.grade-title {
  font-size: 30px;
  text-align: center;
  margin-bottom: 8px;
  color: var(--text-main);
}

.grade-title::after {
  content: "✨";
  margin-left: 6px;
}

.grade-description {
  text-align: center;
  font-size: 16px;
  color: var(--text-sub);
  margin-bottom: 25px;
}

.game-list {
  list-style: none;
  padding: 0;
  margin: 0;
  display: flex;
  flex-direction: row;
  flex-wrap: wrap;
}

.game-item {
  margin-bottom: 18px;
  width: 49%;
  margin: 1% auto
}

.game-link {
  display: block;
  padding: 18px 16px;
  border-radius: 20px;
  background: var(--bg-card);
  text-decoration: none;
  border: 3px solid var(--border-soft);
  box-shadow: var(--shadow-card);
  transition: transform 0.15s, box-shadow 0.15s;
}



/* タイトル */
.game-title {
  display: block;
  font-size: 20px;
  font-weight: bold;
  color: var(--text-main);
}

/* サブ */
.game-sub {
  font-size: 15px;
  margin-top: 4px;
  color: var(--text-sub);
}

.math-grade-container .game-link--flash {
  background: var(--pastel-orange);
  box-shadow: 0 6px 0 var(--pastel-shadow-orange);
}

.math-grade-container .game-link--time {
  background: var(--pastel-blue);
  box-shadow: 0 6px 0 var(--pastel-shadow-blue);
}

.math-grade-container .game-link--drill {
  background: var(--pastel-green);
  box-shadow: 0 6px 0 var(--pastel-shadow-green);
}

.math-grade-container .game-link--survival {
  background: var(--pastel-pink);
  box-shadow: 0 6px 0 var(--pastel-shadow-pink);
}

.game-link:hover {
  transform: translateY(4px);
  box-shadow: 0 0 0 var(--accent-info);
}

.game-link--flash {
  border-color: var(--color-orange);
}

.game-link--flash .game-title::before {
  content: "⚡ ";
}

.game-link--time {
  border-color: var(--color-blue);
}

.game-link--time .game-title::before {
  content: "⏱ ";
}

.game-link--survival {
  border-color: var(--color-pink);
}

.game-link--survival .game-title::before {
  content: "∞ ";
}


.game-link--drill {
  border-color: var(--color-green);
}

.game-link--drill .game-title::before {
  content: "📘 ";
}

/* 勉強リンク */
.math-grade-container .section-link {
  background: var(--pastel-purple);
  padding: 16px 28px;
  border-radius: 50px;
  text-decoration: none;
  font-weight: bold;
  display: inline-block;
  margin: 10px;
  color: var(--text-main);
  box-shadow: 0 8px 0 #b07edb;
  transition: 0.2s;
}

.math-grade-container .section-link:hover {
  transform: scale(1.1);
}

/* PDF */
.math-grade-container .pdf-download-link {
  background: var(--bg-card);
  border: 3px dashed var(--pastel-blue);
  padding: 14px 24px;
  border-radius: 18px;
  text-decoration: none;
  font-weight: bold;
  transition: 0.2s;
}

.math-grade-container .pdf-download-link:hover {
  background: var(--pastel-blue);
}

/* 区切り */
.math-grade-container hr {
  border: none;
  border-top: 4px dotted rgba(0, 0, 0, 0.1);
  margin: 60px 0;
}
/* 数字が変化する時のアニメーション */
#question {
    transition: color 0.1s ease, transform 0.1s ease;
}

/* 不正解時に少し震える演出をJSでクラス追加して制御しても面白いです */
.shake {
    animation: shake 0.2s ease-in-out;
}

@keyframes shake {
    0%, 100% { transform: translateX(0); }
    25% { transform: translateX(-5px); }
    75% { transform: translateX(5px); }
}
修正のポイント