:root {
  --ink: #22333f;
  --muted: #71808a;
  --line: #d7e0e5;
  --paper: #edf3f6;
  --font-sans: "Noto Sans JP", sans-serif;
  --font-serif: "Noto Serif JP", serif;
  --font-display: "Cormorant Garamond", serif;
}

* {
  box-sizing: border-box;
}

html {
  background: var(--paper);
}

body {
  min-width: 320px;
  margin: 0;
  color: var(--ink);
  background:
    linear-gradient(rgba(46, 91, 116, 0.05) 1px, transparent 1px),
    linear-gradient(90deg, rgba(46, 91, 116, 0.05) 1px, transparent 1px),
    var(--paper);
  background-size: 48px 48px;
  font-family: var(--font-sans);
  -webkit-font-smoothing: antialiased;
}

a {
  color: inherit;
}

.deck-header {
  display: grid;
  grid-template-columns: minmax(250px, 0.8fr) minmax(380px, 1.4fr) minmax(240px, 0.8fr);
  gap: 40px;
  align-items: end;
  max-width: 1480px;
  margin: 0 auto;
  padding: 58px 38px 45px;
  border-bottom: 1px solid rgba(48, 83, 101, 0.2);
}

.deck-brand {
  display: flex;
  align-items: center;
  gap: 15px;
  text-decoration: none;
}

.deck-logo {
  width: 58px;
  height: 58px;
  flex: 0 0 auto;
  overflow: visible;
}

.deck-logo img {
  display: block;
  width: 100%;
  height: 100%;
  object-fit: contain;
}

.deck-brand strong {
  display: block;
  font-family: var(--font-display);
  font-size: 31px;
  font-weight: 600;
  line-height: 1;
}

.deck-brand small {
  display: block;
  margin-top: 8px;
  color: var(--muted);
  font-size: 9px;
  font-weight: 600;
  letter-spacing: 0.17em;
}

.deck-heading p {
  margin: 0 0 7px;
  color: #58849b;
  font-family: var(--font-display);
  font-size: 17px;
  letter-spacing: 0.08em;
}

.deck-heading h1 {
  margin: 0;
  font-family: var(--font-serif);
  font-size: clamp(30px, 3.2vw, 48px);
  font-weight: 500;
  letter-spacing: 0.015em;
  line-height: 1.5;
}

.deck-note {
  margin: 0;
  color: var(--muted);
  font-size: 12px;
  line-height: 1.9;
}

.concept-grid {
  display: grid;
  grid-template-columns: repeat(3, minmax(340px, 390px));
  gap: 28px;
  justify-content: center;
  max-width: 1480px;
  margin: 0 auto;
  padding: 48px 34px 70px;
}

.concept {
  position: relative;
  min-width: 0;
  padding: 24px 20px 20px;
  border-top: 4px solid var(--accent);
  background: var(--panel);
  box-shadow: 0 18px 50px rgba(30, 65, 83, 0.09);
}

.concept-blue {
  --accent: #609ed5;
  --panel: #f7fbfe;
}

.concept-mint {
  --accent: #75c3ba;
  --panel: #f7fbfa;
}

.concept-underwater {
  --accent: #61d2cb;
  --panel: #0a3b49;
  color: #e9fbfb;
}

.concept-header > div:first-child {
  display: flex;
  align-items: center;
  gap: 10px;
}

.concept-number {
  display: grid;
  place-items: center;
  width: 35px;
  height: 35px;
  border: 1px solid color-mix(in srgb, var(--accent) 60%, transparent);
  border-radius: 50%;
  color: var(--accent);
  font-family: var(--font-display);
  font-size: 16px;
}

.concept-header > div:first-child p {
  margin: 0;
  color: var(--accent);
  font-family: var(--font-display);
  font-size: 12px;
  font-weight: 600;
  letter-spacing: 0.13em;
}

.concept-header h2 {
  margin: 19px 0 7px;
  font-family: var(--font-serif);
  font-size: 23px;
  font-weight: 600;
}

.concept-header > p {
  min-height: 44px;
  margin: 0;
  color: #77848d;
  font-size: 11px;
  line-height: 1.8;
}

.concept-underwater .concept-header > p {
  color: #a7cdcc;
}

.palette {
  display: flex;
  gap: 6px;
  margin: 16px 0 21px;
}

.palette i {
  width: 31px;
  height: 5px;
}

.concept-blue .palette i:nth-child(1) { background: #2d6f9f; }
.concept-blue .palette i:nth-child(2) { background: #6ba9dc; }
.concept-blue .palette i:nth-child(3) { background: #dfedf8; }
.concept-blue .palette i:nth-child(4) { background: #f3f8fc; }
.concept-mint .palette i:nth-child(1) { background: #347f79; }
.concept-mint .palette i:nth-child(2) { background: #79c6bd; }
.concept-mint .palette i:nth-child(3) { background: #def2ed; }
.concept-mint .palette i:nth-child(4) { background: #f6eaec; }
.concept-underwater .palette i:nth-child(1) { background: #031f2a; }
.concept-underwater .palette i:nth-child(2) { background: #0b5367; }
.concept-underwater .palette i:nth-child(3) { background: #61d2cb; }
.concept-underwater .palette i:nth-child(4) { background: #c9f5f1; }

.device-frame {
  position: relative;
  height: 650px;
  overflow: hidden;
  border: 7px solid #26323a;
  border-radius: 28px;
  background: #fff;
  box-shadow: 0 16px 30px rgba(27, 51, 65, 0.18);
}

.concept-underwater .device-frame {
  border-color: #021c24;
  box-shadow: 0 16px 34px rgba(0, 15, 20, 0.42), 0 0 40px rgba(80, 201, 194, 0.08);
}

.device-speaker {
  position: absolute;
  z-index: 2;
  top: 7px;
  left: 50%;
  width: 46px;
  height: 4px;
  border-radius: 999px;
  background: rgba(20, 27, 31, 0.55);
  transform: translateX(-50%);
}

.device-frame iframe {
  display: block;
  width: 100%;
  height: 100%;
  border: 0;
  background: #fff;
}

.open-concept {
  display: flex;
  align-items: center;
  justify-content: space-between;
  height: 48px;
  margin-top: 14px;
  padding: 0 4px;
  border-bottom: 1px solid rgba(65, 90, 104, 0.25);
  color: #526975;
  font-size: 12px;
  font-weight: 600;
  text-decoration: none;
}

.open-concept span {
  color: var(--accent);
  font-size: 18px;
  transition: transform 160ms ease;
}

.open-concept:hover span {
  transform: translate(3px, -3px);
}

.concept-underwater .open-concept {
  border-color: rgba(145, 217, 214, 0.25);
  color: #b8d8d7;
}

.deck-footer {
  display: flex;
  align-items: center;
  justify-content: space-between;
  max-width: 1400px;
  margin: 0 auto;
  padding: 24px 34px 36px;
  border-top: 1px solid rgba(48, 83, 101, 0.18);
  color: var(--muted);
}

.deck-footer p {
  margin: 0;
  font-family: var(--font-display);
  font-size: 21px;
}

.deck-footer span {
  font-size: 9px;
  letter-spacing: 0.14em;
  text-transform: uppercase;
}

@media (max-width: 1180px) {
  .deck-header {
    grid-template-columns: 1fr 1.2fr;
  }

  .deck-note {
    display: none;
  }

  .concept-grid {
    grid-template-columns: repeat(3, 360px);
    justify-content: start;
    overflow-x: auto;
    scroll-snap-type: x mandatory;
  }

  .concept {
    scroll-snap-align: center;
  }
}

@media (max-width: 700px) {
  .deck-header {
    display: block;
    padding: 30px 20px 28px;
  }

  .deck-logo {
    width: 44px;
    height: 44px;
  }

  .deck-brand strong {
    font-size: 25px;
  }

  .deck-heading {
    margin-top: 32px;
  }

  .deck-heading h1 {
    font-size: 28px;
  }

  .concept-grid {
    grid-template-columns: repeat(3, min(340px, calc(100vw - 34px)));
    gap: 16px;
    padding: 27px 17px 45px;
  }

  .concept {
    padding: 19px 14px 15px;
  }

  .device-frame {
    height: 620px;
  }

  .deck-footer {
    padding-right: 20px;
    padding-left: 20px;
  }
}

@media (prefers-reduced-motion: reduce) {
  * {
    scroll-behavior: auto !important;
    transition-duration: 0.01ms !important;
  }
}