/* ============================
   Layout — Data & Canvas
   ============================ */

/* --- Container --- */
.container {
  width: 100%;
  max-width: var(--content-max-width);
  margin-inline: auto;
  padding-inline: var(--content-padding);
}

/* ============================
   Header & Navigation
   ============================ */
.site-header {
  position: sticky;
  top: 0;
  z-index: 100;
  background-color: rgba(249, 249, 249, 0.92);
  backdrop-filter: blur(8px);
  -webkit-backdrop-filter: blur(8px);
  border-bottom: 1px solid var(--color-border);
}

.site-header .container {
  display: flex;
  align-items: center;
  justify-content: space-between;
  height: 64px;
}

/* Logo */
.site-logo {
  font-size: var(--font-size-md);
  font-weight: var(--font-weight-bold);
  color: var(--color-main);
  letter-spacing: -0.02em;
}

.site-logo span {
  color: var(--color-accent);
}

/* Nav links */
.nav-list {
  display: flex;
  align-items: center;
  gap: var(--space-8);
}

.nav-list a {
  font-size: var(--font-size-sm);
  font-weight: var(--font-weight-medium);
  color: var(--color-sub);
  letter-spacing: 0.02em;
  padding: var(--space-2) 0;
  position: relative;
}

.nav-list a::after {
  content: '';
  position: absolute;
  bottom: -2px;
  left: 0;
  width: 0;
  height: 1px;
  background-color: var(--color-accent);
  transition: width var(--transition-normal);
}

.nav-list a:hover,
.nav-list a.active {
  color: var(--color-main);
}

.nav-list a:hover::after,
.nav-list a.active::after {
  width: 100%;
}

/* Hamburger (Mobile) */
.nav-toggle {
  display: none;
  flex-direction: column;
  justify-content: center;
  gap: 5px;
  width: 28px;
  height: 28px;
  cursor: pointer;
  background: none;
  border: none;
  padding: 0;
}

.nav-toggle span {
  display: block;
  width: 100%;
  height: 1.5px;
  background-color: var(--color-main);
  transition: transform var(--transition-normal), opacity var(--transition-normal);
}

.nav-toggle.open span:nth-child(1) { transform: translateY(6.5px) rotate(45deg); }
.nav-toggle.open span:nth-child(2) { opacity: 0; }
.nav-toggle.open span:nth-child(3) { transform: translateY(-6.5px) rotate(-45deg); }

/* ============================
   Footer
   ============================ */
.site-footer {
  background-color: var(--color-main);
  color: var(--color-white);
  padding: var(--space-16) 0 var(--space-8);
  margin-top: var(--space-24);
}

.footer-inner {
  display: grid;
  grid-template-columns: 1fr auto;
  gap: var(--space-8);
  align-items: start;
  margin-bottom: var(--space-12);
}

.footer-logo {
  font-size: var(--font-size-md);
  font-weight: var(--font-weight-bold);
  color: var(--color-white);
  margin-bottom: var(--space-3);
}

.footer-logo span {
  color: var(--color-accent-light);
}

.footer-tagline {
  font-size: var(--font-size-sm);
  color: var(--color-muted);
}

.footer-nav {
  display: flex;
  flex-direction: column;
  gap: var(--space-3);
  text-align: right;
}

.footer-nav a {
  font-size: var(--font-size-sm);
  color: var(--color-muted);
  transition: color var(--transition-fast);
}

.footer-nav a:hover {
  color: var(--color-white);
}

.footer-bottom {
  border-top: 1px solid rgba(255,255,255,0.1);
  padding-top: var(--space-6);
  display: flex;
  align-items: center;
  justify-content: space-between;
}

.footer-copyright {
  font-size: var(--font-size-xs);
  color: var(--color-muted);
}

.footer-sns {
  display: flex;
  gap: var(--space-4);
}

.footer-sns a {
  font-size: var(--font-size-sm);
  color: var(--color-muted);
  transition: color var(--transition-fast);
}

.footer-sns a:hover {
  color: var(--color-white);
}

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

.section-label {
  display: inline-block;
  font-size: var(--font-size-xs);
  font-weight: var(--font-weight-bold);
  letter-spacing: 0.12em;
  text-transform: uppercase;
  color: var(--color-accent);
  margin-bottom: var(--space-3);
}

.section-title {
  font-size: var(--font-size-xl);
  color: var(--color-main);
}

/* ============================
   Responsive
   ============================ */
@media (max-width: 768px) {
  .nav-toggle {
    display: flex;
  }

  .nav-list {
    display: none;
    position: fixed;
    top: 64px;
    left: 0;
    right: 0;
    z-index: 99;
    background-color: var(--color-base);
    border-bottom: 1px solid var(--color-border);
    flex-direction: column;
    gap: 0;
    padding: var(--space-4) 0;
    box-shadow: 0 4px 12px rgba(0, 0, 0, 0.08);
  }

  .nav-list.open {
    display: flex;
  }

  .nav-list a {
    padding: var(--space-4) var(--content-padding);
    width: 100%;
    font-size: var(--font-size-base);
    text-align: center;
  }

  .nav-list a::after {
    display: none;
  }

  .nav-list a.active {
    font-weight: var(--font-weight-bold);
    color: var(--color-accent);
  }

  .footer-inner {
    grid-template-columns: 1fr;
  }

  .footer-nav {
    text-align: left;
    flex-direction: row;
    flex-wrap: wrap;
    gap: var(--space-4);
  }

  .footer-bottom {
    flex-direction: column;
    gap: var(--space-4);
    text-align: center;
  }
}