/* ============================================
   Base Styles & Design Tokens
   ============================================ */

@import url('https://fonts.googleapis.com/css2?family=Noto+Sans+JP:wght@400;500;700&display=swap');

:root {
  /* Colors */
  --color-primary-dark: #32373c;
  --color-accent-green: #2e7d32;
  --color-accent-green-hover: #1b5e20;
  --color-bg-white: #ffffff;
  --color-bg-light: #f5f5f5;
  --color-bg-hero: #3a3a3a;
  --color-border: #e0e0e0;
  --color-text-primary: #333333;
  --color-text-secondary: #666666;
  --color-text-muted: #999999;

  /* Typography */
  --font-family-base: "Noto Sans JP", "Hiragino Kaku Gothic ProN", "Yu Gothic", sans-serif;
  --font-size-xs: 0.75rem;
  --font-size-sm: 0.875rem;
  --font-size-base: 1rem;
  --font-size-lg: 1.125rem;
  --font-size-xl: 1.5rem;
  --font-size-2xl: 2rem;
  --font-size-3xl: 2.625rem;

  /* Spacing */
  --space-xs: 0.25rem;
  --space-sm: 0.5rem;
  --space-md: 1rem;
  --space-lg: 1.5rem;
  --space-xl: 2rem;
  --space-2xl: 3rem;
  --space-3xl: 4rem;

  /* Layout */
  --max-width: 1200px;
  --sidebar-width: 300px;
  --header-height: 70px;
  --border-radius-sm: 4px;
  --border-radius-md: 8px;
  --border-radius-pill: 9999px;

  /* Shadows */
  --shadow-card: 0 2px 8px rgba(0, 0, 0, 0.08);
  --shadow-header: 0 2px 4px rgba(0, 0, 0, 0.06);
}

/* ============================================
   Base Elements
   ============================================ */

html {
  font-size: 16px;
}

body {
  font-family: var(--font-family-base);
  font-size: var(--font-size-base);
  color: var(--color-text-primary);
  background-color: var(--color-bg-white);
}

/* ============================================
   Layout
   ============================================ */

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

/* ============================================
   Buttons
   ============================================ */

.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  padding: 0.6em 1.6em;
  font-size: var(--font-size-sm);
  font-weight: 500;
  border-radius: var(--border-radius-sm);
  transition: background-color 0.2s, color 0.2s, opacity 0.2s;
  white-space: nowrap;
}

.btn--green {
  background-color: var(--color-accent-green);
  color: #fff;
}

.btn--green:hover {
  background-color: var(--color-accent-green-hover);
}

.btn--outline {
  background-color: transparent;
  border: 1px solid var(--color-accent-green);
  color: var(--color-accent-green);
}

.btn--outline:hover {
  background-color: var(--color-accent-green);
  color: #fff;
}

/* ============================================
   Section Title
   ============================================ */

.section-title {
  font-size: var(--font-size-xl);
  font-weight: 700;
  text-align: center;
  margin-bottom: var(--space-2xl);
}

/* ============================================
   Header
   ============================================ */

.site-header {
  position: sticky;
  top: 0;
  z-index: 100;
  background-color: var(--color-bg-white);
  box-shadow: var(--shadow-header);
  height: var(--header-height);
}

.site-header__inner {
  display: flex;
  align-items: center;
  height: 100%;
  gap: var(--space-lg);
}

.site-header__logo img {
  height: 30px;
  width: auto;
}

.site-header__nav {
  flex: 1;
}

.site-header__nav-list {
  display: flex;
  align-items: center;
  justify-content: center;
  gap: var(--space-lg);
}

.site-header__nav-list a {
  font-size: var(--font-size-sm);
  font-weight: 500;
  color: var(--color-text-primary);
  transition: color 0.2s;
}

.site-header__nav-list a:hover {
  color: var(--color-accent-green);
}

.site-header__entry {
  flex-shrink: 0;
}

/* Hamburger */
.site-header__hamburger {
  display: none;
  flex-direction: column;
  justify-content: center;
  gap: 5px;
  width: 30px;
  height: 30px;
  z-index: 110;
}

.site-header__hamburger span {
  display: block;
  width: 100%;
  height: 2px;
  background-color: var(--color-text-primary);
  transition: transform 0.3s, opacity 0.3s;
}

/* Mobile */
@media (max-width: 767px) {
  .site-header__hamburger {
    display: flex;
    margin-left: auto;
  }

  .site-header__nav {
    position: fixed;
    top: 0;
    right: 0;
    width: 280px;
    height: 100vh;
    background-color: var(--color-bg-white);
    box-shadow: -4px 0 12px rgba(0, 0, 0, 0.1);
    padding: calc(var(--header-height) + var(--space-xl)) var(--space-xl) var(--space-xl);
    transform: translateX(100%);
    transition: transform 0.3s ease;
    z-index: 105;
  }

  .site-header__nav.is-open {
    transform: translateX(0);
  }

  .site-header__nav-list {
    flex-direction: column;
    align-items: flex-start;
    gap: 0;
  }

  .site-header__nav-list li {
    width: 100%;
  }

  .site-header__nav-list a {
    display: block;
    padding: var(--space-md) 0;
    border-bottom: 1px solid var(--color-border);
    font-size: var(--font-size-base);
  }

  .site-header__entry {
    display: none;
  }

  /* Hamburger open state */
  .site-header__hamburger.is-open span:nth-child(1) {
    transform: translateY(7px) rotate(45deg);
  }

  .site-header__hamburger.is-open span:nth-child(2) {
    opacity: 0;
  }

  .site-header__hamburger.is-open span:nth-child(3) {
    transform: translateY(-7px) rotate(-45deg);
  }

  /* Overlay */
  .site-header__overlay {
    display: none;
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    background: rgba(0, 0, 0, 0.4);
    z-index: 104;
  }

  .site-header__overlay.is-active {
    display: block;
  }
}

/* ============================================
   Footer
   ============================================ */

.site-footer {
  background-color: var(--color-primary-dark);
  color: #fff;
  padding: var(--space-3xl) 0 var(--space-xl);
}

.site-footer__inner {
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: var(--space-xl);
}

.site-footer__logo img {
  height: 28px;
  width: auto;
  filter: brightness(0) invert(1);
}

.site-footer__nav ul {
  display: flex;
  flex-wrap: wrap;
  justify-content: center;
  gap: var(--space-md) var(--space-xl);
}

.site-footer__nav a {
  font-size: var(--font-size-sm);
  color: rgba(255, 255, 255, 0.7);
  transition: color 0.2s;
}

.site-footer__nav a:hover {
  color: #fff;
}

.site-footer__copyright {
  font-size: var(--font-size-xs);
  color: rgba(255, 255, 255, 0.5);
}

/* ============================================
   Placeholder Image
   ============================================ */

.placeholder-img {
  background-color: #d0d0d0;
  display: flex;
  align-items: center;
  justify-content: center;
  color: #999;
  font-size: var(--font-size-sm);
}