/* Základní nastavení a barvy */
:root {
   --bg-color: #0d0d0d;
   --text-color: #e0e0e0;
   --accent-color: #8b0000; /* Krvavě červená */
   --card-bg: #1a1a1a;
   --font-main: 'Segoe UI', Tahoma, Geneva, Verdana, sans-serif;
}
body {
   background-color: var(--bg-color);
   color: var(--text-color);
   font-family: var(--font-main);
   margin: 0;
   line-height: 1.6;
   transition: background 0.5s, color 0.5s;
}
/* Styl pro JS interaktivitu */
body.sepia-mode {
   --bg-color: #2b2620;
   --text-color: #d4c4a8;
   --accent-color: #5e3a24;
}
/* Hlavička a navigace */
header {
   background: linear-gradient(rgba(0,0,0,0.8), rgba(0,0,0,0.8)),
               url('https://www.transparenttextures.com/patterns/dark-leather.png');
   padding: 2rem;
   text-align: center;
   border-bottom: 3px solid var(--accent-color);
}
header h1 {
   font-size: 3rem;
   margin: 0;
   text-transform: uppercase;
   letter-spacing: 5px;
   color: var(--accent-color);
}
nav ul {
   list-style: none;
   padding: 0;
   display: flex;
   justify-content: center;
   gap: 20px;
   margin-top: 20px;
}
nav a {
   text-decoration: none;
   color: var(--text-color);
   font-weight: bold;
   transition: 0.3s;
}
nav a:hover, nav a.active {
   color: var(--accent-color);
}
/* Hlavní obsah a Flexbox layout */
.container {
   max-width: 1000px;
   margin: 0 auto;
   padding: 2rem;
}
.intro {
   display: flex; /* Flexbox pro rozložení textu a obrázku */
   align-items: center;
   gap: 40px;
   margin-bottom: 40px;
}
.text-content {
   flex: 2;
}
.image-content {
   flex: 1;
}
.image-content img {
   width: 100%;
   border-radius: 10px;
   filter: grayscale(100%) sepia(20%);
   box-shadow: 0 0 15px var(--accent-color);
}
/* Karty s díly */
.highlights {
   display: flex;
   gap: 20px;
   flex-wrap: wrap; /* Responzivita */
}
.card {
   background-color: var(--card-bg);
   padding: 1.5rem;
   flex: 1;
   min-width: 250px;
   border-left: 4px solid var(--accent-color);
   transition: transform 0.3s;
}
.card:hover {
   transform: translateY(-10px);
}
/* Tlačítko */
button {
   background-color: var(--accent-color);
   color: white;
   border: none;
   padding: 10px 20px;
   cursor: pointer;
   font-weight: bold;
   margin-top: 15px;
}
footer {
   text-align: center;
   padding: 2rem;
   font-size: 0.8rem;
   opacity: 0.6;
}