/* =========================
   HERO
========================= */
.hero-section {
  height: calc(100svh - 1.4rem - 28px);
  display: flex;
  align-items: center;
  justify-content: center;
}

.hero-content {
  text-align: center;
}

.hero-title {
  font-size: 2.8rem;
  margin-bottom: 10px;
}

.hero-text {
  opacity: 0.8;
}

/* =========================
   SECTION BASE
========================= */
.gradation-up {
  background: linear-gradient(rgba(0, 0, 0, 0), var(--bg-base));
  height: 100px;
  margin-top: 40px;
}

.gradation-down {
  background: linear-gradient(var(--bg-base), rgba(0, 0, 0, 0));
  height: 100px;
  margin-bottom: 40px;
}

.section {
  background-color: var(--bg-base);
  padding: 80px 0;
}

/* .bg-light {
  background: #fafafa;
} */

.section-title {
  text-align: center;
  font-size: 2rem;
  font-weight: 700;
  margin-bottom: 40px;
}

.lead {
  text-align: center;
  max-width: 700px;
  margin: 0 auto;
}

/* =========================
   ACTIVITIES
========================= */
.activity-head {
  margin-top: 40px;
  font-size: 1.4rem;
  font-weight: 700;
}

.activity-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(230px, 1fr));
  gap: 25px;
  margin-top: 20px;
}

.activity-card {
  background: #fff;
  border: 1px solid #ddd;
  padding: 20px;
  text-align: center;
  border-radius: 8px;
  display: block;              /* ← aタグでもカードサイズ確保 */
  color: black;              /* ← リンク色を通常文字に揃える */
  transition: 0.2s;
}

.activity-icon {
  height: 80px;
  background: var(--light-bg);
  border-radius: 6px;
  margin-bottom: 10px;
}

.activity-card:hover {
  transform: translateY(-5px);
  border-color: var(--base);
}


/* =========================
   GROUPS
========================= */
.group-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(220px, 1fr));
  gap: 25px;
}

.group-card {
  position: relative;
  background: #fff;
  border: 1px solid #ddd;
  padding-bottom: 10px;
  cursor: pointer;
  overflow: visible;
  display: block;        /* aタグでもクリック領域を確保 */
  color: black;
  transition: 0.2s;
}

.group-img {
  height: 150px;
  background: #e9f4f4;
  display: flex;
  justify-content: center;
  align-items: center;
}

.group-img i {
  font-size: 2.5rem;
  color: var(--base);
}

.group-card h4 {
  text-align: center;
  font-weight: 700;
  margin-top: 10px;
}

.minor-note {
  margin-top: 20px;
  opacity: 0.7;
}

.group-card:hover {
  transform: translateY(-5px);
  border-color: var(--base);
}

/* =========================
   JOIN
========================= */
.join-center {
  text-align: center;
  margin-top: 20px;
}

.join-btn {
  display: inline-block;
  padding: 12px 25px;
  background: var(--base);
  color: var(--text-bg-base);
  border-radius: 6px;
  font-weight: 700;
  transition: 0.2s;
}

.join-btn:hover {
  background: var(--accent);
}

.lead strong {
  color: var(--base);
  font-weight: 700;
}