/* --- GEMEINSAME VARIABLEN --- */
:root {
    --color-primary: #2c3e50;
    --color-secondary: #34495e;
    --color-accent: #3498db;
    --color-success: #2ecc71;
    --color-locked: #bdc3c7;
    --color-bg: #f4f7f6;
    --sidebar-width: 260px;
    --header-height: 60px;
    --footer-height: 40px;
}

/* --- BASIS LAYOUT (für beide Seiten gleich) --- */
body {
    font-family: 'Segoe UI', Tahoma, Geneva, Verdana, sans-serif;
    margin: 0;
    display: flex;
    flex-direction: column;
    height: 100vh;
    background-color: var(--color-bg);
    overflow: hidden;
}

header {
    height: var(--header-height);
    background-color: white;
    display: flex;
    align-items: center;
    padding: 0 20px;
    box-shadow: 0 2px 5px rgba(0,0,0,0.1);
    justify-content: space-between;
    z-index: 100;
}

.logo { font-weight: bold; font-size: 1.4rem; color: var(--color-accent); text-decoration: none; }

.main-wrapper { display: flex; flex: 1; overflow: hidden; }

aside {
    width: var(--sidebar-width);
    background-color: var(--color-primary);
    color: white;
    padding-top: 20px;
}

aside nav a {
    padding: 15px 20px;
    color: #ecf0f1;
    text-decoration: none;
    display: block;
    border-left: 4px solid transparent;
}

aside nav a.active { background-color: var(--color-secondary); border-left: 4px solid var(--color-accent); }

main {
    flex: 1;
    overflow-y: auto;
    padding: 40px;
    display: flex;
    justify-content: center;
    align-items: flex-start;
}

footer {
    height: var(--footer-height);
    background-color: white;
    border-top: 1px solid #ddd;
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 0.8rem;
    color: #7f8c8d;
}

/* --- KOMPONENTE: LERNPFAD (NETZWERK) --- */
.network-container {
    position: relative;
    width: 800px;
    height: 600px;
    background: white;
    border-radius: 15px;
    box-shadow: 0 4px 20px rgba(0,0,0,0.08);
}

.network-svg { position: absolute; top: 0; left: 0; width: 100%; height: 100%; z-index: 1; }
.network-line { stroke: #dcdde1; stroke-width: 4; stroke-linecap: round; }

.node {
    position: absolute;
    z-index: 2;
    display: flex;
    flex-direction: column;
    align-items: center;
    text-decoration: none;
    transform: translate(-50%, -50%);
    transition: transform 0.2s;
}

.node:hover { transform: translate(-50%, -50%) scale(1.1); }

.circle {
    width: 70px;
    height: 70px;
    border-radius: 50%;
    display: flex;
    justify-content: center;
    align-items: center;
    color: white;
    font-weight: bold;
    box-shadow: 0 4px 6px rgba(0,0,0,0.1);
}

.label { margin-top: 8px; font-size: 0.85rem; font-weight: 600; color: #2c3e50; white-space: nowrap; }

.completed .circle { background-color: var(--color-success); }
.active .circle { background-color: var(--color-accent); animation: pulse 2s infinite; }
.locked .circle { background-color: var(--color-locked); }
.locked { pointer-events: none; opacity: 0.7; }

/* --- KOMPONENTE: LEKTIONS-INHALT --- */
.lesson-container {
    max-width: 800px;
    width: 100%;
    background: white;
    padding: 40px;
    border-radius: 15px;
    box-shadow: 0 4px 20px rgba(0,0,0,0.05);
}

.video-placeholder {
    width: 100%; aspect-ratio: 16 / 9; background-color: #2c3e50;
    border-radius: 10px; display: flex; justify-content: center; align-items: center;
    color: white; margin-bottom: 30px; font-style: italic;
}

.btn { padding: 12px 25px; border-radius: 8px; text-decoration: none; font-weight: bold; transition: all 0.2s; cursor: pointer; border: none; display: inline-block;}
.btn-secondary { background-color: #eee; color: #333; }
.btn-success { background-color: var(--color-success); color: white; }

/* --- ANIMATIONEN & ICONS --- */
@keyframes pulse {
    0% { box-shadow: 0 0 0 0 rgba(52, 152, 219, 0.4); }
    70% { box-shadow: 0 0 0 15px rgba(52, 152, 219, 0); }
    100% { box-shadow: 0 0 0 0 rgba(52, 152, 219, 0); }
}

.lock-icon { width: 20px; fill: white; }