:root {
  --primary-50: #fbf8f4;
  --primary-100: #f5ede3;
  --primary-200: #ebd9c7;
  --primary-300: #dfc4a9;
  --primary-400: #d4b08d;
  --primary-500: #c9a47b;
  --primary-600: #b8916a;
  --primary-700: #9a7857;
  --primary-800: #7c5f45;
  --primary-900: #5e4633;

  --secondary-50: #f5f5f5;
  --secondary-100: #e8e8e8;
  --secondary-200: #d4d4d4;
  --secondary-300: #a8a8a8;
  --secondary-400: #737373;
  --secondary-500: #525252;
  --secondary-600: #404040;
  --secondary-700: #2d2d2d;
  --secondary-800: #1a1a1a;
  --secondary-900: #0d0d0d;

  --accent-500: #d4af37;
  --accent-600: #b8992f;
  --accent-700: #9c8327;

  --success-500: #4a8555;
  --success-600: #3b6a44;

  --neutral-white: #ffffff;
  --neutral-background: #fafafa;
  --neutral-surface: #ffffff;
  --neutral-outline: #e0e0e0;

  --spacing-xs: 4px;
  --spacing-sm: 8px;
  --spacing-md: 12px;
  --spacing-lg: 16px;
  --spacing-xl: 20px;
  --spacing-xxl: 24px;
  --spacing-xxxl: 32px;
  --spacing-xxxxl: 48px;

  --radius-sm: 8px;
  --radius-md: 12px;
  --radius-lg: 16px;
  --radius-xl: 20px;
  --radius-full: 9999px;

  --shadow-sm: 0 1px 2px rgba(0, 0, 0, 0.05);
  --shadow-md: 0 2px 4px rgba(0, 0, 0, 0.08);
  --shadow-lg: 0 4px 8px rgba(0, 0, 0, 0.1);
  --shadow-xl: 0 8px 16px rgba(0, 0, 0, 0.12);

  --font-family-en: -apple-system, BlinkMacSystemFont, 'Segoe UI', 'Inter',
    'Roboto', 'Oxygen', 'Ubuntu', 'Cantarell', sans-serif;
  --font-family-ja: -apple-system, BlinkMacSystemFont, 'Hiragino Sans',
    'Noto Sans JP', 'Yu Gothic', sans-serif;

  --transition-fast: 200ms ease-out;
  --transition-normal: 300ms ease-out;
  --transition-slow: 400ms ease-out;
}

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

html {
  font-size: 16px;
  scroll-behavior: smooth;
}

body {
  font-family: var(--font-family-en);
  background-color: var(--neutral-background);
  color: var(--secondary-800);
  line-height: 1.5;
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
}

body[lang='ja'] {
  font-family: var(--font-family-ja);
  line-height: 1.75;
}

img {
  max-width: 100%;
  height: auto;
  display: block;
}

a {
  color: inherit;
  text-decoration: none;
  transition: color var(--transition-fast);
}

button {
  font-family: inherit;
  cursor: pointer;
  border: none;
  background: none;
}

ul,
ol {
  list-style: none;
}

.container {
  width: 100%;
  max-width: 1200px;
  margin: 0 auto;
  padding: 0 var(--spacing-lg);
}

.section {
  padding: var(--spacing-xxxxl) 0;
}

.section-title {
  font-size: 2rem;
  font-weight: 700;
  color: var(--secondary-800);
  text-align: center;
  margin-bottom: var(--spacing-lg);
}

.section-subtitle {
  font-size: 1.125rem;
  color: var(--secondary-500);
  text-align: center;
  max-width: 600px;
  margin: 0 auto var(--spacing-xxxl);
}

.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: var(--spacing-sm);
  padding: var(--spacing-md) var(--spacing-xl);
  font-size: 1rem;
  font-weight: 600;
  border-radius: var(--radius-full);
  transition: all var(--transition-normal);
  white-space: nowrap;
}

.btn-primary {
  background: linear-gradient(
    135deg,
    var(--primary-500) 0%,
    var(--primary-600) 100%
  );
  color: var(--neutral-white);
  box-shadow: var(--shadow-md);
}

.btn-primary:hover {
  background: linear-gradient(
    135deg,
    var(--primary-600) 0%,
    var(--primary-700) 100%
  );
  box-shadow: var(--shadow-lg);
  transform: translateY(-2px);
}

.btn-primary:active {
  transform: translateY(0);
}

.btn-secondary {
  background-color: var(--neutral-white);
  color: var(--primary-600);
  border: 2px solid var(--primary-200);
}

.btn-secondary:hover {
  background-color: var(--primary-50);
  border-color: var(--primary-300);
}

.btn-large {
  padding: var(--spacing-lg) var(--spacing-xxxl);
  font-size: 1.125rem;
}

.text-gradient {
  background: linear-gradient(
    135deg,
    var(--primary-600) 0%,
    var(--accent-600) 100%
  );
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
}

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

@keyframes fadeInUp {
  from {
    opacity: 0;
    transform: translateY(20px);
  }
  to {
    opacity: 1;
    transform: translateY(0);
  }
}

.animate-fade-in {
  animation: fadeInUp var(--transition-normal) ease-out;
}

@media (prefers-color-scheme: dark) {
  body {
    background-color: var(--secondary-900);
    color: var(--neutral-white);
  }

  .section-title {
    color: var(--neutral-white);
  }

  .btn-secondary {
    background-color: var(--secondary-800);
    border-color: var(--secondary-700);
  }
}