/* =====================================================================
   PATS — 設計系統
   ===================================================================== */

:root {
  --brand-50:  #eef2ff;
  --brand-100: #e0e7ff;
  --brand-200: #c7d2fe;
  --brand-500: #3b82f6;
  --brand-600: #2563eb;
  --brand-700: #1d4ed8;
  --brand-900: #1e3a8a;

  --ink-900: #0f172a;
  --ink-700: #334155;
  --ink-500: #64748b;
  --ink-400: #94a3b8;
  --ink-300: #cbd5e1;

  --line:      #e5e7eb;
  --line-soft: #f1f5f9;

  --surface:      #ffffff;
  --surface-sunk: #f8fafc;
  --surface-rail: #ffffff;
  --canvas:       #f6f7fb;

  --danger:  #dc2626;
  --success: #16a34a;
  --warning: #d97706;

  --r-sm: 6px;
  --r-md: 8px;
  --r-lg: 12px;
  --r-xl: 16px;
  --r-full: 999px;

  --shadow-sm: 0 1px 2px rgba(15, 23, 42, .06);
  --shadow-md: 0 4px 12px rgba(15, 23, 42, .06);
  --shadow-lg: 0 12px 32px rgba(15, 23, 42, .10);

  --rail-w: 224px;
  --list-w: 288px;
  --header-h: 52px;

  --ease: cubic-bezier(.4, 0, .2, 1);
}

* { box-sizing: border-box; }

html, body {
  height: 100%;
  margin: 0;
}

body {
  font-family: "Microsoft JhengHei", "PingFang TC", -apple-system, BlinkMacSystemFont,
               "Segoe UI", Roboto, "Helvetica Neue", Arial, sans-serif;
  font-size: 14px;
  line-height: 1.55;
  color: var(--ink-900);
  background: var(--canvas);
  -webkit-font-smoothing: antialiased;
  overflow: hidden;
}

button, input, select, textarea { font: inherit; color: inherit; }
button { cursor: pointer; border: none; background: none; padding: 0; }
a { color: var(--brand-600); text-decoration: none; }
a:hover { text-decoration: underline; }

.material-symbols-outlined {
  font-variation-settings: 'FILL' 0, 'wght' 400, 'GRAD' 0, 'opsz' 24;
  user-select: none;
  line-height: 1;
}

.hidden { display: none !important; }
.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;
}

/* ------------------------------------------------------------- 捲軸樣式 */

.scroll-y { overflow-y: auto; overscroll-behavior: contain; }
.scroll-y::-webkit-scrollbar { width: 8px; }
.scroll-y::-webkit-scrollbar-thumb {
  background: var(--ink-300); border-radius: var(--r-full);
  border: 2px solid transparent; background-clip: content-box;
}
.scroll-y::-webkit-scrollbar-thumb:hover { background: var(--ink-400); background-clip: content-box; }
.scroll-y::-webkit-scrollbar-track { background: transparent; }

/* ================================================================ 元件 */

.btn {
  display: inline-flex; align-items: center; justify-content: center; gap: 8px;
  height: 40px; padding: 0 18px;
  border-radius: var(--r-md);
  font-weight: 500; white-space: nowrap;
  transition: background-color .15s var(--ease), border-color .15s var(--ease),
              color .15s var(--ease), box-shadow .15s var(--ease);
}
.btn:disabled { opacity: .55; cursor: not-allowed; }
.btn .material-symbols-outlined { font-size: 18px; }

.btn-primary { background: var(--brand-600); color: #fff; }
.btn-primary:hover:not(:disabled) { background: var(--brand-700); }

.btn-outline {
  background: var(--surface); color: var(--brand-600);
  border: 1px solid var(--brand-200);
}
.btn-outline:hover:not(:disabled) { background: var(--brand-50); border-color: var(--brand-500); }

.btn-ghost { background: transparent; color: var(--ink-700); border: 1px solid var(--line); }
.btn-ghost:hover:not(:disabled) { background: var(--surface-sunk); }

.btn-quiet { color: var(--ink-500); }
.btn-quiet:hover:not(:disabled) { color: var(--ink-900); }

.btn-danger { background: transparent; color: var(--danger); font-weight: 500; }
.btn-danger:hover:not(:disabled) { text-decoration: underline; }

.btn-block { width: 100%; }

.icon-btn {
  display: inline-flex; align-items: center; justify-content: center;
  width: 34px; height: 34px; border-radius: var(--r-md);
  color: var(--ink-500);
  transition: background-color .15s var(--ease), color .15s var(--ease);
}
.icon-btn:hover { background: var(--surface-sunk); color: var(--ink-900); }
.icon-btn .material-symbols-outlined { font-size: 20px; }

.field { display: flex; flex-direction: column; gap: 6px; }
.field-label {
  display: flex; align-items: center; justify-content: space-between;
  font-size: 12px; color: var(--ink-500);
}
.field-label strong { font-weight: 500; color: var(--ink-700); }

.input-wrap {
  display: flex; align-items: center; gap: 8px;
  height: 42px; padding: 0 12px;
  background: var(--surface);
  border: 1px solid var(--line); border-radius: var(--r-md);
  transition: border-color .15s var(--ease), box-shadow .15s var(--ease);
}
.input-wrap:focus-within {
  border-color: var(--brand-500);
  box-shadow: 0 0 0 3px rgba(59, 130, 246, .12);
}
.input-wrap > .material-symbols-outlined { font-size: 19px; color: var(--ink-400); }
.input-wrap input {
  flex: 1; min-width: 0; height: 100%;
  border: none; outline: none; background: transparent;
}
.input-wrap input::placeholder { color: var(--ink-400); }
.input-wrap .icon-btn { width: 28px; height: 28px; }

.input {
  height: 42px; padding: 0 12px; width: 100%;
  background: var(--surface);
  border: 1px solid var(--line); border-radius: var(--r-md);
  outline: none;
  transition: border-color .15s var(--ease), box-shadow .15s var(--ease);
}
textarea.input {
  height: auto;
  min-height: 84px;
  padding: 10px 12px;
  line-height: 1.45;
  resize: vertical;
}
.input:focus { border-color: var(--brand-500); box-shadow: 0 0 0 3px rgba(59, 130, 246, .12); }

.checkbox { display: inline-flex; align-items: center; gap: 8px; color: var(--ink-700); cursor: pointer; }
.checkbox input { width: 15px; height: 15px; accent-color: var(--brand-600); cursor: pointer; }

.avatar {
  flex: none; display: grid; place-items: center;
  width: 40px; height: 40px; border-radius: var(--r-full);
  background: var(--brand-100); color: var(--brand-700);
  font-weight: 600; font-size: 14px;
  object-fit: cover; overflow: hidden;
  flex-shrink: 0;
}
.avatar img {
  display: block;
  width: 100%; height: 100%;
  object-fit: cover;
  border-radius: inherit;
}
.avatar-sm { width: 32px; height: 32px; font-size: 12px; }
.avatar-lg { width: 44px; height: 44px; }

.badge {
  display: inline-grid; place-items: center;
  min-width: 20px; height: 20px; padding: 0 6px;
  border-radius: var(--r-full);
  background: var(--brand-600); color: #fff;
  font-size: 11px; font-weight: 600;
}

.card {
  background: var(--surface);
  border: 1px solid var(--line);
  border-radius: var(--r-lg);
  box-shadow: var(--shadow-sm);
}

.empty-state {
  display: flex; flex-direction: column; align-items: center; justify-content: center;
  gap: 12px; padding: 40px 24px; text-align: center; margin: auto;
  max-width: 380px;
}
.empty-state .glyph {
  display: grid; place-items: center;
  width: 96px; height: 96px; border-radius: var(--r-full);
  background: var(--brand-50); color: var(--brand-500);
}
.empty-state .glyph .material-symbols-outlined { font-size: 44px; }
.empty-state h3 { margin: 4px 0 0; font-size: 18px; font-weight: 600; }
.empty-state p { margin: 0; color: var(--ink-500); font-size: 13px; }

/* =============================================================== 登入頁 */

.auth {
  display: grid;
  grid-template-columns: minmax(300px, 1fr) 2fr;
  height: 100vh; height: 100dvh;
}

.auth-brand {
  position: relative; overflow: hidden;
  display: flex; flex-direction: column;
  padding: 32px 28px;
  background: var(--surface);
  border-right: 1px solid var(--line);
}
.auth-brand::after {
  content: ''; position: absolute; left: -80px; bottom: -120px;
  width: 340px; height: 340px; border-radius: 50%;
  background: radial-gradient(circle, rgba(37, 99, 235, .10), transparent 68%);
  pointer-events: none;
}
.auth-brand > * { position: relative; z-index: 1; }

.auth-logo { display: flex; align-items: center; gap: 12px; }
.auth-logo-img { width: 48px; height: 48px; flex: none; display: block; }
.auth-logo h1 { margin: 0; font-size: 20px; font-weight: 700; letter-spacing: .5px; }
.auth-logo span { font-size: 12px; color: var(--ink-500); }

.auth-pitch { margin-top: 42px; }
.auth-pitch h2 { margin: 0 0 12px; font-size: 17px; font-weight: 700; }
.auth-pitch p { margin: 0; color: var(--ink-500); font-size: 13px; line-height: 1.9; }

.auth-note {
  margin-top: auto; display: flex; align-items: center; gap: 8px;
  color: var(--brand-600); font-size: 12px;
}
.auth-note .material-symbols-outlined { font-size: 18px; color: var(--ink-400); }

.auth-main {
  display: grid; place-items: center;
  padding: 24px;
  background: var(--canvas);
  overflow-y: auto;
}

.auth-card { width: 100%; max-width: 360px; padding: 28px 26px; }

.auth-mark {
  display: grid; place-items: center; margin: 0 auto 18px;
  width: 52px; height: 52px; border-radius: var(--r-full);
  background: var(--brand-50); color: var(--brand-600);
}
.auth-mark .material-symbols-outlined { font-size: 26px; }

.auth-title { margin: 0; font-size: 26px; font-weight: 700; text-align: center; }
.auth-sub { margin: 6px 0 24px; text-align: center; color: var(--ink-500); font-size: 13px; }

.auth-form { display: flex; flex-direction: column; gap: 16px; }

.auth-divider {
  display: flex; align-items: center; gap: 12px;
  margin: 20px 0 16px; color: var(--ink-400); font-size: 12px;
}
.auth-divider::before, .auth-divider::after {
  content: ''; flex: 1; height: 1px; background: var(--line);
}

/* Google Identity Services 會把官方按鈕渲染進 .google-slot，
   我們只負責讓它水平置中並撐滿卡片寬度。 */
.google-slot { display: flex; justify-content: center; min-height: 42px; }
.google-slot > div { width: 100%; }
/* Android APP 用系統登入，按鈕由我們自己畫 */
.google-slot > .btn-google-native { width: 100%; min-height: 42px; }

.auth-hint {
  margin: 0; padding: 10px 12px;
  background: var(--surface-sunk); border: 1px dashed var(--line);
  border-radius: var(--r-md);
  font-size: 12px; color: var(--ink-500); text-align: center;
}

.auth-footer { margin-top: 18px; text-align: center; font-size: 12px; color: var(--ink-500); }
.auth-download { margin-top: 8px; }
.is-native-app .auth-download, .is-desktop-app .auth-download, .is-ios-browser .auth-download { display: none; }
.auth-ios { display: none; margin-top: 8px; }
.is-ios-browser .auth-ios { display: block; }

.field-note { font-size: 11.5px; color: var(--ink-400); }

/* 忘記密碼的三步驟指示器 */
.steps {
  display: flex;
  align-items: center;
  gap: 6px;
  list-style: none;
  margin: 0 0 18px;
  padding: 0;
}

.step {
  flex: 1;
  display: flex;
  align-items: center;
  gap: 6px;
  font-size: 11.5px;
  color: var(--ink-400);
  white-space: nowrap;
}

.step span {
  display: grid;
  place-items: center;
  width: 20px;
  height: 20px;
  flex: none;
  border-radius: 50%;
  background: var(--surface-sunk);
  border: 1px solid var(--line);
  font-size: 11px;
  font-weight: 600;
}

.step.is-active { color: var(--ink-900); font-weight: 600; }
.step.is-active span { background: var(--brand-600); border-color: var(--brand-600); color: #fff; }
.step.is-done span { background: var(--brand-50); border-color: var(--brand-500); color: var(--brand-700); }

@media (max-width: 380px) {
  .step { font-size: 0; gap: 0; }
  .step span { font-size: 11px; }
}

/* 註冊時的身分選擇 */
.role-group {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 8px;
}

.role-btn {
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 4px;
  padding: 10px 4px;
  border: 1px solid var(--line);
  border-radius: var(--r-md);
  background: var(--surface);
  color: var(--ink-500);
  font-size: 12.5px;
  font-weight: 500;
  cursor: pointer;
  transition: border-color .15s, background .15s, color .15s;
}

.role-btn .material-symbols-outlined { font-size: 20px; }
.role-btn:hover { border-color: var(--brand-500); color: var(--ink-900); }

.role-btn.is-active {
  border-color: var(--brand-600);
  background: var(--brand-50);
  color: var(--brand-700);
  font-weight: 600;
}

.role-hint {
  margin: 8px 0 0;
  font-size: 11.5px;
  color: var(--ink-500);
  line-height: 1.6;
}

/* 信箱：本文輸入框 + 固定網域 */
.email-row {
  display: flex;
  align-items: stretch;
  gap: 6px;
}

.email-row .input-wrap { flex: 1; min-width: 0; }

.email-domain {
  display: flex;
  align-items: center;
  flex: none;
  max-width: 46%;
  padding: 0 10px;
  border: 1px solid var(--line);
  border-radius: var(--r-md);
  background: var(--surface-sunk);
  color: var(--ink-500);
  font-size: 12.5px;
  white-space: nowrap;
}

select.email-domain {
  cursor: pointer;
  color: var(--ink-700);
  appearance: none;
  background-image: none;
}

@media (max-width: 400px) {
  .email-row { flex-direction: column; }
  .email-domain { max-width: none; padding: 8px 10px; }
}

.code-input {
  letter-spacing: 10px;
  font-size: 20px;
  font-weight: 600;
  text-align: center;
}

.form-error {
  display: flex; align-items: center; gap: 8px;
  padding: 9px 12px; border-radius: var(--r-md);
  background: #fef2f2; color: var(--danger); font-size: 12.5px;
}
.form-error .material-symbols-outlined { font-size: 17px; }

/* ============================================================ 應用外框 */

.app {
  display: grid;
  grid-template-columns: var(--rail-w) var(--list-w) minmax(0, 1fr);
  height: 100vh; height: 100dvh;
}
.app[data-list-hidden="true"] { grid-template-columns: var(--rail-w) minmax(0, 1fr); }
.app[data-list-hidden="true"] .list-pane { display: none; }

/* ------------------------------------------------------------- 側邊導覽 */

.rail {
  display: flex; flex-direction: column;
  min-width: 0; padding: 16px 12px;
  background: var(--surface-rail);
  border-right: 1px solid var(--line);
}

.rail-identity {
  display: flex; align-items: center; gap: 12px;
  padding: 4px 8px 20px;
  min-width: 0;
}
.rail-identity .meta { min-width: 0; }
.rail-identity .name {
  font-size: 17px; font-weight: 700; color: var(--brand-900);
  white-space: nowrap; overflow: hidden; text-overflow: ellipsis;
}
.rail-identity .role { font-size: 12px; color: var(--ink-500); }
.rail-identity .status {
  display: flex; align-items: center; gap: 5px;
  font-size: 11.5px; color: var(--success);
}
.rail-identity .status::before {
  content: ''; width: 7px; height: 7px; border-radius: 50%; background: var(--success);
}

.rail-nav { display: flex; flex-direction: column; gap: 2px; }

.rail-link {
  position: relative;
  display: flex; align-items: center; gap: 14px;
  height: 44px; padding: 0 14px;
  border-radius: var(--r-md);
  color: var(--ink-700); font-size: 14px;
  transition: background-color .15s var(--ease), color .15s var(--ease);
}
.rail-link .material-symbols-outlined { font-size: 21px; color: var(--ink-500); }
.rail-link:hover { background: var(--surface-sunk); }
.rail-link.is-active { background: var(--brand-50); color: var(--brand-700); font-weight: 500; }
.rail-link.is-active .material-symbols-outlined { color: var(--brand-600); }
.rail-link.is-active::before {
  content: ''; position: absolute; left: 0; top: 10px; bottom: 10px;
  width: 3px; border-radius: var(--r-full); background: var(--brand-600);
}
.rail-link .count { margin-left: auto; }
.rail-link .label { white-space: nowrap; overflow: hidden; text-overflow: ellipsis; }

.rail-spacer { flex: 1; }
.rail-foot { display: flex; flex-direction: column; gap: 2px; padding-top: 12px; }
.rail-foot .rail-link.is-danger { color: var(--danger); }
.rail-foot .rail-link.is-danger .material-symbols-outlined { color: var(--danger); }

/* ------------------------------------------------------------- 對話列表 */

.list-pane {
  display: flex; flex-direction: column;
  min-width: 0;
  background: var(--surface);
  border-right: 1px solid var(--line);
}

.pane-head {
  display: flex; align-items: center; gap: 10px;
  min-height: var(--header-h); padding: 8px 12px 8px 16px;
  border-bottom: 1px solid var(--line);
}
.pane-head h2 { margin: 0; font-size: 16px; font-weight: 700; color: var(--brand-900); }
.pane-head .hint {
  min-width: 0; font-size: 12px; color: var(--ink-500);
  white-space: nowrap; overflow: hidden; text-overflow: ellipsis;
}
.pane-head .actions { margin-left: auto; display: flex; gap: 2px; }

.pane-search { padding: 12px 14px; }
.pane-search .input-wrap { height: 38px; border-radius: var(--r-full); background: var(--surface-sunk); }

.conv-list { flex: 1; display: flex; flex-direction: column; padding: 0 8px 12px; }

.conv-item {
  flex: none;
  display: flex; align-items: center; gap: 12px;
  width: 100%; padding: 10px 10px;
  border-radius: var(--r-md); text-align: left;
  transition: background-color .12s var(--ease);
}
.conv-item:hover { background: var(--surface-sunk); }
.conv-item.is-active { background: var(--brand-50); }
.conv-item .body { flex: 1; min-width: 0; }
.conv-item .row { display: flex; align-items: baseline; gap: 8px; }
.conv-item .title {
  flex: 1; min-width: 0; font-weight: 500;
  white-space: nowrap; overflow: hidden; text-overflow: ellipsis;
}
.conv-item .time { flex: none; font-size: 11px; color: var(--ink-400); }
.conv-item .preview {
  margin-top: 2px; font-size: 12.5px; color: var(--ink-500);
  white-space: nowrap; overflow: hidden; text-overflow: ellipsis;
}
.conv-item.is-unread .title { font-weight: 700; }
.conv-item.is-unread .preview { color: var(--ink-700); }

/* ---------------------------------------------------------------- 對話 */

.chat-pane {
  display: flex; flex-direction: column;
  min-width: 0;
  min-height: 0; /* 不設時 grid 列會被訊息撐高，輸入框跑出畫面且無法捲動 */
  position: relative;
  background: var(--canvas);
}

.chat-jump {
  position: absolute; right: 20px; bottom: 84px; z-index: 5;
  display: grid; place-items: center;
  width: 44px; height: 44px; border-radius: var(--r-full);
  background: var(--surface); color: var(--ink-700);
  border: 1px solid var(--line);
  box-shadow: 0 6px 18px rgba(15, 23, 42, .16);
  opacity: 0; pointer-events: none; transform: translateY(8px);
  transition: opacity .18s var(--ease), transform .18s var(--ease), background-color .15s var(--ease);
}
.chat-jump.is-visible { opacity: 1; pointer-events: auto; transform: none; }
.chat-jump:hover { background: var(--brand-50); color: var(--brand-700); }
.chat-jump .material-symbols-outlined { font-size: 26px; }
.chat-jump-badge {
  position: absolute; top: -6px; right: -6px;
  min-width: 20px; height: 20px; padding: 0 6px;
  border-radius: var(--r-full);
  background: var(--brand-600); color: #fff;
  font-size: 11px; font-weight: 700; line-height: 20px; text-align: center;
}
@media (prefers-reduced-motion: reduce) {
  .chat-jump { transition: none; }
}

.chat-head {
  display: flex; align-items: center; gap: 10px;
  min-height: var(--header-h); padding: 8px 12px;
  background: var(--surface);
  border-bottom: 1px solid var(--line);
}
.chat-head .meta { flex: 1; min-width: 0; }
.chat-head .title {
  font-weight: 600; white-space: nowrap; overflow: hidden; text-overflow: ellipsis;
}
.chat-head .sub { font-size: 12px; color: var(--ink-500); }
.chat-head .actions {
  margin-left: auto; display: flex; align-items: center; gap: 6px;
  flex-shrink: 0;
}
.chat-back { display: none; }
.call-bar {
  display: none;
  padding: 8px 12px calc(8px + env(safe-area-inset-bottom));
  background: var(--surface);
  border-top: 1px solid var(--line);
}
.call-bar-btn {
  width: 100%;
  height: 44px;
  gap: 8px;
}

.chat-body { flex: 1; min-height: 0; padding: 20px 24px; display: flex; flex-direction: column; gap: 4px; }

.msg-day {
  align-self: center; margin: 14px 0 10px;
  padding: 3px 12px; border-radius: var(--r-full);
  background: var(--surface); border: 1px solid var(--line);
  font-size: 11.5px; color: var(--ink-500);
}

.msg-system {
  align-self: center; margin: 6px 0;
  font-size: 12px; color: var(--ink-500);
}

/* 往上捲載入更早訊息、切換對話時的載入提示 */
.msg-older {
  align-self: center; margin: 8px 0 4px;
  font-size: 12px; color: var(--ink-500);
}
.chat-loading {
  margin: auto; padding: 24px;
  font-size: 13px; color: var(--ink-500);
}

.msg.msg-call-invite {
  max-width: min(680px, 86%);
}
.msg-call-card {
  display: flex;
  align-items: flex-start;
  gap: 12px;
  min-width: 220px;
  padding: 12px 14px;
  border-radius: 14px;
  background: var(--surface);
  border: 1px solid var(--line);
  box-shadow: var(--shadow-sm);
}
.msg.is-mine .msg-call-card {
  background: #eff6ff;
  border-color: #bfdbfe;
}
.msg-call-icon {
  flex: none;
  display: grid;
  place-items: center;
  width: 40px;
  height: 40px;
  border-radius: var(--r-full);
  background: #dcfce7;
  color: #166534;
}
.msg-call-icon .material-symbols-outlined { font-size: 22px; }
.msg-call-body { flex: 1; min-width: 0; }
.msg-call-title { font-size: 14px; font-weight: 600; color: var(--ink-900); }
.msg-call-sub { margin-top: 2px; font-size: 12px; color: var(--ink-500); }
.msg-call-join { margin-top: 10px; width: 100%; }

.msg {
  display: flex; align-items: flex-end; gap: 10px;
  max-width: min(680px, 78%); margin-top: 10px;
}
.msg.is-mine { flex-direction: row-reverse; margin-left: auto; }
.msg.is-tail { margin-top: 2px; }
.msg .avatar { width: 30px; height: 30px; font-size: 11px; }
.msg .stack { min-width: 0; }
.msg .sender { margin-bottom: 3px; font-size: 12px; color: var(--ink-500); }
.msg.is-mine .sender { text-align: right; }

.bubble {
  padding: 9px 13px; border-radius: 14px;
  background: var(--surface); border: 1px solid var(--line);
  box-shadow: var(--shadow-sm);
  white-space: pre-wrap; word-break: break-word;
}
.msg-link {
  color: inherit;
  text-decoration: underline;
  word-break: break-all;
}
.msg-link:hover { opacity: .88; }
.msg.is-mine .msg-link { color: #fff; }
.msg:not(.is-mine) .msg-link { color: var(--brand-700); }
.msg.is-mine .bubble {
  background: var(--brand-600); color: #fff; border-color: var(--brand-600);
}
.msg.is-pending .bubble { opacity: .62; }
.msg .time { margin-top: 4px; font-size: 11px; color: var(--ink-400); }
.msg.is-mine .time { text-align: right; }

.composer {
  display: flex; align-items: flex-end; gap: 10px;
  padding: 12px 16px;
  background: var(--surface);
  border-top: 1px solid var(--line);
}
.composer-attach-wrap {
  position: relative; flex: none;
  width: 42px; height: 42px;
}
.composer-attach {
  display: grid; place-items: center;
  width: 100%; height: 100%; border-radius: var(--r-full);
  color: var(--ink-500); background: var(--surface-sunk);
  border: 1px solid var(--line);
  pointer-events: none; /* 點擊交給覆蓋的 file input（iOS 才能開相簿） */
  transition: background-color .15s var(--ease), color .15s var(--ease);
}
.composer-attach-wrap:hover:not(.is-busy) .composer-attach {
  color: var(--brand-700); background: var(--brand-50);
}
.composer-attach-wrap.is-busy { opacity: .45; }
.composer-attach .material-symbols-outlined { font-size: 22px; }
.composer-file-input {
  position: absolute; inset: 0;
  width: 100%; height: 100%;
  opacity: 0; margin: 0; padding: 0;
  border: 0; cursor: pointer;
  font-size: 16px; /* 避免 iOS 點擊時強制縮放 */
}
.composer-attach-wrap.is-busy .composer-file-input {
  pointer-events: none; cursor: not-allowed;
}
.composer textarea {
  flex: 1; min-height: 42px; max-height: 160px; padding: 10px 14px;
  border: 1px solid var(--line); border-radius: var(--r-lg);
  background: var(--surface-sunk); outline: none; resize: none;
  transition: border-color .15s var(--ease), box-shadow .15s var(--ease);
}
.composer textarea:focus {
  border-color: var(--brand-500); background: var(--surface);
  box-shadow: 0 0 0 3px rgba(59, 130, 246, .12);
}
.composer .send {
  display: grid; place-items: center; flex: none;
  width: 42px; height: 42px; border-radius: var(--r-full);
  background: var(--brand-600); color: #fff;
  transition: background-color .15s var(--ease), transform .12s var(--ease);
}
.composer .send:hover:not(:disabled) { background: var(--brand-700); }
.composer .send:disabled { background: var(--ink-300); cursor: not-allowed; }

.bubble.is-image {
  padding: 4px; overflow: hidden;
  background: transparent; border: 0; box-shadow: none;
}
.msg.is-mine .bubble.is-image { background: transparent; border: 0; }
.msg-image {
  display: block;
  max-width: min(240px, 70vw);
  max-height: 320px;
  width: auto; height: auto;
  border-radius: 12px;
  object-fit: contain; /* cover 會把直向文件裁成怪圖 */
  cursor: zoom-in;
  background: var(--surface-sunk);
}
.msg-image-expired {
  padding: 12px 14px;
  border-radius: 12px;
  background: var(--surface-sunk);
  color: var(--ink-500);
  font-size: 13px;
  border: 1px dashed var(--line);
}
.msg.is-mine .msg-image-expired {
  background: rgba(255,255,255,.16);
  color: rgba(255,255,255,.9);
  border-color: rgba(255,255,255,.28);
}
.img-viewer-backdrop {
  position: fixed; inset: 0; z-index: 80;
  display: flex; align-items: center; justify-content: center;
  padding: 24px 24px calc(88px + env(safe-area-inset-bottom, 0px));
  background: rgba(0,0,0,.78);
  cursor: zoom-out;
}
.img-viewer-pic {
  /* 不可用 100%：父層高度不確定時整個上限失效，長圖會往下溢出被下載列擋住 */
  max-width: min(960px, calc(100vw - 48px));
  max-height: calc(100vh - 112px);
  max-height: calc(100dvh - 112px - env(safe-area-inset-bottom, 0px));
  width: auto; height: auto;
  object-fit: contain;
  border-radius: 8px;
  box-shadow: 0 16px 48px rgba(0,0,0,.45);
  cursor: default;
}
.img-viewer-toolbar {
  position: fixed;
  left: 0; right: 0; bottom: 0;
  z-index: 81;
  display: flex; justify-content: center; align-items: center;
  gap: 12px;
  padding: 16px 20px calc(16px + env(safe-area-inset-bottom, 0px));
  background: linear-gradient(transparent, rgba(0,0,0,.55));
  cursor: default;
}
.img-viewer-download {
  min-width: 120px; min-height: 44px;
  padding: 10px 22px;
  border: 0; border-radius: 999px;
  background: #fff; color: #111;
  font-size: 15px; font-weight: 600;
  cursor: pointer;
  box-shadow: 0 4px 16px rgba(0,0,0,.28);
}
.img-viewer-download:disabled {
  opacity: .55; cursor: not-allowed;
}
.img-viewer-download:hover:not(:disabled) {
  background: #f3f4f6;
}

/* ================================================================ 設定 */

.settings-pane { min-width: 0; background: var(--canvas); overflow-y: auto; }
.settings-inner { max-width: 720px; margin: 0 auto; padding: 36px 24px 56px; }

/* 設定頁：頂端返回列＋分組清單（每組圓角卡片，項目之間細縫分隔） */
.set-page { max-width: 720px; margin: 0 auto; min-height: 100%; }
.set-bar {
  position: sticky; top: 0; z-index: 3;
  display: flex; align-items: center; gap: 12px;
  min-height: 60px; padding: 10px 16px;
  padding-top: max(10px, env(safe-area-inset-top));
  background: var(--canvas);
}
.set-bar-title { margin: 0; font-size: 20px; font-weight: 600; }
.set-back { width: 40px; height: 40px; flex: none; }
.set-back .material-symbols-outlined { font-size: 24px; }
/* 桌機有左側導覽列，設定首頁不需要返回鍵 */
.set-bar.is-home .set-back { display: none; }
.set-bar.is-home { padding-left: 24px; }

.set-body { padding: 0 16px 40px; }
.set-section { margin-top: 18px; }
.set-label {
  margin: 0 0 8px 6px;
  font-size: 13px; font-weight: 600; color: var(--brand-700);
}
.set-group {
  display: flex; flex-direction: column; gap: 2px;
  border-radius: 20px; overflow: hidden;
}
.set-item {
  display: flex; align-items: center; gap: 14px; width: 100%;
  min-height: 64px; padding: 14px 20px;
  background: var(--surface); text-align: left;
  border-radius: 4px;
}
.set-group > .set-item:first-child { border-top-left-radius: 20px; border-top-right-radius: 20px; }
.set-group > .set-item:last-child { border-bottom-left-radius: 20px; border-bottom-right-radius: 20px; }
button.set-item, label.set-item { cursor: pointer; transition: background-color .15s var(--ease); }
button.set-item:hover, label.set-item:hover { background: var(--surface-sunk); }
button.set-item:active, label.set-item:active { background: var(--brand-50); }
.set-text { display: flex; flex-direction: column; gap: 2px; min-width: 0; flex: 1; }
.set-title { font-size: 16px; font-weight: 500; color: var(--ink-900); }
.set-sub { font-size: 13px; color: var(--ink-500); line-height: 1.5; overflow-wrap: anywhere; }
.set-chevron { color: var(--ink-400); font-size: 22px; flex: none; }
.set-item.is-danger .set-title { color: var(--danger); }

.set-radio input { width: 20px; height: 20px; flex: none; accent-color: var(--brand-600); cursor: pointer; }
.set-radio:has(input:checked) { background: var(--brand-50); }

.set-form { flex-direction: column; align-items: stretch; gap: 12px; padding: 18px 20px; cursor: default; }
.set-form-actions { display: flex; justify-content: flex-end; gap: 10px; }

.set-hint { margin: 14px 6px 0; font-size: 13px; color: var(--ink-500); line-height: 1.7; }
.set-actions { display: flex; justify-content: center; margin-top: 24px; }
.set-actions .btn { min-width: 220px; height: 44px; }

.settings-title { margin: 0; font-size: 24px; font-weight: 700; }
.settings-lead { margin: 8px 0 28px; color: var(--ink-500); font-size: 13px; }

.settings-card { padding: 20px 22px; margin-bottom: 20px; }

.settings-card-head { display: flex; gap: 14px; align-items: flex-start; margin-bottom: 18px; }
.settings-card-head .glyph {
  display: grid; place-items: center; flex: none;
  width: 34px; height: 34px; border-radius: var(--r-md);
  background: var(--brand-50); color: var(--brand-600);
}
.settings-card-head .glyph .material-symbols-outlined { font-size: 20px; }
.settings-card-head h3 { margin: 0; font-size: 15px; font-weight: 700; }
.settings-card-head p { margin: 4px 0 0; font-size: 12.5px; color: var(--ink-500); line-height: 1.7; }

.settings-grid { display: grid; grid-template-columns: 1fr 1fr; gap: 16px; }

.admin-user-list { display: flex; flex-direction: column; gap: 10px; }
.admin-loading, .admin-empty {
  padding: 18px 4px; color: var(--ink-500); font-size: 13px; text-align: center;
}
.admin-user-row {
  display: flex; align-items: center; gap: 12px;
  padding: 12px; border: 1px solid var(--line); border-radius: var(--r-md);
  background: var(--surface-sunk);
}
.admin-user-meta { min-width: 0; flex: 1; }
.admin-user-name {
  font-weight: 600; font-size: 14px;
  white-space: nowrap; overflow: hidden; text-overflow: ellipsis;
}
.admin-user-sub {
  margin-top: 2px; font-size: 12px; color: var(--ink-500);
  white-space: nowrap; overflow: hidden; text-overflow: ellipsis;
}
.admin-user-actions { display: flex; flex-wrap: wrap; gap: 6px; justify-content: flex-end; }
.admin-user-actions .btn { height: 34px; padding: 0 12px; font-size: 12.5px; }
.btn.is-danger-text { color: var(--danger); border-color: #fecaca; }
.btn.is-danger-text:hover:not(:disabled) { background: #fef2f2; }

.radio-card {
  display: flex; align-items: center; gap: 12px;
  padding: 12px 16px; margin-bottom: 10px;
  border: 1px solid var(--line); border-radius: var(--r-md);
  background: var(--surface); cursor: pointer;
  transition: border-color .15s var(--ease), background-color .15s var(--ease),
              box-shadow .15s var(--ease);
}
.radio-card:hover { border-color: var(--brand-200); background: var(--surface-sunk); }
.radio-card input { width: 16px; height: 16px; accent-color: var(--brand-600); cursor: pointer; }
.radio-card .label { font-weight: 500; }
.radio-card .desc { font-size: 12px; color: var(--ink-500); }
.radio-card:has(input:checked) {
  border-color: var(--brand-600); background: var(--brand-50);
  box-shadow: inset 3px 0 0 var(--brand-600);
}

.usage-row {
  display: flex; align-items: center; gap: 8px;
  margin-top: 10px; font-size: 12.5px; color: var(--ink-500);
}
.usage-row .material-symbols-outlined { font-size: 18px; }

.settings-actions {
  display: flex; justify-content: flex-end; gap: 12px;
  padding-top: 20px; border-top: 1px solid var(--line);
}

.tip-card {
  padding: 20px; text-align: center;
  background: var(--brand-50); border: 1px solid var(--brand-100);
  border-radius: var(--r-lg);
}
.tip-card .glyph {
  display: grid; place-items: center; margin: 0 auto 12px;
  width: 40px; height: 40px; border-radius: var(--r-full);
  background: var(--surface); color: var(--brand-600);
}
.tip-card h4 { margin: 0 0 8px; font-size: 14px; font-weight: 700; color: var(--brand-900); }
.tip-card p { margin: 0; font-size: 12px; color: var(--ink-500); line-height: 1.8; }

/* 帳號切換頁 */
.switch-wrap { display: grid; place-items: center; min-height: 100%; padding: 24px; }
.switch-card {
  position: relative; overflow: hidden;
  width: 100%; max-width: 384px; padding: 34px 32px 28px; text-align: center;
}
.switch-card::before {
  content: ''; position: absolute; inset: 0 0 auto; height: 4px;
  background: linear-gradient(90deg, var(--brand-600) 0 45%, var(--brand-100) 45%);
}
.switch-card .switch-head {
  text-align: left; font-size: 17px; font-weight: 700; color: var(--ink-900);
}
.switch-card .glyph {
  display: grid; place-items: center; margin: 22px auto 20px;
  width: 62px; height: 62px; border-radius: var(--r-full);
  background: var(--brand-50); color: var(--brand-600);
}
.switch-card .glyph .material-symbols-outlined { font-size: 30px; }
.switch-card h3 { margin: 0 0 10px; font-size: 17px; font-weight: 700; }
.switch-card p { margin: 0 0 24px; font-size: 12.5px; color: var(--ink-500); line-height: 1.9; }
.switch-card .btn { width: 100%; height: 44px; }
.switch-card .btn + .btn { margin-top: 12px; }

/* ============================================================== 對話框 */

.modal-backdrop {
  position: fixed; inset: 0; z-index: 60;
  display: grid; place-items: center; padding: 20px;
  background: rgba(15, 23, 42, .38);
  backdrop-filter: blur(2px);
  animation: fade-in .16s var(--ease);
}
.modal {
  width: 100%; max-width: 420px; padding: 22px;
  background: var(--surface); border-radius: var(--r-lg);
  box-shadow: var(--shadow-lg);
  animation: pop-in .18s var(--ease);
}
.modal h3 { margin: 0 0 6px; font-size: 17px; font-weight: 700; }
.modal .lead { margin: 0 0 18px; font-size: 12.5px; color: var(--ink-500); white-space: pre-line; }
.modal .fields { display: flex; flex-direction: column; gap: 14px; }
.modal .actions { display: flex; justify-content: flex-end; gap: 10px; margin-top: 22px; }

.menu {
  position: fixed; z-index: 70; min-width: 184px; padding: 6px;
  background: var(--surface); border: 1px solid var(--line);
  border-radius: var(--r-md); box-shadow: var(--shadow-lg);
  animation: pop-in .12s var(--ease);
}
.menu button {
  display: flex; align-items: center; gap: 10px;
  width: 100%; padding: 9px 10px; border-radius: var(--r-sm);
  text-align: left; color: var(--ink-700); font-size: 13px;
}
.menu button:hover { background: var(--surface-sunk); }
.menu button.is-danger { color: var(--danger); }
.menu button .material-symbols-outlined { font-size: 18px; }

.toast-stack {
  position: fixed; z-index: 90; left: 50%; bottom: 26px; transform: translateX(-50%);
  display: flex; flex-direction: column; gap: 8px; align-items: center;
  pointer-events: none;
}
.toast {
  padding: 10px 18px; border-radius: var(--r-full);
  background: var(--ink-900); color: #fff; font-size: 13px;
  box-shadow: var(--shadow-lg);
  animation: pop-in .18s var(--ease);
}
.toast.is-error { background: var(--danger); }
.toast.is-success { background: var(--success); }

/* ============================================================== 語音通話 */

.chat-head .call-btn {
  color: #fff;
  background: var(--success);
  width: 40px;
  height: 40px;
}
.chat-head .call-btn:hover { background: #15803d; color: #fff; }
.chat-head .call-btn .material-symbols-outlined { font-size: 22px; }

.signal-badge {
  margin: 0 10px 10px;
  padding: 8px 10px;
  border-radius: var(--r-md);
  font-size: 11px;
  line-height: 1.35;
  text-align: center;
}
.signal-badge.is-ok { background: #dcfce7; color: #166534; }
.signal-badge.is-wait { background: #fef9c3; color: #854d0e; }
.signal-badge.is-bad { background: #fee2e2; color: #991b1b; }

.signal-strip {
  display: none;
  flex: none;
  padding: 6px 12px;
  font-size: 11.5px;
  font-weight: 500;
  text-align: center;
  border-bottom: 1px solid var(--line);
}
.signal-strip.is-ok { background: #dcfce7; color: #166534; }
.signal-strip.is-wait { background: #fef9c3; color: #854d0e; }
.signal-strip.is-bad { background: #fee2e2; color: #991b1b; }

.rail-mobile-only { display: none !important; }
.mobile-me { display: none !important; }

.call-layer {
  position: fixed; inset: 0; z-index: 80;
  display: grid; place-items: center; padding: 20px;
  background: rgba(15, 23, 42, .72);
}
.call-card {
  width: min(380px, 100%); padding: 36px 24px 28px; text-align: center;
  background: linear-gradient(180deg, #0f766e 0%, #115e59 45%, #134e4a 100%);
  color: #fff;
  border-radius: 28px; box-shadow: var(--shadow-lg);
}
.call-card .avatar {
  margin: 0 auto 16px;
  background: rgba(255,255,255,.18);
  color: #fff;
}
.call-card h2 { margin: 0 0 6px; font-size: 22px; color: #fff; }
.call-card p { margin: 0; color: rgba(255,255,255,.82); font-size: 14px; }
.call-remotes {
  position: absolute;
  width: 1px; height: 1px;
  overflow: hidden;
  clip: rect(0 0 0 0);
}
.call-actions { display: flex; justify-content: center; gap: 18px; margin-top: 30px; }
.call-round {
  display: grid; place-items: center;
  width: 60px; height: 60px; border-radius: var(--r-full);
  background: rgba(255,255,255,.16); color: #fff;
}
.call-round.is-danger { background: #ef4444; color: #fff; }
.call-round.is-ok { background: #22c55e; color: #fff; }
.call-round .material-symbols-outlined { font-size: 28px; }
.call-round.is-ok-soft { background: rgba(255,255,255,.22); color: #fff; }
#call-remote { display: none; }

/* 視訊通話：對方畫面鋪滿，自己畫面在右上小窗；撥號／響鈴時自己畫面全螢幕預覽 */
.call-stage { display: none; }
.call-layer.is-video {
  padding: 0;
  place-items: stretch;
  background: #000;
}
.call-layer.is-video .call-stage {
  display: block;
  position: absolute; inset: 0;
  overflow: hidden;
  background: #0b0f14;
}
.call-remote-video {
  display: none;
  width: 100%; height: 100%;
  object-fit: cover;
  background: #000;
}
.call-remote-video.is-contain { object-fit: contain; }
.call-layer.has-remote-video .call-remote-video { display: block; }
.call-local-video {
  position: absolute;
  top: calc(16px + env(safe-area-inset-top));
  right: 16px;
  z-index: 2;
  width: min(28vw, 160px);
  aspect-ratio: 3 / 4;
  object-fit: cover;
  border-radius: 16px;
  border: 2px solid rgba(255,255,255,.35);
  background: #111;
  box-shadow: 0 8px 24px rgba(0,0,0,.35);
  transform: scaleX(-1);
}
.call-layer.is-preview:not(.has-remote-video) .call-local-video {
  top: 0; right: 0;
  width: 100%; height: 100%;
  aspect-ratio: auto;
  border: 0; border-radius: 0;
  box-shadow: none;
}
.call-tap-hint {
  display: none;
  position: absolute; left: 50%; top: 50%;
  transform: translate(-50%, -50%);
  padding: 10px 18px;
  border-radius: var(--r-full);
  background: rgba(0,0,0,.6);
  color: #fff; font-size: 14px;
}
.call-layer.needs-tap .call-tap-hint { display: block; }
.call-layer.is-video .call-card {
  position: relative; z-index: 3;
  width: 100%; height: 100%;
  display: flex; flex-direction: column; justify-content: space-between;
  padding: calc(24px + env(safe-area-inset-top)) 20px calc(28px + env(safe-area-inset-bottom));
  border-radius: 0;
  box-shadow: none;
  background: linear-gradient(to bottom, rgba(0,0,0,.55), transparent 24%, transparent 68%, rgba(0,0,0,.6));
  pointer-events: none;
}
.call-layer.is-video .call-head,
.call-layer.is-video .call-actions { pointer-events: auto; }
.call-layer.is-video .call-head h2,
.call-layer.is-video .call-head p { text-shadow: 0 1px 4px rgba(0,0,0,.6); }
.call-layer.is-video.has-remote-video:not(.remote-cam-off) .call-head .avatar { display: none; }
.call-layer.remote-cam-off .call-remote-video { visibility: hidden; }
.call-local-video.is-back { transform: none; }
.call-remote-note {
  position: absolute; left: 50%; top: 50%;
  transform: translate(-50%, -50%);
  padding: 8px 16px;
  border-radius: var(--r-full);
  background: rgba(255,255,255,.14);
  color: #fff; font-size: 14px;
  white-space: nowrap;
}
.call-layer.is-video .call-round.is-off:not(.is-danger):not(.is-ok) { background: #fff; color: #111827; }
.call-layer.is-video .call-actions { margin-top: 0; }
.call-layer.is-video .call-round:not(.is-danger):not(.is-ok) {
  background: rgba(255,255,255,.2);
  backdrop-filter: blur(6px);
}

/* 群組視訊：1 位對方全螢幕、2 位上下（橫向時左右）分割、3 位 2×2 由自己補第 4 格 */
.call-grid {
  display: none;
  grid-template-columns: 1fr; grid-auto-rows: 1fr;
}
.call-layer.is-group-video .call-remote-video { display: none !important; }
.call-layer.is-group-video .call-grid {
  position: absolute; inset: 0; z-index: 1;
  display: grid; gap: 2px;
}
.call-grid[data-count="0"] { visibility: hidden; }
.call-grid[data-count="2"] { grid-template-rows: 1fr 1fr; }
.call-grid[data-count="3"],
.call-grid[data-count="4"] { grid-template-columns: 1fr 1fr; grid-template-rows: 1fr 1fr; }
@media (min-aspect-ratio: 1/1) {
  .call-grid[data-count="2"] { grid-template-columns: 1fr 1fr; grid-template-rows: 1fr; }
}
.call-tile {
  position: relative;
  min-width: 0; min-height: 0;
  overflow: hidden;
  background: #111827;
}
.call-tile video {
  width: 100%; height: 100%;
  object-fit: cover;
  display: block;
}
.call-tile.cam-off video { visibility: hidden; }
.call-tile-avatar {
  display: none;
  position: absolute; left: 50%; top: 50%;
  transform: translate(-50%, -60%);
  width: 64px; height: 64px;
  place-items: center;
  border-radius: 50%;
  background: rgba(255,255,255,.16);
  color: #fff; font-size: 24px; font-weight: 600;
}
.call-tile.cam-off .call-tile-avatar { display: grid; }
.call-tile-name {
  position: absolute; left: 8px; top: 8px;
  max-width: calc(100% - 16px);
  padding: 2px 10px;
  border-radius: var(--r-full);
  background: rgba(0,0,0,.5);
  color: #fff; font-size: 13px;
  overflow: hidden; text-overflow: ellipsis; white-space: nowrap;
}
.call-tile-note {
  position: absolute; left: 50%; top: 50%;
  transform: translate(-50%, 28px);
  color: rgba(255,255,255,.85); font-size: 13px;
  white-space: nowrap;
}
.call-grid[data-count="2"] .call-tile:first-child .call-tile-name,
.call-grid[data-count="3"] .call-tile:nth-child(-n+2) .call-tile-name,
.call-grid[data-count="4"] .call-tile:nth-child(-n+2) .call-tile-name {
  top: calc(8px + env(safe-area-inset-top));
}
/* 只有一位對方時名字與頂部標題重複 */
.call-grid[data-count="1"] .call-tile-name { display: none; }
.call-layer.grid-4 .call-local-video {
  top: 50%; right: 0;
  width: calc(50% - 1px); height: 50%;
  aspect-ratio: auto;
  border: 0; border-radius: 0;
  box-shadow: none;
}
.call-audio-strip {
  position: absolute; left: 0; right: 0; z-index: 2;
  bottom: calc(132px + env(safe-area-inset-bottom));
  display: flex; flex-wrap: wrap; justify-content: center; gap: 6px;
  padding: 0 16px;
  pointer-events: none;
}
.call-layer:not(.is-group-video) .call-audio-strip { display: none; }
.call-chip {
  padding: 4px 12px;
  border-radius: var(--r-full);
  background: rgba(0,0,0,.55);
  color: #fff; font-size: 13px;
}
.call-chip::after { content: "（語音）"; opacity: .75; }

.loading-veil {
  position: fixed; inset: 0; z-index: 100;
  display: grid; place-items: center;
  background: var(--canvas);
}
.spinner {
  width: 30px; height: 30px; border-radius: 50%;
  border: 3px solid var(--brand-100); border-top-color: var(--brand-600);
  animation: spin .7s linear infinite;
}

@keyframes spin { to { transform: rotate(360deg); } }
@keyframes fade-in { from { opacity: 0; } }
@keyframes pop-in { from { opacity: 0; transform: translateY(6px) scale(.98); } }

/* ============================================================= 響應式 */

/* 中型視窗：導覽列收成圖示 */
@media (max-width: 1100px) {
  :root { --rail-w: 72px; --list-w: 264px; }
  .rail { padding: 16px 10px; align-items: center; }
  .rail-identity { flex-direction: column; gap: 6px; padding: 4px 0 18px; }
  .rail-identity .meta { display: none; }
  .rail-link { justify-content: center; padding: 0; gap: 0; }
  .rail-link .label, .rail-link .count { display: none; }
  .rail-link.is-active::before { display: none; }
  .rail-nav, .rail-foot { width: 100%; }
}

/* 平板：設定頁單欄 */
@media (max-width: 900px) {
  .settings-grid { grid-template-columns: 1fr; }
}

/* 手機：單欄內容 + 底部 Tab；聊天時全螢幕 */
@media (max-width: 720px) {
  :root {
    --rail-w: 0px;
    --list-w: 0px;
    --header-h: 56px;
    --mobile-tab-h: 58px;
  }

  body { overflow: hidden; }

  /* —— 登入頁：品牌精簡、表單為主 —— */
  .auth {
    grid-template-columns: 1fr;
    min-height: 100dvh;
    overflow-y: auto;
  }
  .auth-brand {
    border-right: none;
    border-bottom: 1px solid var(--line);
    padding: 18px 20px 14px;
  }
  .auth-brand::after { display: none; }
  .auth-logo h1 { font-size: 22px; }
  .auth-pitch { margin-top: 10px; }
  .auth-pitch h2 { font-size: 18px; margin: 0; }
  .auth-pitch p { display: none; }
  .auth-note { margin-top: 12px; font-size: 12px; }
  .auth-main {
    padding: 16px 16px calc(28px + env(safe-area-inset-bottom));
    align-items: start;
    place-items: start center;
  }
  .auth-card {
    border: none;
    box-shadow: none;
    background: transparent;
    padding: 12px 0 24px;
    max-width: 420px;
  }
  .auth-title { font-size: 22px; }
  .auth-sub { margin-bottom: 18px; }
  .auth-mark { width: 44px; height: 44px; margin-bottom: 12px; }

  /* —— App 外框 —— */
  .app {
    grid-template-columns: 1fr;
    grid-template-rows: minmax(0, 1fr) auto;
    height: 100dvh;
    max-height: 100dvh;
  }
  .app[data-list-hidden="true"] { grid-template-columns: 1fr; }

  /* 聊天全螢幕：藏底部 Tab，對話區佔滿 */
  .app[data-mobile="chat"] {
    grid-template-rows: minmax(0, 1fr);
  }
  .app[data-mobile="chat"] .rail { display: none; }

  .rail-desktop-only { display: none !important; }
  .rail-mobile-only { display: flex !important; }

  .rail {
    grid-row: 2;
    grid-column: 1;
    flex-direction: column;
    align-items: stretch;
    gap: 0;
    padding: 0;
    border-right: none;
    border-top: 1px solid var(--line);
    background: var(--surface);
    box-shadow: 0 -6px 20px rgba(15, 23, 42, .05);
  }
  .rail-identity,
  .rail-spacer,
  .rail-foot { display: none; }

  .rail-nav {
    display: flex;
    flex-direction: row;
    justify-content: space-around;
    align-items: stretch;
    gap: 0;
    width: 100%;
    padding: 4px 4px calc(4px + env(safe-area-inset-bottom));
  }

  .rail-link {
    position: relative;
    flex: 1;
    flex-direction: column;
    justify-content: center;
    gap: 2px;
    width: auto;
    max-width: none;
    height: var(--mobile-tab-h);
    min-height: var(--mobile-tab-h);
    padding: 6px 2px;
    border-radius: var(--r-md);
    font-size: 10px;
    line-height: 1.2;
  }
  .rail-link .material-symbols-outlined { font-size: 22px; }
  .rail-link .label {
    display: block;
    max-width: 100%;
    font-size: 10px;
    white-space: nowrap;
    overflow: hidden;
    text-overflow: ellipsis;
  }
  .rail-link .count {
    position: absolute;
    top: 4px;
    left: 50%;
    margin-left: 6px;
  }
  .rail-link.is-active::before { display: none; }
  .rail-link.is-active {
    background: transparent;
    color: var(--brand-700);
  }
  .rail-link.is-active .material-symbols-outlined { color: var(--brand-600); }

  .list-pane,
  .chat-pane,
  .settings-pane,
  #guardian-pane {
    grid-row: 1;
    grid-column: 1;
    border-right: none;
    min-height: 0;
    height: 100%;
    max-height: 100%;
  }

  .signal-strip { display: block; }

  /* 列表 ↔ 聊天 互斥 */
  .app[data-mobile="list"] .chat-pane:not(.hidden) { display: none; }
  .app[data-mobile="chat"] .list-pane:not(.hidden) { display: none; }
  .app[data-list-hidden="true"] .list-pane { display: none !important; }
  .app[data-list-hidden="true"] .chat-pane { display: none !important; }
  .app[data-list-hidden="true"] .settings-pane:not(.hidden),
  .app[data-list-hidden="true"] #guardian-pane:not(.hidden) {
    display: block;
  }

  .pane-head {
    padding: 10px 12px 10px 14px;
    min-height: var(--header-h);
    padding-top: max(10px, env(safe-area-inset-top));
  }
  .pane-head h2 { font-size: 18px; }
  .pane-search { padding: 8px 12px 10px; }

  .conv-list { padding: 0 6px calc(8px + env(safe-area-inset-bottom)); }
  .conv-item { padding: 12px 10px; min-height: 64px; }
  .conv-item .title { font-size: 15px; }
  .conv-item .preview { font-size: 13px; }

  .chat-back { display: inline-flex; }
  .chat-head {
    padding: 8px 10px;
    padding-top: max(8px, env(safe-area-inset-top));
    gap: 8px;
  }
  .chat-head .title { font-size: 16px; }
  .chat-body {
    padding: 12px 12px 8px;
    -webkit-overflow-scrolling: touch;
  }
  .msg { max-width: 86%; }
  .msg .avatar { display: grid; }
  .bubble { font-size: 15px; padding: 10px 12px; }

  .mobile-me {
    display: grid !important;
    place-items: center;
    width: 36px;
    height: 36px;
    flex: none;
    padding: 0;
    border: none;
    cursor: pointer;
  }

  .composer {
    gap: 8px;
    padding: 8px 10px calc(8px + env(safe-area-inset-bottom));
  }
  .chat-jump {
    right: 12px;
    bottom: calc(72px + env(safe-area-inset-bottom));
  }
  .composer textarea {
    min-height: 40px;
    font-size: 16px; /* 避免 iOS 聚焦放大 */
  }
  .call-bar { display: none !important; }
  .chat-head .call-btn {
    width: 44px;
    height: 44px;
    min-width: 44px;
  }

  .settings-inner {
    padding: 20px 16px calc(28px + env(safe-area-inset-bottom));
  }
  .settings-title { font-size: 20px; }
  .set-bar { padding-left: 8px; }
  .set-bar.is-home { padding-left: 8px; }
  .set-bar.is-home .set-back { display: inline-flex; }
  .set-body { padding: 0 12px calc(28px + env(safe-area-inset-bottom)); }
  .set-form-actions .btn { flex: 1; }
  .set-actions .btn { width: 100%; }
  .settings-actions { flex-direction: column-reverse; }
  .settings-actions .btn { width: 100%; }

  .admin-user-row { flex-wrap: wrap; }
  .admin-user-actions { width: 100%; }
  .admin-user-actions .btn { flex: 1; }

  .modal-backdrop { padding: 12px; align-items: end; }
  .modal {
    max-width: none;
    width: 100%;
    border-radius: 16px 16px 0 0;
    padding: 18px 16px calc(18px + env(safe-area-inset-bottom));
  }

  .toast-stack { bottom: calc(72px + env(safe-area-inset-bottom)); }
  .app[data-mobile="chat"] ~ .toast-stack,
  body:has(.app[data-mobile="chat"]:not(.hidden)) .toast-stack {
    bottom: calc(24px + env(safe-area-inset-bottom));
  }

  .call-card {
    width: min(100%, 360px);
    border-radius: 24px;
    padding: 28px 20px 24px;
  }
}

@media (prefers-reduced-motion: reduce) {
  *, *::before, *::after {
    animation-duration: .01ms !important;
    transition-duration: .01ms !important;
  }
}