/* ====== LAYOUT (HEADER, SIDEBAR, HERO, FOOTER) ====== */

/* --- HEADER & NAVIGATION --- */
header {
    position: sticky;
    top: 0;
    z-index: 100;
    /* Safe Area Insets: Verhindert, dass der Header unter einer Smartphone-Notch (z.B. iPhone) klebt */
    padding: calc(var(--space-s) + env(safe-area-inset-top, 0px)) 5% var(--space-s) 5%;
    background-color: rgba(42, 44, 58, 0.8);
    backdrop-filter: blur(10px);
    border-bottom: 1px solid var(--primary-color);
    transition: background-color 0.3s ease, border-bottom 0.3s ease;
}

nav {
    display: flex;
    align-items: center;
    gap: var(--space-m);
}

.logo {
    flex-shrink: 0;
    color: var(--accent-color);
    font-size: 1.8rem;
    font-weight: 700;
    text-decoration: none;
}

.nav-cluster-right {
    display: flex;
    align-items: center;
    margin-left: auto;
    gap: var(--space-m);
}

.burger {
    display: none;
    cursor: pointer;
    z-index: 101;
}

.burger div {
    width: 25px;
    height: 3px;
    margin: 5px;
    background-color: var(--text-color);
    transition: all 0.3s ease;
}

/* --- HERO SECTION --- */
.hero {
    position: relative;
    z-index: 1;
    display: flex;
    align-items: center;
    justify-content: center;
    /* Next Level: dvh verhindert Layout-Sprünge beim Scrollen auf Mobile */
    min-height: 80dvh; 
    padding: var(--space-xxl) 5%;
    text-align: center;
}

.hero::before {
    content: '';
    position: absolute;
    inset: 0;
    z-index: -1;
    background: rgba(42, 44, 58, 0.7);
}

.hero-text h1 {
    margin-bottom: 1rem;
    background: linear-gradient(45deg, var(--primary-color), var(--accent-color));
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
}

.hero-text p {
    max-width: 60ch;
    margin-inline: auto;
    margin-bottom: var(--space-l);
    font-size: 1.2rem;
}

/* --- MAIN LAYOUT & SIDEBAR --- */
.page-with-sidebar {
    display: grid;
    grid-template-columns: minmax(250px, 280px) 1fr;
    gap: var(--space-l);
    padding: var(--space-l) 5%;
    align-items: flex-start;
}

.main-column {
    min-width: 0;
    /* Next Level: Container Query Setup. 
       Ab hier überwacht der Browser die Breite DIESES Containers! */
    container-type: inline-size;
    container-name: main;
}

.sidebar-nav {
    position: sticky;
    top: 100px;
    display: flex;
    flex-direction: column;
    /* Next Level: dvh hier ebenfalls implementiert */
    max-height: calc(100dvh - 120px); 
    padding: var(--space-m);
    background: rgba(58, 61, 78, 0.5);
    backdrop-filter: blur(10px);
    border-left: 2px solid var(--primary-color);
    box-shadow: inset 0 0 0 1px rgba(255, 255, 255, 0.1);
}

.sidebar-nav h3 {
    flex-shrink: 0;
    padding-bottom: var(--space-xs);
    margin-bottom: var(--space-s);
    border-bottom: 1px solid var(--secondary-color);
    font-size: var(--fs-500);
}

.sidebar-nav ul {
    padding-right: 10px;
    list-style: none;
    overflow-y: auto;
}

.sidebar-nav ul::-webkit-scrollbar {
    width: 6px;
}

.sidebar-nav ul::-webkit-scrollbar-track {
    background: transparent;
}

.sidebar-nav ul::-webkit-scrollbar-thumb {
    background-color: var(--primary-color);
}

.sidebar-nav a {
    display: block;
    padding: var(--space-xs) var(--space-s);
    border-left: 3px solid transparent;
    font-size: var(--fs-200);
    transition: all 0.2s ease;
}

.sidebar-nav a:hover {
    color: var(--primary-color);
    border-left-color: var(--primary-color);
    transform: translateX(5px);
}

.sidebar-nav a.active {
    background-color: rgba(248, 180, 217, 0.1);
    color: var(--primary-color);
    font-weight: 700;
    border-left-color: var(--primary-color);
    transform: translateX(5px);
}

.sidebar-nav > ul > li {
    margin-bottom: var(--space-s);
}

.sidebar-nav .chapter-title {
    padding: 0.2rem var(--space-s);
    color: var(--accent-color);
    cursor: default;
    font-size: var(--fs-300);
    font-weight: 700;
    letter-spacing: 0.5px;
    text-transform: uppercase;
}

.sidebar-nav .lektion-list {
    margin-top: var(--space-xs);
    margin-left: var(--space-s);
    padding-left: var(--space-s);
    border-left: 2px solid var(--secondary-color);
    list-style: none;
}

.sidebar-nav .lektion-list a {
    font-weight: 400;
}

.sidebar-nav .lektion-list a.active {
    font-weight: 700;
}

/* --- CONTENT SECTIONS & PAGES --- */
section {
    scroll-margin-top: 120px;
}

.content-section {
    max-width: 1200px;
    margin-inline: auto;
    padding: var(--space-xxl) 5%;
    /* Next Level: Auch die Home-Sections werden zu Container-Kontexten */
    container-type: inline-size;
    container-name: main;
}

.content-page {
    padding: var(--space-xl);
    background: var(--bg-light);
    border: 1px solid var(--secondary-color);
}

.breadcrumb {
    margin-bottom: var(--space-l);
    font-size: var(--fs-300);
}

.learning-content h2 {
    margin-top: var(--space-xl);
    margin-bottom: var(--space-m);
    padding-left: var(--space-s);
    border-left: 4px solid var(--accent-color);
    text-align: left;
}

.learning-content h3 {
    margin-top: var(--space-xl);
    margin-bottom: var(--space-m);
}

.learning-content h4 {
    margin-top: var(--space-l);
    margin-bottom: var(--space-s);
}

.learning-content h5 {
    margin-top: var(--space-m);
    margin-bottom: var(--space-xs);
}

.learning-content hr {
    height: 1px;
    margin-block: var(--space-xl);
    background-image: linear-gradient(to right, transparent, var(--secondary-color), transparent);
    border: 0;
}

.learning-content p,
.learning-content ul {
    margin-bottom: var(--space-m);
    line-height: 1.7;
}

.learning-content ul {
    padding-left: var(--space-m);
    list-style-position: inside;
}

.learning-content strong {
    color: var(--accent-color);
}

/* --- FOOTER --- */
footer {
    /* Safe-Area für Home-Balken unten auf modernen Handys */
    padding: var(--space-l) 5% calc(var(--space-l) + env(safe-area-inset-bottom, 0px)) 5%;
    margin-top: var(--space-xxl);
    border-top: 1px solid var(--secondary-color);
    text-align: center;
}

.footer-actions {
    margin-bottom: var(--space-m);
}

#changeThemeBtn {
    border-bottom: 1px dotted var(--secondary-color);
    color: var(--secondary-color);
    cursor: pointer;
    font-weight: 600;
    text-decoration: none;
    transition: color 0.2s ease, border-color 0.2s ease;
}

#changeThemeBtn:hover {
    border-bottom-color: var(--primary-color);
    color: var(--primary-color);
}