/* ページ全体の基本設定 */
* {
  box-sizing: border-box;
}

html,
body {
  width: 100%;
  height: 100%;
  margin: 0;
}

body {
  overflow: hidden;
  color: white;
  font-family:
    "Yu Gothic",
    "Meiryo",
    sans-serif;
  background:
    radial-gradient(
      circle at center,
      #252525 0%,
      #101010 45%,
      #000000 100%
    );
}

/* 入口ページ */
.entrance {
  position: relative;
  display: flex;
  align-items: center;
  justify-content: center;
  width: 100%;
  min-height: 100vh;
  min-height: 100svh;
  overflow: hidden;
}

/* ステージ床のような明かり */
.entrance::after {
  position: absolute;
  bottom: -12%;
  left: 50%;
  width: 90%;
  height: 35%;
  content: "";
  background: radial-gradient(
    ellipse at center,
    rgba(255, 255, 255, 0.18) 0%,
    rgba(255, 255, 255, 0.04) 38%,
    transparent 72%
  );
  transform: translateX(-50%);
}

/* タイトル部分 */
.title-area {
  position: relative;
  z-index: 10;
  width: 92%;
  max-width: 1100px;
  padding: 40px 20px;
  text-align: center;
}

.welcome {
  margin: 0 0 12px;
  color: #cccccc;
  font-size: clamp(16px, 2vw, 25px);
  letter-spacing: 0.3em;
}

h1 {
  display: flex;
  align-items: baseline;
  justify-content: center;
  gap: 0.18em;
  margin: 0;
  line-height: 1.15;
  white-space: nowrap;
}

/* Project2の文字 */
.project2 {
  font-family:
    "Arial Black",
    "Arial",
    sans-serif;
  font-size: clamp(48px, 11vw, 145px);
  letter-spacing: -0.06em;
  animation: stage-color 6s infinite;
}

/* 倶楽部の文字 */
.club {
  color: #eeeeee;
  font-size: clamp(25px, 5vw, 65px);
  font-weight: bold;
  letter-spacing: 0.05em;
  text-shadow:
    0 0 5px white,
    0 0 15px rgba(255, 255, 255, 0.6);
}

/* Project2 Official Site */
.subtitle {
  margin: 18px 0 35px;
  color: #d4d4d4;
  font-size: clamp(13px, 2vw, 20px);
  letter-spacing: 0.2em;
}

/* ENTERボタン */
.enter-button {
  display: inline-block;
  min-width: 170px;
  padding: 13px 34px;
  border: 1px solid rgba(255, 255, 255, 0.75);
  border-radius: 30px;
  color: white;
  font-size: 18px;
  letter-spacing: 0.22em;
  text-decoration: none;
  background: rgba(255, 255, 255, 0.08);
  transition:
    background 0.3s,
    color 0.3s,
    box-shadow 0.3s;
}

.enter-button:hover {
  color: #111111;
  background: white;
  box-shadow:
    0 0 12px white,
    0 0 30px rgba(255, 255, 255, 0.65);
}

.notice {
  margin-top: 18px;
  color: #aaaaaa;
  font-size: 13px;
}

/* 舞台照明 */
.light {
  position: absolute;
  top: -25%;
  width: 25%;
  height: 120%;
  opacity: 0.23;
  filter: blur(15px);
  transform-origin: top center;
}

.light-left {
  left: 5%;
  background: linear-gradient(
    to bottom,
    rgba(255, 20, 100, 0.95),
    transparent 75%
  );
  transform: rotate(-22deg);
  animation: light-left 5s ease-in-out infinite alternate;
}

.light-center {
  left: 38%;
  background: linear-gradient(
    to bottom,
    rgba(70, 140, 255, 0.95),
    transparent 75%
  );
  animation: light-center 4s ease-in-out infinite alternate;
}

.light-right {
  right: 5%;
  background: linear-gradient(
    to bottom,
    rgba(255, 220, 40, 0.95),
    transparent 75%
  );
  transform: rotate(22deg);
  animation: light-right 5.5s ease-in-out infinite alternate;
}

/* Project2の色変化 */
@keyframes stage-color {
  0% {
    color: #ff315f;
    text-shadow:
      0 0 8px #ff315f,
      0 0 24px #ff315f;
  }

  20% {
    color: #d348ff;
    text-shadow:
      0 0 8px #d348ff,
      0 0 24px #d348ff;
  }

  40% {
    color: #3b9cff;
    text-shadow:
      0 0 8px #3b9cff,
      0 0 24px #3b9cff;
  }

  60% {
    color: #ffffff;
    text-shadow:
      0 0 8px #ffffff,
      0 0 28px #ffffff;
  }

  80% {
    color: #ffe13b;
    text-shadow:
      0 0 8px #ffe13b,
      0 0 24px #ffe13b;
  }

  100% {
    color: #ff315f;
    text-shadow:
      0 0 8px #ff315f,
      0 0 24px #ff315f;
  }
}

/* 照明の動き */
@keyframes light-left {
  from {
    transform: rotate(-28deg) translateX(-8%);
  }

  to {
    transform: rotate(-8deg) translateX(18%);
  }
}

@keyframes light-center {
  from {
    transform: rotate(-12deg) translateX(-18%);
  }

  to {
    transform: rotate(12deg) translateX(18%);
  }
}

@keyframes light-right {
  from {
    transform: rotate(28deg) translateX(8%);
  }

  to {
    transform: rotate(8deg) translateX(-18%);
  }
}

/* スマートフォン向け */
@media (max-width: 600px) {
  .title-area {
    padding: 25px 12px;
  }

  h1 {
    flex-direction: column;
    align-items: center;
    gap: 4px;
    white-space: normal;
  }

  .project2 {
    font-size: clamp(52px, 19vw, 90px);
  }

  .club {
    font-size: clamp(27px, 9vw, 45px);
  }

  .subtitle {
    margin-top: 16px;
    letter-spacing: 0.1em;
  }

  .light {
    width: 40%;
  }
}

/* 動きを抑える設定をしている端末への配慮 */
@media (prefers-reduced-motion: reduce) {
  .project2,
  .light {
    animation: none;
  }

  .project2 {
    color: #56b8ff;
    text-shadow:
      0 0 8px #56b8ff,
      0 0 24px #56b8ff;
  }
}