* { box-sizing: border-box; }
html, body { height: 100%; }
body {
  margin: 0;
  font-family: var(--font-ui);
  font-size: var(--fs-base);
  color: var(--ink);
  background: var(--bg);
  overflow: hidden;
}
button, input, textarea, select { font-family: inherit; font-size: inherit; color: inherit; }
:focus-visible {
  outline: 2px solid var(--focus-ring);
  outline-offset: 2px;
  border-radius: 4px;
}

.app {
  display: grid;
  grid-template-columns: var(--rail-width) var(--list-width) 1fr;
  grid-template-rows: var(--topbar-height) 1fr;
  grid-template-areas:
    "topbar topbar topbar"
    "rail   list   reading";
  height: 100vh;
  width: 100vw;
}
.app.calendar-mode {
  grid-template-columns: 1fr;
}

/* ---- Topbar ---- */
.topbar {
  grid-area: topbar;
  display: flex;
  align-items: center;
  gap: var(--sp-4);
  padding: 0 var(--sp-4);
  background: var(--primary);
  border-bottom: 1px solid var(--primary-dark);
  z-index: 10;
}
.topbar .brand {
  display: flex;
  align-items: center;
  gap: var(--sp-2);
  font-weight: 700;
  font-size: var(--fs-md);
  color: #FFFFFF;
  white-space: nowrap;
}
.brand .mark {
  width: 22px; height: 22px;
  border-radius: 6px;
  background: #FFFFFF;
  display: inline-block;
  position: relative;
}
.brand .mark::after {
  content: "";
  position: absolute; inset: 5px;
  border-radius: 3px;
  background: var(--primary);
  clip-path: polygon(0 0, 100% 50%, 0 100%);
}
.topbar .search {
  flex: 1;
  max-width: 640px;
  position: relative;
}
.app-switcher {
  display: flex;
  background: rgba(255,255,255,0.14);
  border-radius: 999px;
  padding: 3px;
  gap: 2px;
  flex-shrink: 0;
}
.app-tab {
  border: none; background: transparent;
  color: rgba(255,255,255,0.85);
  font-size: var(--fs-sm); font-weight: 600;
  padding: 6px 14px;
  border-radius: 999px;
  cursor: pointer;
  transition: background var(--dur-fast) var(--ease), color var(--dur-fast) var(--ease);
}
.app-tab:hover { background: rgba(255,255,255,0.12); color: white; }
.app-tab.active { background: #FFFFFF; color: var(--primary-dark); }
.topbar .search input {
  width: 100%;
  height: 34px;
  border: 1px solid var(--primary-dark);
  background: rgba(255,255,255,0.16);
  color: #FFFFFF;
  border-radius: var(--radius-sm);
  padding: 0 var(--sp-3) 0 34px;
  transition: background var(--dur-fast) var(--ease), border-color var(--dur-fast) var(--ease);
}
.topbar .search input::placeholder { color: rgba(255,255,255,0.75); }
.topbar .search input:focus {
  background: #FFFFFF;
  color: var(--ink);
  border-color: var(--primary-dark);
  outline: none;
}
.topbar .search input:focus::placeholder { color: var(--ink-faint); }
.topbar .search .icon {
  position: absolute; left: var(--sp-2); top: 50%; transform: translateY(-50%);
  color: rgba(255,255,255,0.85);
  pointer-events: none;
}
.topbar .search input:focus ~ .icon { color: var(--ink-faint); }
.topbar .actions { margin-left: auto; display: flex; align-items: center; gap: var(--sp-2); }
.msg-meta .avatar,
.avatar {
  width: 30px; height: 30px; border-radius: 50%;
  background: var(--primary);
  color: white;
  display: flex; align-items: center; justify-content: center;
  font-size: var(--fs-xs); font-weight: 700;
}
.topbar .avatar {
  background: #FFFFFF;
  color: var(--primary-dark);
}

/* ---- Rail (folders) ---- */
.rail {
  grid-area: rail;
  background: var(--surface);
  border-right: 1px solid var(--border);
  overflow-y: auto;
  padding: var(--sp-3) var(--sp-2);
  display: flex;
  flex-direction: column;
  gap: var(--sp-1);
}
.compose-btn {
  display: flex; align-items: center; gap: var(--sp-2);
  margin: 0 var(--sp-2) var(--sp-4);
  padding: var(--sp-3) var(--sp-3);
  background: var(--primary);
  color: white;
  border: none;
  border-radius: var(--radius-sm);
  font-weight: 600;
  cursor: pointer;
  transition: background var(--dur-fast) var(--ease), transform var(--dur-fast) var(--ease);
}
.compose-btn:hover { background: var(--primary-dark); }
.compose-btn:active { transform: scale(0.98); }

.folder-item {
  display: flex; align-items: center; gap: var(--sp-2);
  padding: var(--sp-2) var(--sp-3);
  border-radius: var(--radius-sm);
  cursor: pointer;
  color: var(--ink-muted);
  font-size: var(--fs-sm);
  user-select: none;
  transition: background var(--dur-fast) var(--ease), color var(--dur-fast) var(--ease);
}
.folder-item:hover { background: var(--surface-sunken); color: var(--ink); }
.folder-item.active {
  background: var(--primary-tint);
  color: var(--primary-dark);
  font-weight: 600;
}
.folder-item .icon { width: 16px; flex-shrink: 0; opacity: 0.85; }
.folder-item .name { flex: 1; overflow: hidden; text-overflow: ellipsis; white-space: nowrap; }
.folder-item .count { font-family: var(--font-mono); font-size: var(--fs-xs); color: var(--ink-faint); }
.folder-item.active .count { color: var(--primary); }
.rail .section-label {
  font-size: var(--fs-xs);
  text-transform: uppercase;
  letter-spacing: 0.06em;
  color: var(--ink-faint);
  padding: var(--sp-3) var(--sp-3) var(--sp-1);
}

/* ---- Message list ---- */
.list-pane {
  grid-area: list;
  background: var(--surface);
  border-right: 1px solid var(--border);
  display: flex;
  flex-direction: column;
  overflow: hidden;
}
.list-pane .list-header {
  display: flex; align-items: center; justify-content: space-between;
  padding: var(--sp-3) var(--sp-4);
  border-bottom: 1px solid var(--border);
}
.list-pane .list-header h2 { font-size: var(--fs-md); margin: 0; }
.list-pane .list-header .filters { display: flex; gap: var(--sp-1); }
.pill {
  border: 1px solid var(--border);
  background: transparent;
  color: var(--ink-muted);
  padding: 3px 10px;
  border-radius: 999px;
  font-size: var(--fs-xs);
  cursor: pointer;
  transition: all var(--dur-fast) var(--ease);
}
.pill.active { background: var(--ink); color: white; border-color: var(--ink); }
.pill:hover:not(.active) { border-color: var(--ink-muted); color: var(--ink); }

.message-list { overflow-y: auto; flex: 1; }
.message-item {
  position: relative;
  display: flex;
  gap: var(--sp-3);
  padding: var(--sp-3) var(--sp-4);
  border-bottom: 1px solid var(--border);
  cursor: pointer;
  transition: background var(--dur-fast) var(--ease);
}
.message-item:hover { background: var(--surface-sunken); }
.message-item.selected { background: var(--primary-tint); }
.message-item.unread { background: linear-gradient(to right, var(--accent-tint) 0, transparent 3px); }
.message-item .unread-dot {
  width: 8px; height: 8px; border-radius: 50%;
  background: var(--accent);
  flex-shrink: 0;
  margin-top: 6px;
  opacity: 0;
}
.message-item.unread .unread-dot { opacity: 1; }
.message-item .body { flex: 1; min-width: 0; }
.message-item .row1 { display: flex; justify-content: space-between; gap: var(--sp-2); }
.message-item .from {
  font-size: var(--fs-sm);
  color: var(--ink);
  overflow: hidden; text-overflow: ellipsis; white-space: nowrap;
}
.message-item.unread .from { font-weight: 700; }
.message-item .time {
  font-family: var(--font-mono);
  font-size: var(--fs-xs);
  color: var(--ink-faint);
  flex-shrink: 0;
}
.message-item .subject {
  font-size: var(--fs-sm);
  margin-top: 2px;
  overflow: hidden; text-overflow: ellipsis; white-space: nowrap;
}
.message-item.unread .subject { font-weight: 600; }
.message-item .preview {
  font-size: var(--fs-xs);
  color: var(--ink-faint);
  margin-top: 2px;
  overflow: hidden; text-overflow: ellipsis; white-space: nowrap;
}
.message-item .flag-dot { color: var(--accent); }
.quick-actions {
  position: absolute; right: var(--sp-2); top: 50%; transform: translate(8px, -50%);
  display: flex; gap: 2px;
  opacity: 0;
  transition: opacity var(--dur-fast) var(--ease), transform var(--dur-fast) var(--ease);
  background: var(--surface);
  border-radius: var(--radius-sm);
  box-shadow: 0 1px 4px rgba(0,0,0,0.12);
}
.message-item:hover .quick-actions { opacity: 1; transform: translate(0, -50%); }
.qa-btn {
  width: 28px; height: 28px;
  border: none; background: transparent;
  display: flex; align-items: center; justify-content: center;
  cursor: pointer;
  color: var(--ink-muted);
  border-radius: var(--radius-sm);
}
.qa-btn:hover { background: var(--surface-sunken); color: var(--ink); }

/* ---- Reading pane ---- */
.reading-pane { grid-area: reading; background: var(--surface); overflow-y: auto; display: flex; flex-direction: column; }
.reading-pane .empty-state {
  margin: auto;
  text-align: center;
  color: var(--ink-faint);
  max-width: 280px;
}
.reading-pane .empty-state .glyph { font-size: 40px; margin-bottom: var(--sp-3); opacity: 0.5; }
.reading-toolbar {
  display: flex; align-items: center; gap: var(--sp-1);
  padding: var(--sp-2) var(--sp-4);
  border-bottom: 1px solid var(--border);
}
.tb-btn {
  height: 32px; padding: 0 var(--sp-2);
  border: 1px solid transparent;
  background: transparent;
  border-radius: var(--radius-sm);
  color: var(--ink-muted);
  display: flex; align-items: center; gap: 6px;
  cursor: pointer;
  font-size: var(--fs-sm);
}
.tb-btn:hover { background: var(--surface-sunken); color: var(--ink); }
.reading-content { padding: var(--sp-5) var(--sp-6); max-width: 820px; }
.reading-content h1 { font-size: var(--fs-xl); margin: 0 0 var(--sp-3); }
.msg-meta { display: flex; gap: var(--sp-3); align-items: flex-start; margin-bottom: var(--sp-4); }
.msg-meta .avatar { flex-shrink: 0; }
.msg-meta .who strong { font-size: var(--fs-md); }
.msg-meta .who .addr { font-size: var(--fs-xs); color: var(--ink-faint); }
.msg-meta .when { margin-left: auto; font-family: var(--font-mono); font-size: var(--fs-xs); color: var(--ink-faint); }
.msg-body { font-size: var(--fs-md); line-height: 1.65; color: var(--ink); }
.msg-body p { margin: 0 0 1em; }

/* ---- Compose panel — inline, lives in the same reading-pane slot as a message ---- */
.compose-panel {
  display: flex;
  flex-direction: column;
  height: 100%;
  min-height: 0;
}
.compose-topbar {
  display: flex; align-items: center; gap: var(--sp-2);
  padding: var(--sp-3) var(--sp-4);
  border-bottom: 1px solid var(--border);
  flex-shrink: 0;
}
.compose-topbar .title { font-weight: 600; font-size: var(--fs-md); }
.compose-topbar .spacer { flex: 1; }
.compose-fields { padding: var(--sp-3) var(--sp-4); flex-shrink: 0; }
.compose-fields .field {
  display: flex; align-items: center;
  border-bottom: 1px solid var(--border);
  padding: 8px 0;
}
.compose-fields .field label { width: 60px; color: var(--ink-faint); font-size: var(--fs-xs); flex-shrink: 0; }
.compose-fields .field input {
  flex: 1; border: none; outline: none; font-size: var(--fs-sm); background: transparent;
}
.compose-fields .field .toggle-cc {
  font-size: var(--fs-xs); color: var(--primary); background: none; border: none; cursor: pointer; padding: 0;
}
.compose-editor-wrap {
  flex: 1;
  min-height: 0;
  display: flex;
  flex-direction: column;
  padding: 0 var(--sp-4) var(--sp-3);
  overflow: hidden;
}
.ql-toolbar.ql-snow {
  border: none !important;
  border-bottom: 1px solid var(--border) !important;
  border-radius: 0;
  background: var(--surface);
  padding: 6px 4px;
}
.ql-toolbar.ql-snow .ql-formats { margin-right: 6px; }
.ql-toolbar.ql-snow button,
.ql-toolbar.ql-snow .ql-picker-label {
  border-radius: 4px;
}
.ql-toolbar.ql-snow button:hover,
.ql-toolbar.ql-snow button.ql-active,
.ql-toolbar.ql-snow .ql-picker-label:hover,
.ql-toolbar.ql-snow .ql-picker-item:hover {
  color: var(--primary) !important;
}
.ql-toolbar.ql-snow button:hover .ql-stroke,
.ql-toolbar.ql-snow button.ql-active .ql-stroke { stroke: var(--primary) !important; }
.ql-toolbar.ql-snow button:hover .ql-fill,
.ql-toolbar.ql-snow button.ql-active .ql-fill { fill: var(--primary) !important; }
.ql-container.ql-snow {
  border: none !important;
  font-family: var(--font-ui);
  font-size: var(--fs-md);
  flex: 1;
  overflow-y: auto;
}
.ql-editor { padding: var(--sp-3) 4px; }
.ql-editor blockquote {
  border-left: 3px solid var(--border-strong);
  color: var(--ink-muted);
  padding-left: var(--sp-3);
  margin-left: 0;
}
.compose-editor { flex: 1; min-height: 180px; display: flex; flex-direction: column; border: 1px solid var(--border); border-radius: var(--radius-sm); overflow: hidden; }

/* ---- Attachment chips (compose) ---- */
.attachment-chips {
  display: flex; flex-wrap: wrap; gap: var(--sp-2);
  padding: var(--sp-2) 0 0;
}
.attachment-chip {
  display: flex; align-items: center; gap: 6px;
  background: var(--surface-sunken);
  border: 1px solid var(--border);
  border-radius: 999px;
  padding: 5px 8px 5px 10px;
  font-size: var(--fs-xs);
  color: var(--ink-muted);
}
.attachment-chip.uploading { opacity: 0.7; }
.attachment-chip .chip-name { color: var(--ink); font-weight: 500; max-width: 160px; overflow: hidden; text-overflow: ellipsis; white-space: nowrap; }
.attachment-chip .chip-remove {
  border: none; background: transparent; color: var(--ink-faint);
  cursor: pointer; width: 16px; height: 16px; display: flex; align-items: center; justify-content: center;
  border-radius: 50%; flex-shrink: 0;
}
.attachment-chip .chip-remove:hover { background: var(--danger-tint); color: var(--danger); }

/* ---- Attachment chips (reading pane, received messages) ---- */
.reading-attachments {
  display: flex; flex-wrap: wrap; gap: var(--sp-2);
  margin: var(--sp-3) 0 var(--sp-4);
  padding-top: var(--sp-3);
  border-top: 1px solid var(--border);
}
.reading-attachment {
  display: flex; align-items: center; gap: var(--sp-2);
  border: 1px solid var(--border);
  border-radius: var(--radius-sm);
  padding: var(--sp-2) var(--sp-3);
  cursor: pointer;
  transition: background var(--dur-fast) var(--ease), border-color var(--dur-fast) var(--ease);
  text-decoration: none;
  color: inherit;
}
.reading-attachment:hover { background: var(--surface-sunken); border-color: var(--border-strong); }
.reading-attachment .file-icon {
  width: 32px; height: 32px; border-radius: 6px;
  background: var(--primary-tint); color: var(--primary-dark);
  display: flex; align-items: center; justify-content: center; flex-shrink: 0;
}
.reading-attachment .file-name { font-size: var(--fs-sm); font-weight: 500; max-width: 180px; overflow: hidden; text-overflow: ellipsis; white-space: nowrap; }
.reading-attachment .file-size { font-size: var(--fs-xs); color: var(--ink-faint); }
.compose-actions {
  display: flex; align-items: center; gap: var(--sp-2);
  padding: var(--sp-3) var(--sp-4);
  border-top: 1px solid var(--border);
  flex-shrink: 0;
}
.send-btn {
  background: var(--primary); color: white; border: none;
  padding: var(--sp-2) var(--sp-4);
  border-radius: var(--radius-sm); font-weight: 600; cursor: pointer;
}
.send-btn:hover { background: var(--primary-dark); }
.send-btn:disabled { opacity: 0.5; cursor: not-allowed; }
.discard-link {
  background: none; border: none; color: var(--ink-muted); font-size: var(--fs-sm);
  cursor: pointer; padding: var(--sp-2) var(--sp-3);
}
.discard-link:hover { color: var(--danger); }

/* ---- Toasts ---- */
.toast-stack {
  position: fixed; bottom: var(--sp-4); left: 50%; transform: translateX(-50%);
  display: flex; flex-direction: column; gap: var(--sp-2);
  z-index: 100;
}
.toast {
  background: var(--ink); color: white;
  padding: var(--sp-2) var(--sp-3) var(--sp-2) var(--sp-4);
  border-radius: var(--radius-sm);
  font-size: var(--fs-sm);
  box-shadow: 0 4px 16px rgba(0,0,0,0.2);
  animation: toast-in var(--dur-med) var(--ease);
  display: flex; align-items: center; gap: var(--sp-3);
}
.toast-action {
  background: transparent; border: none;
  color: #7EC4F0;
  font-weight: 700; font-size: var(--fs-sm);
  cursor: pointer; padding: 4px 6px; border-radius: 4px;
  flex-shrink: 0;
}
.toast-action:hover { background: rgba(255,255,255,0.12); }
@keyframes toast-in { from { opacity: 0; transform: translateY(8px); } to { opacity: 1; transform: translateY(0); } }

/* ---- Scrollbars ---- */
::-webkit-scrollbar { width: 10px; height: 10px; }
::-webkit-scrollbar-thumb { background: var(--border-strong); border-radius: 6px; }
::-webkit-scrollbar-track { background: transparent; }

/* ---- Loading / skeleton ---- */
.skeleton {
  background: linear-gradient(90deg, var(--surface-sunken) 25%, var(--border) 37%, var(--surface-sunken) 63%);
  background-size: 400% 100%;
  animation: shimmer 1.4s ease infinite;
  border-radius: 4px;
}
@keyframes shimmer { 0% { background-position: 100% 0; } 100% { background-position: -100% 0; } }

/* ---- Mobile pane nav (hidden on desktop) ---- */
.mobile-nav {
  display: none;
  align-items: center;
  gap: var(--sp-1);
  padding: var(--sp-2) var(--sp-3);
  background: var(--surface);
  border-bottom: 1px solid var(--border);
}
.mobile-nav .back-btn {
  display: flex; align-items: center; gap: 4px;
  background: none; border: none;
  color: var(--primary);
  font-size: var(--fs-sm); font-weight: 600;
  padding: var(--sp-1) var(--sp-2);
  cursor: pointer;
}
.mobile-nav .title { font-weight: 700; font-size: var(--fs-md); flex: 1; }
.mobile-nav .hamburger {
  width: 32px; height: 32px; border: none; background: transparent;
  display: flex; align-items: center; justify-content: center;
  color: var(--ink); cursor: pointer; border-radius: var(--radius-sm);
}
.mobile-nav .hamburger:hover { background: var(--surface-sunken); }

.rail-scrim {
  display: none;
  position: fixed; inset: 0;
  background: rgba(0,0,0,0.35);
  z-index: 39;
}

/* ---- Responsive ---- */
@media (max-width: 1080px) and (min-width: 761px) {
  .app { grid-template-columns: 64px var(--list-width) 1fr; }
  .rail .name, .rail .count, .compose-btn span, .section-label { display: none; }
  .compose-btn { justify-content: center; }
}

@media (max-width: 760px) {
  .app {
    grid-template-columns: 1fr;
    grid-template-rows: var(--topbar-height) auto 1fr;
    grid-template-areas: "topbar" "mobilenav" "stage";
  }
  .topbar .search { display: none; }
  .mobile-nav { display: flex; grid-area: mobilenav; }

  /* rail becomes a slide-in drawer over everything */
  .rail {
    position: fixed; top: 0; left: 0; bottom: 0;
    width: 82vw; max-width: 300px;
    z-index: 40;
    transform: translateX(-100%);
    transition: transform var(--dur-med) var(--ease);
    box-shadow: 2px 0 24px rgba(0,0,0,0.2);
  }
  .rail.open { transform: translateX(0); }
  .rail .name, .rail .count, .compose-btn span, .section-label { display: initial; }
  .rail-scrim.open { display: block; }

  /* list and reading pane share one "stage" area, only one visible at a time */
  .list-pane, .reading-pane, .compose-panel-host {
    grid-area: stage;
    border-right: none;
  }
  .list-pane { display: none; }
  .reading-pane { display: none; }
  .app[data-mobile-view="list"] .list-pane { display: flex; }
  .app[data-mobile-view="reading"] .reading-pane { display: flex; }
  .list-pane .list-header { display: none; } /* title now lives in mobile-nav */

  .compose-fields .field label { width: 44px; }
  .reading-content { padding: var(--sp-4); }
}