/* =========================================================================
   共享 Todo List · 公共任务墙 / 出发板（DEPARTURE WALL）
   Token 与规则严格对齐 docs/UI-SPEC.md v1.1
   ========================================================================= */

:root {
  /* 核心色（6 个） */
  --ink: #10141A;
  --panel: #1A2028;
  --chalk: #F2EFE6;
  --signal: #FFD02E;
  --go: #6BE3A2;
  --stop: #FF6B5A;

  /* 派生色 */
  --chalk-62: rgba(242, 239, 230, .62);
  --chalk-40: rgba(242, 239, 230, .40);
  --line: rgba(242, 239, 230, .14);
  --hover: rgba(242, 239, 230, .06);
  --signal-dim: rgba(255, 208, 46, .14);
  --go-dim: rgba(107, 227, 162, .12);
  --stop-dim: rgba(255, 107, 90, .12);

  /* 字体 */
  --font-sans: "PingFang SC", "Hiragino Sans GB", "Noto Sans CJK SC",
    "Source Han Sans SC", "Microsoft YaHei", system-ui, -apple-system,
    "Segoe UI", sans-serif;
  --font-mono: "SF Mono", "JetBrains Mono", "Cascadia Mono", Menlo, Consolas,
    "Liberation Mono", monospace;
  --font-emoji: "Apple Color Emoji", "Segoe UI Emoji", "Noto Color Emoji";

  /* 字号 */
  --fs-display: 44px;
  --fs-count: 32px;
  --fs-title: 18px;
  --fs-input: 18px;
  --fs-body: 15px;
  --fs-meta: 13px;
  --fs-label: 12px;

  /* 间距与布局 */
  --space-1: 4px;
  --space-2: 8px;
  --space-3: 12px;
  --space-4: 16px;
  --space-5: 24px;
  --space-6: 32px;
  --space-7: 48px;
  --space-8: 64px;
  --radius: 2px;
  --rule: 1px solid var(--line);
  --content-max: 880px;
  --page-gutter: 24px;
  --board-padding: 40px;

  /* 动效 */
  --motion-fast: 120ms;
  --motion-base: 200ms;
  --motion-slow: 320ms;
  --motion-flash: 900ms;
  --ease-base: cubic-bezier(.2, .8, .2, 1);
}

/* ---------- Reset ---------- */

*,
*::before,
*::after {
  box-sizing: border-box;
}

html {
  -webkit-text-size-adjust: 100%;
  text-size-adjust: 100%;
}

body {
  margin: 0;
  min-width: 0;
  background-color: var(--ink);
  background-image:
    linear-gradient(rgba(242, 239, 230, .03) 1px, transparent 1px),
    linear-gradient(90deg, rgba(242, 239, 230, .03) 1px, transparent 1px);
  background-size: 48px 48px;
  background-attachment: fixed;
  color: var(--chalk);
  font-family: var(--font-sans), var(--font-emoji);
  font-size: var(--fs-body);
  line-height: 1.6;
  -webkit-font-smoothing: antialiased;
  overflow-x: hidden;
}

/* 6px 信号黄安全线（全站唯一高饱和大面积色） */
body::before {
  content: "";
  position: fixed;
  inset: 0 0 auto 0;
  height: 6px;
  background: var(--signal);
  z-index: 90;
  pointer-events: none;
}

[hidden] {
  display: none !important;
}

h1,
h2,
p,
ul,
li {
  margin: 0;
}

ul {
  padding: 0;
  list-style: none;
}

button,
input {
  font: inherit;
  color: inherit;
}

button {
  border: 0;
  background: none;
  cursor: pointer;
}

button:disabled,
input:disabled {
  cursor: not-allowed;
}

::selection {
  background: var(--signal);
  color: var(--ink);
}

:focus-visible {
  outline: 2px solid var(--signal);
  outline-offset: 2px;
}

/* 内联 SVG 图标：20×20，线宽 1.75 */
.icon {
  width: 20px;
  height: 20px;
  flex: none;
  fill: none;
  stroke: currentColor;
  stroke-width: 1.75;
  stroke-linecap: round;
  stroke-linejoin: round;
}

.icon-sprite {
  position: absolute;
  width: 0;
  height: 0;
  overflow: hidden;
}

.sr-only {
  position: absolute !important;
  width: 1px !important;
  height: 1px !important;
  padding: 0 !important;
  margin: -1px !important;
  overflow: hidden !important;
  clip: rect(0 0 0 0) !important;
  clip-path: inset(50%) !important;
  white-space: nowrap !important;
  border: 0 !important;
}

.skip-link {
  position: fixed;
  top: var(--space-2);
  left: var(--space-2);
  z-index: 120;
  padding: 10px 14px;
  background: var(--signal);
  color: var(--ink);
  font-weight: 700;
  text-decoration: none;
  border-radius: var(--radius);
  transform: translateY(-160%);
  transition: transform var(--motion-fast) ease-out;
}

.skip-link:focus-visible {
  transform: translateY(0);
  outline-color: var(--ink);
}

/* ---------- 顶部品牌区 ---------- */

.board-header,
.board {
  width: 100%;
  max-width: calc(var(--content-max) + var(--page-gutter) * 2);
  margin-inline: auto;
  padding-inline: var(--page-gutter);
}

.board-header {
  position: relative;
  display: flex;
  align-items: flex-start;
  justify-content: space-between;
  gap: var(--space-5);
  padding-top: calc(6px + var(--space-7));
  padding-bottom: var(--space-5);
  border-bottom: 2px solid rgba(242, 239, 230, .85);
}

/* 标题区下方 2px + 4px 间隔 + 1px 双细线 */
.board-header::after {
  content: "";
  position: absolute;
  left: var(--page-gutter);
  right: var(--page-gutter);
  bottom: -5px;
  height: 1px;
  background: var(--line);
}

.brand {
  min-width: 0;
}

h1 {
  font-size: var(--fs-display);
  font-weight: 800;
  line-height: 1.1;
  letter-spacing: 0;
}

.kicker {
  margin-top: var(--space-2);
  color: var(--chalk-62);
  font-size: var(--fs-label);
  font-weight: 400;
  line-height: 1.4;
}

.kicker-latin {
  letter-spacing: .16em;
  font-weight: 700;
}

.kicker-sep {
  color: var(--chalk-40);
}

.board-header-right {
  display: flex;
  flex-direction: column;
  align-items: flex-end;
  gap: var(--space-2);
  flex: none;
}

.presence {
  display: inline-flex;
  align-items: center;
  gap: var(--space-2);
  min-height: 20px;
  color: var(--chalk-62);
  font-size: var(--fs-meta);
  white-space: nowrap;
}

.presence-dot {
  width: 8px;
  height: 8px;
  border-radius: 50%;
  background: var(--go);
  flex: none;
}

body[data-connection="reconnecting"] .presence-dot {
  background: var(--signal);
  animation: breathe 1.6s ease-in-out infinite;
}

body[data-connection="offline"] .presence-dot {
  background: var(--stop);
}

.nickname-btn {
  display: inline-flex;
  align-items: center;
  gap: var(--space-2);
  min-height: 44px;
  max-width: 100%;
  padding: 0 var(--space-3);
  border: 1px solid var(--line);
  border-radius: var(--radius);
  color: var(--chalk-62);
  font-size: var(--fs-body);
  background: transparent;
  transition: background var(--motion-fast) ease-out, color var(--motion-fast) ease-out;
}

.nickname-btn .icon {
  width: 16px;
  height: 16px;
}

.nickname-btn:hover {
  background: var(--hover);
  color: var(--chalk);
}

/* ---------- 主区域 ---------- */

.board {
  padding-bottom: var(--space-8);
}

.board-toolbar {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: var(--space-4);
  flex-wrap: wrap;
  margin-top: var(--space-6);
}

.remaining {
  display: flex;
  align-items: baseline;
  gap: 6px;
  min-width: 0;
  white-space: nowrap;
}

.remaining-label,
.remaining-unit {
  color: var(--chalk-62);
  font-size: 13px;
}

.remaining strong {
  color: var(--signal);
  font-family: var(--font-mono);
  font-size: var(--fs-count);
  font-weight: 700;
  line-height: 1.1;
  font-variant-numeric: tabular-nums;
}

.filters {
  display: flex;
  gap: var(--space-2);
  flex-wrap: wrap;
}

.filter-btn {
  min-height: 44px;
  padding: 0 var(--space-4);
  border: 1px solid var(--line);
  border-radius: var(--radius);
  color: var(--chalk-62);
  font-size: var(--fs-body);
  background: transparent;
  transition: background var(--motion-fast) ease-out, color var(--motion-fast) ease-out, border-color var(--motion-fast) ease-out;
}

.filter-btn:hover:not(:disabled) {
  background: var(--hover);
  color: var(--chalk);
}

.filter-btn[aria-pressed="true"] {
  background: var(--signal);
  border-color: var(--signal);
  color: var(--ink);
  font-weight: 700;
}

.filter-btn[aria-pressed="true"]:focus-visible {
  outline-color: var(--ink);
}

.filter-btn:disabled {
  opacity: .4;
}

/* ---------- 新增任务 ---------- */

.add-form {
  display: grid;
  grid-template-columns: minmax(0, 1fr) auto;
  align-items: start;
  gap: var(--space-2) var(--space-3);
  margin-top: var(--space-5);
  margin-bottom: var(--space-6);
}

.add-input-wrap {
  position: relative;
  min-width: 0;
}

#new-todo {
  width: 100%;
  height: 52px;
  padding: 0 84px 0 var(--space-4);
  border: 1px solid var(--line);
  border-radius: var(--radius);
  background: var(--panel);
  color: var(--chalk);
  font-size: var(--fs-input);
  line-height: 1.4;
  transition: border-color var(--motion-fast) ease-out, box-shadow var(--motion-fast) ease-out;
}

#new-todo::placeholder {
  color: var(--chalk-40);
}

#new-todo:hover:not(:disabled) {
  border-color: rgba(242, 239, 230, .28);
}

#new-todo:focus {
  outline: none;
  border-color: var(--signal);
  box-shadow: 0 0 0 2px rgba(255, 208, 46, .2);
}

#new-todo[aria-invalid="true"] {
  border-color: var(--stop);
}

#new-todo:disabled {
  opacity: .5;
}

.char-count {
  position: absolute;
  top: 50%;
  right: var(--space-3);
  transform: translateY(-50%);
  color: var(--chalk-62);
  font-family: var(--font-mono);
  font-size: var(--fs-meta);
  font-variant-numeric: tabular-nums;
  pointer-events: none;
}

.char-count.is-over {
  color: var(--stop);
}

.add-btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: var(--space-2);
  min-width: 112px;
  height: 52px;
  padding: 0 var(--space-5);
  border: 1px solid var(--signal);
  border-radius: var(--radius);
  background: var(--signal);
  color: var(--ink);
  font-size: var(--fs-body);
  font-weight: 700;
  transition: filter var(--motion-fast) ease-out, transform var(--motion-fast) ease-out;
}

.add-btn:hover:not(:disabled) {
  filter: brightness(1.05);
}

.add-btn:active:not(:disabled) {
  transform: translateY(1px);
}

.add-btn:disabled {
  opacity: .4;
}

.add-btn .icon {
  width: 18px;
  height: 18px;
  stroke-width: 2;
}

.field-error {
  display: flex;
  align-items: center;
  gap: 6px;
  color: var(--stop);
  font-size: var(--fs-meta);
  line-height: 1.45;
}

.field-error .icon {
  width: 16px;
  height: 16px;
  flex: none;
}

.add-form > .field-error {
  grid-column: 1 / -1;
  margin-top: -2px;
}

/* ---------- 列表状态 ---------- */

.list-status {
  margin: 0 0 var(--space-2);
  color: var(--chalk-62);
  font-size: var(--fs-meta);
}

.list-state {
  min-height: 240px;
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  gap: var(--space-4);
  padding: var(--space-6) var(--space-4);
  color: var(--chalk-62);
  text-align: center;
}

.list-state .state-icon {
  color: var(--chalk-40);
  width: 48px;
  height: 48px;
}

.list-state .state-icon.go {
  color: var(--go);
}

.list-state .state-text {
  font-size: var(--fs-body);
  max-width: 34em;
}

.list-state .state-retry {
  display: inline-flex;
  align-items: center;
  gap: var(--space-2);
  min-height: 44px;
  padding: 0 var(--space-4);
  border: 1px solid var(--signal);
  border-radius: var(--radius);
  color: var(--signal);
  font-weight: 700;
}

.list-state .state-retry:hover {
  background: var(--signal-dim);
}

/* 空状态里的空印章轮廓 */
.empty-stamp {
  display: inline-block;
  padding: 6px 12px;
  border: 1.5px solid var(--chalk-40);
  border-radius: var(--radius);
  color: var(--chalk-40);
  font-size: 22px;
  font-weight: 700;
  transform: rotate(-6deg);
}

/* 骨架 */
.skeleton-row {
  width: 100%;
  max-width: 640px;
  display: grid;
  grid-template-columns: 22px 44px minmax(0, 1fr);
  align-items: center;
  gap: var(--space-3);
  padding: 14px 8px;
  border-bottom: 1px dashed var(--line);
  text-align: left;
}

.skeleton-row:last-child {
  border-bottom: 0;
}

.skeleton-block,
.skeleton-line {
  background: var(--panel);
  border-radius: var(--radius);
}

.skeleton-block {
  width: 22px;
  height: 22px;
}

.skeleton-lines {
  display: flex;
  flex-direction: column;
  gap: var(--space-2);
}

.skeleton-line {
  height: 16px;
  width: 60%;
}

.skeleton-line.secondary {
  height: 12px;
  width: 40%;
}

.skeleton-row.shimmer .skeleton-block,
.skeleton-row.shimmer .skeleton-line {
  background-image: linear-gradient(90deg, var(--panel) 0%, #242c36 50%, var(--panel) 100%);
  background-size: 200% 100%;
  animation: shimmer 1.4s linear infinite;
}

.list-state .slow-hint {
  color: var(--chalk-62);
  font-size: var(--fs-meta);
}

/* ---------- 任务列表与任务行 ---------- */

.todo-list {
  border-top: 1px solid var(--line);
  transition: opacity var(--motion-fast) ease-out;
}

.todo-list.is-fading {
  opacity: .25;
}

.todo-row {
  position: relative;
  display: grid;
  grid-template-columns: 40px 44px minmax(0, 1fr) auto;
  align-items: start;
  column-gap: var(--space-3);
  min-height: 72px;
  padding: 14px 8px;
  border-bottom: 1px dashed var(--line);
  transition: background var(--motion-fast) ease-out, opacity var(--motion-base) ease-out;
}

.todo-row:hover,
.todo-row:focus-within {
  background: var(--hover);
  box-shadow: inset 2px 0 0 var(--signal);
}

.todo-row[data-state="completed"] {
  background: var(--go-dim);
}

.todo-row[data-state="completed"]:hover,
.todo-row[data-state="completed"]:focus-within {
  background: rgba(107, 227, 162, .17);
}

.todo-row[data-state="dragging"] {
  opacity: .55;
  background: var(--panel);
}

.todo-row[data-state="editing"] {
  background: var(--panel);
}

.todo-row[data-state="delete-target"],
.todo-row[data-state="delete-target"]:hover,
.todo-row[data-state="delete-target"]:focus-within {
  box-shadow: inset 3px 0 0 var(--stop);
}

.todo-row.row-enter {
  animation: row-in var(--motion-base) var(--ease-base) both;
}

.todo-row.row-closing {
  overflow: hidden;
  opacity: 0;
  transform: translateY(0);
}

.todo-seq {
  color: var(--chalk-40);
  font-family: var(--font-mono);
  font-size: 24px;
  line-height: 1.55;
  font-variant-numeric: tabular-nums;
  text-align: center;
  user-select: none;
}

/* 复选框：22×22 视觉，44×44 热区 */
.checkbox-hit {
  display: grid;
  place-items: center;
  width: 44px;
  height: 44px;
  margin-top: -8px;
  cursor: pointer;
}

.todo-checkbox {
  appearance: none;
  -webkit-appearance: none;
  width: 22px;
  height: 22px;
  margin: 0;
  border: 2px solid var(--chalk-62);
  border-radius: var(--radius);
  background: transparent;
  display: grid;
  place-items: center;
  cursor: pointer;
  transition: background var(--motion-fast) ease-out, border-color var(--motion-fast) ease-out;
}

.todo-checkbox:hover:not(:disabled) {
  border-color: var(--chalk);
}

.todo-checkbox:checked {
  background: var(--go);
  border-color: var(--go);
}

.todo-checkbox:disabled {
  opacity: .4;
}

.checkbox-box {
  display: contents;
}

.check-icon {
  width: 14px;
  height: 14px;
  fill: none;
  stroke: var(--ink);
  stroke-width: 3;
  stroke-linecap: round;
  stroke-linejoin: round;
  opacity: 0;
  transform: scale(.6);
  transition: opacity 160ms ease-out, transform 160ms ease-out;
}

.todo-checkbox:checked + .checkbox-box .check-icon {
  opacity: 1;
  transform: scale(1);
}

.todo-content {
  min-width: 0;
  padding-top: 1px;
}

.todo-title-line {
  display: flex;
  align-items: flex-start;
  gap: var(--space-2);
  min-width: 0;
}

.todo-title {
  flex: 1 1 auto;
  min-width: 0;
  display: -webkit-box;
  -webkit-box-orient: vertical;
  -webkit-line-clamp: 2;
  overflow: hidden;
  padding: 8px 0;
  margin: -8px 0;
  color: var(--chalk);
  font-size: var(--fs-title);
  font-weight: 500;
  line-height: 1.55;
  text-align: left;
  overflow-wrap: anywhere;
  word-break: break-word;
  border-radius: var(--radius);
  transition: color var(--motion-fast) ease-out;
}

.todo-title:hover {
  color: var(--signal);
}

.todo-row[data-state="completed"] .todo-title {
  color: var(--chalk-62);
  text-decoration: line-through;
  text-decoration-thickness: 1.5px;
  text-decoration-color: var(--chalk-62);
}

.todo-stamp {
  display: none;
  flex: none;
  margin-top: 3px;
  padding: 2px 6px;
  border: 1.5px solid var(--go);
  border-radius: var(--radius);
  color: var(--go);
  font-size: 11px;
  font-weight: 700;
  line-height: 1.4;
  white-space: nowrap;
  transform: rotate(-6deg);
}

.todo-row[data-state="completed"] .todo-stamp {
  display: inline-block;
  animation: stamp-in var(--motion-base) var(--ease-base) both;
}

.todo-meta {
  display: flex;
  flex-wrap: wrap;
  align-items: baseline;
  gap: 0;
  margin-top: 2px;
  color: var(--chalk-62);
  font-size: var(--fs-meta);
  line-height: 1.45;
  overflow-wrap: anywhere;
}

.meta-time {
  font-family: var(--font-mono);
  font-variant-numeric: tabular-nums;
  white-space: nowrap;
}

/* 编辑态 */
.edit-form {
  margin-top: var(--space-1);
}

.edit-input {
  width: 100%;
  height: 44px;
  padding: 0 var(--space-3);
  border: 1px solid var(--signal);
  border-radius: var(--radius);
  background: var(--ink);
  color: var(--chalk);
  font-size: var(--fs-title);
  line-height: 1.55;
}

.edit-input:focus {
  outline: 2px solid var(--signal);
  outline-offset: 2px;
}

.edit-error {
  margin-top: 6px;
}

.todo-row[data-state="editing"] .todo-title-line {
  display: none;
}

.todo-row[data-state="editing"] .edit-form[hidden] {
  display: block !important;
}

.todo-actions {
  display: flex;
  align-items: flex-start;
  justify-content: flex-end;
  margin-top: -8px;
}

.row-actions {
  display: flex;
  gap: 2px;
}

.edit-actions {
  display: none;
  gap: var(--space-2);
  padding-top: var(--space-2);
}

.todo-row[data-state="editing"] .row-actions {
  display: none;
}

.todo-row[data-state="editing"] .edit-actions {
  display: flex;
}

.icon-btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 4px;
  width: 44px;
  height: 44px;
  border-radius: var(--radius);
  color: var(--chalk-62);
  opacity: .55;
  transition: background var(--motion-fast) ease-out, color var(--motion-fast) ease-out, opacity var(--motion-fast) ease-out;
}

.todo-row:hover .icon-btn:not([aria-disabled="true"]),
.todo-row:focus-within .icon-btn:not([aria-disabled="true"]) {
  opacity: 1;
}

.icon-btn:hover:not([aria-disabled="true"]):not(:disabled) {
  background: var(--hover);
  color: var(--chalk);
}

.icon-btn.delete-btn:hover:not([aria-disabled="true"]):not(:disabled) {
  color: var(--stop);
}

.icon-btn:disabled,
.icon-btn[aria-disabled="true"] {
  opacity: .32;
  cursor: not-allowed;
}

.drag-handle {
  cursor: grab;
}

.drag-handle:active {
  cursor: grabbing;
}

.drag-handle .icon {
  width: 20px;
  height: 20px;
}

.action-label {
  display: none;
  font-size: var(--fs-meta);
  line-height: 1;
}

.up-btn,
.down-btn {
  display: none;
}

.btn-save,
.btn-cancel,
.btn-primary,
.btn-secondary,
.btn-danger {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  min-height: 44px;
  padding: 0 var(--space-4);
  border: 1px solid var(--line);
  border-radius: var(--radius);
  font-size: var(--fs-body);
  font-weight: 700;
  transition: background var(--motion-fast) ease-out, opacity var(--motion-fast) ease-out;
}

.btn-save,
.btn-primary {
  background: var(--signal);
  border-color: var(--signal);
  color: var(--ink);
}

.btn-save:hover,
.btn-primary:hover {
  filter: brightness(1.05);
}

.btn-cancel,
.btn-secondary {
  background: transparent;
  color: var(--chalk-62);
}

.btn-cancel:hover,
.btn-secondary:hover {
  background: var(--hover);
  color: var(--chalk);
}

.btn-danger {
  background: var(--stop);
  border-color: var(--stop);
  color: var(--ink);
}

.btn-danger:hover {
  filter: brightness(1.05);
}

/* 远端更新闪线 */
.remote-flash {
  position: absolute;
  top: 0;
  bottom: 0;
  left: 0;
  width: 2px;
  background: var(--go);
  opacity: 0;
  pointer-events: none;
}

.todo-row.flash .remote-flash {
  animation: remote-flash var(--motion-flash) ease-out both;
}

/* 拖放指示线 */
.drop-line {
  position: absolute;
  left: 0;
  right: 0;
  height: 2px;
  background: var(--signal);
  opacity: 0;
  pointer-events: none;
}

.drop-line-before {
  top: -1px;
}

.drop-line-after {
  bottom: -1px;
}

.todo-row.drop-before .drop-line-before,
.todo-row.drop-after .drop-line-after {
  opacity: 1;
}

body.is-dragging {
  cursor: grabbing;
  user-select: none;
}

/* ---------- Footer ---------- */

.board-footer {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: var(--space-4);
  flex-wrap: wrap;
  margin-top: var(--space-5);
  padding-top: var(--space-4);
  border-top: 1px solid var(--line);
  color: var(--chalk-62);
  font-size: var(--fs-meta);
}

.footer-count {
  font-family: var(--font-mono);
  font-variant-numeric: tabular-nums;
}

.footer-remaining {
  display: none;
}

.clear-completed {
  min-height: 44px;
  padding: 0 var(--space-2);
  color: var(--chalk-62);
  font-size: var(--fs-body);
  text-decoration: none;
}

.clear-completed:hover:not(:disabled):not([aria-disabled="true"]) {
  color: var(--stop);
  text-decoration: underline;
  text-underline-offset: 4px;
}

.clear-completed:disabled,
.clear-completed[aria-disabled="true"] {
  opacity: .32;
  cursor: not-allowed;
}

.sync-status {
  display: inline-flex;
  align-items: center;
  gap: var(--space-2);
  color: var(--chalk-62);
  white-space: nowrap;
}

.sync-dot {
  width: 8px;
  height: 8px;
  border-radius: 50%;
  background: var(--go);
  flex: none;
}

body[data-connection="reconnecting"] .sync-dot {
  background: var(--signal);
  animation: breathe 1.6s ease-in-out infinite;
}

body[data-connection="offline"] .sync-dot {
  background: var(--stop);
}

body[data-connection="offline"] .sync-status {
  color: var(--stop);
}

/* ---------- 连接横幅 ---------- */

.connection-banner {
  position: sticky;
  top: 0;
  z-index: 40;
  display: flex;
  align-items: center;
  gap: var(--space-3);
  min-height: 44px;
  padding: 10px max(var(--page-gutter), calc((100vw - var(--content-max)) / 2));
  background: var(--signal-dim);
  border-left: 3px solid var(--signal);
  color: var(--chalk);
  font-size: 14px;
}

.connection-banner[data-state="offline"] {
  background: var(--stop-dim);
  border-left-color: var(--stop);
}

.banner-dot {
  width: 8px;
  height: 8px;
  border-radius: 50%;
  background: var(--signal);
  flex: none;
}

.connection-banner[data-state="offline"] .banner-dot {
  background: var(--stop);
}

.banner-text {
  flex: 1 1 auto;
  min-width: 0;
}

.banner-retry {
  flex: none;
  min-height: 44px;
  padding: 0 var(--space-2);
  color: var(--signal);
  font-weight: 700;
  text-decoration: underline;
  text-underline-offset: 3px;
}

.connection-banner[data-state="offline"] .banner-retry {
  color: var(--stop);
}

/* ---------- Dialog ---------- */

dialog {
  padding: var(--space-5);
  border: 1px solid var(--line);
  border-radius: var(--radius);
  background: var(--panel);
  color: var(--chalk);
  box-shadow: none;
}

dialog::backdrop {
  background: rgba(0, 0, 0, .55);
}

dialog[open] {
  animation: dialog-in var(--motion-base) var(--ease-base) both;
}

.confirm-dialog {
  width: min(360px, calc(100vw - var(--space-6)));
  border-color: var(--stop);
}

.confirm-dialog h2,
.nickname-dialog h2 {
  font-size: 20px;
  font-weight: 800;
  line-height: 1.4;
  overflow-wrap: anywhere;
}

.confirm-dialog > p,
.nickname-dialog > p {
  margin-top: var(--space-2);
  color: var(--chalk-62);
  font-size: var(--fs-body);
}

.dialog-actions {
  display: flex;
  justify-content: flex-end;
  gap: var(--space-2);
  margin-top: var(--space-5);
}

.dialog-actions button {
  min-width: 88px;
}

.dialog-error {
  margin-top: var(--space-3);
}

.nickname-dialog {
  position: fixed;
  top: 96px;
  right: calc((100vw - var(--content-max)) / 2 + var(--page-gutter));
  left: auto;
  width: 320px;
  max-width: calc(100vw - var(--space-6));
  margin: 0;
}

.nickname-field {
  position: relative;
  margin-top: var(--space-4);
}

.nickname-field input {
  width: 100%;
  height: 48px;
  padding: 0 64px 0 var(--space-3);
  border: 1px solid var(--line);
  border-radius: var(--radius);
  background: var(--ink);
  color: var(--chalk);
  font-size: var(--fs-input);
}

.nickname-field input:focus {
  outline: none;
  border-color: var(--signal);
  box-shadow: 0 0 0 2px rgba(255, 208, 46, .2);
}

.nickname-field input[aria-invalid="true"] {
  border-color: var(--stop);
}

.nickname-field .char-count {
  right: var(--space-3);
}

/* ---------- Toast ---------- */

.toast-region {
  position: fixed;
  left: 50%;
  bottom: max(var(--space-5), env(safe-area-inset-bottom));
  z-index: 100;
  display: flex;
  flex-direction: column;
  gap: var(--space-2);
  width: min(420px, calc(100vw - var(--space-6)));
  transform: translateX(-50%);
  pointer-events: none;
}

.toast {
  display: flex;
  align-items: flex-start;
  gap: var(--space-3);
  padding: 12px 14px;
  border: 1px solid var(--line);
  border-left: 3px solid var(--signal);
  border-radius: var(--radius);
  background: var(--panel);
  color: var(--chalk);
  font-size: var(--fs-body);
  line-height: 1.5;
  pointer-events: auto;
  animation: toast-in 180ms var(--ease-base) both;
}

.toast[data-type="error"] {
  border-left-color: var(--stop);
}

.toast-text {
  flex: 1 1 auto;
  min-width: 0;
  overflow-wrap: anywhere;
}

.toast-close {
  flex: none;
  width: 44px;
  height: 44px;
  margin: -10px -10px -10px 0;
  display: inline-flex;
  align-items: center;
  justify-content: center;
  color: var(--chalk-62);
  border-radius: var(--radius);
}

.toast-close:hover {
  background: var(--hover);
  color: var(--chalk);
}

.toast-close .icon {
  width: 14px;
  height: 14px;
}

/* ---------- 动效 ---------- */

@keyframes breathe {
  0%, 100% { opacity: 1; }
  50% { opacity: .35; }
}

@keyframes shimmer {
  from { background-position: 200% 0; }
  to { background-position: -200% 0; }
}

@keyframes row-in {
  from { opacity: 0; transform: translateY(-4px); }
  to { opacity: 1; transform: translateY(0); }
}

@keyframes stamp-in {
  from { opacity: 0; transform: rotate(-6deg) scale(.9); }
  to { opacity: 1; transform: rotate(-6deg) scale(1); }
}

@keyframes remote-flash {
  0% { opacity: 1; }
  100% { opacity: 0; }
}

@keyframes toast-in {
  from { opacity: 0; transform: translateY(8px); }
  to { opacity: 1; transform: translateY(0); }
}

@keyframes dialog-in {
  from { opacity: 0; transform: translateY(8px); }
  to { opacity: 1; transform: translateY(0); }
}

@keyframes sheet-up {
  from { transform: translateY(100%); }
  to { transform: translateY(0); }
}

/* ---------- 平板 ---------- */

@media (max-width: 1023px) and (min-width: 768px) {
  :root {
    --content-max: 720px;
  }

  h1 {
    font-size: 38px;
  }
}

/* ---------- 移动端（360–767px） ---------- */

@media (max-width: 767px) {
  :root {
    --fs-display: 30px;
    --fs-count: 28px;
    --fs-title: 16px;
    --fs-input: 16px;
    --fs-meta: 12px;
    --page-gutter: 16px;
    --board-padding: 20px;
  }

  body {
    background-image: none;
  }

  .board-header {
    flex-wrap: wrap;
    gap: var(--space-3);
    padding-top: calc(6px + var(--space-5));
    padding-bottom: var(--space-4);
  }

  h1 {
    font-size: var(--fs-display);
  }

  .kicker {
    order: 3;
    flex-basis: 100%;
  }

  .kicker-sep {
    display: none;
  }

  .kicker-latin {
    margin-right: var(--space-1);
  }

  .board-header-right {
    margin-left: auto;
    align-items: flex-end;
    gap: var(--space-1);
  }

  .presence {
    min-height: 16px;
  }

  .nickname-btn {
    min-height: 44px;
    padding: 0 var(--space-2);
    font-size: var(--fs-meta);
  }

  .board-toolbar {
    margin-top: var(--space-5);
    gap: var(--space-3);
  }

  .filters {
    width: 100%;
    gap: var(--space-2);
  }

  .filter-btn {
    flex: 1 1 0;
    min-width: 0;
    padding: 0 var(--space-2);
    font-size: var(--fs-body);
  }

  /* 新增区吸顶 */
  .add-form {
    position: sticky;
    top: 0;
    z-index: 10;
    grid-template-columns: minmax(0, 1fr);
    gap: var(--space-2);
    margin: var(--space-4) calc(-1 * var(--page-gutter)) var(--space-4);
    padding: var(--space-3) var(--page-gutter) var(--space-4);
    background: var(--ink);
    border-bottom: 1px solid var(--line);
  }

  #new-todo {
    height: 48px;
    padding-right: 72px;
  }

  .add-btn {
    width: 100%;
    height: 48px;
  }

  .list-status {
    margin-top: var(--space-3);
  }

  .todo-list {
    margin-top: var(--space-2);
  }

  .todo-row {
    grid-template-columns: 28px 44px minmax(0, 1fr);
    column-gap: var(--space-2);
    min-height: 0;
    padding: 14px 4px;
  }

  .todo-seq {
    font-size: 20px;
    padding-top: 2px;
  }

  .checkbox-hit {
    width: 44px;
    height: 44px;
    margin-top: -10px;
  }

  .todo-content {
    padding-top: 0;
  }

  .todo-actions {
    grid-column: 2 / -1;
    justify-content: flex-start;
    flex-wrap: wrap;
    gap: 2px;
    margin-top: 2px;
  }

  .row-actions {
    flex-wrap: wrap;
    gap: 2px;
  }

  .icon-btn {
    width: 44px;
    height: 44px;
  }

  .up-btn,
  .down-btn {
    display: inline-flex;
    width: auto;
    min-width: 64px;
    padding: 0 var(--space-2);
  }

  .action-label {
    display: inline;
  }

  .drag-handle {
    display: none;
  }

  .edit-actions {
    padding-top: 0;
  }

  .todo-stamp {
    font-size: 10px;
  }

  .board-footer {
    font-size: var(--fs-meta);
    gap: var(--space-2);
  }

  .footer-remaining {
    display: inline;
  }

  .clear-completed {
    padding: 0;
    font-size: var(--fs-body);
  }

  .connection-banner {
    padding-inline: var(--page-gutter);
    font-size: 13px;
  }

  dialog {
    padding: var(--space-5) var(--space-4);
  }

  .confirm-dialog,
  .nickname-dialog {
    position: fixed;
    inset: auto 0 0 0;
    width: 100%;
    max-width: none;
    margin: 0;
    border-right: 0;
    border-bottom: 0;
    border-left: 0;
    border-radius: 2px 2px 0 0;
    padding-bottom: max(var(--space-5), env(safe-area-inset-bottom));
  }

  .confirm-dialog[open],
  .nickname-dialog[open] {
    animation: sheet-up var(--motion-slow) var(--ease-base) both;
  }

  .dialog-actions {
    flex-direction: row;
  }

  .dialog-actions button {
    flex: 1 1 0;
  }

  .toast-region {
    bottom: max(var(--space-4), env(safe-area-inset-bottom));
  }
}

/* 触屏 / 无精确指针：隐藏拖拽手柄，显示上移/下移 */
@media (hover: none), (pointer: coarse) {
  .drag-handle {
    display: none;
  }

  .up-btn,
  .down-btn {
    display: inline-flex;
    width: auto;
    min-width: 64px;
    padding: 0 var(--space-2);
  }

  .action-label {
    display: inline;
  }
}

/* 排序仅在「全部」视图可用 */
body:not([data-view="all"]) .drag-handle,
body:not([data-view="all"]) .up-btn,
body:not([data-view="all"]) .down-btn {
  display: none;
}

/* 断线时操作禁用态 */
body[data-connection="reconnecting"] .todo-checkbox,
body[data-connection="offline"] .todo-checkbox,
body[data-connection="reconnecting"] .icon-btn,
body[data-connection="offline"] .icon-btn {
  opacity: .32;
  pointer-events: none;
}

/* ---------- 高对比 ---------- */

@media (prefers-contrast: more) {
  :root {
    --line: rgba(242, 239, 230, .35);
  }

  .todo-row {
    border-bottom-style: solid;
  }

  :focus-visible {
    outline-width: 3px;
  }
}

/* ---------- Reduced motion ---------- */

@media (prefers-reduced-motion: reduce) {
  *,
  *::before,
  *::after {
    animation-duration: .01ms !important;
    animation-iteration-count: 1 !important;
    transition-duration: .01ms !important;
    scroll-behavior: auto !important;
  }

  .skeleton-row.shimmer .skeleton-block,
  .skeleton-row.shimmer .skeleton-line {
    background-image: none;
  }

  .todo-row.flash .remote-flash {
    animation: none;
    opacity: 1;
  }
}