白黒画像が拡大縮小するローディングアニメーション

<!-- ローディングオーバーレイ -->
<div class="loading-overlay">
    <div class="loading-image"></div>
    <div class="loading-dots">
        <span></span>
        <span></span>
        <span></span>
    </div>
</div>

<!-- 霧のオーバーレイ -->
<div class="fog-overlay"></div>

<!-- ヒーローセクション -->
<section class="hero-section">
    <div class="hero-content">
        <h1 class="hero-title">Nature Awaits</h1>
        <p class="hero-subtitle">Discover the Beauty Around You</p>
    </div>
</section>

* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}

body {
    font-family: 'Georgia', serif;
    overflow: hidden;
    background: #0a0a0a;
}

/* ローディングオーバーレイ */
.loading-overlay {
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    display: flex;
    align-items: center;
    justify-content: center;
    background: #0a0a0a;
    z-index: 9999;
    overflow: hidden;
    opacity: 1;
    animation: fadeOutLoading 0.5s ease 8s forwards;
}

/* 画像本体 - パルス→拡大 */
.loading-image {
    width: 100vw;
    height: 100vh;
    background-image: url('/img/autumn-leaves.jpg');
    background-size: cover;
    background-position: center;
    transform: scale(0.1);
    border-radius: 20px;
    animation: pulseAndZoom 8s cubic-bezier(0.4, 0, 0.2, 1) forwards;
}

/* ローディングドット */
.loading-dots {
    position: absolute;
    top: 50%;
    left: 50%;
    transform: translate(-50%, -50%);
    display: flex;
    gap: 12px;
    z-index: 10000;
    opacity: 1;
    animation: fadeOutDots 0.5s 6s forwards;
}

.loading-dots span {
    width: 12px;
    height: 12px;
    border-radius: 50%;
    background: rgba(255, 255, 255, 0.9);
    animation: dotPulse 1.5s ease-in-out infinite;
}

.loading-dots span:nth-child(2) {
    animation-delay: 0.2s;
}

.loading-dots span:nth-child(3) {
    animation-delay: 0.4s;
}

/* ドットのパルスアニメーション */
@keyframes dotPulse {
    0%, 100% {
        opacity: 0.3;
        transform: scale(0.8);
    }
    50% {
        opacity: 1;
        transform: scale(1.2);
    }
}

/* ドットのフェードアウト */
@keyframes fadeOutDots {
    to {
        opacity: 0;
    }
}

/* 霧のオーバーレイ */
.fog-overlay {
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    background: radial-gradient(circle, rgba(255, 255, 255, 0.95) 0%, rgba(255, 255, 255, 0.85) 100%);
    opacity: 0;
    z-index: 10000;
    pointer-events: none;
    animation: fogLifecycle 10s ease 7.5s forwards;
}

/* パルス→拡大アニメーション */
@keyframes pulseAndZoom {
    /* パルス1回目 */
    0% {
        transform: scale(0.1);
        opacity: 0.6;
        filter: grayscale(1);
    }
    12.5% {
        transform: scale(0.12);
        opacity: 0.7;
        filter: grayscale(1);
    }
    25% {
        transform: scale(0.1);
        opacity: 0.6;
        filter: grayscale(1);
    }
    /* パルス2回目 */
    37.5% {
        transform: scale(0.12);
        opacity: 0.7;
        filter: grayscale(1);
    }
    50% {
        transform: scale(0.1);
        opacity: 0.6;
        filter: grayscale(1);
    }
    /* パルス3回目 */
    62.5% {
        transform: scale(0.12);
        opacity: 0.7;
        filter: grayscale(1);
    }
    75% {
        transform: scale(0.1);
        opacity: 0.6;
        filter: grayscale(1);
    }
    /* カラーに移行 */
    87.5% {
        transform: scale(0.1);
        opacity: 0.8;
        filter: grayscale(0);
    }
    /* 目一杯拡大 */
    100% {
        transform: scale(4);
        opacity: 1;
        filter: grayscale(0);
    }
}

/* ローディングのフェードアウト */
@keyframes fadeOutLoading {
    to {
        opacity: 0;
        visibility: hidden;
    }
}

/* 霧のライフサイクル */
@keyframes fogLifecycle {
    0% {
        opacity: 0;
    }
    15% {
        opacity: 1;
    }
    50% {
        opacity: 1;
    }
    70% {
        opacity: 0.25;
    }
    100% {
        opacity: 0;
    }
}

/* ヒーローセクション */
.hero-section {
    position: relative;
    width: 100%;
    height: 100vh;
    background-image: url('/img/autumn-leaves.jpg');
    background-size: cover;
    background-position: center;
    display: flex;
    flex-direction: column;
    align-items: center;
    justify-content: center;
    opacity: 0;
    animation: fadeInHero 1s ease 8s forwards;
}

@keyframes fadeInHero {
    to {
        opacity: 1;
    }
}

.hero-section::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    background: linear-gradient(135deg, rgba(10, 10, 10, 0.6) 0%, rgba(10, 10, 10, 0.3) 100%);
}

.hero-content {
    position: relative;
    z-index: 1;
    text-align: center;
    color: white;
}

.hero-title {
    font-size: clamp(2.5rem, 8vw, 5rem);
    font-weight: 200;
    letter-spacing: 0.15em;
    margin-bottom: 1.5rem;
    opacity: 0;
    transform: translateY(40px) scale(0.95);
    animation: revealTitle 1.2s cubic-bezier(0.16, 1, 0.3, 1) 9.5s forwards;
    text-shadow: 0 2px 20px rgba(0, 0, 0, 0.5);
}

.hero-subtitle {
    font-size: clamp(1rem, 3vw, 1.8rem);
    font-weight: 300;
    letter-spacing: 0.08em;
    opacity: 0;
    transform: translateY(30px);
    animation: revealSubtitle 1s cubic-bezier(0.16, 1, 0.3, 1) 10.2s forwards;
    text-shadow: 0 2px 15px rgba(0, 0, 0, 0.4);
}

@keyframes revealTitle {
    to {
        opacity: 1;
        transform: translateY(0) scale(1);
    }
}

@keyframes revealSubtitle {
    to {
        opacity: 0.95;
        transform: translateY(0);
    }
}