/* ホームページ専用スタイル */

.main-content-area {
  padding: 0;
  width: 100%;
  margin: 0;
  display: block;
  justify-content: flex-start;
  align-items: stretch;
}

.landing-overview {
  display: flex;
  flex-direction: column;
  width: 100%;
  min-height: 100%;
}

.feature-section {
  --feature-bg: #0b1830;
  --feature-overlay: linear-gradient(120deg, rgba(7, 20, 45, 0.92), rgba(7, 20, 45, 0.78));
  position: relative;
  min-height: clamp(560px, 100vh, 820px);
  display: flex;
  align-items: center;
  justify-content: center;
  padding: clamp(4rem, 10vw, 7rem) clamp(1.5rem, 6vw, 4.5rem);
  color: #ffffff;
  overflow: hidden;
  isolation: isolate;
}

.feature-section::before,
.feature-section::after {
  content: "";
  position: absolute;
  inset: 0;
  z-index: -2;
  transition: opacity 0.8s ease, transform 0.8s ease;
}

.feature-section::before {
  background: var(--feature-bg);
  transform: scale(1.06);
  opacity: 0.6;
}

.feature-section::after {
  z-index: -1;
  background: var(--feature-overlay);
  opacity: 0.85;
}

.feature-section.is-active::before {
  opacity: 1;
  transform: scale(1);
}

.feature-section.is-active::after {
  opacity: 0.82;
}

.feature-inner {
  width: min(100%, 1050px);
  margin: 0 auto;
  display: flex;
  align-items: center;
  gap: clamp(1.75rem, 3.5vw, 4.5rem);
}

.feature-section:nth-of-type(even) .feature-inner {
  flex-direction: row-reverse;
}

.feature-media {
  flex: 1 1 45%;
  display: flex;
  justify-content: center;
  align-items: center;
}

.feature-media img,
.feature-media video {
  width: 100%;
  max-width: 440px;
  border-radius: 24px;
  box-shadow: 0 18px 45px rgba(10, 16, 35, 0.35);
  border: 1px solid rgba(255, 255, 255, 0.18);
}

.feature-media img {
  aspect-ratio: 4 / 3;
  object-fit: cover;
}

.feature-media video {
  aspect-ratio: 16 / 9;
  object-fit: cover;
  background-color: #000;
  pointer-events: none;
  user-select: none;
}

.feature-content {
  flex: 1 1 55%;
  display: grid;
  gap: clamp(0.9rem, 1.8vw, 1.5rem);
  text-align: left;
  line-height: 1.6;
}

.feature-badge {
  display: inline-flex;
  align-items: center;
  gap: 0.5rem;
  padding: 0.4rem 0.85rem;
  border-radius: 999px;
  background-color: rgba(255, 255, 255, 0.18);
  border: 1px solid rgba(255, 255, 255, 0.35);
  font-size: 0.9rem;
  font-weight: 600;
  letter-spacing: 0.06em;
  text-transform: uppercase;
}

.feature-title {
  font-size: clamp(2.1rem, 3.2vw, 2.7rem);
  font-weight: 700;
  line-height: 1.2;
  margin: 0;
}

.feature-lead {
  margin: 0;
  font-size: clamp(1.02rem, 2vw, 1.25rem);
  font-weight: 500;
}

.feature-description {
  margin: 0;
  font-size: clamp(0.98rem, 1.7vw, 1.1rem);
  color: rgba(255, 255, 255, 0.88);
}

.feature-actions {
  display: flex;
  flex-wrap: wrap;
  gap: clamp(0.75rem, 2vw, 1.25rem);
  margin-top: clamp(0.4rem, 1.2vw, 1.2rem);
  margin-bottom: 0;
}

.feature-welcome .feature-actions {
  margin-bottom: clamp(3rem, 10vw, 4.5rem);
}

.feature-note {
  margin-top: clamp(0.4rem, 1.2vw, 1.2rem);
  padding: 0.9rem 1.1rem;
  border-radius: 16px;
  background-color: rgba(255, 255, 255, 0.16);
  border: 1px solid rgba(255, 255, 255, 0.35);
  font-weight: 600;
  text-align: center;
}

.feature-note--desktop-only {
  color: #ffffff;
}

.cta-link {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  padding: 0.75rem 1.6rem;
  border-radius: 999px;
  border: 1px solid transparent;
  background-color: rgba(255, 255, 255, 0.92);
  color: #0d1f36;
  font-weight: 700;
  font-size: 0.95rem;
  text-decoration: none;
  transition: transform 0.3s ease, box-shadow 0.3s ease, background-color 0.3s ease;
  box-shadow: 0 15px 30px rgba(15, 23, 42, 0.18);
}

.cta-link:hover,
.cta-link:focus-visible {
  transform: translateY(-2px);
  box-shadow: 0 18px 36px rgba(15, 23, 42, 0.25);
}

.cta-link:focus-visible {
  outline: 3px solid rgba(255, 255, 255, 0.7);
  outline-offset: 2px;
}

.cta-link--ghost {
  background-color: transparent;
  border-color: rgba(255, 255, 255, 0.65);
  color: #ffffff;
  box-shadow: inset 0 0 0 1px rgba(255, 255, 255, 0.35);
}

.cta-link--ghost:hover,
.cta-link--ghost:focus-visible {
  background-color: rgba(255, 255, 255, 0.12);
  box-shadow: inset 0 0 0 1px rgba(255, 255, 255, 0.6);
}

.scroll-indicator {
  position: absolute;
  left: 50%;
  bottom: clamp(1.5rem, 5vw, 3.5rem);
  display: inline-flex;
  flex-direction: column;
  align-items: center;
  gap: 0.75rem;
  transform: translateX(-50%);
  letter-spacing: 0.45em;
  font-size: 0.85rem;
  text-transform: uppercase;
  color: rgba(255, 255, 255, 0.7);
  pointer-events: none;
  animation: indicatorFloat 2.8s ease-in-out infinite;
}

.scroll-indicator__bar {
  display: block;
  width: 1px;
  height: 46px;
  background: linear-gradient(to bottom, rgba(255, 255, 255, 0.8), rgba(255, 255, 255, 0));
}

@keyframes indicatorFloat {
  0%,
  100% {
    transform: translate(-50%, 0);
  }
  50% {
    transform: translate(-50%, 12px);
  }
}

/* セクション別の背景設定 */
.feature-welcome {
  --feature-bg: radial-gradient(circle at 20% 20%, rgba(71, 135, 218, 0.25), transparent 55%), #12213d;
  --feature-overlay: linear-gradient(135deg, rgba(11, 18, 35, 0.88), rgba(23, 56, 96, 0.72));
}

.feature-references {
  --feature-bg: radial-gradient(circle at 80% 20%, rgba(107, 174, 233, 0.35), transparent 60%), #14304f;
  --feature-overlay: linear-gradient(135deg, rgba(18, 52, 86, 0.88), rgba(36, 85, 122, 0.75));
}

.feature-game {
  --feature-bg: radial-gradient(circle at 25% 25%, rgba(204, 111, 255, 0.28), transparent 60%), #2b1346;
  --feature-overlay: linear-gradient(135deg, rgba(52, 18, 78, 0.88), rgba(122, 41, 92, 0.7));
}

.feature-toeic {
  --feature-bg: radial-gradient(circle at 78% 25%, rgba(74, 190, 218, 0.32), transparent 60%), #10304a;
  --feature-overlay: linear-gradient(135deg, rgba(10, 45, 95, 0.9), rgba(24, 118, 148, 0.72));
}

.feature-toefl {
  --feature-bg: radial-gradient(circle at 28% 20%, rgba(120, 165, 212, 0.28), transparent 60%), #152c45;
  --feature-overlay: linear-gradient(135deg, rgba(14, 38, 66, 0.9), rgba(70, 92, 128, 0.72));
}

@media (max-width: 1100px) {
  .feature-media img {
    border-radius: 20px;
  }
}

@media (max-width: 960px) {
  .feature-section {
    padding: clamp(3rem, 12vw, 5rem) clamp(1.5rem, 8vw, 3rem);
  }

  .feature-inner {
    flex-direction: column;
    text-align: center;
  }

  .feature-section:nth-of-type(even) .feature-inner {
    flex-direction: column;
  }

  .feature-media,
  .feature-content {
    flex: 1 1 auto;
    width: 100%;
  }

  .feature-content {
    text-align: center;
    align-items: center;
  }

  .feature-actions {
    justify-content: center;
  }
}

@media (max-width: 720px) {
  .feature-section {
    min-height: clamp(520px, 100vh, 720px);
  }

  .feature-media img {
    aspect-ratio: 16 / 10;
  }

  .feature-content {
    text-align: left;
    align-items: start;
  }

  .feature-actions {
    width: 100%;
    flex-direction: column;
    align-items: center;
  }

  .feature-welcome .feature-actions {
    margin-bottom: clamp(4rem, 18vw, 6rem);
  }

  .cta-link {
    width: auto;
    max-width: min(220px, 100%);
    padding: 0.75rem 1.4rem;
  }
}

@media (max-width: 560px) {
  .feature-media img {
    border-radius: 18px;
    box-shadow: 0 12px 30px rgba(10, 16, 35, 0.28);
  }

  .feature-badge {
    font-size: 0.85rem;
    padding: 0.35rem 0.7rem;
  }

  .feature-title {
    font-size: clamp(2rem, 6vw, 2.6rem);
  }

  .feature-lead,
  .feature-description {
    font-size: 1rem;
  }

  .scroll-indicator {
    font-size: 0.75rem;
    letter-spacing: 0.35em;
  }
}

@media (prefers-reduced-motion: reduce) {
  .feature-section,
  .feature-section::before,
  .feature-section::after,
  .cta-link,
  .scroll-indicator {
    animation: none !important;
    transition: none !important;
  }

  .feature-section::before {
    transform: none;
    opacity: 1;
  }
}