:root {
    --primary: #4169e1;
    --primary-light: #edf2ff;
    --background: #ffffff;
    --surface: #f7f8fc;
    --text: #182033;
    --muted: #778096;
    --border: #e9ebf2;
    --card: #ffffff;
}

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

html {
    scroll-behavior: smooth;
}

body {
    font-family: 'Inter', sans-serif;
    background: var(--background);
    color: var(--text);
    transition: background 0.3s ease, color 0.3s ease;
    position: relative;
    overflow-x: hidden;
}

body.dark {
    --background: #101522;
    --surface: #171e2d;
    --text: #f0f3fa;
    --muted: #a1abc0;
    --border: #293247;
    --card: #171e2d;
    --primary-light: #202d4a;
}

/* =========================================
   ÖZEL SAYFA GEÇİŞ VE EKRAN ANIMASYONLARI (MODERN TRANSITION)
   ========================================= */

/* Sayfa İlk Açılırken (Smooth Page Enter Animation) */
body {
    animation: pageEnter 0.5s cubic-bezier(0.16, 1, 0.3, 1) forwards;
}

@keyframes pageEnter {
    from {
        opacity: 0;
        transform: translateY(12px) scale(0.99);
    }
    to {
        opacity: 1;
        transform: translateY(0) scale(1);
    }
}

/* Karta Tıklanınca Sayfadan Çıkış Animasyonu (Perspective Zoom Exit) */
body.page-exit {
    pointer-events: none;
    animation: pageExit 0.35s cubic-bezier(0.4, 0, 0.2, 1) forwards !important;
}

@keyframes pageExit {
    0% {
        opacity: 1;
        transform: scale(1) translateY(0);
        filter: blur(0px);
    }
    100% {
        opacity: 0;
        transform: scale(0.96) translateY(15px);
        filter: blur(4px);
    }
}

/* =========================================
   ARKA PLAN BİLGİ/MATEMATİK VİBE EFEKTİ
   ========================================= */
.bg-symbols {
    position: fixed;
    top: 0;
    left: 0;
    width: 100vw;
    height: 100vh;
    overflow: hidden;
    z-index: 0;
    pointer-events: none;
    opacity: 0.35;
}

body.dark .bg-symbols {
    opacity: 0.25;
}

.bg-symbols span {
    position: absolute;
    display: block;
    font-family: 'Courier New', Courier, monospace;
    font-weight: 800;
    color: var(--primary);
    font-size: 20px;
    bottom: -100px;
    animation: floatUp 12s linear infinite;
    user-select: none;
}

.bg-symbols span:nth-child(1) { left: 5%; animation-duration: 10s; animation-delay: 0s; font-size: 22px; }
.bg-symbols span:nth-child(2) { left: 18%; animation-duration: 14s; animation-delay: 2s; font-size: 16px; }
.bg-symbols span:nth-child(3) { left: 30%; animation-duration: 11s; animation-delay: 4s; font-size: 24px; }
.bg-symbols span:nth-child(4) { left: 42%; animation-duration: 15s; animation-delay: 1s; font-size: 18px; }
.bg-symbols span:nth-child(5) { left: 55%; animation-duration: 13s; animation-delay: 3s; font-size: 26px; }
.bg-symbols span:nth-child(6) { left: 68%; animation-duration: 12s; animation-delay: 5s; font-size: 20px; }
.bg-symbols span:nth-child(7) { left: 78%; animation-duration: 16s; animation-delay: 2s; font-size: 17px; }
.bg-symbols span:nth-child(8) { left: 88%; animation-duration: 11s; animation-delay: 4s; font-size: 23px; }
.bg-symbols span:nth-child(9) { left: 12%; animation-duration: 17s; animation-delay: 3s; font-size: 19px; }
.bg-symbols span:nth-child(10) { left: 48%; animation-duration: 13s; animation-delay: 6s; font-size: 21px; }
.bg-symbols span:nth-child(11) { left: 62%; animation-duration: 18s; animation-delay: 1s; font-size: 18px; }
.bg-symbols span:nth-child(12) { left: 93%; animation-duration: 14s; animation-delay: 0s; font-size: 22px; }

@keyframes floatUp {
    0% {
        transform: translateY(0) rotate(0deg);
        opacity: 0;
    }
    15% {
        opacity: 1;
    }
    85% {
        opacity: 1;
    }
    100% {
        transform: translateY(-115vh) rotate(360deg);
        opacity: 0;
    }
}

/* =========================================
   GENEL YERLEŞİM VE BİLEŞENLER
   ========================================= */
.container {
    width: 90%;
    max-width: 1150px;
    margin: auto;
    position: relative;
    z-index: 2;
}

/* Cam Efekti (Glassmorphism Header) */
.header {
    height: 75px;
    border-bottom: 1px solid var(--border);
    background: rgba(255, 255, 255, 0.85);
    backdrop-filter: blur(12px);
    -webkit-backdrop-filter: blur(12px);
    position: sticky;
    top: 0;
    z-index: 100;
    transition: background 0.3s ease, border-color 0.3s ease;
}

body.dark .header {
    background: rgba(16, 21, 34, 0.85);
}

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

.logo {
    display: flex;
    align-items: center;
    gap: 8px;
    font-size: 22px;
    font-weight: 800;
    text-decoration: none;
    color: var(--text);
}

.logo > span:last-child {
    color: var(--primary);
    margin-left: -8px;
}

.logo-icon {
    background: var(--primary);
    color: white;
    width: 34px;
    height: 34px;
    border-radius: 10px;
    display: grid;
    place-items: center;
}

.nav-links {
    display: flex;
    gap: 35px;
}

.nav-links a {
    text-decoration: none;
    color: var(--muted);
    font-size: 14px;
    font-weight: 600;
    transition: .2s;
}

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

.theme-btn {
    width: 40px;
    height: 40px;
    border