:root {
  --bg: #F3FAFD;
  --bg-deep: #E4F3FA;
  --ink: #1F4E66;
  --ink-soft: #4F7C93;
  --blue: #3FA9DC;
  --blue-deep: #1E6FA8;
  --sky: #DCF0F8;
  --shadow: 0 8px 24px rgba(31, 78, 102, 0.12);
}

* { box-sizing: border-box; margin: 0; padding: 0; }

html { scroll-behavior: smooth; }

body {
  font-family: "Zen Maru Gothic", "Noto Sans JP", sans-serif;
  background: var(--bg);
  color: var(--ink);
  line-height: 1.7;
}

a { text-decoration: none; color: inherit; }
ul { list-style: none; }

.sr-only {
  position: absolute;
  width: 1px;
  height: 1px;
  padding: 0;
  margin: -1px;
  overflow: hidden;
  clip: rect(0, 0, 0, 0);
  white-space: nowrap;
  border: 0;
}

.demo-badge {
  position: fixed;
  top: 0;
  left: 0;
  right: 0;
  z-index: 200;
  background: linear-gradient(90deg, var(--blue-deep), var(--blue));
  color: #fff;
  text-align: center;
  font-size: 0.72rem;
  letter-spacing: 0.15em;
  font-weight: 700;
  padding: 4px 0;
}

/* ===== Header ===== */
.site-header {
  position: sticky;
  top: 22px;
  z-index: 100;
  background: rgba(243, 250, 253, 0.85);
  backdrop-filter: blur(8px);
  border-bottom: 1px solid rgba(31, 78, 102, 0.1);
}

.header-inner {
  max-width: 1100px;
  margin: 0 auto;
  padding: 10px 24px;
  display: flex;
  align-items: center;
  justify-content: space-between;
}

.logo {
  display: flex;
  align-items: center;
}

.logo-img {
  height: 46px;
  width: auto;
  display: block;
}

.site-nav {
  display: flex;
  align-items: center;
  gap: 24px;
  font-size: 0.9rem;
  font-weight: 500;
}

.site-nav a { opacity: 0.75; transition: opacity 0.2s; }
.site-nav a:hover { opacity: 1; }

/* ===== Banner ===== */
.banner {
  position: relative;
  overflow: hidden;
  background: linear-gradient(160deg, #DCF0F8 0%, #EDF8FC 45%, #F3FAFD 100%);
  padding: 48px 24px 56px;
  text-align: center;
}

.banner-image-wrap {
  max-width: 1100px;
  margin: 0 auto;
}

.banner-image-wrap img {
  display: block;
  width: 100%;
  height: auto;
  border-radius: 24px;
  box-shadow: 0 20px 45px rgba(31, 78, 102, 0.18);
}

.banner-actions {
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 16px;
  margin-top: 32px;
}

.banner-actions .btn {
  min-width: 260px;
  text-align: center;
}

.btn {
  display: inline-block;
  padding: 14px 30px;
  border-radius: 999px;
  font-weight: 700;
  font-size: 0.95rem;
  transition: transform 0.2s, box-shadow 0.2s;
}

.btn-primary {
  background: var(--blue);
  color: #fff;
  box-shadow: 0 8px 20px rgba(63, 169, 220, 0.45);
}
.btn-primary:hover { transform: translateY(-2px); box-shadow: 0 10px 24px rgba(63, 169, 220, 0.55); }

.btn-accent {
  background: var(--blue-deep);
  color: #fff;
  box-shadow: 0 8px 20px rgba(30, 111, 168, 0.45);
}
.btn-accent:hover { transform: translateY(-2px); box-shadow: 0 10px 24px rgba(30, 111, 168, 0.55); }

.btn-outline {
  background: #fff;
  color: var(--ink);
  border: 1.5px solid rgba(31, 78, 102, 0.2);
}
.btn-outline:hover { transform: translateY(-2px); border-color: var(--blue); }

/* ===== Contents ===== */
.contents {
  max-width: 1100px;
  margin: 0 auto;
  padding: 80px 24px 40px;
}

.section-head {
  text-align: center;
  margin-bottom: 44px;
}

.section-head h2 {
  font-size: 1.8rem;
  font-weight: 900;
  margin-bottom: 10px;
}

.section-head p {
  color: var(--ink-soft);
  font-size: 0.95rem;
}

.card-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(260px, 1fr));
  gap: 22px;
}

.card {
  display: block;
  background: #fff;
  border-radius: 20px;
  padding: 28px 24px;
  box-shadow: var(--shadow);
  border-top: 4px solid var(--accent, var(--blue));
  transition: transform 0.25s, box-shadow 0.25s;
}

.card:hover {
  transform: translateY(-6px);
  box-shadow: 0 14px 30px rgba(31, 78, 102, 0.18);
}

.card-summary {
  display: flex;
  align-items: center;
  gap: 14px;
  cursor: pointer;
  list-style: none;
}
.card-summary::-webkit-details-marker { display: none; }

.card[open] .card-summary { margin-bottom: 14px; }

.card-icon {
  font-size: 1.7rem;
  flex-shrink: 0;
  display: inline-flex;
  align-items: center;
  justify-content: center;
  width: 48px;
  height: 48px;
  border-radius: 14px;
  background: color-mix(in srgb, var(--accent, var(--blue)) 15%, white);
}

.card-title {
  font-size: 1.1rem;
  font-weight: 700;
  color: var(--ink);
}

.card-tags {
  display: flex;
  flex-wrap: wrap;
  gap: 8px;
}

.card-tags li {
  font-size: 0.8rem;
  font-weight: 500;
  border-radius: 999px;
  overflow: hidden;
}

.card-tags li a,
.card-tags li {
  color: var(--ink-soft);
  background: var(--sky);
}

.card-tags li a {
  display: block;
  padding: 6px 12px;
  border-radius: 999px;
  transition: background 0.2s, color 0.2s;
}

.card-tags li:has(a) {
  padding: 0;
  background: none;
}

.card-tags li a:hover,
.card-tags li a:focus-visible {
  background: var(--blue);
  color: #fff;
}

.card-highlight {
  background: linear-gradient(160deg, #EAF7FC, #ffffff);
}

/* ===== Concept strip ===== */
.concept-strip {
  text-align: center;
  padding: 70px 24px;
  font-size: clamp(1.05rem, 2.2vw, 1.3rem);
  font-weight: 700;
  color: var(--ink);
  background: linear-gradient(160deg, #E4F3FA, #F3FAFD);
}

/* ===== Footer ===== */
.site-footer {
  text-align: center;
  padding: 40px 24px 50px;
  font-size: 0.8rem;
  color: var(--ink-soft);
}

.footer-note { margin-top: 6px; opacity: 0.7; }

/* ===== Room page ===== */
.room-header {
  position: sticky;
  top: 22px;
  z-index: 100;
  background: rgba(243, 250, 253, 0.85);
  backdrop-filter: blur(8px);
  border-bottom: 1px solid rgba(31, 78, 102, 0.1);
}

.room-header .header-inner {
  max-width: 780px;
}

.room-main {
  max-width: 780px;
  margin: 0 auto;
  padding: 40px 24px 80px;
}

.room-breadcrumb {
  display: flex;
  align-items: center;
  gap: 8px;
  font-size: 0.85rem;
  color: var(--ink-soft);
  margin-bottom: 28px;
}

.room-breadcrumb a { opacity: 0.75; transition: opacity 0.2s; }
.room-breadcrumb a:hover { opacity: 1; }

.room-hero {
  display: flex;
  align-items: center;
  gap: 18px;
  background: #fff;
  border-radius: 20px;
  padding: 28px;
  box-shadow: var(--shadow);
  border-top: 4px solid var(--accent, var(--blue));
  margin-bottom: 32px;
}

.room-hero-icon {
  font-size: 2.2rem;
  flex-shrink: 0;
  display: inline-flex;
  align-items: center;
  justify-content: center;
  width: 64px;
  height: 64px;
  border-radius: 16px;
  background: color-mix(in srgb, var(--accent, var(--blue)) 15%, white);
}

.room-hero-text .room-category {
  font-size: 0.8rem;
  font-weight: 700;
  color: var(--ink-soft);
  margin-bottom: 4px;
}

.room-hero-text h1 {
  font-size: 1.5rem;
  font-weight: 900;
  color: var(--ink);
}

.room-body {
  background: #fff;
  border-radius: 20px;
  padding: 32px 28px;
  box-shadow: var(--shadow);
}

.room-body p {
  margin-bottom: 16px;
  color: var(--ink-soft);
}

.room-body p:last-child { margin-bottom: 0; }

.room-placeholder {
  display: flex;
  align-items: center;
  gap: 14px;
  background: var(--sky);
  border-radius: 14px;
  padding: 18px 20px;
  font-size: 0.9rem;
  color: var(--ink);
}

.room-placeholder-icon { font-size: 1.4rem; flex-shrink: 0; }

.room-back {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  margin-top: 32px;
  font-weight: 700;
  color: var(--blue-deep);
}

.room-intro {
  color: var(--ink-soft);
  margin-bottom: 20px;
}

.room-choice-grid {
  display: flex;
  flex-direction: column;
  gap: 12px;
}

.room-choice {
  display: flex;
  align-items: center;
  gap: 14px;
  padding: 16px 18px;
  border-radius: 14px;
  background: var(--sky);
  color: var(--ink);
  transition: background 0.2s, color 0.2s, transform 0.2s;
}

.room-choice:hover,
.room-choice:focus-visible {
  background: var(--blue);
  color: #fff;
  transform: translateY(-2px);
}

.room-choice-icon {
  font-size: 1.3rem;
  flex-shrink: 0;
}

.room-choice-title {
  flex: 1;
  font-weight: 700;
}

.room-choice-arrow {
  font-size: 1.3rem;
  opacity: 0.6;
}

/* ===== Responsive ===== */
@media (max-width: 640px) {
  .site-nav { gap: 14px; font-size: 0.8rem; }
  .site-nav a:not(:last-child) { display: none; }
  .banner { padding: 56px 20px 64px; }
  .contents { padding: 56px 16px 20px; }

  .card-grid {
    grid-template-columns: repeat(3, 1fr);
    gap: 8px;
  }

  .card {
    padding: 12px 8px;
    border-radius: 14px;
    border-top-width: 3px;
  }

  .card-summary {
    flex-direction: column;
    gap: 6px;
    text-align: center;
  }

  .card[open] .card-summary { margin-bottom: 10px; }

  .card-icon {
    width: 36px;
    height: 36px;
    font-size: 1.2rem;
    border-radius: 10px;
  }

  .card-title {
    font-size: 0.72rem;
    line-height: 1.3;
  }

  .card-tags li {
    font-size: 0.68rem;
    padding: 4px 8px;
  }

  .card-tags li a {
    padding: 4px 8px;
  }

  .room-main { padding: 28px 16px 60px; }

  .room-hero {
    flex-direction: column;
    text-align: center;
    padding: 24px 20px;
  }

  .room-hero-text h1 { font-size: 1.25rem; }

  .room-body { padding: 24px 18px; }
}