/* ========================================
   ZÁKLADNÍ NASTAVENÍ
======================================== */

* {
    box-sizing: border-box;
}

html {
    scroll-behavior: smooth;
}

body {
    margin: 0;
    font-family: Arial, sans-serif;
    background-color: #f1f5f9;
    color: #1e293b;
    line-height: 1.6;
}

/* ========================================
   ROZLOŽENÍ STRÁNKY
======================================== */

.layout {
    display: flex;
    align-items: flex-start;
    gap: 20px;
    min-height: 100vh;
    padding: 20px;
}

/* ========================================
   NAVBAR
======================================== */

.navbar {
    position: sticky;
    top: 20px;
    flex: 0 0 240px;
    width: 240px;
    min-width: 0;
    height: calc(100vh - 40px);
    padding: 20px;
    background-color: #0f172a;
    border-radius: 16px;
    overflow-x: hidden;
    overflow-y: auto;
    transition: flex-basis 0.3s ease, width 0.3s ease, padding 0.3s ease;
}

.navbar-title {
    font-size: 18px;
    font-weight: bold;
    color: #e3e6eb;
    margin: 0 0 20px;
    text-align: center;
}

/* ========================================
   TLAČÍTKO NAVBARU
======================================== */

.toggle-btn {
    display: block;
    width: 40px;
    height: 40px;
    margin-left: auto;
    margin-bottom: 25px;
    border: none;
    border-radius: 10px;
    background-color: #1e293b;
    color: white;
    font-size: 22px;
    cursor: pointer;
    transition: background-color 0.2s;
}

.toggle-btn:hover {
    background-color: #334155;
}

/* ========================================
   ODKAZY V NAVBARU
======================================== */

.nav-links {
    list-style: none;
    padding: 0;
    margin: 0;
}

.nav-links li {
    margin-bottom: 12px;
}

.nav-links a {
    display: flex;
    align-items: center;
    gap: 15px;
    width: 100%;
    min-height: 46px;
    padding: 12px;
    color: #cbd5e1;
    text-decoration: none;
    white-space: nowrap;
    border-radius: 10px;
    transition: background-color 0.2s, color 0.2s;
}

.nav-links a:hover,
.nav-links a:focus-visible {
    background-color: #1e293b;
    color: white;
}

.icon {
    flex: 0 0 24px;
    text-align: center;
    font-size: 21px;
}

.link-text {
    min-width: 0;
    overflow: hidden;
    text-overflow: ellipsis;
}

/* ========================================
   HLAVNÍ OBSAH
======================================== */

.content {
    flex: 1 1 0;
    min-width: 0;
    width: 100%;
}

/* ========================================
   JEDNOTLIVÉ SEKCE
======================================== */

section {
    width: 100%;
    min-width: 0;
    padding: 30px;
    margin: 0 0 20px;
    background-color: white;
    border: 1px solid #e2e8f0;
    border-radius: 16px;
    box-shadow: 0 4px 12px rgba(0, 0, 0, 0.05);
    scroll-margin-top: 20px;
    overflow-wrap: anywhere;
}

section h1 {
    margin-top: 0;
    color: #0f172a;
    font-size: 32px;
    line-height: 1.25;
}

section h2 {
    margin-top: 0;
    color: #0f172a;
    font-size: 25px;
    line-height: 1.3;
}

/* ========================================
   ZMENŠENÝ NAVBAR
======================================== */

.navbar.collapsed {
    flex: 0 0 80px;
    width: 80px;
    padding: 20px 10px;
}

.navbar.collapsed .toggle-btn {
    margin-left: auto;
    margin-right: auto;
}

.navbar.collapsed .nav-links a {
    justify-content: center;
    gap: 0;
    padding: 12px 0;
}

.navbar.collapsed .link-text,
.navbar.collapsed .navbar-title {
    display: none;
}

/* ========================================
   ROZBALOVACÍ SEZNAMY
======================================== */

details {
    font-size: 14px;
    color: #1e293b;
    margin-top: 15px;
    padding: 15px;
    border: 1px solid #cbd5e1;
    border-radius: 10px;
    background-color: #f8fafc;
}

summary {
    font-size: 16px;
    font-weight: bold;
    color: #0f172a;
    cursor: pointer;
    line-height: 1.5;
}

summary:hover {
    color: #4f46e5;
}

details p {
    margin-top: 15px;
    color: #475569;
    line-height: 1.7;
}

/* ========================================
   KATEGORIE MATERIÁLŮ
======================================== */

.zakladka {
    font-size: 14px;
    color: #1e293b;
    margin-top: 15px;
    padding: 15px;
    border: 1px solid #5ad25a;
    border-radius: 10px;
    background-color: #b1dab12a;
}

.stredni {
    font-size: 14px;
    color: #1e293b;
    margin-top: 15px;
    padding: 15px;
    border: 1px solid #5a84d2;
    border-radius: 10px;
    background-color: #b1b2da2a;
}

.vysvetleni-box {
    font-size: 14px;
    color: #1e293b;
    margin-top: 15px;
    padding: 15px;
    border: 1px solid #de8f3f;
    border-radius: 10px;
    background-color: #dad0b12a;
}

/* ========================================
   VÝBĚR TESTU
======================================== */

.test-selection {
    display: flex;
    flex-direction: column;
    gap: 12px;
    width: 100%;
    max-width: 450px;
    margin-top: 25px;
}

.test-selection label {
    width: auto;
    height: auto;
    position: static;
    display: block;
    background: none;
    border-radius: 0;
    box-shadow: none;
    cursor: default;
    font-weight: bold;
    font-size: 14px;
    color: #1e293b;
}

.test-selection select {
    width: 100%;
    min-width: 0;
    padding: 12px;
    border: 1px solid #cbd5e1;
    border-radius: 10px;
    background-color: white;
    color: #1e293b;
    font-size: 15px;
    cursor: pointer;
}

.test-selection select:focus {
    outline: 2px solid #818cf8;
    outline-offset: 2px;
}

/* ========================================
   TLAČÍTKA TESTOVÁNÍ
======================================== */

.test-selection button,
#testContainer button {
    padding: 12px 20px;
    border: none;
    border-radius: 10px;
    background-color: #4f46e5;
    color: white;
    font-size: 15px;
    cursor: pointer;
    transition: background-color 0.2s, transform 0.2s;
}

.test-selection button:hover:not(:disabled),
#testContainer button:hover {
    background-color: #4338ca;
}

.test-selection button:active:not(:disabled),
#testContainer button:active {
    transform: translateY(1px);
}

.test-selection button:disabled,
.test-selection select:disabled {
    opacity: 0.5;
    cursor: not-allowed;
}

/* ========================================
   KARTY OTÁZEK
======================================== */

.question {
    width: 100%;
    min-width: 0;
    margin-top: 20px;
    padding: 20px;
    border: 1px solid #e2e8f0;
    border-radius: 12px;
    background-color: #f8fafc;
}

.question h4 {
    margin-top: 0;
    color: #1e293b;
    line-height: 1.5;
}

.answer {
    display: block;
    margin: 12px 0;
    cursor: pointer;
    line-height: 1.5;
}

.answer input {
    width: auto;
    height: auto;
    visibility: visible;
    margin-right: 8px;
    accent-color: #4f46e5;
}

/* ========================================
   VÝSLEDEK TESTU
======================================== */

.test-result {
    margin-top: 25px;
    padding: 20px;
    border: 1px solid #c7d2fe;
    border-radius: 12px;
    background-color: #eef2ff;
    color: #312e81;
}

.test-result h3 {
    margin-top: 0;
}

/* ========================================
   PŘEPÍNAČ SVĚTLÉHO / TMAVÉHO REŽIMU
   HTML: <input type="checkbox" id="darkmode-toggle">
         <label for="darkmode-toggle"> ... SVG ikony ... </label>
======================================== */

#darkmode-toggle {
    position: absolute;
    width: 1px;
    height: 1px;
    padding: 0;
    margin: -1px;
    overflow: hidden;
    clip: rect(0, 0, 0, 0);
    white-space: nowrap;
    border: 0;
}

#darkmode-toggle + label {
    position: relative;
    display: block;
    flex: 0 0 50px;
    width: 50px;
    min-width: 50px;
    height: 26px;
    margin: 0;
    padding: 0;
    background: #e2e8f0;
    border: 1px solid #cbd5e1;
    border-radius: 999px;
    box-shadow: inset 0 2px 5px rgba(15, 23, 42, 0.18);
    cursor: pointer;
    transition: background-color 0.3s, border-color 0.3s;
}

#darkmode-toggle + label::after {
    content: "";
    position: absolute;
    top: 3px;
    left: 3px;
    width: 18px;
    height: 18px;
    background: linear-gradient(180deg, #ffcc89, #d8860b);
    border-radius: 50%;
    box-shadow: 0 2px 6px rgba(0, 0, 0, 0.25);
    transition: transform 0.3s, background 0.3s;
}

#darkmode-toggle:checked + label {
    background: #242424;
    border-color: #475569;
}

#darkmode-toggle:checked + label::after {
    transform: translateX(24px);
    background: linear-gradient(180deg, #777, #3a3a3a);
}

#darkmode-toggle + label svg {
    position: absolute;
    top: 6px;
    z-index: 1;
    width: 12px;
    height: 12px;
    pointer-events: none;
}

#darkmode-toggle + label svg.sun {
    left: 6px;
    fill: #ffffff;
    transition: fill 0.3s;
}

#darkmode-toggle + label svg.moon {
    right: 6px;
    fill: #64748b;
    transition: fill 0.3s;
}

#darkmode-toggle:checked + label svg.sun {
    fill: #64748b;
}

#darkmode-toggle:checked + label svg.moon {
    fill: #ffffff;
}

#darkmode-toggle:focus-visible + label {
    outline: 2px solid #818cf8;
    outline-offset: 3px;
}

/* ========================================
   MOBILNÍ ZAŘÍZENÍ
======================================== */

@media (max-width: 600px) {
    .layout {
        gap: 10px;
        padding: 10px;
    }

    .navbar {
        flex-basis: 150px;
        width: 150px;
        padding: 12px;
    }

    .navbar.collapsed {
        flex-basis: 60px;
        width: 60px;
        padding: 12px 6px;
    }

    .nav-links a {
        gap: 8px;
        padding: 10px 6px;
        font-size: 13px;
    }

    .icon {
        flex-basis: 22px;
        font-size: 19px;
    }

    section {
        padding: 15px;
    }

    section h1 {
        font-size: 25px;
    }

    section h2 {
        font-size: 21px;
    }

    .question {
        padding: 15px;
    }
}

/* ========================================
   MENŠÍ MOBILY
======================================== */

@media (max-width: 380px) {
    .layout {
        gap: 8px;
        padding: 8px;
    }

    .navbar {
        flex-basis: 125px;
        width: 125px;
        padding: 8px;
    }

    .navbar.collapsed {
        flex-basis: 50px;
        width: 50px;
        padding: 8px 4px;
    }

    .nav-links a {
        font-size: 12px;
    }

    section {
        padding: 12px;
    }
}

/* ========================================
   OMEZENÍ ANIMACÍ
======================================== */

@media (prefers-reduced-motion: reduce) {
    *,
    *::before,
    *::after {
        scroll-behavior: auto !important;
        transition-duration: 0.01ms !important;
    }
}