/* ============================================================
   Language Switcher (Omada-pattern adapted to ITSN-ServiceHTML)
   - Pill button in nav (right of menu, left of Contact CTA)
   - Click → fullscreen overlay with backdrop + panel
   - Close on backdrop click / X button / ESC
   ============================================================ */

/* ---------- Pill button in nav ---------- */
.lang-switch {
  display: inline-flex;
  align-items: center;
  margin: 0 var(--space-3, 0.75rem);
}

.lang-switch__toggle {
  appearance: none;
  border: 1px solid var(--color-gray-300, #CED4DA);
  background: var(--color-white, #FFFFFF);
  color: var(--color-text, #0A0E1A);
  border-radius: 999px;
  padding: 8px 14px;
  font-size: 0.8125rem;
  font-family: var(--font-mono, "JetBrains Mono", monospace);
  letter-spacing: 0.04em;
  line-height: 1;
  cursor: pointer;
  white-space: nowrap;
  transition: border-color var(--duration-fast, 200ms) var(--ease-out-quint, ease),
              background-color var(--duration-fast, 200ms) var(--ease-out-quint, ease),
              transform var(--duration-fast, 200ms) var(--ease-out-quint, ease);
}

.lang-switch__toggle::before {
  content: "";
  display: inline-block;
  width: 14px;
  height: 14px;
  margin-right: 6px;
  vertical-align: -2px;
  background-color: currentColor;
  -webkit-mask: url("data:image/svg+xml;utf8,<svg xmlns='http://www.w3.org/2000/svg' viewBox='0 0 24 24' fill='none' stroke='currentColor' stroke-width='1.75' stroke-linecap='round' stroke-linejoin='round'><circle cx='12' cy='12' r='10'/><path d='M2 12h20'/><path d='M12 2a15 15 0 0 1 0 20'/><path d='M12 2a15 15 0 0 0 0 20'/></svg>") no-repeat center / contain;
          mask: url("data:image/svg+xml;utf8,<svg xmlns='http://www.w3.org/2000/svg' viewBox='0 0 24 24' fill='none' stroke='currentColor' stroke-width='1.75' stroke-linecap='round' stroke-linejoin='round'><circle cx='12' cy='12' r='10'/><path d='M2 12h20'/><path d='M12 2a15 15 0 0 1 0 20'/><path d='M12 2a15 15 0 0 0 0 20'/></svg>") no-repeat center / contain;
}

.lang-switch__toggle:hover {
  border-color: var(--color-itsn-blue, #1796D5);
  background: var(--color-off-white, #FAFAFA);
}

.lang-switch__toggle:focus-visible {
  outline: 2px solid var(--color-itsn-blue, #1796D5);
  outline-offset: 2px;
}

/* ---------- Mobile menu version (in hamburger menu) ---------- */
.lang-switch--menu {
  display: flex;
  gap: var(--space-3, 0.75rem);
  margin-top: var(--space-6, 1.5rem);
  padding-top: var(--space-4, 1rem);
  border-top: 1px solid var(--color-gray-300, #CED4DA);
  flex-wrap: wrap;
}

.lang-switch--menu a {
  font-family: var(--font-mono, "JetBrains Mono", monospace);
  font-size: 0.75rem;
  letter-spacing: 0.08em;
  text-transform: uppercase;
  color: var(--color-text-sub, #868E96);
  text-decoration: none;
  padding: 6px 12px;
  border: 1px solid var(--color-gray-300, #CED4DA);
  border-radius: 999px;
  transition: color var(--duration-fast, 200ms) var(--ease-out-quint, ease),
              border-color var(--duration-fast, 200ms) var(--ease-out-quint, ease);
}

.lang-switch--menu a:hover,
.lang-switch--menu a[aria-current="true"] {
  color: var(--color-itsn-blue, #1796D5);
  border-color: var(--color-itsn-blue, #1796D5);
}

/* ---------- Overlay modal ---------- */
.lang-overlay[hidden] {
  display: none;
}

.lang-overlay {
  position: fixed;
  inset: 0;
  z-index: 9999;
  animation: lang-fade-in var(--duration-base, 400ms) var(--ease-out-quint, ease);
}

@keyframes lang-fade-in {
  from { opacity: 0; }
  to   { opacity: 1; }
}

.lang-overlay__backdrop {
  position: absolute;
  inset: 0;
  background: rgba(10, 14, 26, 0.45);
  backdrop-filter: blur(4px);
  -webkit-backdrop-filter: blur(4px);
}

.lang-overlay__panel {
  position: absolute;
  top: 80px;
  right: 24px;
  width: 260px;
  background: var(--color-white, #FFFFFF);
  border: 1px solid var(--color-gray-300, #CED4DA);
  border-radius: 16px;
  padding: 24px 20px 20px;
  box-shadow: 0 20px 60px rgba(10, 14, 26, 0.20);
  animation: lang-slide-in var(--duration-base, 400ms) var(--ease-out-quint, ease);
}

@keyframes lang-slide-in {
  from { transform: translateY(-12px); opacity: 0; }
  to   { transform: translateY(0);     opacity: 1; }
}

.lang-overlay__panel::before {
  /* ロゴ三原色のトップアクセント */
  content: "";
  position: absolute;
  top: 0;
  left: 16px;
  right: 16px;
  height: 3px;
  border-radius: 0 0 2px 2px;
  background: var(--gradient-itsn, linear-gradient(135deg, #1796D5 0%, #00A06C 35%, #E03B14 70%, #E55A20 100%));
}

.lang-overlay__close {
  position: absolute;
  top: 12px;
  right: 14px;
  width: 28px;
  height: 28px;
  border: none;
  background: transparent;
  font-size: 22px;
  line-height: 1;
  cursor: pointer;
  color: var(--color-text-sub, #868E96);
  border-radius: 50%;
  display: flex;
  align-items: center;
  justify-content: center;
  transition: background-color var(--duration-fast, 200ms) var(--ease-out-quint, ease);
}

.lang-overlay__close:hover {
  background: var(--color-gray-100, #F1F3F5);
  color: var(--color-text, #0A0E1A);
}

.lang-overlay__title {
  margin: 0 0 14px;
  font-family: var(--font-mono, "JetBrains Mono", monospace);
  font-size: 0.6875rem;
  letter-spacing: 0.12em;
  text-transform: uppercase;
  color: var(--color-text-sub, #868E96);
  font-weight: 700;
}

.lang-overlay__links {
  display: flex;
  flex-direction: column;
  gap: 2px;
}

.lang-overlay__links a {
  display: block;
  padding: 11px 14px;
  border-radius: 10px;
  text-decoration: none;
  color: var(--color-text, #0A0E1A);
  font-size: 0.9375rem;
  font-weight: 500;
  transition: background-color var(--duration-fast, 200ms) var(--ease-out-quint, ease),
              color var(--duration-fast, 200ms) var(--ease-out-quint, ease),
              transform var(--duration-fast, 200ms) var(--ease-out-quint, ease);
}

.lang-overlay__links a:hover {
  background: var(--color-off-white, #FAFAFA);
  color: var(--color-itsn-blue, #1796D5);
  transform: translateX(2px);
}

.lang-overlay__links a[aria-current="true"] {
  color: var(--color-itsn-blue, #1796D5);
  font-weight: 700;
  background: linear-gradient(to right, rgba(23, 150, 213, 0.06), transparent);
}

.lang-overlay__links a[aria-current="true"]::after {
  content: "●";
  float: right;
  color: var(--color-itsn-blue, #1796D5);
  font-size: 0.625rem;
  line-height: 1.5;
}

/* ---------- Mobile responsive ---------- */
@media (max-width: 767px) {
  .lang-switch {
    margin: 0 var(--space-2, 0.5rem);
  }
  .lang-switch__toggle {
    padding: 6px 10px;
    font-size: 0.75rem;
  }
  .lang-overlay__panel {
    top: 70px;
    right: 16px;
    left: 16px;
    width: auto;
  }
}

/* ---------- Reduced motion ---------- */
@media (prefers-reduced-motion: reduce) {
  .lang-overlay,
  .lang-overlay__panel,
  .lang-overlay__links a {
    animation: none;
    transition: none;
  }
}