:root {
    --bg-color: #100ace;
    --spot-color: #2b52ff; 
    --text-white: #ffffff;
    --extreme-easing: cubic-bezier(0.85, 0, 0.15, 1);
    --out-easing: cubic-bezier(0.23, 1, 0.32, 1);
}

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

/* body {
    background-color: var(--bg-color);
    font-family: 'Inter', sans-serif;
    //ページのスクロールを妨げないよう、ここでのoverflow: hiddenは外しておきます
} */

/* --- ノイズ設定 --- */
.noise-overlay {
    position: absolute; /* fixedからabsoluteに変更し、KV内に収めます */
    inset: 0;
    z-index: 999;
    pointer-events: none;
    opacity: 0.18; 
}

.noise-overlay::before {
    content: "";
    position: absolute;
    inset: -100%;
    background: #fff;
    filter: url(#noiseFilter);
    mix-blend-mode: overlay;
    animation: noiseAnim 0.2s steps(2) infinite;
}

@keyframes noiseAnim {
    0% { transform: translate(0,0); }
    10% { transform: translate(-1%, -1%); }
    30% { transform: translate(1%, 1%); }
    50% { transform: translate(-0.5%, 1.5%); }
    70% { transform: translate(1.5%, -0.5%); }
    90% { transform: translate(-1%, 0.5%); }
    100% { transform: translate(0,0); }
}

/* --- メインビジュアル（縦幅固定版） --- */
.main-visual {
    position: relative;
    width: 100%;
    height: 600px; /* PC・タブレットでの固定サイズ */
    display: flex;
    justify-content: center;
    align-items: center;
    overflow: hidden;
    background-color: var(--bg-color);
}

.stage-container {
    position: absolute;
    inset: 0;
    z-index: 1;
}

.spotlight {
    position: absolute;
    background-color: var(--spot-color);
    border-radius: 50%;
    pointer-events: none;
    mix-blend-mode: screen; 
    opacity: 0.8;
}

.spot-1 { 
    width: 46vw; height: 46vw; top: -30%; 
    --start-x: -50%; --mid-x: 10%; --end-x: 80%;
    animation: moveFocus-1 7s var(--extreme-easing) infinite alternate; 
}
.spot-2 { 
    width: 30vw; height: 30vw; bottom: -10%; 
    --start-x: 100%; --mid-x: 35%; --end-x: -20%;
    animation: moveFocus-2 5.2s var(--extreme-easing) infinite alternate; 
    animation-delay: -1s; 
}
.spot-3 { 
    width: 46vw; height: 46vw; top: 15%; 
    --start-x: -30%; --mid-x: 60%; --end-x: 110%;
    animation: moveFocus-3 8.5s var(--extreme-easing) infinite alternate; 
    animation-delay: -2.5s; 
}
.spot-4 { 
    width: 30vw; height: 30vw; bottom: 20%; 
    --start-x: 110%; --mid-x: 85%; --end-x: 0%;
    animation: moveFocus-4 6s var(--extreme-easing) infinite alternate; 
    animation-delay: -4s; 
}

@keyframes moveFocus-1 {
    0%   { left: var(--start-x); filter: blur(80px); transform: scale(1.3); }
    25%  { filter: blur(0px); transform: scale(1); }
    50%  { left: var(--mid-x); }
    100% { left: var(--end-x); filter: blur(80px); transform: scale(1.3); }
}

@keyframes moveFocus-2 {
    0%   { left: var(--start-x); filter: blur(80px); transform: scale(1.3); }
    50%  { left: var(--mid-x); }
    75%  { filter: blur(0px); transform: scale(1); }
    100% { left: var(--end-x); filter: blur(80px); transform: scale(1.3); }
}

@keyframes moveFocus-3 {
    0%   { left: var(--start-x); filter: blur(80px); transform: scale(1.3); }
    50%  { left: var(--mid-x); filter: blur(0px); transform: scale(1); }
    100% { left: var(--end-x); filter: blur(80px); transform: scale(1.3); }
}

@keyframes moveFocus-4 {
    0%   { left: var(--start-x); filter: blur(80px); transform: scale(1.3); }
    40%  { filter: blur(0px); transform: scale(1); }
    50%  { left: var(--mid-x); }
    100% { left: var(--end-x); filter: blur(80px); transform: scale(1.3); }
}

/* --- 枠線とテキスト --- */
.frame-container {
    position: relative;
    padding: 60px 80px;
    z-index: 100;
    transform: scale(1.1);
    transform-origin: center;
}

.border-svg {
    position: absolute;
    inset: 0;
    width: 100%;
    height: 100%;
    fill: none;
}

.border-svg rect {
    stroke: var(--text-white);
    stroke-width: 2px;
    visibility: hidden;
}

.is-active .border-svg rect {
    visibility: visible;
    animation: drawOnce 2.5s var(--out-easing) forwards;
}

@keyframes drawOnce {
    from { stroke-dashoffset: var(--path-length); }
    to { stroke-dashoffset: 0; }
}

.content {
    text-align: center;
    overflow: hidden;
}

.title {
    color: var(--text-white);
    font-weight: 400;
    font-size: clamp(1rem, 3.2vw, 2.4rem);
    line-height: 1.2;
    /* letter-spacing: -0.04em; */
    display: flex;
    flex-wrap: wrap;
    justify-content: center;
}

.line {
    display: inline-block;
    opacity: 0;
    transform: translateY(100%);
}

.line-1 { margin-right: 0.28em; }

.is-active .line {
    animation: slideUp 1.2s var(--out-easing) forwards;
}

.is-active .line-2 { animation-delay: 0.05s; }

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

/* --- レスポンシブ --- */
@media (max-width: 768px) {
    .main-visual {
        height: 450px; /* モバイルでは少し高さを抑える */
    }
    .frame-container { 
        padding: 40px 25px; 
        width: 85%; 
        transform: scale(1.1); 
    }
    .line { display: block; width: 100%; }
    .line-1 { margin-right: 0; }
    .title { font-size: 1.5rem; }
}