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

body {
    font-family: 'Segoe UI', Tahoma, Geneva, Verdana, sans-serif;
    background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    min-height: 100vh;
    padding: 20px;
}

.container {
    max-width: 1200px;
    margin: 0 auto;
    background: white;
    border-radius: 15px;
    box-shadow: 0 20px 60px rgba(0, 0, 0, 0.3);
    overflow: hidden;
}

/* Hlavička */
.header {
    background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    color: white;
    padding: 30px;
    text-align: center;
}

.header h1 {
    font-size: 2.5em;
    margin-bottom: 10px;
    text-shadow: 2px 2px 4px rgba(0, 0, 0, 0.2);
}

.header p {
    font-size: 1.2em;
    opacity: 0.9;
}

/* Navigace */
.nav {
    background: #f8f9fa;
    padding: 15px 30px;
    border-bottom: 2px solid #e9ecef;
}

.nav a {
    display: inline-block;
    margin-right: 20px;
    padding: 10px 20px;
    background: white;
    color: #667eea;
    text-decoration: none;
    border-radius: 5px;
    transition: all 0.3s;
    font-weight: 600;
}

.nav a:hover {
    background: #667eea;
    color: white;
    transform: translateY(-2px);
    box-shadow: 0 4px 8px rgba(0, 0, 0, 0.2);
}

/* Obsah */
.content {
    padding: 40px;
}

/* Tlačítka */
.btn {
    display: inline-block;
    padding: 15px 30px;
    margin: 10px 5px;
    background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    color: white;
    text-decoration: none;
    border: none;
    border-radius: 8px;
    cursor: pointer;
    font-size: 1.1em;
    font-weight: 600;
    transition: all 0.3s;
    box-shadow: 0 4px 15px rgba(102, 126, 234, 0.4);
}

.btn:hover {
    transform: translateY(-3px);
    box-shadow: 0 6px 20px rgba(102, 126, 234, 0.6);
}

.btn-secondary {
    background: linear-gradient(135deg, #f093fb 0%, #f5576c 100%);
    box-shadow: 0 4px 15px rgba(245, 87, 108, 0.4);
}

.btn-success {
    background: linear-gradient(135deg, #4facfe 0%, #00f2fe 100%);
    box-shadow: 0 4px 15px rgba(79, 172, 254, 0.4);
}

/* Karty */
.card {
    background: white;
    border-radius: 10px;
    padding: 30px;
    margin: 20px 0;
    box-shadow: 0 4px 6px rgba(0, 0, 0, 0.1);
    transition: all 0.3s;
}

.card:hover {
    box-shadow: 0 8px 15px rgba(0, 0, 0, 0.15);
    transform: translateY(-5px);
}

.card h2 {
    color: #667eea;
    margin-bottom: 20px;
    font-size: 1.8em;
}

.card h3 {
    color: #764ba2;
    margin: 20px 0 10px 0;
    font-size: 1.3em;
}

/* Formuláře */
.form-group {
    margin-bottom: 25px;
}

.form-group label {
    display: block;
    margin-bottom: 8px;
    font-weight: 600;
    color: #333;
    font-size: 1.1em;
}

.form-group input[type="text"],
.form-group input[type="number"],
.form-group textarea,
.form-group select {
    width: 100%;
    padding: 12px;
    border: 2px solid #e9ecef;
    border-radius: 8px;
    font-size: 1em;
    transition: all 0.3s;
}

.form-group input:focus,
.form-group textarea:focus,
.form-group select:focus {
    outline: none;
    border-color: #667eea;
    box-shadow: 0 0 0 3px rgba(102, 126, 234, 0.1);
}

/* Test kód */
.test-code {
    font-size: 2em;
    font-weight: bold;
    color: #667eea;
    background: #f8f9fa;
    padding: 20px;
    border-radius: 10px;
    text-align: center;
    margin: 20px 0;
    border: 3px dashed #667eea;
}

/* Úlohy */
.uloha {
    background: #f8f9fa;
    border-left: 5px solid #667eea;
    padding: 25px;
    margin: 25px 0;
    border-radius: 8px;
}

.uloha-header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    margin-bottom: 15px;
    padding-bottom: 15px;
    border-bottom: 2px solid #e9ecef;
}

.uloha-cislo {
    font-size: 1.5em;
    font-weight: bold;
    color: #667eea;
}

.uloha-body {
    background: #764ba2;
    color: white;
    padding: 5px 15px;
    border-radius: 20px;
    font-weight: 600;
}

.uloha-zadani {
    font-size: 1.1em;
    line-height: 1.8;
    margin: 15px 0;
    color: #333;
}

.poduloha {
    background: white;
    padding: 15px;
    margin: 15px 0;
    border-radius: 5px;
    border-left: 3px solid #764ba2;
}

.poduloha-oznaceni {
    font-weight: bold;
    color: #764ba2;
    margin-bottom: 8px;
}

/* Odpovědní pole */
.answer-input {
    width: 200px;
    padding: 10px;
    border: 2px solid #667eea;
    border-radius: 5px;
    font-size: 1em;
    margin-top: 10px;
}

/* Výběr odpovědí */
.multiple-choice {
    margin: 20px 0;
}

.choice-option {
    display: block;
    padding: 15px;
    margin: 10px 0;
    background: white;
    border: 2px solid #e9ecef;
    border-radius: 8px;
    cursor: pointer;
    transition: all 0.3s;
}

.choice-option:hover {
    background: #f8f9fa;
    border-color: #667eea;
}

.choice-option input[type="radio"] {
    margin-right: 10px;
    transform: scale(1.3);
}

.choice-option.selected {
    background: #667eea;
    color: white;
    border-color: #667eea;
}

/* Tabulka výsledků */
.results-table {
    width: 100%;
    border-collapse: collapse;
    margin: 20px 0;
}

.results-table th,
.results-table td {
    padding: 15px;
    text-align: left;
    border-bottom: 1px solid #e9ecef;
}

.results-table th {
    background: #667eea;
    color: white;
    font-weight: 600;
}

.results-table tr:hover {
    background: #f8f9fa;
}

.status-completed {
    color: #28a745;
    font-weight: bold;
}

.status-pending {
    color: #ffc107;
    font-weight: bold;
}

/* Skóre */
.score-display {
    font-size: 3em;
    font-weight: bold;
    text-align: center;
    margin: 30px 0;
}

.score-value {
    color: #667eea;
}

.score-max {
    color: #999;
}

.score-percentage {
    font-size: 0.5em;
    color: #764ba2;
    display: block;
    margin-top: 10px;
}

/* Alert zprávy */
.alert {
    padding: 20px;
    margin: 20px 0;
    border-radius: 8px;
    font-size: 1.1em;
}

.alert-success {
    background: #d4edda;
    border: 2px solid #c3e6cb;
    color: #155724;
}

.alert-info {
    background: #d1ecf1;
    border: 2px solid #bee5eb;
    color: #0c5460;
}

.alert-warning {
    background: #fff3cd;
    border: 2px solid #ffeaa7;
    color: #856404;
}

/* Responsivní design */
@media (max-width: 768px) {
    .container {
        border-radius: 0;
    }
    
    .content {
        padding: 20px;
    }
    
    .header h1 {
        font-size: 1.8em;
    }
    
    .nav a {
        display: block;
        margin: 10px 0;
    }
    
    .btn {
        display: block;
        width: 100%;
        margin: 10px 0;
    }
}

/* Animace */
@keyframes fadeIn {
    from {
        opacity: 0;
        transform: translateY(20px);
    }
    to {
        opacity: 1;
        transform: translateY(0);
    }
}

.fade-in {
    animation: fadeIn 0.5s ease-in;
}

/* Loading spinner */
.spinner {
    border: 4px solid #f3f3f3;
    border-top: 4px solid #667eea;
    border-radius: 50%;
    width: 40px;
    height: 40px;
    animation: spin 1s linear infinite;
    margin: 20px auto;
}

@keyframes spin {
    0% { transform: rotate(0deg); }
    100% { transform: rotate(360deg); }
}