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

body {
    font-family: 'Segoe UI', Arial, sans-serif;
    background: linear-gradient(180deg, #2b78e4 0%, #7d57f0 100%);
    min-height: 100vh;
    color: #333;
    padding-bottom: 50px;
}

/* Header */
header {
    text-align: center;
    color: white;
    padding: 60px 20px 40px;
}

header h1 {
    font-size: 3.5rem;
    font-weight: 800;
}

header p {
    font-size: 1.1rem;
    opacity: 0.9;
}

/* Navigace s bílými kolečky přesně podle zadání */
.nav-container {
    display: flex;
    justify-content: center;
    gap: 12px;
    flex-wrap: wrap;
    max-width: 950px;
    margin: 30px auto 0;
}

.topic-circle {
    text-decoration: none;
    background: white;
    color: #7d57f0;
    width: 42px;
    height: 42px;
    display: flex;
    align-items: center;
    justify-content: center;
    border-radius: 50%;
    font-weight: bold;
    font-size: 0.95rem;
    box-shadow: 0 4px 15px rgba(0,0,0,0.2);
    transition: 0.3s;
}

.topic-circle:hover {
    transform: scale(1.15);
    background: #eef2ff;
}

/* Karta tématu - zaoblení a stín podle obrázku */
.container {
    max-width: 900px;
    margin: 40px auto;
    padding: 0 20px;
}

.topic-card {
    background: white;
    border-radius: 35px; /* Výrazné zaoblení */
    padding: 50px;
    margin-bottom: 50px;
    box-shadow: 0 20px 50px rgba(0,0,0,0.2);
    scroll-margin-top: 30px;
}

.topic-badge {
    background: #7d57f0;
    color: white;
    padding: 7px 18px;
    border-radius: 12px;
    font-size: 0.9rem;
    font-weight: bold;
    display: inline-block;
    margin-bottom: 20px;
}

h2 {
    font-size: 2.3rem;
    color: #2c3e50;
    margin-bottom: 30px;
}

.card-body p {
    margin-bottom: 20px;
    line-height: 1.7;
    color: #444;
    text-align: justify;
}

.card-body strong {
    color: #2b78e4;
}

.vocab-tip {
    font-style: italic;
    background: #f8f9ff;
    padding: 15px;
    border-left: 5px solid #7d57f0;
    border-radius: 8px;
    margin: 25px 0;
}

/* Sloupce se slovíčky */
.vocab-columns {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 30px;
    margin-top: 40px;
    background: #fdfdff;
    padding: 30px;
    border-radius: 25px;
    border: 1px solid #f0f0f0;
}

.col h3 {
    font-size: 0.8rem;
    text-transform: uppercase;
    color: #a0a0a0;
    margin-bottom: 15px;
    letter-spacing: 1.5px;
}

.col ul {
    list-style: none;
}

.col li {
    margin-bottom: 12px;
    color: #555;
    font-size: 1rem;
    padding-left: 25px;
    position: relative;
}

.col li::before {
    content: "▸"; /* Šipka podle obrázku */
    color: #7d57f0;
    position: absolute;
    left: 0;
}

footer {
    text-align: center;
    color: white;
    padding: 20px;
    opacity: 0.7;
    font-size: 0.9rem;
}

/* Mobilní optimalizace */
@media (max-width: 768px) {
    .vocab-columns { grid-template-columns: 1fr; }
    .topic-card { padding: 30px; }
    header h1 { font-size: 2.2rem; }
}