:root {
  --sakutio-brand-primary: #2563eb;
  --sakutio-brand-primary-deep: #1d4ed8;
  --sakutio-brand-navy: #1e3a8a;
  --sakutio-brand-indigo: #4f46e5;
  --sakutio-brand-soft: #eff6ff;
  --sakutio-brand-soft-2: #dbeafe;
  --sakutio-brand-border: #93c5fd;

  --sakutio-bg: #f3f6f8;
  --sakutio-surface: #fafbfc;
  --sakutio-surface-soft: #f5f7fa;
  --sakutio-raised: #ffffff;
  --sakutio-border: #dde4ea;

  --sakutio-heading: #111827;
  --sakutio-text: #374151;
  --sakutio-text-muted: #5f6b76;

  --sakutio-link: #1d4ed8;
  --sakutio-link-hover: #1e3a8a;
  --sakutio-link-underline: #93c5fd;

  --sakutio-point-bg: #eff6ff;
  --sakutio-point-border: #bfdbfe;
  --sakutio-point-text: #1e3a8a;

  --sakutio-caution-bg: #fffbeb;
  --sakutio-caution-border: #fde68a;
  --sakutio-caution-text: #92400e;

  --sakutio-info-bg: #eef8f4;
  --sakutio-info-border: #b9ddcf;
  --sakutio-info-text: #315f51;

  --sakutio-danger: #b91c1c;
  --sakutio-danger-bg: #fef2f2;
  --sakutio-marker: #ffe27a;

  --sakutio-radius-sm: 8px;
  --sakutio-radius-md: 12px;
  --sakutio-radius-lg: 16px;

  color: var(--sakutio-text);
  background: var(--sakutio-bg);
  font-family: "Segoe UI", "Hiragino Sans", "Yu Gothic UI", Meiryo, sans-serif;
  font-synthesis: none;
  text-rendering: optimizeLegibility;
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
}

* { box-sizing: border-box; }
html { scroll-behavior: smooth; scrollbar-gutter: stable; }
body { margin: 0; min-width: 320px; background: var(--sakutio-bg); color: var(--sakutio-text); }
a { color: inherit; }
button, input, select, textarea { font: inherit; }

:focus-visible {
  outline: 3px solid rgba(37, 99, 235, 0.35);
  outline-offset: 3px;
  border-radius: 4px;
}