/* Hintergrund */
body {
    margin: 0;
    padding: 0;
    background: url("img/background.png") no-repeat center center/cover;
    font-family: Arial, sans-serif;
    min-height: 100vh;
    overflow-x: hidden;
    position: relative;
}

/* Titel */
.title {
    text-align: center;
    margin-top: 20px;
    color: white;
    text-shadow: 2px 2px 8px black;
    font-size: 2rem;
}

/* Kalender */
.calendar {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(90px, 1fr));
    gap: 15px;
    padding: 20px;
    width: 95%;
    max-width: 700px;
    margin: auto;
    position: relative;
    z-index: 500;
}

/* Türchen */
.door {
    background: rgba(255,255,255,0.2);
    border: 2px solid white;
    border-radius: 12px;
    height: 90px;
    display: flex;
    align-items: center;
    justify-content: center;
    backdrop-filter: blur(4px);
    color: white;
    cursor: pointer;
    font-size: 1.8rem;
    text-shadow: 1px 1px 4px black;
    transition: 0.3s;
}

.door.open {
    background: rgba(0,180,0,0.6);
    border-color: #00ff88;
    box-shadow: 0 0 10px #00ff88;
}

/* Popup Hintergrund */
.popup-bg {
    position: fixed;
    top:0; left:0;
    width:100%; height:100%;
    background: rgba(0,0,0,0.6);
    display:none;
    z-index: 900;
}

/* Popup Fenster */
.popup {
    position: fixed;
    top:50%; left:50%;
    transform: translate(-50%, -50%);
    background:white;
    padding:20px;
    border-radius:14px;
    width:85%;
    max-width:350px;
    display:none;
    z-index: 1000;
    text-align:center;
}

/* Schneefall */
.snow {
    position: fixed;
    top:0; left:0;
    width:100%; height:100%;
    pointer-events:none;
    background-image: url("img/snow.png");
    animation: snow 12s linear infinite;
    opacity: 0.7;
    z-index:200;
}

@keyframes snow {
    from { background-position: 0 0; }
    to   { background-position: 0 1000px; }
}