:root {
  /* =========================
     Color
  ========================= */
  --color-bg: #f3f3f1;
  --color-bg-subtle: #ececea;
  --color-bg-muted: #e6e7e3;
  --color-surface: #ffffff;
  --color-surface-strong: #fbfbf9;
  --color-border: #d7d9d3;
  --color-border-strong: #bcc3bc;

  --color-text: #111111;
  --color-text-strong: #000000;
  --color-text-muted: #50565d;
  --color-text-subtle: #747b84;
  --color-text-on-dark: #ffffff;

  --color-brand-red: #e60013;
  --color-brand-blue: #0081cc;
  --color-brand-red-soft: rgba(230, 0, 19, 0.08);
  --color-brand-blue-soft: rgba(0, 129, 204, 0.08);
  --color-accent: var(--color-brand-red);
  --color-accent-secondary: var(--color-brand-blue);

  --color-shadow: rgba(15, 23, 42, 0.07);
  --color-shadow-strong: rgba(15, 23, 42, 0.14);
  --color-overlay: rgba(17, 17, 17, 0.58);

  --gradient-brand: linear-gradient(
    135deg,
    var(--color-brand-red) 0%,
    var(--color-brand-blue) 100%
  );
  --gradient-surface: linear-gradient(
    180deg,
    rgba(255, 255, 255, 1) 0%,
    rgba(243, 243, 241, 1) 100%
  );

  /* =========================
     Typography
  ========================= */
  --font-family-base: "Noto Sans JP", "Hiragino Sans", "Yu Gothic",
    "YuGothic", "Meiryo", sans-serif;
  --font-family-en: "Inter", "Helvetica Neue", Arial, sans-serif;

  --font-size-2xs: 1.2rem;
  --font-size-xs: 1.3rem;
  --font-size-sm: 1.4rem;
  --font-size-md: 1.6rem;
  --font-size-lg: 1.8rem;
  --font-size-xl: 2rem;
  --font-size-2xl: 2.4rem;
  --font-size-3xl: clamp(3rem, 2.3rem + 1.9vw, 4.6rem);
  --font-size-4xl: clamp(4rem, 3rem + 2.8vw, 6.8rem);
  --font-size-5xl: clamp(5rem, 3.8rem + 4vw, 8.8rem);

  --line-height-tight: 1.15;
  --line-height-snug: 1.4;
  --line-height-base: 1.8;
  --line-height-relaxed: 2.05;

  --letter-spacing-tight: -0.03em;
  --letter-spacing-base: 0.02em;
  --letter-spacing-wide: 0.08em;
  --letter-spacing-wider: 0.14em;

  --font-weight-regular: 400;
  --font-weight-medium: 500;
  --font-weight-semibold: 600;
  --font-weight-bold: 700;

  /* =========================
     Layout
  ========================= */
  --container-width: 1360px;
  --container-wide: 1560px;
  --container-narrow: 1040px;
  --container-padding: 28px;
  --header-height: 84px;
  --header-height-mobile: 64px;

  --section-space-y: clamp(84px, 9vw, 160px);
  --section-space-y-sm: clamp(56px, 6vw, 104px);
  --grid-gap: 24px;
  --grid-gap-lg: 48px;
  --grid-gap-xl: clamp(40px, 5vw, 88px);

  /* =========================
     Spacing
  ========================= */
  --space-2xs: 4px;
  --space-xs: 8px;
  --space-sm: 12px;
  --space-md: 16px;
  --space-lg: 24px;
  --space-xl: 32px;
  --space-2xl: 48px;
  --space-3xl: 64px;
  --space-4xl: 96px;
  --space-5xl: 128px;

  /* =========================
     Radius
  ========================= */
  --radius-xs: 6px;
  --radius-sm: 10px;
  --radius-md: 16px;
  --radius-lg: 24px;
  --radius-xl: 32px;
  --radius-pill: 999px;

  /* =========================
     Shadow
  ========================= */
  --shadow-sm: 0 8px 24px var(--color-shadow);
  --shadow-md: 0 18px 44px var(--color-shadow);
  --shadow-lg: 0 28px 72px var(--color-shadow-strong);

  /* =========================
     Motion
  ========================= */
  --transition-fast: 0.2s ease;
  --transition-base: 0.35s ease;
  --transition-slow: 0.6s ease;

  /* =========================
     Z-index
  ========================= */
  --z-loader: 1000;
  --z-header: 900;
  --z-overlay: 850;
  --z-drawer: 950;
  --z-dropdown: 800;
}

@media (max-width: 767px) {
  :root {
    --container-padding: 16px;
    --grid-gap: 16px;
    --grid-gap-lg: 24px;
    --grid-gap-xl: 32px;
  }
}

@media (prefers-reduced-motion: reduce) {
  :root {
    --transition-fast: 0.01ms linear;
    --transition-base: 0.01ms linear;
    --transition-slow: 0.01ms linear;
  }
}