@import url('https://fonts.googleapis.com/css2?family=Space+Grotesk:wght@300;400;600;700&family=Inter:wght@300;400;600&display=swap');

:root {
    /* DEFAULT DARK THEME (Cyberpunk) */
    --bg-dark: #050505;
    --bg-card: rgba(18, 18, 18, 0.6);
    --primary: #00f2ea;
    --secondary: #7000ff;
    --text-main: #ffffff;
    --text-muted: #a0a0a0;
    --glass: rgba(255, 255, 255, 0.03);
    --border: rgba(255, 255, 255, 0.1);
    --glow: 0 0 20px rgba(0, 242, 234, 0.15);
    --nav-bg: rgba(5, 5, 5, 0.8);
    --shadow: 0 10px 30px rgba(0,0,0,0.5);
}

[data-theme="light"] {
    /* LIGHT THEME (Laboratory) */
    --bg-dark: #f0f2f5;
    --bg-card: rgba(255, 255, 255, 0.5);
    --primary: #009995; /* Tmavší cyan pro čitelnost na bílé */
    --secondary: #6c5ce7;
    --text-main: #2d3436;
    --text-muted: #636e72;
    --glass: rgba(255, 255, 255, 0.9);
    --border: rgba(0, 0, 0, 0.1);
    --glow: 0 0 15px rgba(0, 153, 149, 0.2);
    --nav-bg: rgba(240, 242, 245, -0.1);
    --shadow: 0 10px 20px rgba(0, 0, 0, 0.7);
}

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

body {
    background-color: var(--bg-dark);
    color: var(--text-main);
    font-family: 'Inter', sans-serif;
    line-height: 1.6;
    overflow-x: hidden;
    transition: background-color 0.4s ease, color 0.4s ease;
}

h1, h2, h3, h4 {
    font-family: 'Space Grotesk', sans-serif;
    font-weight: 700;
    color: var(--text-main);
}

a { text-decoration: none; color: inherit; transition: 0.3s; }

/* --- NAVIGATION --- */
.navbar {
    position: fixed;
    top: 0;
    width: 100%;
    padding: 1rem 2rem;
    display: flex;
    justify-content: space-between;
    align-items: center;
    background: var(--nav-bg);
    backdrop-filter: blur(15px);
    -webkit-backdrop-filter: blur(15px);
    border-bottom: 1px solid var(--border);
    z-index: 1000;
    transition: background 0.3s;
}

.logo {
    font-size: 1.5rem;
    font-weight: 700;
    background: linear-gradient(90deg, var(--primary), var(--secondary));
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    text-transform: uppercase;
    letter-spacing: 2px;
}

.nav-right {
    display: flex;
    align-items: center;
    gap: 2rem;
}

.nav-links {
    display: flex;
    gap: 2rem;
}

.nav-links a {
    color: var(--text-muted);
    font-size: 0.9rem;
    text-transform: uppercase;
    letter-spacing: 1px;
    font-weight: 600;
}

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

/* Theme Toggle Button */
.theme-toggle {
    background: none;
    border: 1px solid var(--border);
    color: var(--text-main);
    padding: 0.5rem;
    border-radius: 50%;
    cursor: pointer;
    font-size: 1.2rem;
    width: 40px;
    height: 40px;
    display: flex;
    align-items: center;
    justify-content: center;
    transition: 0.3s;
}

.theme-toggle:hover {
    background: var(--glass);
    color: var(--primary);
    border-color: var(--primary);
}

/* --- HERO SECTION --- */
.hero {
    min-height: 80vh;
    display: flex;
    flex-direction: column;
    justify-content: center;
    align-items: center;
    text-align: center;
    padding: 6rem 1rem 2rem 1rem;
    position: relative;
}

.hero::before {
    content: '';
    position: absolute;
    width: 100%;
    height: 100%;
    background: radial-gradient(circle at 50% 50%, rgba(112, 0, 255, 0.15) 0%, transparent 70%);
    z-index: -1;
    pointer-events: none;
}

.hero h1 {
    font-size: clamp(2.5rem, 5vw, 4.5rem); /* Responsive font size */
    margin-bottom: 1rem;
    line-height: 1.1;
    text-shadow: 0 0 20px rgba(0,0,0,0.5);
}

.hero p {
    font-size: 1.2rem;
    color: var(--text-muted);
    max-width: 600px;
    margin-bottom: 2rem;
}

.cta-btn {
    padding: 1rem 2.5rem;
    background: transparent;
    border: 1px solid var(--primary);
    color: var(--primary);
    font-family: 'Space Grotesk', sans-serif;
    font-weight: 700;
    text-transform: uppercase;
    letter-spacing: 2px;
    cursor: pointer;
    transition: 0.3s;
    background: rgba(0, 242, 234, 0.05);
}

.cta-btn:hover {
    background: var(--primary);
    color: #fff; /* White text on hover for better contrast */
    box-shadow: 0 0 20px var(--primary);
}

/* --- GRID LAYOUTS --- */
.container {
    max-width: 1200px;
    margin: 0 auto;
    padding: 4rem 2rem;
}

.section-title {
    font-size: 2.5rem;
    margin-bottom: 3rem;
    border-left: 5px solid var(--primary);
    padding-left: 1rem;
}

.grid-3 {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
    gap: 2rem;
}

/* --- CARDS --- */
.card {
    background: var(--bg-card);
    border: 1px solid var(--border);
    padding: 2rem;
    border-radius: 16px;
    transition: 0.3s;
    backdrop-filter: blur(10px);
    box-shadow: var(--shadow);
}

.card:hover {
    transform: translateY(-5px);
    border-color: var(--primary);
    box-shadow: 0 15px 40px rgba(0,0,0,0.2);
}

.card-icon {
    font-size: 2rem;
    color: var(--primary);
    margin-bottom: 1rem;
}

.card h3 { margin-bottom: 0.5rem; }
.card p { color: var(--text-muted); font-size: 0.95rem; }

/* --- TERMINAL STYLE (Always Dark) --- */
.terminal-box {
    background: #0d0d0d; /* Vždy tmavé */
    border: 1px solid #333;
    border-radius: 8px;
    padding: 1.5rem;
    margin: 1.5rem 0;
    font-family: 'Courier New', monospace;
    position: relative;
    color: #fff; /* Vždy bílý text */
    box-shadow: inset 0 0 20px rgba(0,0,0,0.5);
}

.terminal-header {
    display: flex;
    gap: 8px;
    margin-bottom: 1rem;
    border-bottom: 1px solid #333;
    padding-bottom: 0.5rem;
}

.dot { width: 10px; height: 10px; border-radius: 50%; }
.red { background: #ff5f56; }
.yellow { background: #ffbd2e; }
.green { background: #27c93f; }

.code-block {
    color: #00f2ea;
    font-size: 1rem;
    line-height: 1.5;
}

.label {
    color: #888;
    font-size: 0.75rem;
    text-transform: uppercase;
    display: block;
    margin-bottom: 5px;
}

/* --- ARTICLES LOGIC --- */
.full-article {
    display: none; /* Defaultně skryto */
    margin-top: 2rem;
    padding-top: 2rem;
    border-top: 1px solid var(--border);
    animation: fadeIn 0.5s ease;
}

@keyframes fadeIn {
    from { opacity: 0; transform: translateY(10px); }
    to { opacity: 1; transform: translateY(0); }
}

/* --- FOOTER --- */
footer {
    border-top: 1px solid var(--border);
    padding: 2rem;
    text-align: center;
    color: var(--text-muted);
    background: var(--bg-card);
    margin-top: auto;
}

/* --- RESPONSIVE --- */
@media (max-width: 768px) {
    .navbar { flex-direction: column; gap: 1rem; padding: 1rem; }
    .nav-right { flex-direction: column; gap: 1rem; width: 100%; }
    .nav-links { gap: 1.5rem; justify-content: center; }
    .hero h1 { font-size: 2.5rem; }
}

/* --- HERO SECTION VYLEPŠENÍ PRO TESSERACT --- */
.hero {
    position: relative;
    overflow: hidden; /* Zabrání přetečení levitujícího stínu mimo sekci */
}
.full-screen-bg {
    position: fixed; 
    /* Uděláme obrázek o 10 % větší, aby při pohybu nevykoukl okraj */
    top: -5vh; 
    left: -6vw;
    width: 110vw; 
    height: 110vh; 
    object-fit: cover; 
    z-index: -10; 
    opacity: 0.15; 
    pointer-events: none; 
    
    /* Kombinovaná animace (levitace + dýchání) */
    animation: bg-levitate 15s ease-in-out infinite;
}

/* Animace jemné levitace a pulzování průhlednosti */
@keyframes bg-levitate {
    0% { 
        transform: translateY(0);
        opacity: 0.15; 
    }
    50% { 
        transform: translateY(-30px); /* Obrázek pomalu vyjede o 30px nahoru */
        opacity: 0.25; /* A lehce se rozsvítí */
    }
    100% { 
        transform: translateY(0);
        opacity: 0.15; 
    }
}
/* Jemná animace pulzování průhlednosti */
@keyframes bg-pulse {
    0%, 100% { opacity: 0.15; }
    50% { opacity: 0.25; }
}
.hero-content {
    position: relative;
    z-index: 1; /* Vynutí text nad obrázkem */
    display: flex;
    flex-direction: column;
    align-items: center;
    text-align: center;
}

/* Úprava pro mobilní zařízení */
@media (max-width: 992px) {
    .hero-content {
	padding-top: 10rem;
        flex-direction: column-reverse;
        text-align: center;
        gap: 2rem;
    }
    .hero-text {
        text-align: center;
    }
    .tesseract-img {
        max-width: 250px;
    }
}
/* --- MODAL FORMULÁŘ --- */
.modal {
    display: none;
    position: fixed;
    z-index: 2000;
    left: 0;
    top: 0;
    width: 100%;
    height: 100%;
    background-color: rgba(0, 0, 0, 0.8);
    backdrop-filter: blur(5px);
    align-items: center;
    justify-content: center;
}

.modal-content {
    position: relative;
    width: 90%;
    max-width: 500px;
    animation: fadeIn 0.3s ease;
}

.close-modal {
    position: absolute;
    top: 15px;
    right: 20px;
    color: var(--text-muted);
    font-size: 28px;
    font-weight: bold;
    cursor: pointer;
    transition: 0.3s;
}

.close-modal:hover { color: #ff5f56; }

.form-group { margin-bottom: 1.5rem; }

.form-input {
    width: 100%;
    padding: 12px 15px;
    background: rgba(0, 0, 0, 0.3);
    border: 1px solid var(--border);
    border-radius: 8px;
    color: var(--text-main);
    font-family: 'Inter', sans-serif;
    transition: 0.3s;
    outline: none;
}

.form-input:focus {
    border-color: var(--primary);
    box-shadow: 0 0 10px rgba(0, 242, 234, 0.1);
}