/* ==========================
   Grundlayout
   ========================== */

* {
    box-sizing: border-box;
}

html,
body {
    margin: 0;
    padding: 0;
    min-height: 100%;
}

body {
    min-height: 100vh;

    display: grid;
    grid-template-rows: 60px minmax(0, 1fr) 50px;

    font-family: Arial, Helvetica, sans-serif;
    background: #f5f5f5;
}


/* ==========================
   Header
   ========================== */

.header {

    position: sticky;
    top: 0;
    z-index: 1000;


    background: #003366;
    color: white;

    display: flex;
    justify-content: space-between;
    align-items: center;

    padding: 0 20px;
}

.header nav {
    display: flex;
    align-items: center;
    gap: 20px;
}

.header a {
    color: white;
    text-decoration: none;
}

.header a:hover {
    text-decoration: underline;
}


/* ==========================
   Hauptlayout
   ========================== */

.layout {
    width: min(calc(100% - 40px), 1400px);

    margin: 0 auto;
    padding: 20px 0;

    overflow-y: auto;
}


/* ==========================
   Hauptbereich
   ========================== */
.center {
    width: 100%;
    min-width: 0;

    background: transparent;
    border: 0;
    border-radius: 0;

    overflow: visible;
}

.center-header {
    position: sticky;
    top: 0;

    padding: 20px 25px;

    background: white;
    border-bottom: 1px solid #ddd;

    z-index: 10;
}

.center-content {
    padding: 25px;
}


/* ==========================
   Footer
   ========================== */

.footer {
    background: #003366;
    color: white;

    display: flex;
    align-items: center;
    justify-content: center;
}


/* ==========================
   Listen
   ========================== */

ul {
    padding-left: 1.2em;
}

ul ul {
    padding-left: 0.8em;
}

ul ul ul {
    padding-left: 0.8em;
}


/* ==========================
   Kartenübersicht
   ========================== */

.lecture-grid {
    display: grid;

    grid-template-columns:
        repeat(3, minmax(0, 1fr));

    gap: 30px;

    align-items: stretch;

    margin: 30px 0;
}


.lecture-card {
    position: relative;

    min-width: 0;

    padding: 24px;
    padding-top: 0px;

    background: white;

    border: 1px solid #ddd;
    border-radius: 16px;

    overflow: hidden;

    box-shadow:
        0 8px 18px rgba(0, 0, 0, 0.08);

    cursor: pointer;

    transition:
        transform 0.2s,
        box-shadow 0.2s,
        border-color 0.2s;
}

.lecture-card:hover {
    transform: translateY(-4px);

    border-color: #003366;

    box-shadow:
        0 14px 28px rgba(0, 0, 0, 0.15);
}


/* Unsichtbarer Link über der gesamten Karte */

.lecture-card-link {
    position: absolute;
    inset: 0;

    z-index: 10;

    border-radius: inherit;
}

.lecture-card-link:focus-visible {
    outline: 4px solid #ffbf47;
    outline-offset: -4px;
}


/* Überschrift */

.lecture-card h2 {
    position: relative;
    
    margin-bottom: 16px;

    color: #003366;

    z-index: 1; 
}


/* Schmales horizontales Bild unter der Überschrift */

.lecture-card-image {
    display: block;

    width: calc(100% + 48px);
    height: 40px;

    margin:
        0
        -24px
        20px
        -24px;

    object-fit: cover;

    border-radius: 0;
}


/* ==========================
   Tablet
   ========================== */

@media (max-width: 1000px) {
    .lecture-grid {
        grid-template-columns:
            repeat(2, minmax(0, 1fr));
    }
}


/* ==========================
   Smartphone
   ========================== */

@media (max-width: 700px) {
    body {
        grid-template-rows: auto minmax(0, 1fr) 50px;
    }

    .header {
        flex-direction: column;
        align-items: flex-start;

        gap: 14px;

        padding: 16px 20px;
    }

    .header nav {
        width: 100%;

        flex-wrap: wrap;

        gap: 10px 18px;
    }

    .layout {
        width: calc(100% - 24px);

        padding: 12px 0;
    }

    .center-content {
        padding: 20px;
    }

    .lecture-grid {
        grid-template-columns: minmax(0, 1fr);

        gap: 20px;
    }
}


.block-image {
    display: block;

    width: 100%;
    height: 200px;

    object-fit: cover;

    border-radius: 12px;

    margin-bottom: 20px;
}

.logo {
    display: block;

    height: 20px;
    width: auto;
}