */
}

/* Project Grid Stilleri */
.project-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
    gap: 30px;
    margin-top: 50px;
}

.project-card {
    background-color: var(--color-background-primary);
    border-radius: 10px;
    box-shadow: 0 4px 15px var(--color-shadow);
    padding: 30px;
    text-align: left;
    transition: transform 0.3s ease, box-shadow 0.3s ease, background-color 0.3s ease;
}

.project-card:hover {
    transform: translateY(-10px);
    box-shadow: 0 8px 25px var(--color-shadow);
}

.project-card h3 {
    font-size: 1.8em;
    color: var(--color-text-primary);
    margin-bottom: 15px;
}

.project-card p {
    font-size: 1em;
    color: var(--color-text-secondary);
    line-height: 1.6;
    margin-bottom: 15px;
}

.project-card .status {
    display: inline-block;
    background-color: var(--color-accent-primary);
    color: var(--color-white);
    padding: 5px 15px;
    border-radius: 20px;
    font-size: 0.8em;
    font-weight: 600;
}

/* Contact Info Stilleri */
.contact-info {
    display: flex;
    flex-direction: column;
    align-items: center;
    margin-top: 30px;
}

.contact-info p,
.contact-info a {
    display: flex;
    align-items: center;
    margin: 10px 0;
    font-size: 1.1em;
    color: var(--color-text-primary);
    text-decoration: none;
}

.contact-info p i,
.contact-info a i {
    font-size: 1.3em;
    margin-right: 10px;
    color: var(--color-accent-primary);
}

.contact-info a:hover {
    color: var(--color-accent-primary);
}

/* Footer */
footer {
    background-color: var(--color-footer-background);
    color: var(--color-footer-text);
    padding: 40px 0;
    font-size: 0.85em;
    text-align: center;
    transition: background-color 0.3s ease, color 0.3s ease;
}

footer .container {
    border-top: 1px solid rgba(255,255,255,0.1);
    padding-top: 30px;
}

.footer-links {
    margin-bottom: 20px;
}

.footer-links a {
    color: var(--color-footer-text);
    text-decoration: none;
    margin: 0 15px;
    transition: color 0.3s ease;
}

.footer-links a:hover {
    color: var(--color-header-text); /* Using header text color for hover */
}

footer p {
    margin-top: 20px;
    color: var(--color-footer-text);
}

/* Modals */
.modal {
    display: none; /* Varsayılan olarak gizli */
    position: fixed; /* Sayfanın tamamını kaplar */
    z-index: 2000; /* Diğer her şeyin üzerinde */
    left: 0;
    top: 0;
    width: 100%;
    height: 100%;
    overflow: auto; /* İçerik sığmazsa kaydırma çubuğu */
    background-color: var(--color-modal-background); /* Yarı saydam siyah arka plan */
    backdrop-filter: blur(5px); /* Arka planı bulanıklaştır */
    -webkit-backdrop-filter: blur(5px);
}

.modal-content {
    background-color: var(--color-modal-content-background);
    margin: 10% auto; /* Üstten ve alttan boşluk, ortalanmış */
    padding: 20px; /* Adjusted padding */
    border: 1px solid var(--color-shadow);
    width: 80%; /* Genişlik */
    max-width: 700px;
    border-radius: 10px;
    position: relative;
    box-shadow: 0 5px 15px var(--color-shadow);
    animation: modalOpen 0.3s ease-out;
    transition: background-color 0.3s ease;
}

.modal-content h2 {
    color: var(--color-text-primary);
    font-size: 2em;
    margin-bottom: 20px;
}

.modal-content p {
    color: var(--color-text-secondary);
    text-align: left;
    font-size: 1em;
    line-height: 1.8;
    word-wrap: break-word; /* Ensures long words break and wrap */
    word-break: break-word; /* Ensures long words break and wrap */
}

.close-button {
    color: var(--color-text-primary);
    position: absolute;
    top: 15px;
    right: 25px;
    font-size: 35px;
    font-weight: bold;
    cursor: pointer;
    transition: color 0.3s ease;
}

.close-button:hover,
.close-button:focus {
    color: var(--color-accent-secondary);
    text-decoration: none;
    cursor: pointer;
}

@keyframes modalOpen {
    from { opacity: 0; transform: translateY(-50px); }
    to { opacity: 1; transform: translateY(0); }
}

/* Animasyonlar */
@keyframes gradientAnimation {
    0% { background-position: 0% 50%; }
    50% { background-position: 100% 50%; }
    100% { background-position: 0% 50%; }
}

/* Responsive Tasarım */
@media (max-width: 768px) {
    header .container {
        flex-direction: row; /* Keep logo and toggle on same row */
        justify-content: space-between; /* Space between logo and toggle */
        align-items: center;
    }

    nav.main-nav,
    .language-selector.main-lang-selector,
    .theme-switch-wrapper:not(.mobile-theme-switch) {
        display: none; /* Hide desktop nav and theme switcher on mobile */
    }

    .menu-toggle {
        display: block; /* Show hamburger icon on mobile */
    }

    .mobile-theme-switch {
        margin-top: 30px;
    }

    .mobile-menu {
        position: fixed;
        top: 0;
        left: 0;
        width: 100%;
        height: 100%;
        background-color: var(--color-header-background); /* Dark overlay */
        z-index: 999;
        display: flex;
        flex-direction: column;
        justify-content: center;
        align-items: center;
        transform: translateX(100%); /* Start off-screen to the right */
        transition: transform 0.3s ease-in-out, background-color 0.3s ease;
    }

    .mobile-menu.is-open {
        transform: translateX(0); /* Slide in */
    }

    .mobile-menu nav ul {
        list-style: none;
        padding: 0;
        text-align: center;
        margin-bottom: 30px;
    }

    .mobile-menu nav ul li {
        margin: 20px 0;
    }

    .mobile-menu nav ul li a {
        color: var(--color-header-text);
        text-decoration: none;
        font-size: 1.8em;
        font-weight: 600;
        transition: color 0.3s ease;
    }

    .mobile-menu nav ul li a:hover {
        color: var(--color-accent-primary);
    }

    .mobile-menu .language-selector select {
        background-color: var(--color-header-background);
        color: var(--color-header-text);
        border: 1px solid var(--color-footer-text);
        padding: 10px 20px;
        border-radius: 5px;
        font-size: 1.2em;
        cursor: pointer;
        appearance: none;
        -webkit-appearance: none;
        -moz-appearance: none;
        background-image: url('data:image/svg+xml;charset=US-ASCII,%3Csvg%20xmlns%3D%22http%3A%2F%2Fwww.w3.org%2F2000%2Fsvg%22%20width%3D%22292.4%22%20height%3D%22292.4%22%3E%3Cpath%20fill%3D%22%23ffffff%22%20d%3D%22M287%2069.4a17.6%2017.6%200%200%200-13-5.4H18.4c-6.5%200-12.3%203.2-16.1%208.1-3.8%204.9-4.6%2011-2.4%2017.4l133.7%20163.5c3.8%204.9%209.6%208.1%2016.1%208.1s12.3-3.2%2016.1-8.1L289.4%2094.7c2.2-6.4%201.4-12.5-2.4-17.4z%22%2F%3E%3C%2Fsvg%3E');
        background-repeat: no-repeat;
        background-position: right 15px center;
        background-size: 15px auto;
    }

    .hero-section {
        padding: 120px 0; /* Increased padding for mobile */
        min-height: auto; /* Allow height to be determined by content */
    }

    .hero-section h1 {
        font-size: 2.5em;
    }

    .hero-section p {
        font-size: 1.1em;
    }

    .section h2 {
        font-size: 2.2em;
    }

    .footer-links a {
        display: block;
        margin: 10px 0;
    }

    .modal-content {
        width: 95%;
        margin: 0 auto; /* Remove vertical margin */
        max-height: 100vh; /* Limit height to viewport height */
        overflow-y: auto; /* Enable vertical scrolling */
    }
}