CSSだけで作るエレクトリックに歪むグローカード

<main class="kumonosu-main-container">
  <svg class="kumonosu-svg-container">
    <defs>
      <filter id="kumonosu-turbulent-displace" colorInterpolationFilters="sRGB" x="-20%" y="-20%" width="140%" height="140%">
        <feTurbulence type="turbulence" baseFrequency="0.02" numOctaves="10" result="noise1" seed="1" />
        <feOffset in="noise1" dx="0" dy="0" result="offsetNoise1">
          <animate attributeName="dy" values="490; 0" dur="6s" repeatCount="indefinite" calcMode="linear" />
        </feOffset>

        <feTurbulence type="turbulence" baseFrequency="0.02" numOctaves="10" result="noise2" seed="1" />
        <feOffset in="noise2" dx="0" dy="0" result="offsetNoise2">
          <animate attributeName="dy" values="0; -490" dur="6s" repeatCount="indefinite" calcMode="linear" />
        </feOffset>

        <feTurbulence type="turbulence" baseFrequency="0.02" numOctaves="10" result="noise1" seed="2" />
        <feOffset in="noise1" dx="0" dy="0" result="offsetNoise3">
          <animate attributeName="dx" values="700; 0" dur="6s" repeatCount="indefinite" calcMode="linear" />
        </feOffset>

        <feTurbulence type="turbulence" baseFrequency="0.02" numOctaves="10" result="noise2" seed="2" />
        <feOffset in="noise2" dx="0" dy="0" result="offsetNoise4">
          <animate attributeName="dx" values="0; -700" dur="6s" repeatCount="indefinite" calcMode="linear" />
        </feOffset>

        <feComposite in="offsetNoise1" in2="offsetNoise2" result="part1" />
        <feComposite in="offsetNoise3" in2="offsetNoise4" result="part2" />
        <feBlend in="part1" in2="part2" mode="color-dodge" result="combinedNoise" />

        <feDisplacementMap in="SourceGraphic" in2="combinedNoise" scale="30" xChannelSelector="R" yChannelSelector="B" />
      </filter>
    </defs>
  </svg>

  <div class="kumonosu-card-container">
    <div class="kumonosu-inner-container">
      <div class="kumonosu-border-outer">
        <div class="kumonosu-main-card"></div>
      </div>
      <div class="kumonosu-glow-layer-1"></div>
      <div class="kumonosu-glow-layer-2"></div>
    </div>

    <div class="kumonosu-overlay-1"></div>
    <div class="kumonosu-overlay-2"></div>
    <div class="kumonosu-background-glow"></div>

    <div class="kumonosu-content-container">
      <div class="kumonosu-content-main">
        <p class="kumonosu-title">KUMONOSU Electric</p>
      </div>
    </div>
  </div>
</main>

/* CSS Variables */
:root {
  --kumonosu-electric-border-color: #ff3c3c;
  --kumonosu-electric-light-color: oklch(from var(--kumonosu-electric-border-color) l c h);
  --kumonosu-gradient-color: oklch(
    from var(--kumonosu-electric-border-color) 0.3 calc(c / 2) h / 0.4
  );
  --kumonosu-color-neutral-900: oklch(0.185 0 0);
  --kumonosu-card-padding: clamp(1.5rem, 6vw, 3rem);
}

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

body {
  font-family: system-ui, -apple-system, sans-serif;
  background-color: oklch(0.145 0 0);
  color: oklch(0.985 0 0);
  min-height: 100vh;
  display: flex;
  align-items: center;
  justify-content: center;
  overflow-x: hidden;
}

.kumonosu-main-container {
  display: flex;
  align-items: center;
  justify-content: center;
  width: 100%;
  padding: 20px;
}

.kumonosu-svg-container {
  position: absolute;
  width: 0;
  height: 0;
}

/* Card container */
.kumonosu-card-container {
  padding: 2px;
  border-radius: 24px;
  position: relative;
  background: linear-gradient(
      -30deg,
      var(--kumonosu-gradient-color),
      transparent,
      var(--kumonosu-gradient-color)
    ),
    linear-gradient(
      to bottom,
      var(--kumonosu-color-neutral-900),
      var(--kumonosu-color-neutral-900)
    );
  width: 100%;
  max-width: 500px; /* 横長設定 */
}

.kumonosu-inner-container {
  position: relative;
  width: 100%;
}

.kumonosu-border-outer {
  border: 2px solid rgba(221, 132, 72, 0.5);
  border-radius: 24px;
  padding-right: 4px;
  padding-bottom: 4px;
}

.kumonosu-main-card {
  width: 100%;
  aspect-ratio: 2 / 1; /* 横長比率 */
  border-radius: 24px;
  border: 2px solid var(--kumonosu-electric-border-color);
  margin-top: -4px;
  margin-left: -4px;
  filter: url(#kumonosu-turbulent-displace);
}

/* Glow layers */
.kumonosu-glow-layer-1,
.kumonosu-glow-layer-2 {
  border-radius: 24px;
  width: 100%;
  height: 100%;
  position: absolute;
  top: 0;
  left: 0;
  pointer-events: none;
}

.kumonosu-glow-layer-1 {
  border: 2px solid rgba(221, 132, 72, 0.6);
  filter: blur(1px);
}

.kumonosu-glow-layer-2 {
  border: 2px solid var(--kumonosu-electric-light-color);
  filter: blur(4px);
}

/* Overlays */
.kumonosu-overlay-1,
.kumonosu-overlay-2 {
  position: absolute;
  inset: 0;
  border-radius: 24px;
  mix-blend-mode: overlay;
  transform: scale(1.05);
  filter: blur(16px);
  pointer-events: none;
}

.kumonosu-overlay-1 {
  opacity: 1;
  background: linear-gradient(-30deg, white, transparent 30%, transparent 70%, white);
}

.kumonosu-overlay-2 {
  opacity: 0.5;
  background: linear-gradient(-30deg, white, transparent 30%, transparent 70%, white);
}

.kumonosu-background-glow {
  position: absolute;
  inset: 0;
  border-radius: 24px;
  filter: blur(32px);
  transform: scale(1.1);
  opacity: 0.3;
  z-index: -1;
  background: linear-gradient(
    -30deg,
    var(--kumonosu-electric-light-color),
    transparent,
    var(--kumonosu-electric-border-color)
  );
}

/* Content container */
.kumonosu-content-container {
  position: absolute;
  inset: 0;
  display: flex;
  flex-direction: column;
  pointer-events: none;
}

.kumonosu-content-main {
  display: flex;
  flex-direction: column;
  padding: var(--kumonosu-card-padding);
  height: 100%;
}

/* Typography */
.kumonosu-title {
  font-size: clamp(1.5rem, 6vw, 2.5rem);
  line-height: 1.1;
  font-weight: 500;
  margin-top: auto; /* 下側に配置 */
  pointer-events: auto;
}