/* MTSCOS AI · 青瓷卷主题 · 语言切换公共样式（全站注入）
 * --------------------------------------------------------------------
 * 与 frontend/templates/index.html 内联 .mtscos-modal 保持像素一致。
 * 额外补：右下角浮动语言切换器（.i18n-fab），用于缺少 header-lang 按钮的页面。
 * 覆盖层顺序：z-index 9997/9998，不干扰 admin 的模态层（通常 9999+）。
 * ------------------------------------------------------------------ */

/* ---------- 青瓷卷主题变量兜底（当页面没有设计系统 token 时生效）---------- */
:root {
  --mts-i18n-primary: #3B5B8C;
  --mts-i18n-primary-dark: #2E4A72;
  --mts-i18n-primary-soft: rgba(59,91,140,.09);
  --mts-i18n-secondary: #C78B4A;
  --mts-i18n-text-primary: #2C3039;
  --mts-i18n-text-secondary: #4F545E;
  --mts-i18n-text-muted: #7D828C;
  --mts-i18n-bg-card: rgba(253,251,247,.95);
  --mts-i18n-bg-card-alt: rgba(249,245,236,.82);
  --mts-i18n-bg-glass: rgba(253,251,247,0.82);
  --mts-i18n-bg-input: rgba(239,235,225,.78);
  --mts-i18n-bg-elevated: rgba(249,245,236,.65);
  --mts-i18n-border-subtle: rgba(59,91,140,.10);
  --mts-i18n-border-strong: rgba(59,91,140,.20);
  --mts-i18n-shadow-sm: 0 1px 2px rgba(44,48,57,.04);
  --mts-i18n-shadow-md: 0 4px 14px rgba(44,48,57,.06);
  --mts-i18n-shadow-lg: 0 12px 30px rgba(44,48,57,.08);
  --mts-i18n-mask-color: rgba(253,251,247,0.88);
}

/* ---------- 语言按钮（页眉 header-lang 版）· 与 index.html 完全对齐 ---------- */
.header-lang,
button.header-lang,
a.header-lang {
  cursor: pointer;
  display: inline-flex !important;
  align-items: center; justify-content: center;
  gap: 4px;
  padding: 6px 12px;
  min-height: 34px;
  border-radius: 10px;
  color: var(--theme-text-primary, var(--mts-i18n-text-primary));
  background: var(--theme-bg-glass, var(--mts-i18n-bg-glass));
  border: 1px solid var(--theme-border-subtle, var(--mts-i18n-border-subtle));
  box-shadow: var(--theme-shadow-sm, var(--mts-i18n-shadow-sm));
  backdrop-filter: blur(8px); -webkit-backdrop-filter: blur(8px);
  transition: background .22s cubic-bezier(.4,0,.2,1),
              border-color .22s cubic-bezier(.4,0,.2,1),
              color .22s cubic-bezier(.4,0,.2,1),
              box-shadow .22s cubic-bezier(.4,0,.2,1),
              transform .18s ease;
  text-decoration: none;
  font-size: 13px;
  font-weight: 700;
  letter-spacing: .2px;
}
.header-lang:hover {
  background: var(--theme-primary-soft, var(--mts-i18n-primary-soft));
  border-color: var(--theme-border-strong, var(--mts-i18n-border-strong));
  color: var(--theme-primary, var(--mts-i18n-primary));
  box-shadow: var(--theme-shadow-md, var(--mts-i18n-shadow-md));
  transform: translateY(-1px);
}
.header-lang i + span,
.header-lang svg + span { margin-left: 2px; }

/* ---------- 语言 MODAL · 宣纸玻璃 ---------- */
.mtscos-modal {
  position: fixed; inset: 0; z-index: 9997;
  display: none; align-items: center; justify-content: center;
  background: var(--el-mask-color, var(--mts-i18n-mask-color));
  backdrop-filter: blur(10px) saturate(1.05);
  -webkit-backdrop-filter: blur(10px) saturate(1.05);
  animation: mts-celadon-mask-in .28s cubic-bezier(.4,0,.2,1) both;
}
@keyframes mts-celadon-mask-in { from { opacity: 0; } to { opacity: 1; } }
.mtscos-modal[aria-hidden="false"],
.mtscos-modal.is-open { display: flex; }
.mtscos-modal-inner {
  width: min(520px, 90vw);
  background:
    linear-gradient(160deg,
      var(--theme-bg-card, var(--mts-i18n-bg-card)),
      var(--theme-bg-card-alt, var(--mts-i18n-bg-card-alt)));
  border: 1px solid var(--theme-border-strong, var(--mts-i18n-border-strong));
  border-radius: 18px;
  padding: 22px 22px 20px;
  box-shadow: var(--theme-shadow-lg, var(--mts-i18n-shadow-lg)),
              inset 0 1px 0 rgba(255,255,255,.55);
  animation: mts-celadon-card-in .34s cubic-bezier(.2,.9,.2,1.1) both;
}
@keyframes mts-celadon-card-in {
  from { opacity: 0; transform: translateY(10px) scale(.985); }
  to   { opacity: 1; transform: translateY(0) scale(1); }
}
.mtscos-modal-inner--sm { width: min(360px, 90vw); padding: 18px; text-align: center; }
.mtscos-modal-header {
  display: flex; align-items: center; justify-content: space-between; margin-bottom: 14px;
}
.mtscos-modal-title {
  margin: 0; font-size: 17px; font-weight: 800;
  color: var(--theme-text-primary, var(--mts-i18n-text-primary));
  letter-spacing: 0.2px;
}
.mtscos-modal-title i {
  color: var(--theme-primary, var(--mts-i18n-primary));
  margin-right: 6px;
  filter: drop-shadow(0 1px 0 rgba(215, 200, 170, 0.35));
}
.mtscos-modal-close {
  background: var(--theme-bg-input, var(--mts-i18n-bg-input));
  border: 1px solid var(--theme-border-subtle, var(--mts-i18n-border-subtle));
  border-radius: 10px; width: 32px; height: 32px;
  color: var(--theme-text-secondary, var(--mts-i18n-text-secondary));
  cursor: pointer; font-size: 14px;
  transition: color .18s ease, border-color .18s ease,
              background .18s ease, transform .18s ease;
}
.mtscos-modal-close:hover {
  color: var(--theme-primary, var(--mts-i18n-primary));
  background: var(--theme-primary-soft, var(--mts-i18n-primary-soft));
  border-color: var(--theme-border-strong, var(--mts-i18n-border-strong));
  transform: rotate(90deg);
}
.mtscos-modal-desc {
  margin: 0 0 14px; font-size: 12.5px;
  color: var(--theme-text-secondary, var(--mts-i18n-text-secondary));
  font-weight: 600; letter-spacing: 0.15px;
  line-height: 1.5;
}
#lang-options {
  display: grid; grid-template-columns: repeat(2, 1fr); gap: 10px;
}
.mtscos-modal-footer {
  margin-top: 14px; padding-top: 14px;
  border-top: 1px solid var(--theme-border-subtle, var(--mts-i18n-border-subtle));
  display: flex; align-items: center; justify-content: space-between; gap: 10px;
}
.mtscos-modal-tip { font-size: 11.5px; color: var(--theme-text-muted, var(--mts-i18n-text-muted)); font-weight: 600; }
.mtscos-modal-btn {
  background: linear-gradient(135deg,
              var(--theme-primary, var(--mts-i18n-primary)),
              color-mix(in srgb,
                var(--theme-primary, var(--mts-i18n-primary)) 68%,
                var(--theme-secondary, var(--mts-i18n-secondary)) 32%));
  color: #FDFBF7;
  border: 0; border-radius: 10px;
  padding: 6px 14px;
  font-size: 12.5px; font-weight: 800; letter-spacing: 0.3px;
  cursor: pointer;
  box-shadow: 0 3px 8px rgba(59, 91, 140, 0.18),
              inset 0 1px 0 rgba(255,255,255,.18);
  transition: transform .18s ease, box-shadow .18s ease, filter .18s ease;
}
.mtscos-modal-btn:hover {
  transform: translateY(-1px);
  box-shadow: 0 6px 16px rgba(59, 91, 140, 0.22),
              inset 0 1px 0 rgba(255,255,255,.2);
  filter: brightness(1.04);
}
.mtscos-modal-btn:active { transform: translateY(0); }

/* 语言选项卡 */
.lang-option {
  display: flex; align-items: center; gap: 10px;
  padding: 12px 14px;
  border-radius: 12px; text-align: left; cursor: pointer;
  font-size: 13.5px; font-weight: 700;
  transition: background .2s cubic-bezier(.4,0,.2,1),
              border-color .2s cubic-bezier(.4,0,.2,1),
              box-shadow .2s cubic-bezier(.4,0,.2,1),
              transform .18s ease;
  color: var(--theme-text-primary, var(--mts-i18n-text-primary));
  background: var(--theme-bg-elevated, var(--mts-i18n-bg-elevated));
  border: 1px solid var(--theme-border-subtle, var(--mts-i18n-border-subtle));
  box-shadow: inset 0 1px 0 rgba(255,255,255,.45);
}
.lang-option:hover {
  background: var(--theme-bg-card, var(--mts-i18n-bg-card));
  border-color: var(--theme-border-strong, var(--mts-i18n-border-strong));
  box-shadow: var(--theme-shadow-sm, var(--mts-i18n-shadow-sm));
  transform: translateY(-1px);
}
.lang-option.is-active {
  background: var(--theme-primary-soft, var(--mts-i18n-primary-soft));
  border-color: var(--theme-primary, var(--mts-i18n-primary));
  color: var(--theme-primary-dark, var(--mts-i18n-primary-dark));
  box-shadow: 0 0 0 3px rgba(59,91,140,0.06),
              inset 0 1px 0 rgba(255,255,255,.5);
}
.lang-option .lang-flag { font-size: 18px; line-height: 1; }
.lang-option .lang-body { flex: 1; min-width: 0; }
.lang-option .lang-label { display: block; }
.lang-option .lang-tip { display: block; color: var(--theme-text-muted, var(--mts-i18n-text-muted)); font-weight: 500; font-size: 11px; margin-top: 2px; }
.lang-option.is-active .lang-tip { color: var(--theme-primary, var(--mts-i18n-primary)); opacity: .85; }
.lang-option .lang-check {
  color: var(--theme-primary, var(--mts-i18n-primary));
  display: inline-flex; align-items: center; justify-content: center;
  width: 18px; height: 18px;
  transition: transform .3s cubic-bezier(.3,1.6,.5,1);
}
.lang-option.is-active .lang-check { transform: scale(1.2); }

/* 二维码模态（占位） */
#qr-canvas {
  width: 240px; height: 240px; margin: 0 auto 14px;
  border-radius: 14px;
  border: 1px solid var(--theme-border-strong, var(--mts-i18n-border-strong));
  background: var(--theme-bg-color-overlay, #FFFFFF);
  display: flex; align-items: center; justify-content: center;
  color: var(--theme-text-primary, var(--mts-i18n-text-primary));
  font-weight: 700; font-size: 13px; padding: 10px;
  text-align: center; overflow: hidden;
  box-shadow: var(--theme-shadow-md, var(--mts-i18n-shadow-md));
}
.qr-grid {
  display: grid; grid-template-columns: repeat(21, 1fr); gap: 1px;
  aspect-ratio: 1 / 1; width: 100%; max-width: 220px;
}

/* ---------- 深色模式回落 · 墨夜青瓷 ---------- */
body[data-theme="dark"] .mtscos-modal,
.mtscos-modal--dark { --mts-i18n-mask-color: rgba(17,22,34,.82); }
body[data-theme="dark"] .mtscos-modal-inner,
.mtscos-modal--dark .mtscos-modal-inner {
  border-color: rgba(107,139,187,.22);
}
body[data-theme="dark"] .mtscos-modal-title,
.mtscos-modal--dark .mtscos-modal-title { color: #E8E6DF; }
body[data-theme="dark"] .mtscos-modal-desc,
.mtscos-modal--dark .mtscos-modal-desc { color: #A9AFBC; }
body[data-theme="dark"] .lang-option,
.mtscos-modal--dark .lang-option {
  background: rgba(37,43,63,.72);
  border-color: rgba(107,139,187,.14);
  color: #E8E6DF;
  box-shadow: inset 0 1px 0 rgba(255,255,255,.04);
}
body[data-theme="dark"] .lang-option:hover,
.mtscos-modal--dark .lang-option:hover { background: rgba(42,48,68,.9); border-color: rgba(107,139,187,.28); }
body[data-theme="dark"] .lang-option.is-active,
.mtscos-modal--dark .lang-option.is-active {
  background: rgba(107,139,187,.14);
  border-color: #8FA7CB;
  color: #DDE4F1;
  box-shadow: 0 0 0 3px rgba(107,139,187,0.10);
}
body[data-theme="dark"] .mtscos-modal-close,
.mtscos-modal--dark .mtscos-modal-close {
  background: rgba(37,43,63,.8);
  color: #A9AFBC;
  border-color: rgba(107,139,187,.14);
}
body[data-theme="dark"] .mtscos-modal-close:hover,
.mtscos-modal--dark .mtscos-modal-close:hover { color: #8FA7CB; background: rgba(107,139,187,.14); border-color: rgba(107,139,187,.28); }

/* ---------- 浮动按钮 FAB：页面没有 header-lang 时自动注入 ---------- */
.i18n-fab {
  position: fixed; right: 18px; bottom: 18px; z-index: 9998;
  width: 48px; height: 48px; border-radius: 50%;
  display: inline-flex; align-items: center; justify-content: center;
  font-weight: 800; font-size: 13px; letter-spacing: .3px;
  cursor: pointer; color: #FDFBF7; user-select: none;
  background: linear-gradient(135deg, var(--theme-primary, var(--mts-i18n-primary)),
    color-mix(in srgb,
      var(--theme-primary, var(--mts-i18n-primary)) 72%,
      var(--theme-secondary, var(--mts-i18n-secondary)) 28%));
  border: 1px solid rgba(255,255,255,.22);
  box-shadow: 0 8px 24px rgba(59, 91, 140, 0.25),
              inset 0 1px 0 rgba(255,255,255,.18);
  transition: transform .18s cubic-bezier(.4,0,.2,1),
              box-shadow .18s cubic-bezier(.4,0,.2,1),
              filter .18s ease;
  -webkit-tap-highlight-color: transparent;
}
.i18n-fab:hover { transform: translateY(-2px) scale(1.02); filter: brightness(1.04); box-shadow: 0 12px 28px rgba(59, 91, 140, 0.3), inset 0 1px 0 rgba(255,255,255,.22); }
.i18n-fab:active { transform: translateY(0) scale(0.98); }
.i18n-fab i { margin-right: 2px; }

/* 移动端自适应 FAB 缩小 */
@media (max-width: 520px) {
  .i18n-fab { width: 42px; height: 42px; font-size: 12px; right: 14px; bottom: 14px; }
  #lang-options { grid-template-columns: 1fr; }
}

/* 高对比模式 a11y */
@media (prefers-contrast: more) {
  .header-lang,
  .lang-option { border-width: 1.25px; }
  .mtscos-modal-inner { border-color: var(--mts-i18n-primary); }
}

/* 减少动画用户偏好 */
@media (prefers-reduced-motion: reduce) {
  *, *::before, *::after {
    animation-duration: 0.001ms !important;
    transition-duration: 0.001ms !important;
  }
}