:root {
  --bg: #0b0f14;
  --bg-soft: #111822;
  --bg-strong: #0d141d;
  --line: rgba(148, 163, 184, 0.2);
  --text: #e2e8f0;
  --text-muted: #a1b0c3;
  --accent: #22d3ee;
  --accent-soft: rgba(34, 211, 238, 0.15);
  --shadow: 0 20px 40px rgba(2, 6, 23, 0.55);
  --radius-lg: 22px;
  --radius-md: 16px;
  --radius-sm: 10px;
  --max-width: 1100px;
}

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

body {
  margin: 0;
  font-family: "Hiragino Kaku Gothic ProN", "Noto Sans JP", "Yu Gothic", "Meiryo",
    system-ui, sans-serif;
  background: radial-gradient(circle at top, rgba(34, 211, 238, 0.08), transparent 45%),
    var(--bg);
  color: var(--text);
  line-height: 1.7;
  letter-spacing: 0.01em;
}

html {
  scroll-behavior: smooth;
}

a {
  color: inherit;
  text-decoration: none;
}

a:focus-visible {
  outline: 2px solid var(--accent);
  outline-offset: 3px;
}

.skip-link {
  position: absolute;
  left: 24px;
  top: 16px;
  z-index: 20;
  padding: 10px 14px;
  border-radius: 999px;
  background: var(--accent);
  color: #031016;
  font-weight: 700;
  transform: translateY(-160%);
  transition: transform 0.2s ease;
}

.skip-link:focus {
  transform: translateY(0);
}

.container {
  width: min(100%, var(--max-width));
  margin: 0 auto;
  padding: 0 24px;
}

.site-header {
  position: sticky;
  top: 0;
  z-index: 10;
  background: rgba(11, 15, 20, 0.92);
  backdrop-filter: blur(12px);
  border-bottom: 1px solid var(--line);
}

.header-inner {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 18px 0;
  gap: 24px;
}

.site-title {
  font-weight: 600;
  letter-spacing: 0.06em;
  font-size: 14px;
  color: var(--text);
}

.header-nav {
  display: flex;
  gap: 18px;
  font-size: 13px;
  color: var(--text-muted);
}

.header-nav a {
  padding-bottom: 4px;
  border-bottom: 1px solid transparent;
  transition: color 0.2s ease, border-color 0.2s ease;
}

.header-nav a:hover {
  color: var(--text);
  border-color: var(--accent);
}

/* Translation UI: subtle button that matches the dark header */
.translate-button {
  padding: 8px 14px;
  border-radius: 999px;
  border: 1px solid rgba(226, 232, 240, 0.24);
  background: rgba(9, 14, 20, 0.72);
  color: var(--text);
  font-size: 12px;
  font-weight: 600;
  line-height: 1;
  cursor: pointer;
  transition: background-color 0.2s ease, border-color 0.2s ease, color 0.2s ease;
}

.translate-button:hover {
  background: rgba(34, 211, 238, 0.08);
  border-color: rgba(34, 211, 238, 0.45);
}

.translate-button:focus-visible {
  outline: 2px solid var(--accent);
  outline-offset: 2px;
}

.hero {
  padding: 88px 0 76px;
  position: relative;
  overflow: hidden;
}

.hero::before {
  content: "";
  position: absolute;
  inset: -20% -10% auto -10%;
  height: 140%;
  background: radial-gradient(circle at 20% 20%, rgba(34, 211, 238, 0.08), transparent 55%),
    radial-gradient(circle at 80% 30%, rgba(34, 211, 238, 0.05), transparent 60%);
  opacity: 0.6;
  animation: hero-drift 18s ease-in-out infinite;
  pointer-events: none;
}

.hero-inner {
  position: relative;
  z-index: 1;
}

.hero-inner {
  max-width: 900px;
}

.section-eyebrow {
  color: var(--accent);
  letter-spacing: 0.22em;
  text-transform: uppercase;
  font-size: 11px;
}

.hero-title {
  font-size: clamp(32px, 4.1vw, 46px);
  line-height: 1.24;
  letter-spacing: 0.01em;
  margin: 0 0 18px;
}

.hero-text {
  font-size: 17px;
  color: var(--text-muted);
  max-width: 780px;
  margin: 0;
  text-wrap: normal;
  overflow-wrap: normal;
  word-break: normal;
}

.hero-actions {
  display: flex;
  gap: 16px;
  flex-wrap: wrap;
  margin: 24px 0 0;
}

/* Translation note: small disclaimer for auto-translated English readers */
.translation-note {
  margin: 14px 0 0;
  max-width: 680px;
  font-size: 12px;
  color: var(--text-muted);
}

.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 8px;
  padding: 12px 22px;
  border-radius: 999px;
  border: 1px solid transparent;
  font-weight: 600;
  font-size: 14px;
  transition: transform 0.2s ease, box-shadow 0.2s ease, border-color 0.2s ease,
    background-color 0.2s ease, color 0.2s ease;
}

.btn:focus-visible {
  outline: 2px solid var(--accent);
  outline-offset: 2px;
}

.btn-primary {
  background: linear-gradient(120deg, rgba(34, 211, 238, 0.9), rgba(34, 211, 238, 0.65));
  color: #031016;
  box-shadow: 0 12px 26px rgba(34, 211, 238, 0.25);
}

.btn-ghost {
  border-color: rgba(34, 211, 238, 0.4);
  color: var(--text);
  background: rgba(9, 14, 20, 0.7);
}

.btn.small {
  padding: 10px 18px;
  font-size: 13px;
}

.btn:hover {
  transform: translateY(-2px);
  box-shadow: 0 10px 22px rgba(34, 211, 238, 0.2);
}

.btn-primary:hover {
  background: linear-gradient(120deg, rgba(34, 211, 238, 0.98), rgba(34, 211, 238, 0.75));
}

.btn-ghost:hover {
  border-color: rgba(34, 211, 238, 0.7);
  background: rgba(34, 211, 238, 0.08);
}

.btn:active {
  transform: translateY(0);
  box-shadow: none;
}

.hero-meta {
  display: flex;
  align-items: center;
  gap: 16px;
  color: var(--text-muted);
  font-size: 13px;
}

.divider {
  width: 32px;
  height: 1px;
  background: var(--line);
}


.section {
  padding: 90px 0;
}

.section:nth-of-type(even) {
  background: var(--bg-strong);
}

.section-header {
  margin-bottom: 32px;
}

.section-header h2 {
  font-size: clamp(24px, 4vw, 34px);
  margin: 12px 0 0;
}

.game-grid {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 32px;
  align-items: stretch;
}

.game-panel {
  background: var(--bg-soft);
  padding: 30px;
  border-radius: var(--radius-md);
  border: 1px solid rgba(34, 211, 238, 0.12);
  transition: transform 0.2s ease, border-color 0.2s ease, box-shadow 0.2s ease;
}

.game-panel h3 {
  margin: 6px 0 0;
  font-size: 22px;
}

.game-panel h4 {
  margin: 20px 0 0;
  font-size: 17px;
}

.game-panel p {
  color: var(--text-muted);
}

.game-number {
  display: inline-flex;
  align-items: center;
  margin: 0;
  padding: 5px 10px;
  border-radius: 999px;
  border: 1px solid rgba(34, 211, 238, 0.36);
  background: var(--accent-soft);
  color: var(--accent);
  font-size: 12px;
  font-weight: 700;
  letter-spacing: 0.08em;
}

.game-version {
  margin: 8px 0 0;
  font-size: 13px;
  color: var(--text-muted);
  letter-spacing: 0.04em;
}

.game-shot {
  margin: 22px 0 0;
}

.game-preview-video,
.game-shot img {
  display: block;
  width: 100%;
  max-width: min(720px, 100%);
  border-radius: 14px;
  border: 1px solid rgba(34, 211, 238, 0.18);
  box-shadow: 0 16px 30px rgba(2, 6, 23, 0.35);
  height: auto;
  margin: 0 auto;
}

.titration-preview {
  position: relative;
  display: grid;
  place-items: center;
  width: 100%;
  max-width: min(720px, 100%);
  min-height: 290px;
  margin: 22px auto 0;
  overflow: hidden;
  border-radius: 14px;
  border: 1px solid rgba(34, 211, 238, 0.18);
  background:
    radial-gradient(circle at 30% 10%, rgba(34, 211, 238, 0.16), transparent 36%),
    radial-gradient(circle at 78% 22%, rgba(167, 139, 250, 0.18), transparent 38%),
    rgba(2, 6, 23, 0.36);
  box-shadow: 0 16px 30px rgba(2, 6, 23, 0.35);
}

.preview-buret {
  position: absolute;
  top: 24px;
  left: 50%;
  width: 28px;
  height: 94px;
  transform: translateX(-50%);
  border: 2px solid rgba(226, 232, 240, 0.46);
  border-radius: 0 0 10px 10px;
  background: linear-gradient(180deg, rgba(248, 250, 252, 0.08), rgba(34, 211, 238, 0.16));
}

.preview-buret::after {
  content: "";
  position: absolute;
  left: 50%;
  bottom: -30px;
  width: 6px;
  height: 30px;
  transform: translateX(-50%);
  border-radius: 0 0 999px 999px;
  background: rgba(226, 232, 240, 0.48);
}

.preview-beaker {
  position: relative;
  width: min(250px, 72%);
  height: 180px;
  margin-top: 58px;
  overflow: hidden;
  border: 4px solid rgba(226, 232, 240, 0.38);
  border-top: 0;
  border-radius: 0 0 28px 28px;
  background: rgba(255, 255, 255, 0.03);
}

.preview-beaker::before {
  content: "";
  position: absolute;
  top: 0;
  left: -4%;
  z-index: 2;
  width: 108%;
  height: 10px;
  border: 3px solid rgba(226, 232, 240, 0.36);
  border-bottom: 0;
  border-radius: 12px 12px 0 0;
}

.preview-liquid {
  position: absolute;
  left: 0;
  bottom: 0;
  width: 100%;
  height: 58%;
  background: linear-gradient(180deg, #38bdf8, #34d399);
  box-shadow: inset 0 18px 30px rgba(255, 255, 255, 0.16), inset 0 -22px 34px rgba(0, 0, 0, 0.18);
}

.preview-liquid::before {
  content: "";
  position: absolute;
  top: -9px;
  left: -10%;
  width: 120%;
  height: 22px;
  border-radius: 50%;
  background: rgba(255, 255, 255, 0.24);
}

.preview-readout {
  position: absolute;
  right: 18px;
  bottom: 18px;
  display: grid;
  gap: 2px;
  min-width: 82px;
  padding: 10px 12px;
  border-radius: 10px;
  border: 1px solid rgba(34, 211, 238, 0.28);
  background: rgba(2, 6, 23, 0.62);
}

.preview-readout span {
  color: var(--text-muted);
  font-size: 11px;
  letter-spacing: 0.14em;
  text-transform: uppercase;
}

.preview-readout strong {
  color: #cffafe;
  font-family: ui-monospace, SFMono-Regular, Menlo, Consolas, monospace;
  font-size: 24px;
  line-height: 1;
}

.game-highlights {
  list-style: none;
  padding: 0;
  margin: 24px 0;
  display: grid;
  gap: 10px;
  color: var(--text-muted);
}

.game-highlights li {
  padding-left: 18px;
  position: relative;
}

.game-highlights li::before {
  content: "";
  position: absolute;
  left: 0;
  top: 10px;
  width: 6px;
  height: 6px;
  border-radius: 999px;
  background: var(--accent);
}

.game-actions {
  display: flex;
  gap: 14px;
  flex-wrap: wrap;
}



.concept-card {
  background: var(--bg-soft);
  padding: 28px 32px;
  border-radius: var(--radius-md);
  border: 1px solid rgba(34, 211, 238, 0.1);
  transition: transform 0.2s ease, border-color 0.2s ease, box-shadow 0.2s ease;
}

.card-grid {
  display: grid;
  grid-template-columns: repeat(3, minmax(0, 1fr));
  gap: 24px;
}

.experience-card {
  background: var(--bg-soft);
  padding: 26px;
  border-radius: var(--radius-md);
  border: 1px solid rgba(34, 211, 238, 0.12);
  min-height: 200px;
  transition: transform 0.2s ease, border-color 0.2s ease, box-shadow 0.2s ease;
}

.experience-card h3 {
  margin-top: 0;
}

.experience-card p {
  color: var(--text-muted);
}

.update-list {
  display: grid;
  gap: 16px;
  list-style: none;
  margin: 0;
  padding: 0;
}

.update-item {
  display: flex;
  gap: 18px;
  align-items: center;
  background: var(--bg-soft);
  padding: 14px 20px;
  border-radius: var(--radius-sm);
  border: 1px solid rgba(34, 211, 238, 0.1);
  transition: transform 0.2s ease, border-color 0.2s ease, box-shadow 0.2s ease;
}

.update-date {
  font-size: 13px;
  color: var(--accent);
  min-width: 96px;
}

.update-text {
  color: var(--text-muted);
}

.about-grid {
  display: grid;
  grid-template-columns: 1fr;
  gap: 32px;
  align-items: start;
}

.about-card {
  background: var(--bg-soft);
  padding: 24px;
  border-radius: var(--radius-md);
  border: 1px solid rgba(34, 211, 238, 0.1);
  transition: transform 0.2s ease, border-color 0.2s ease, box-shadow 0.2s ease;
}

.about-card dl {
  margin: 0;
  display: grid;
  gap: 16px;
}

.about-card dt {
  font-size: 12px;
  color: var(--text-muted);
  text-transform: uppercase;
  letter-spacing: 0.12em;
  margin-bottom: 6px;
}

.about-card dd {
  margin: 0;
  font-size: 15px;
}

.site-footer {
  border-top: 1px solid var(--line);
  padding: 28px 0;
  font-size: 13px;
  color: var(--text-muted);
}

.footer-inner {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 16px;
}

.back-to-top {
  color: var(--accent);
}

.reveal {
  opacity: 0;
  transform: translateY(20px);
  transition: opacity 0.6s ease, transform 0.6s ease;
}

.reveal.is-visible {
  opacity: 1;
  transform: translateY(0);
}

.game-panel:hover,
.concept-card:hover,
.experience-card:hover,
.update-item:hover,
.about-card:hover {
  transform: translateY(-3px);
  border-color: rgba(34, 211, 238, 0.3);
  box-shadow: 0 16px 30px rgba(2, 6, 23, 0.35);
}

@keyframes hero-drift {
  0%,
  100% {
    transform: translate3d(0, 0, 0);
  }
  50% {
    transform: translate3d(10px, -8px, 0);
  }
}

@media (max-width: 980px) {
  .hero-grid,
  .game-grid,
  .about-grid {
    grid-template-columns: 1fr;
  }

  .header-nav {
    display: none;
  }
}

@media (max-width: 720px) {
  .hero {
    padding-top: 90px;
  }

  .hero-actions,
  .game-actions {
    flex-direction: column;
    align-items: stretch;
  }

  .card-grid {
    grid-template-columns: 1fr;
  }

  .update-item {
    flex-direction: column;
    align-items: flex-start;
  }

  .footer-inner {
    flex-direction: column;
    align-items: flex-start;
  }

  .translate-button {
    padding: 7px 12px;
    font-size: 11px;
  }

  .translation-note {
    font-size: 11px;
  }
}

@media (prefers-reduced-motion: reduce) {
  html {
    scroll-behavior: auto;
  }

  *,
  *::before,
  *::after {
    animation: none !important;
    transition: none !important;
  }

  .reveal {
    opacity: 1;
    transform: none;
  }
}