/* =============================================
   BASE — Reset, CSS Variables, Typography
   ============================================= */

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

:root {
  /* Brand Colors */
  --color-orange:      #FF5A14;
  --color-black:       #000000;
  --color-dark:        #0A0A0A;
  --color-dark-2:      #111111;
  --color-white:       #FFFFFF;
  --color-off-white:   #F5F5F5;
  --color-gray-light:  #E5E5E5;
  --color-gray-muted:  #6B6B6B;

  /* Typography */
  --font-sans: 'Inter', 'Noto Sans JP', system-ui, -apple-system, BlinkMacSystemFont, sans-serif;

  --fs-xs:   0.75rem;   /* 12px */
  --fs-sm:   0.875rem;  /* 14px */
  --fs-base: 1rem;      /* 16px */
  --fs-lg:   1.125rem;  /* 18px */
  --fs-xl:   1.25rem;   /* 20px */
  --fs-2xl:  1.5rem;    /* 24px */
  --fs-3xl:  1.875rem;  /* 30px */
  --fs-4xl:  2.25rem;   /* 36px */
  --fs-5xl:  3rem;      /* 48px */
  --fs-6xl:  3.75rem;   /* 60px */
  --fs-7xl:  4.5rem;    /* 72px */

  /* Spacing (base unit: 4px) */
  --space-1:  0.25rem;
  --space-2:  0.5rem;
  --space-3:  0.75rem;
  --space-4:  1rem;
  --space-5:  1.25rem;
  --space-6:  1.5rem;
  --space-8:  2rem;
  --space-10: 2.5rem;
  --space-12: 3rem;
  --space-14: 3.5rem;
  --space-16: 4rem;
  --space-20: 5rem;
  --space-24: 6rem;
  --space-32: 8rem;

  /* Layout */
  --max-width:     1280px;
  --header-height: 72px;
  --section-py:    6rem;

  /* Transitions */
  --transition-fast:   0.15s ease-out;
  --transition-base:   0.25s ease-out;
  --transition-slow:   0.4s ease-out;
}

html {
  scroll-behavior: smooth;
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
}

body {
  font-family: var(--font-sans);
  font-size: var(--fs-base);
  line-height: 1.6;
  color: var(--color-dark);
  background-color: var(--color-white);
}

/* --- Typography Scale --- */
h1, h2, h3, h4, h5, h6 {
  font-weight: 700;
  line-height: 1.15;
  letter-spacing: -0.02em;
  color: inherit;
}

h1 { font-size: clamp(var(--fs-4xl), 6vw, var(--fs-7xl)); }
h2 { font-size: clamp(var(--fs-3xl), 4vw, var(--fs-5xl)); }
h3 { font-size: clamp(var(--fs-xl), 2.5vw, var(--fs-3xl)); }
h4 { font-size: var(--fs-xl); }

p {
  line-height: 1.7;
  color: var(--color-gray-muted);
}

a {
  color: inherit;
  text-decoration: none;
}

img, svg {
  display: block;
  max-width: 100%;
}

ul {
  list-style: none;
}

button {
  font-family: var(--font-sans);
  cursor: pointer;
  border: none;
  background: none;
}

input, textarea, select {
  font-family: var(--font-sans);
}

/* --- Overline Label --- */
.overline {
  display: inline-block;
  font-size: var(--fs-xs);
  font-weight: 600;
  letter-spacing: 0.12em;
  text-transform: uppercase;
  color: var(--color-orange);
  margin-bottom: var(--space-4);
}

/* --- Section Heading Block --- */
.section-header {
  margin-bottom: var(--space-12);
}

.section-header h2 {
  color: var(--color-dark);
  margin-bottom: var(--space-4);
}

.section-header p {
  font-size: var(--fs-lg);
  max-width: 560px;
}

.section-header.centered {
  text-align: center;
}

.section-header.centered p {
  margin: 0 auto;
}