/* 20周年記念オープニングアニメーション */
#anniversary-opening {
    position: fixed;
    top: 0;
    left: 0;
    width: 100vw;
    height: 100vh;
    z-index: 999999;
    display: flex;
    align-items: center;
    justify-content: center;
    background-color: #000000;
    overflow: hidden;
}

#anniversary-opening.hidden {
    display: none;
}

#anniversary-opening.fade-out {
    animation: whiteout 1s ease-in-out forwards;
}

/* ローディング画面 */
#anniversary-loading {
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    display: flex;
    flex-direction: column;
    align-items: center;
    justify-content: center;
    background-color: #000000;
    z-index: 11;
    opacity: 1;
    transition: opacity 0.5s ease-out;
}

#anniversary-loading.loaded {
    opacity: 0;
    pointer-events: none;
}

.loading-spinner {
    width: 50px;
    height: 50px;
    border: 4px solid rgba(255, 255, 255, 0.3);
    border-top: 4px solid #ffffff;
    border-radius: 50%;
    animation: spin 1s linear infinite;
    margin-bottom: 20px;
}

@keyframes spin {
    0% { transform: rotate(0deg); }
    100% { transform: rotate(360deg); }
}

.loading-text {
    font-family: 'Courier New', 'Courier', monospace;
    font-size: 18px;
    font-weight: 700;
    color: #ffffff;
    letter-spacing: 0.2em;
}

/* 背景画像レイヤー */
.anniversary-bg-layer {
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    background-size: cover;
    background-position: center;
    background-repeat: no-repeat;
    opacity: 0;
    transition: opacity 0.8s ease-in-out;
}

.anniversary-bg-layer.active {
    opacity: 1;
}

#anniversary-counter {
    font-family: 'Courier New', 'Courier', monospace;
    font-size: clamp(100px, 18vw, 200px);
    font-weight: 700;
    color: #ffffff;
    text-shadow: 0 0 40px rgba(0, 0, 0, 0.8),
                 0 0 20px rgba(0, 0, 0, 0.6);
    letter-spacing: 0.1em;
    user-select: none;
    position: relative;
    z-index: 10;
    width: 5em;
    text-align: center;
    display: inline-block;
    opacity: 0;
    transition: opacity 0.8s ease-in;
}

#anniversary-counter.show {
    opacity: 1;
}

@keyframes whiteout {
    0% {
        background-color: rgba(0, 0, 0, 0);
    }
    100% {
        background-color: rgba(255, 255, 255, 1);
    }
}

/* スクロール無効化 */
body.opening-active {
    overflow: hidden;
    height: 100vh;
}