:root {
  --ink: #1f2328;
  --sub: #57606a;
  --line: #d0d7de;
  --accent: #1f3a5f;
  --accent-soft: #eef3f8;
  --paper: #ffffff;
  --canvas: #f6f5f1;
  --radius: 12px;
  color-scheme: light;
}

* {
  box-sizing: border-box;
}

html {
  scroll-behavior: smooth;
}

body {
  background: var(--paper);
  color: var(--ink);
  font-family:
    "Noto Sans JP", "Hiragino Sans", "Hiragino Kaku Gothic ProN", "Yu Gothic UI", system-ui,
    sans-serif;
  font-size: 17px;
  line-height: 1.8;
  margin: 0;
}

img,
video {
  display: block;
  height: auto;
  max-width: 100%;
}

a {
  color: var(--accent);
}

h1,
h2,
h3 {
  line-height: 1.35;
  margin: 0;
}

h1 {
  font-size: clamp(2rem, 5vw, 3.25rem);
  letter-spacing: 0.02em;
}

h2 {
  font-size: clamp(1.5rem, 3vw, 2rem);
  margin-bottom: 1rem;
}

h3 {
  font-size: 1.2rem;
  margin-bottom: 0.5rem;
}

p {
  margin: 0;
}

.wrap {
  margin: 0 auto;
  max-width: 1080px;
  padding: 0 20px;
}

.eyebrow {
  color: var(--accent);
  font-size: 0.8rem;
  font-weight: 700;
  letter-spacing: 0.2em;
  margin-bottom: 0.75rem;
}

.lead {
  color: var(--sub);
  max-width: 44em;
}

/* ナビゲーション */
.nav {
  backdrop-filter: blur(8px);
  background: rgb(255 255 255 / 0.9);
  border-bottom: 1px solid var(--line);
  position: sticky;
  top: 0;
  z-index: 10;
}

.nav-inner {
  align-items: center;
  display: flex;
  gap: 24px;
  justify-content: space-between;
  min-height: 60px;
}

.nav-logo img {
  height: 28px;
  width: auto;
}

.nav nav {
  display: flex;
  flex-wrap: wrap;
  gap: 4px 20px;
  font-size: 0.9rem;
}

.nav nav a {
  color: var(--ink);
  text-decoration: none;
}

.nav nav a:hover {
  color: var(--accent);
  text-decoration: underline;
}

/* ヒーロー */
.hero {
  background: linear-gradient(var(--canvas), var(--paper));
  padding: 72px 0 56px;
}

.hero-inner {
  display: grid;
  gap: 24px;
}

.hero-shot {
  margin-top: 24px;
}

.section-shot {
  margin-top: 40px;
}

.actions {
  display: flex;
  flex-wrap: wrap;
  gap: 12px;
}

.button {
  border: 1px solid var(--accent);
  border-radius: 999px;
  color: var(--accent);
  display: inline-block;
  font-weight: 700;
  padding: 10px 22px;
  text-decoration: none;
}

.button.primary {
  background: var(--accent);
  color: #fff;
}

.button:hover {
  opacity: 0.85;
}

/* セクション */
main > section {
  padding: 72px 0;
}

.band {
  background: var(--canvas);
}

.cards {
  display: grid;
  gap: 16px;
  grid-template-columns: repeat(auto-fit, minmax(240px, 1fr));
  list-style: none;
  margin: 0;
  padding: 0;
}

.cards li {
  background: var(--paper);
  border: 1px solid var(--line);
  border-radius: var(--radius);
  padding: 24px;
}

.cards p {
  color: var(--sub);
  font-size: 0.95rem;
}

/* スクリーンショットと動画 */
.shot {
  background: var(--paper);
  border: 1px solid var(--line);
  border-radius: var(--radius);
  box-shadow: 0 12px 40px rgb(31 58 95 / 0.12);
  margin: 0;
  overflow: hidden;
}

.shot.paper {
  background: #e9ecef;
  padding: 16px;
}

.shot.paper img {
  box-shadow: 0 4px 16px rgb(0 0 0 / 0.12);
  margin: 0 auto;
  max-height: 640px;
  width: auto;
}

/* スクリーンショットの上に、動画を開くボタンを重ねる */
.shot.demo {
  position: relative;
}

.play {
  align-items: center;
  background: rgb(31 58 95 / 0.92);
  border: 0;
  border-radius: 999px;
  bottom: 24px;
  box-shadow: 0 8px 24px rgb(0 0 0 / 0.25);
  color: #fff;
  cursor: pointer;
  display: inline-flex;
  font: inherit;
  font-weight: 700;
  gap: 10px;
  left: 50%;
  padding: 12px 22px 12px 16px;
  position: absolute;
  transform: translateX(-50%);
}

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

.play:focus-visible,
.close:focus-visible {
  outline: 3px solid #7b9cc0;
  outline-offset: 2px;
}

.play-icon {
  background: #fff;
  border-radius: 50%;
  display: inline-block;
  height: 28px;
  position: relative;
  width: 28px;
}

.play-icon::after {
  border-bottom: 7px solid transparent;
  border-left: 11px solid var(--accent);
  border-top: 7px solid transparent;
  content: "";
  left: 10px;
  position: absolute;
  top: 7px;
}

/* 操作動画のモーダル */
.demo-dialog {
  background: var(--paper);
  border: 0;
  border-radius: var(--radius);
  box-shadow: 0 24px 80px rgb(0 0 0 / 0.35);
  max-width: min(1100px, calc(100vw - 32px));
  padding: 0;
  width: 100%;
}

.demo-dialog::backdrop {
  background: rgb(15 23 34 / 0.7);
}

.demo-dialog-head {
  align-items: center;
  border-bottom: 1px solid var(--line);
  display: flex;
  justify-content: space-between;
  padding: 10px 16px;
}

.demo-dialog-head p {
  color: var(--sub);
  font-size: 0.9rem;
}

.close {
  background: none;
  border: 1px solid var(--line);
  border-radius: 999px;
  cursor: pointer;
  font: inherit;
  font-size: 0.85rem;
  padding: 4px 14px;
}

.demo-dialog video {
  width: 100%;
}

.shot figcaption {
  border-top: 1px solid var(--line);
  color: var(--sub);
  font-size: 0.85rem;
  padding: 10px 16px;
}

.feature {
  align-items: center;
  display: grid;
  gap: 40px;
  grid-template-columns: minmax(0, 1fr) minmax(0, 1.1fr);
  margin-top: 72px;
}

.feature.reverse > :first-child {
  order: 2;
}

.feature p {
  color: var(--sub);
}

.points {
  margin: 16px 0 0;
  padding-left: 1.2em;
}

.points li + li {
  margin-top: 4px;
}

.developer {
  align-items: center;
  display: grid;
  gap: 24px;
  grid-template-columns: minmax(0, 1.4fr) minmax(0, 1fr);
}

.developer p {
  color: var(--sub);
}

.footer {
  border-top: 1px solid var(--line);
  color: var(--sub);
  font-size: 0.85rem;
  padding: 32px 0;
}

.footer .wrap {
  align-items: center;
  display: flex;
  justify-content: space-between;
}

.footer img {
  height: 24px;
  width: auto;
}

@media (max-width: 760px) {
  .nav nav {
    font-size: 0.8rem;
    gap: 4px 12px;
  }

  .feature,
  .developer {
    grid-template-columns: minmax(0, 1fr);
  }

  .feature.reverse > :first-child {
    order: 0;
  }

  main > section {
    padding: 56px 0;
  }
}