:root {
  --primary: #0066ff;
  --primary-light: #4d94ff;
  --primary-dark: #0052cc;
  --on-primary: #ffffff;
  --primary-container: #e6f0ff;
  --on-primary-container: #003080;

  --secondary: #6366f1;
  --secondary-light: #818cf8;
  --on-secondary: #ffffff;
  --secondary-container: #eef2ff;
  --on-secondary-container: #3730a3;

  --accent: #ff6b6b;
  --accent-light: #ff8a8a;
  --on-accent: #ffffff;

  --background: #f8fafc;
  --surface: #ffffff;
  --surface-elevated: #ffffff;
  --surface-variant: #f1f5f9;
  --surface-container: #e2e8f0;
  --on-surface: #0f172a;
  --on-surface-variant: #64748b;

  --outline: #e2e8f0;
  --outline-variant: #cbd5e1;

  --error: #ef4444;
  --error-light: #fca5a5;
  --on-error: #ffffff;
  --error-container: #fef2f2;
  --on-error-container: #b91c1c;

  --success: #10b981;
  --success-light: #6ee7b7;
  --on-success: #ffffff;
  --success-container: #ecfdf5;
  --on-success-container: #065f46;

  --warning: #f59e0b;
  --warning-light: #fcd34d;
  --on-warning: #ffffff;
  --warning-container: #fffbeb;
  --on-warning-container: #b45309;

  --info: #0ea5e9;
  --info-light: #7dd3fc;
  --on-info: #ffffff;
  --info-container: #f0f9ff;
  --on-info-container: #0369a1;

  --today-background: #fff7ed;
  --today-border: #f97316;
  --today-accent: #ea580c;

  --upcoming-background: #f0f9ff;
  --upcoming-border: #0ea5e9;
  --upcoming-accent: #0284c7;

  --gradient-primary-start: #0066ff;
  --gradient-primary-end: #6366f1;
  --gradient-accent-start: #ff6b6b;
  --gradient-accent-end: #f59e0b;
  --gradient-success-start: #10b981;
  --gradient-success-end: #0ea5e9;

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

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

  --shadow-sm: 0 1px 3px rgba(0, 0, 0, 0.1);
  --shadow-md: 0 4px 6px rgba(0, 0, 0, 0.1);
  --shadow-lg: 0 10px 15px rgba(0, 0, 0, 0.1);
  --shadow-xl: 0 20px 25px rgba(0, 0, 0, 0.1);

  --font-family-base: 'Noto Sans JP', 'Inter', -apple-system, BlinkMacSystemFont,
    'Segoe UI', sans-serif;
  --font-family-heading: 'Noto Sans JP', 'Inter', -apple-system,
    BlinkMacSystemFont, 'Segoe UI', sans-serif;

  --transition-fast: 150ms ease;
  --transition-normal: 300ms ease;
  --transition-slow: 500ms ease;

  --max-width: 1200px;
  --header-height: 64px;
}

@media (prefers-color-scheme: dark) {
  :root {
    --background: #0f172a;
    --surface: #1e293b;
    --surface-elevated: #334155;
    --surface-variant: #1e293b;
    --surface-container: #334155;
    --on-surface: #f8fafc;
    --on-surface-variant: #94a3b8;

    --outline: #475569;
    --outline-variant: #334155;

    --error-container: #4c1d1d;
    --on-error-container: #fca5a5;

    --success-container: #064e3b;
    --on-success-container: #6ee7b7;

    --warning-container: #78350f;
    --on-warning-container: #fcd34d;

    --info-container: #0c4a6e;
    --on-info-container: #7dd3fc;

    --today-background: #431407;
    --upcoming-background: #0c4a6e;
  }
}

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

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

body {
  font-family: var(--font-family-base);
  font-size: 1rem;
  line-height: 1.6;
  color: var(--on-surface);
  background-color: var(--background);
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
}

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

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

a:hover {
  color: var(--primary-light);
}

button {
  font-family: inherit;
  cursor: pointer;
  border: none;
  background: none;
  padding: 0;
}

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

@media (min-width: 768px) {
  .container {
    padding: 0 var(--spacing-lg);
  }
}

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

.section-header {
  text-align: center;
  margin-bottom: var(--spacing-xl);
}

.section-title {
  font-family: var(--font-family-heading);
  font-size: 2rem;
  font-weight: 700;
  color: var(--on-surface);
  margin-bottom: var(--spacing-sm);
}

.section-subtitle {
  font-size: 1.125rem;
  color: var(--on-surface-variant);
  max-width: 600px;
  margin: 0 auto;
}

.button {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: var(--spacing-sm);
  padding: 12px 24px;
  font-size: 1rem;
  font-weight: 600;
  border-radius: var(--radius-md);
  transition: all var(--transition-fast);
  text-decoration: none;
  white-space: nowrap;
}

.button-primary {
  background: linear-gradient(
    135deg,
    var(--gradient-primary-start),
    var(--gradient-primary-end)
  );
  color: var(--on-primary);
  box-shadow: var(--shadow-md);
}

.button-primary:hover {
  transform: translateY(-2px);
  box-shadow: var(--shadow-lg);
}

.button-secondary {
  background: var(--surface);
  color: var(--on-surface);
  border: 2px solid var(--outline);
}

.button-secondary:hover {
  border-color: var(--primary);
  color: var(--primary);
}

.button-accent {
  background: linear-gradient(
    135deg,
    var(--gradient-accent-start),
    var(--gradient-accent-end)
  );
  color: var(--on-accent);
  box-shadow: var(--shadow-md);
}

.button-accent:hover {
  transform: translateY(-2px);
  box-shadow: var(--shadow-lg);
}

.icon {
  width: 24px;
  height: 24px;
  stroke-width: 2;
}

.icon-sm {
  width: 20px;
  height: 20px;
}

.icon-lg {
  width: 32px;
  height: 32px;
}

.icon-xl {
  width: 48px;
  height: 48px;
}

.card {
  background: var(--surface);
  border-radius: var(--radius-lg);
  padding: var(--spacing-lg);
  box-shadow: var(--shadow-md);
  transition: transform var(--transition-normal),
    box-shadow var(--transition-normal);
}

.card:hover {
  transform: translateY(-4px);
  box-shadow: var(--shadow-xl);
}

.fade-in {
  animation: fadeIn 0.6s ease-out;
}

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

.fade-up {
  animation: fadeUp 0.6s ease-out;
}

@keyframes fadeUp {
  from {
    opacity: 0;
    transform: translateY(40px);
  }
  to {
    opacity: 1;
    transform: translateY(0);
  }
}

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

.visually-hidden {
  position: absolute;
  width: 1px;
  height: 1px;
  margin: -1px;
  padding: 0;
  overflow: hidden;
  clip: rect(0, 0, 0, 0);
  border: 0;
}