:root {
  --bg-canvas: #f6f8fa;
  --bg-surface: #ffffff;
  --bg-subtle: #eef2f6;

  --text-primary: #1c2430;
  --text-secondary: #4a5568;
  --text-muted: #718096;

  --border-color: #dde3ea;

  /* BodyCalc: グレー (Gray) */
  --gray-main: #525b66;
  --gray-dark: #3b424b;
  --gray-soft: #ebedf0;
  --gray-tint: #f7f8f9;
  --gray-border: #c5cbd3;

  /* Nutrient: 水色 (Sky Blue / Light Blue) */
  --sky-main: #0ea5e9;
  --sky-dark: #0284c7;
  --sky-soft: #e0f2fe;
  --sky-tint: #f4faff;
  --sky-border: #93dbfc;

  /* KanPo: 茶 (Herbal Brown) */
  --brown-main: #8b5a2b;
  --brown-dark: #6b421b;
  --brown-soft: #f5ebe1;
  --brown-tint: #fcf9f5;
  --brown-border: #dcbfa3;

  --shadow-card: 0 2px 10px rgba(15, 23, 42, 0.05), 0 1px 2px rgba(15, 23, 42, 0.03);
  --shadow-card-hover: 0 12px 26px -4px rgba(15, 23, 42, 0.11), 0 4px 10px -2px rgba(15, 23, 42, 0.05);

  --font-sans: 'Plus Jakarta Sans', 'Noto Sans JP', -apple-system, BlinkMacSystemFont, sans-serif;
  --font-mono: 'JetBrains Mono', ui-monospace, SFMono-Regular, Menlo, monospace;
}

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

body {
  font-family: var(--font-sans);
  background-color: var(--bg-canvas);
  color: var(--text-primary);
  line-height: 1.6;
  min-height: 100vh;
  display: flex;
  flex-direction: column;
  -webkit-font-smoothing: antialiased;
}

.container {
  width: 100%;
  max-width: 980px;
  margin: 0 auto;
  padding: 0 1.25rem;
}

/* Header */
.site-header {
  background-color: var(--bg-surface);
  border-bottom: 1px solid var(--border-color);
  padding: 1rem 0;
}

.header-inner {
  display: flex;
  align-items: center;
  justify-content: space-between;
}

.brand {
  display: inline-flex;
  align-items: center;
  gap: 0.65rem;
  text-decoration: none;
  color: var(--text-primary);
}

.brand-icon {
  width: 2rem;
  height: 2rem;
  border-radius: 7px;
  background-color: #2b3544;
  color: #ffffff;
  display: inline-flex;
  align-items: center;
  justify-content: center;
}

.brand-title {
  font-size: 1.1rem;
  font-weight: 700;
  letter-spacing: -0.02em;
}

.brand-domain {
  font-family: var(--font-mono);
  font-size: 0.75rem;
  color: var(--text-muted);
  background-color: var(--bg-subtle);
  padding: 0.15rem 0.45rem;
  border-radius: 4px;
}

/* Main Content */
.main-content {
  flex: 1;
  display: flex;
  align-items: center;
  padding: 3rem 0;
}

.portal-intro {
  margin-bottom: 2rem;
}

.portal-heading {
  font-size: clamp(1.35rem, 2.5vw, 1.75rem);
  font-weight: 700;
  letter-spacing: -0.02em;
  margin-bottom: 0.35rem;
}

.portal-sub {
  font-size: 0.92rem;
  color: var(--text-secondary);
}

/* 3-Card Grid */
.tools-grid {
  display: grid;
  grid-template-columns: repeat(3, minmax(0, 1fr));
  gap: 1.25rem;
}

.tool-card {
  display: flex;
  flex-direction: column;
  justify-content: space-between;
  background-color: var(--bg-surface);
  border: 1.5px solid var(--border-color);
  border-radius: 12px;
  text-decoration: none;
  color: inherit;
  box-shadow: var(--shadow-card);
  overflow: hidden;
  transition: transform 0.16s ease, box-shadow 0.16s ease, border-color 0.16s ease;
  cursor: pointer;
}

.tool-card:hover {
  transform: translateY(-3px);
  box-shadow: var(--shadow-card-hover);
}

.tool-card.card-gray {
  border-color: var(--gray-border);
  background-color: var(--gray-tint);
}
.tool-card.card-sky {
  border-color: var(--sky-border);
  background-color: var(--sky-tint);
}
.tool-card.card-brown {
  border-color: var(--brown-border);
  background-color: var(--brown-tint);
}

.tool-card-bar {
  height: 7px;
  width: 100%;
}

.card-gray .tool-card-bar {
  background-color: var(--gray-main);
}
.card-sky .tool-card-bar {
  background-color: var(--sky-main);
}
.card-brown .tool-card-bar {
  background-color: var(--brown-main);
}

.tool-card-content {
  padding: 1.4rem 1.35rem 1.25rem;
  display: flex;
  flex-direction: column;
  gap: 0.65rem;
}

.tool-meta {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 0.5rem;
}

.tool-badge {
  font-size: 0.74rem;
  font-weight: 700;
  padding: 0.22rem 0.6rem;
  border-radius: 6px;
}

.card-gray .tool-badge {
  background-color: var(--gray-soft);
  color: var(--gray-dark);
}
.card-sky .tool-badge {
  background-color: var(--sky-soft);
  color: var(--sky-dark);
}
.card-brown .tool-badge {
  background-color: var(--brown-soft);
  color: var(--brown-dark);
}

.tool-path {
  font-family: var(--font-mono);
  font-size: 0.75rem;
  color: var(--text-muted);
}

.tool-name {
  font-size: 1.4rem;
  font-weight: 700;
  letter-spacing: -0.02em;
  line-height: 1.25;
}

.card-gray .tool-name {
  color: var(--gray-dark);
}
.card-sky .tool-name {
  color: var(--sky-dark);
}
.card-brown .tool-name {
  color: var(--brown-dark);
}

.tool-jp {
  font-size: 0.9rem;
  font-weight: 600;
  color: var(--text-primary);
}

.tool-desc {
  font-size: 0.84rem;
  color: var(--text-secondary);
  line-height: 1.6;
  margin-top: 0.15rem;
}

.tool-card-action {
  padding: 0.85rem 1.35rem;
  display: flex;
  align-items: center;
  justify-content: space-between;
  font-size: 0.86rem;
  font-weight: 700;
  color: #ffffff;
  transition: filter 0.15s ease;
}

.card-gray .tool-card-action {
  background-color: var(--gray-main);
}
.card-sky .tool-card-action {
  background-color: var(--sky-main);
}
.card-brown .tool-card-action {
  background-color: var(--brown-main);
}

.tool-card:hover .tool-card-action {
  filter: brightness(0.92);
}

.arrow-icon {
  transition: transform 0.15s ease;
}

.tool-card:hover .arrow-icon {
  transform: translateX(3px);
}

/* Footer */
.site-footer {
  border-top: 1px solid var(--border-color);
  background-color: var(--bg-surface);
  padding: 1.1rem 0;
  font-size: 0.76rem;
  color: var(--text-muted);
  text-align: center;
}

@media (max-width: 820px) {
  .main-content {
    padding: 2rem 0;
  }
  .tools-grid {
    grid-template-columns: 1fr;
  }
}