@charset "UTF-8";
@view-transition {
  navigation: auto;
}
:root {
  --color-top: #2ea3e0;
  --color-about: #f23159;
  --card: #ffffff;
  --text: #111111;
  --text-muted: #aaaaaa;
  --vt-duration: 1400ms;
}

*,
*::before,
*::after {
  box-sizing: border-box;
}

body {
  margin: 0;
  color: var(--text);
  font-family: "Hiragino Sans", "Noto Sans JP", sans-serif;
}

main {
  position: relative;
  isolation: isolate;
  overflow: hidden;
  /* ビュー遷移のスナップショットの指定 */
  view-transition-name: page;
  min-height: 100vh;
  width: 100%;
  padding: clamp(16px, 4vw, 32px);
  display: grid;
  place-items: center;
}
main.top {
  background: var(--color-top);
}
main.about {
  background: var(--color-about);
}

.card {
  position: relative;
  /* ビュー遷移のスナップショットの指定 */
  view-transition-name: card;
  z-index: 10000;
  width: min(400px, 100%);
  margin-inline: auto;
  border-radius: 24px;
  background: var(--card);
  padding: clamp(24px, 5vw, 40px) clamp(24px, 5vw, 40px) clamp(24px, 4vw, 32px);
  display: grid;
  row-gap: 24px;
}

.card__above {
  display: grid;
  gap: 16px;
}

.card__title {
  margin: 0;
  font-size: clamp(2rem, 4vw, 2.4rem);
  line-height: 1.4;
  font-weight: 600;
  letter-spacing: -0.02em;
}

.card__desc {
  margin: 0;
  color: #555;
  line-height: 1.6;
  font-size: 0.95rem;
}

.card__nav {
  display: grid;
  gap: 16px;
}

.nav-btn {
  display: block;
  border-radius: 999px;
  padding: 14px 20px;
  text-decoration: none;
  text-align: center;
  font-size: 0.95rem;
  font-weight: 600;
  transition: opacity 0.2s;
}
.nav-btn:hover {
  opacity: 0.78;
}
.nav-btn.is-active {
  background: #f4f4f4;
  color: #111;
}
.nav-btn:not(.is-active) {
  background: #111;
  color: #fff;
}

.card__below {
  margin: 0;
  padding-top: 16px;
  border-top: 1px solid #efefef;
  font-size: 0.8rem;
  color: var(--text-muted);
  text-align: center;
}

/* デフォルトでのアニメーション停止 */
::view-transition-old(root),
::view-transition-new(root) {
  animation: none;
}

::view-transition-group(page) {
  animation-duration: var(--vt-duration);
}

::view-transition-old(page) {
  animation: none;
}

::view-transition-new(page) {
  will-change: transform;
  animation: page-slide-in var(--vt-duration) cubic-bezier(0.77, 0, 0.18, 1) forwards;
}

::view-transition-group(card) {
  animation-duration: var(--vt-duration);
}

::view-transition-old(card),
::view-transition-new(card) {
  animation: none;
}

/* ======================================
Right → Left
====================================== */
@keyframes page-slide-in {
  from {
    transform: translateX(100%);
  }
  to {
    transform: translateX(0%);
  }
}
/* ======================================
Reduced Motion
====================================== */
@media (prefers-reduced-motion: reduce) {
  ::view-transition-old(page),
  ::view-transition-new(page),
  ::view-transition-old(card),
  ::view-transition-new(card) {
    animation: none;
  }
}