/* Reset and base styles */
* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}

body {
    font-family: 'Noto Serif JP', serif;
    color: #000;
    background-color: #fefefe;
    overflow-x: hidden;
    position: relative;
    min-height: 100vh;
}

/* Background animation container */
#background-animation {
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    z-index: 1;
    pointer-events: none;
}

/* Content overlay */
#content-overlay {
    position: relative;
    z-index: 10;
    background: rgba(254, 254, 254, 0.85);
    backdrop-filter: blur(1px);
    -webkit-backdrop-filter: blur(1px);
    min-height: 100vh;
    padding: 2rem;
}

/* Header styles */
header {
    text-align: center;
    margin-bottom: 4rem;
    padding: 2rem 0;
}

.main-title {
    font-size: 4rem;
    font-weight: 700;
    letter-spacing: 0.1em;
    margin-bottom: 1rem;
    text-shadow: 2px 2px 4px rgba(0, 0, 0, 0.1);
}

.subtitle {
    font-size: 1.5rem;
    font-weight: 400;
    letter-spacing: 0.2em;
    opacity: 0.8;
}

/* Main content */
main {
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 2rem;
}

.content-section {
    margin-bottom: 4rem;
    padding: 2rem;
    background: rgba(255, 255, 255, 0.6);
    border-radius: 8px;
    backdrop-filter: blur(3px);
    -webkit-backdrop-filter: blur(3px);
    box-shadow: 0 4px 6px rgba(0, 0, 0, 0.05);
}

.content-section h2 {
    font-size: 2.5rem;
    font-weight: 700;
    margin-bottom: 1.5rem;
    letter-spacing: 0.05em;
    border-bottom: 2px solid #000;
    padding-bottom: 0.5rem;
}

.content-placeholder {
    font-size: 1.2rem;
    line-height: 1.8;
    letter-spacing: 0.02em;
}

.content-placeholder p {
    margin-bottom: 1rem;
}

.content-placeholder ul {
    list-style: none;
    padding-left: 0;
}

.content-placeholder li {
    margin-bottom: 0.8rem;
    padding-left: 1.5rem;
    position: relative;
}

.content-placeholder li::before {
    content: "♪";
    position: absolute;
    left: 0;
    color: #333;
    font-weight: bold;
}

/* Footer */
footer {
    text-align: center;
    padding: 2rem;
    margin-top: 4rem;
    border-top: 1px solid rgba(0, 0, 0, 0.1);
    font-size: 0.9rem;
    opacity: 0.7;
}

/* Responsive design */
@media (max-width: 768px) {
    .main-title {
        font-size: 2.5rem;
    }
    
    .subtitle {
        font-size: 1.2rem;
    }
    
    .content-section h2 {
        font-size: 2rem;
    }
    
    .content-placeholder {
        font-size: 1.1rem;
    }
    
    #content-overlay {
        padding: 1rem;
    }
    
    main {
        padding: 0 1rem;
    }
    
    .content-section {
        padding: 1.5rem;
        margin-bottom: 2rem;
    }
}

@media (max-width: 480px) {
    .main-title {
        font-size: 2rem;
    }
    
    .subtitle {
        font-size: 1rem;
    }
    
    .content-section h2 {
        font-size: 1.5rem;
    }
    
    .content-placeholder {
        font-size: 1rem;
    }
}



/* Floating elements for media art animation */
.floating-element {
    position: absolute;
    pointer-events: none;
    font-family: 'Noto Serif JP', serif;
    font-weight: 400;
    white-space: nowrap;
    user-select: none;
    z-index: 11;
    transition: all 0.3s ease;
}

/* Keyframe animations */
@keyframes float {
    0% {
        transform: translateX(0) translateY(0) rotate(0deg);
    }
    25% {
        transform: translateX(100px) translateY(-50px) rotate(90deg);
    }
    50% {
        transform: translateX(-50px) translateY(100px) rotate(180deg);
    }
    75% {
        transform: translateX(-100px) translateY(-100px) rotate(270deg);
    }
    100% {
        transform: translateX(0) translateY(0) rotate(360deg);
    }
}

@keyframes drift {
    0% {
        transform: translateX(-100vw) translateY(0) rotate(0deg);
    }
    100% {
        transform: translateX(100vw) translateY(-20px) rotate(360deg);
    }
}

@keyframes spiral {
    0% {
        transform: translateX(0) translateY(0) rotate(0deg) scale(0.5);
    }
    50% {
        transform: translateX(50px) translateY(50px) rotate(180deg) scale(1);
    }
    100% {
        transform: translateX(0) translateY(0) rotate(360deg) scale(0.5);
    }
}

/* Additional animation variations */
.floating-element:nth-child(3n) {
    animation-name: drift !important;
}

.floating-element:nth-child(5n) {
    animation-name: spiral !important;
}

.floating-element:nth-child(7n) {
    animation-direction: reverse;
}

.floating-element:nth-child(11n) {
    animation-timing-function: ease-in-out;
}

/* Blur effect enhancement */
#background-animation::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    background: linear-gradient(
        45deg,
        rgba(255, 255, 255, 0.1) 0%,
        rgba(255, 255, 255, 0.05) 50%,
        rgba(255, 255, 255, 0.1) 100%
    );
    z-index: 3;
    pointer-events: none;
}

/* Performance optimizations */
.floating-element {
    will-change: transform, opacity;
    backface-visibility: hidden;
    perspective: 1000px;
}

/* Mobile optimizations */
@media (max-width: 768px) {
    .floating-element {
        font-size: 12px !important;
    }
    
    #background-animation {
        backdrop-filter: blur(1px);
        -webkit-backdrop-filter: blur(1px);
    }
}

@media (prefers-reduced-motion: reduce) {
    .floating-element {
        animation: none !important;
        opacity: 0.1 !important;
    }
}

/* ==== animation.js 用の最終仕上げ ==== */

/* 1) 舞台を全面に固定し、はみ出す文字を隠す */
#background-animation{
    inset: 0;              /* top:0;left:0;width/height:100% と同義 */
    position: fixed;
    overflow: hidden;      /* ← これが無いとスクロールバーが出る */
    z-index: 1;            /* 背景なので overlay より下で OK */
    pointer-events: none;  /* クリック貫通 */
}

/* 2) 浮遊文字の基本スタイル強化（重複 OK、あとに書けば上書き） */
.floating-element{
    will-change: transform, opacity; /* パフォーマンス最適化 */
    backface-visibility: hidden;
    perspective: 1000px;
    animation: float 20s linear infinite; /* JS が上書きするのでデフォルト値だけ */
}

/* 3) 必要なら keyframes を上書き（今の動きで満足なら飛ばしていい） */
@keyframes float{
    0%   { transform: translateY(100vh) rotate(0deg);   }
    100% { transform: translateY(-120vh) rotate(360deg);}
}