:root {
  color-scheme: light;
  --bg: #f4f8fc;
  --bg-elevated: rgba(255, 255, 255, 0.92);
  --surface: #ffffff;
  --text: #12233a;
  --text-subtle: #4f627a;
  --line: rgba(18, 35, 58, 0.12);
  --line-strong: rgba(18, 35, 58, 0.22);
  --accent: #007d8f;
  --accent-soft: rgba(0, 125, 143, 0.14);
  --accent-strong: #04526c;
  --hero-grad-a: rgba(15, 110, 204, 0.2);
  --hero-grad-b: rgba(0, 157, 129, 0.2);
  --shadow-soft: 0 16px 40px rgba(16, 37, 68, 0.1);
  --shadow-strong: 0 28px 70px rgba(16, 37, 68, 0.16);
  --radius-xl: 26px;
  --radius-lg: 18px;
  --radius-md: 12px;
  --trans: 0.28s ease;
}

:root[data-theme="dark"] {
  color-scheme: dark;
  --bg: #07111f;
  --bg-elevated: rgba(9, 20, 37, 0.86);
  --surface: #0e1d34;
  --text: #eaf2ff;
  --text-subtle: #adc0db;
  --line: rgba(173, 192, 219, 0.2);
  --line-strong: rgba(173, 192, 219, 0.34);
  --accent: #3fc5d8;
  --accent-soft: rgba(63, 197, 216, 0.18);
  --accent-strong: #89dfe8;
  --hero-grad-a: rgba(34, 116, 202, 0.34);
  --hero-grad-b: rgba(34, 167, 139, 0.28);
  --shadow-soft: 0 24px 52px rgba(0, 0, 0, 0.42);
  --shadow-strong: 0 32px 84px rgba(0, 0, 0, 0.55);
}

* {
  box-sizing: border-box;
}

html,
body {
  margin: 0;
  min-height: 100%;
}

body {
  font-family: "Avenir Next", "Hiragino Kaku Gothic ProN", "Yu Gothic UI", "Noto Sans JP", sans-serif;
  background:
    radial-gradient(125% 85% at 8% 0%, var(--hero-grad-a), transparent 52%),
    radial-gradient(95% 65% at 95% 0%, var(--hero-grad-b), transparent 58%),
    var(--bg);
  color: var(--text);
  line-height: 1.7;
}

body::before {
  content: "";
  position: fixed;
  inset: 0;
  pointer-events: none;
  background-image: linear-gradient(transparent 97%, rgba(255, 255, 255, 0.07) 100%);
  background-size: 100% 24px;
  mix-blend-mode: soft-light;
  opacity: 0.35;
}

.page {
  opacity: 0;
  transform: translateY(10px);
  transition: opacity 0.55s ease, transform 0.55s ease;
}

.page.is-ready {
  opacity: 1;
  transform: translateY(0);
}

body.page-fade-out .page {
  opacity: 0;
  transform: translateY(8px);
}

.top-controls {
  max-width: 980px;
  margin: 0 auto;
  display: flex;
  justify-content: space-between;
  align-items: center;
  gap: 12px;
  padding: 22px clamp(16px, 4.2vw, 42px) 0;
}

.theme-toggle,
.language-select {
  border: 1px solid var(--line);
  border-radius: 999px;
  background: var(--bg-elevated);
  backdrop-filter: blur(10px);
  color: var(--text);
  font: inherit;
  box-shadow: var(--shadow-soft);
}

.theme-toggle {
  padding: 9px 15px;
  cursor: pointer;
  transition: transform var(--trans), box-shadow var(--trans), border-color var(--trans);
}

.theme-toggle:hover {
  transform: translateY(-1px);
  border-color: var(--line-strong);
  box-shadow: var(--shadow-strong);
}

.language-select {
  padding: 8px 12px;
}

.hero,
.main-content,
.footer-inner {
  max-width: 980px;
  margin: 0 auto;
  padding: 0 clamp(16px, 4.2vw, 42px);
}

.hero {
  padding-top: 16px;
}

.hero-card {
  background: linear-gradient(140deg, var(--bg-elevated), var(--surface));
  border: 1px solid var(--line);
  border-radius: var(--radius-xl);
  padding: clamp(24px, 4.5vw, 40px);
  box-shadow: var(--shadow-strong);
  position: relative;
  overflow: hidden;
}

.hero-card::after {
  content: "";
  position: absolute;
  top: -40px;
  right: -40px;
  width: 180px;
  height: 180px;
  border-radius: 50%;
  background: radial-gradient(circle, var(--accent-soft), transparent 72%);
}

.badge {
  position: relative;
  z-index: 1;
  display: inline-flex;
  align-items: center;
  gap: 8px;
  padding: 6px 12px;
  border-radius: 999px;
  background: var(--accent-soft);
  color: var(--accent-strong);
  font-size: 12px;
  font-weight: 700;
  letter-spacing: 0.04em;
  text-transform: uppercase;
}

.hero-title {
  position: relative;
  z-index: 1;
  margin: 14px 0 10px;
  font-size: clamp(28px, 4.2vw, 44px);
  letter-spacing: 0.01em;
  line-height: 1.2;
}

.hero-subtitle {
  position: relative;
  z-index: 1;
  margin: 0;
  color: var(--text-subtle);
  font-size: clamp(14px, 2vw, 16px);
  max-width: 66ch;
}

.link-row {
  position: relative;
  z-index: 1;
  margin-top: 18px;
  display: flex;
  flex-wrap: wrap;
  gap: 10px;
}

.link-row a {
  color: var(--text);
  text-decoration: none;
  font-weight: 600;
  padding: 10px 14px;
  border-radius: 999px;
  border: 1px solid var(--line);
  background: var(--bg-elevated);
  transition: transform var(--trans), box-shadow var(--trans);
}

.link-row a:hover {
  transform: translateY(-1px);
  box-shadow: var(--shadow-soft);
}

.main-content {
  padding-top: 24px;
  padding-bottom: 8px;
}

.section {
  margin-bottom: 18px;
}

.panel {
  background: var(--bg-elevated);
  border: 1px solid var(--line);
  border-radius: var(--radius-lg);
  box-shadow: var(--shadow-soft);
  overflow: hidden;
}

.section-header {
  padding: 20px 24px 16px;
  border-bottom: 1px solid var(--line);
}

.section-title {
  margin: 0;
  font-size: clamp(20px, 2.8vw, 24px);
  line-height: 1.35;
}

.section-note {
  margin: 6px 0 0;
  color: var(--text-subtle);
  font-size: 13.5px;
}

.spec-list {
  margin: 0;
}

.spec-item {
  display: grid;
  grid-template-columns: minmax(170px, 230px) minmax(0, 1fr);
  gap: 14px;
  padding: 15px 24px;
  border-top: 1px solid var(--line);
}

.spec-item:first-child {
  border-top: none;
}

.spec-item dt {
  margin: 0;
  font-weight: 700;
  color: var(--text);
}

.spec-item dd {
  margin: 0;
  color: var(--text-subtle);
}

.spec-item dd strong {
  color: var(--text);
  font-weight: 700;
}

.footer {
  padding: 14px 0 40px;
}

.footer-inner {
  color: var(--text-subtle);
  font-size: 12.5px;
}

.reveal {
  opacity: 0;
  transform: translateY(18px);
  transition: opacity 0.5s ease, transform 0.5s ease;
}

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

@media (max-width: 760px) {
  .top-controls {
    flex-wrap: wrap;
  }

  .spec-item {
    grid-template-columns: 1fr;
    gap: 6px;
    padding: 14px 18px;
  }

  .section-header {
    padding: 18px 18px 14px;
  }

  .hero-card {
    padding: 22px 18px;
  }
}

@media (prefers-reduced-motion: reduce) {
  .page,
  .reveal,
  .theme-toggle,
  .link-row a {
    transition: none;
  }
}