/* CSS Reset & Variables */
* {
  margin: 0;
  padding: 0;
  box-sizing: border-box;
}

body {
  font-family: "Yu Gothic", "YuGothic", "Hiragino Sans", "Meiryo", sans-serif;
  /* アプリのブランドカラー（ダークネイビー）を背景に採用し、没入感を高める */
  background: linear-gradient(135deg, #030b25 0%, #0f224a 100%);
  color: #ffffff;
  height: 100vh;
  height: 100dvh;
  display: flex;
  justify-content: center;
  align-items: center;
  overflow: hidden;
}

/* Layout */
.splash-container {
  text-align: center;
  padding: 2rem;
  width: 100%;
}

.splash-content {
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 24px;
}

/* Icon / Logo */
.logo-circle {
  width: 140px;
  height: 140px;
  background-color: transparent;
  border-radius: 50%;
  display: flex;
  justify-content: center;
  align-items: center;
  box-shadow: none;
  /* 読み込み時に少し弾むようなアニメーション */
  animation: popIn 1s cubic-bezier(0.175, 0.885, 0.32, 1.275) forwards;
  opacity: 0;
  transform: scale(0.5);
  margin-bottom: 16px;
  overflow: hidden;
}

.splash-logo {
  width: 100%;
  height: 100%;
  object-fit: contain;
}

/* Typography */
.welcome-title {
  font-size: 32px;
  font-weight: 300;
  line-height: 1.4;
  letter-spacing: 2px;
  opacity: 0;
  /* ロゴの後にフワッと浮き上がるアニメーション */
  animation: fadeInUp 0.8s ease forwards 0.4s;
}

.app-name {
  font-size: 52px;
  font-weight: bold;
  color: #00d282;
  display: block;
  margin-top: 8px;
}

.welcome-subtitle {
  font-size: 18px;
  color: rgba(255, 255, 255, 0.7);
  margin-bottom: 32px;
  opacity: 0;
  animation: fadeInUp 0.8s ease forwards 0.6s;
}

/* Call to Action Button */
.start-button {
  display: inline-block;
  background-color: #00d282;
  color: #030b25;
  text-decoration: none;
  font-size: 18px;
  font-weight: bold;
  padding: 18px 56px;
  border-radius: 50px;
  /* 丸みを持たせて親しみやすく */
  transition: all 0.3s ease;
  opacity: 0;
  animation: fadeInUp 0.8s ease forwards 0.8s;
  box-shadow: 0 4px 15px rgba(0, 210, 130, 0.3);
}

.start-button:hover {
  transform: translateY(-4px);
  box-shadow: 0 8px 25px rgba(0, 210, 130, 0.5);
  background-color: #00e68f;
}

.start-button:active {
  transform: translateY(1px);
}

/* Animations */
@keyframes popIn {
  0% {
    opacity: 0;
    transform: scale(0.5);
  }

  100% {
    opacity: 1;
    transform: scale(1);
  }
}

@keyframes fadeInUp {
  0% {
    opacity: 0;
    transform: translateY(20px);
  }

  100% {
    opacity: 1;
    transform: translateY(0);
  }
}