/* ─── CSS Variables & Theme ─────────────────────────────────────────────── */

:root {
  --color-bg: #f1f5f9;
  --color-surface: #ffffff;
  --color-surface-hover: #f8fafc;
  --color-border: #e2e8f0;
  --color-text: #1e293b;
  --color-text-muted: #64748b;
  --color-primary: #3b82f6;
  --color-primary-hover: #2563eb;
  --color-danger: #ef4444;
  --color-danger-hover: #dc2626;
  --color-col-bg: #f1f5f9;
  --color-card-bg: #ffffff;
  --color-shadow: rgba(0, 0, 0, 0.08);
  --color-overlay: rgba(0, 0, 0, 0.4);
  --color-drop: rgba(59, 130, 246, 0.15);
  --radius: 8px;
  --radius-sm: 4px;
  --col-width: 280px;
  --transition: 0.15s ease;
}

[data-theme="dark"] {
  --color-bg: #0f172a;
  --color-surface: #1e293b;
  --color-surface-hover: #243148;
  --color-border: #334155;
  --color-text: #f1f5f9;
  --color-text-muted: #94a3b8;
  --color-primary: #60a5fa;
  --color-primary-hover: #3b82f6;
  --color-danger: #f87171;
  --color-danger-hover: #ef4444;
  --color-col-bg: #1e293b;
  --color-card-bg: #263148;
  --color-shadow: rgba(0, 0, 0, 0.3);
  --color-overlay: rgba(0, 0, 0, 0.6);
  --color-drop: rgba(96, 165, 250, 0.15);
}

/* ─── Base ──────────────────────────────────────────────────────────────── */

*, *::before, *::after {
  box-sizing: border-box;
  margin: 0;
  padding: 0;
}

html, body {
  height: 100%;
  font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', 'Helvetica Neue', sans-serif;
  background: var(--color-bg);
  color: var(--color-text);
  font-size: 14px;
  line-height: 1.5;
}

body {
  display: flex;
  flex-direction: column;
  overflow: hidden;
}

button {
  cursor: pointer;
  border: none;
  background: none;
  font: inherit;
  color: inherit;
}

input, textarea, select {
  font: inherit;
  color: inherit;
}

/* ─── Top Bar ────────────────────────────────────────────────────────────── */

#top-bar {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 12px;
  padding: 10px 16px;
  background: var(--color-surface);
  border-bottom: 1px solid var(--color-border);
  flex-shrink: 0;
  flex-wrap: wrap;
  min-height: 56px;
}

.top-bar-left {
  display: flex;
  align-items: center;
  gap: 10px;
  flex-wrap: wrap;
}

.top-bar-right {
  display: flex;
  align-items: center;
  gap: 8px;
  flex-wrap: wrap;
}

.app-title {
  font-size: 18px;
  font-weight: 700;
  color: var(--color-primary);
  letter-spacing: -0.3px;
}

.board-selector-wrap {
  display: flex;
  align-items: center;
  gap: 4px;
}

#board-selector {
  padding: 5px 8px;
  border: 1px solid var(--color-border);
  border-radius: var(--radius-sm);
  background: var(--color-bg);
  max-width: 180px;
  cursor: pointer;
}

#board-selector:focus {
  outline: 2px solid var(--color-primary);
}

.search-wrap {
  display: flex;
  align-items: center;
  gap: 6px;
  position: relative;
}

#search-input {
  padding: 5px 10px;
  border: 1px solid var(--color-border);
  border-radius: 20px;
  background: var(--color-bg);
  width: 180px;
  transition: width var(--transition), border-color var(--transition);
}

#search-input:focus {
  outline: none;
  border-color: var(--color-primary);
  width: 220px;
}

.search-count {
  font-size: 12px;
  color: var(--color-text-muted);
  white-space: nowrap;
}

/* ─── Buttons ────────────────────────────────────────────────────────────── */

.btn, button.btn {
  display: inline-flex;
  align-items: center;
  gap: 4px;
  padding: 5px 12px;
  border-radius: var(--radius-sm);
  font-size: 13px;
  font-weight: 500;
  transition: background var(--transition), opacity var(--transition);
  white-space: nowrap;
}

.btn:disabled {
  opacity: 0.5;
  cursor: not-allowed;
}

.btn-primary {
  background: var(--color-primary);
  color: #fff;
}

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

.btn-secondary {
  background: var(--color-border);
  color: var(--color-text);
}

.btn-secondary:hover:not(:disabled) {
  background: var(--color-text-muted);
  color: #fff;
}

.btn-danger {
  background: var(--color-danger);
  color: #fff;
}

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

#btn-add-board,
#btn-rename-board,
#btn-delete-board {
  width: 28px;
  height: 28px;
  border-radius: var(--radius-sm);
  display: inline-flex;
  align-items: center;
  justify-content: center;
  background: var(--color-bg);
  border: 1px solid var(--color-border);
  font-size: 14px;
}

#btn-add-board:hover,
#btn-rename-board:hover { background: var(--color-primary); color: #fff; border-color: var(--color-primary); }
#btn-delete-board:hover { background: var(--color-danger); color: #fff; border-color: var(--color-danger); }

#btn-add-col,
#btn-export,
#btn-theme,
#btn-lang {
  padding: 5px 10px;
  border-radius: var(--radius-sm);
  background: var(--color-bg);
  border: 1px solid var(--color-border);
  font-size: 13px;
}

#btn-add-col:hover:not(:disabled),
#btn-export:hover:not(:disabled),
#btn-theme:hover,
#btn-lang:hover {
  background: var(--color-primary);
  color: #fff;
  border-color: var(--color-primary);
}

#btn-import-label {
  padding: 5px 10px;
  border-radius: var(--radius-sm);
  background: var(--color-bg);
  border: 1px solid var(--color-border);
  font-size: 13px;
  cursor: pointer;
  user-select: none;
}

#btn-import-label:hover {
  background: var(--color-primary);
  color: #fff;
  border-color: var(--color-primary);
}

/* ─── Board Main ─────────────────────────────────────────────────────────── */

#board-main {
  flex: 1;
  overflow: hidden;
  display: flex;
  flex-direction: column;
}

.empty-state {
  display: flex;
  align-items: center;
  justify-content: center;
  height: 100%;
  color: var(--color-text-muted);
  font-size: 16px;
  text-align: center;
  padding: 40px;
}

/* ─── Columns ────────────────────────────────────────────────────────────── */

.columns-container {
  display: flex;
  align-items: flex-start;
  gap: 16px;
  padding: 20px;
  overflow-x: auto;
  overflow-y: auto;
  height: 100%;
}

.columns-container::-webkit-scrollbar {
  height: 6px;
  width: 6px;
}

.columns-container::-webkit-scrollbar-thumb {
  background: var(--color-border);
  border-radius: 3px;
}

.column {
  flex-shrink: 0;
  width: var(--col-width);
  background: var(--color-col-bg);
  border-radius: var(--radius);
  border: 1px solid var(--color-border);
  display: flex;
  flex-direction: column;
  max-height: calc(100vh - 140px);
  position: relative;
  transition: box-shadow var(--transition), opacity var(--transition);
}

.column.dragging {
  opacity: 0.5;
  box-shadow: 0 4px 20px var(--color-shadow);
}

.column.drop-active {
  background: var(--color-drop);
  border-color: var(--color-primary);
}

.column-header {
  display: flex;
  align-items: center;
  gap: 6px;
  padding: 12px 12px 8px;
  border-bottom: 1px solid var(--color-border);
  cursor: grab;
  user-select: none;
}

.column-header:active {
  cursor: grabbing;
}

.col-name {
  font-weight: 600;
  flex: 1;
  cursor: text;
  overflow: hidden;
  text-overflow: ellipsis;
  white-space: nowrap;
}

.col-count {
  background: var(--color-border);
  border-radius: 10px;
  padding: 1px 7px;
  font-size: 12px;
  font-weight: 600;
  color: var(--color-text-muted);
  flex-shrink: 0;
}

.btn-col-menu {
  width: 24px;
  height: 24px;
  border-radius: var(--radius-sm);
  font-size: 16px;
  color: var(--color-text-muted);
  display: flex;
  align-items: center;
  justify-content: center;
}

.btn-col-menu:hover {
  background: var(--color-border);
  color: var(--color-text);
}

/* Column dropdown menu */
.col-menu-dropdown {
  position: absolute;
  top: 46px;
  right: 8px;
  background: var(--color-surface);
  border: 1px solid var(--color-border);
  border-radius: var(--radius);
  box-shadow: 0 4px 16px var(--color-shadow);
  z-index: 100;
  min-width: 150px;
}

.col-menu-dropdown.hidden {
  display: none;
}

.col-menu-item {
  display: block;
  width: 100%;
  padding: 8px 14px;
  text-align: left;
  font-size: 13px;
  border-radius: 0;
}

.col-menu-item:hover {
  background: var(--color-bg);
}

.col-menu-item:first-child { border-radius: var(--radius) var(--radius) 0 0; }
.col-menu-item:last-child { border-radius: 0 0 var(--radius) var(--radius); }

/* ─── Cards Container ────────────────────────────────────────────────────── */

.cards-container {
  flex: 1;
  overflow-y: auto;
  padding: 8px;
  display: flex;
  flex-direction: column;
  gap: 6px;
  min-height: 40px;
}

.cards-container::-webkit-scrollbar {
  width: 4px;
}

.cards-container::-webkit-scrollbar-thumb {
  background: var(--color-border);
  border-radius: 2px;
}

/* ─── Cards ──────────────────────────────────────────────────────────────── */

.card {
  background: var(--color-card-bg);
  border-radius: var(--radius-sm);
  border: 1px solid var(--color-border);
  display: flex;
  align-items: stretch;
  cursor: pointer;
  transition: box-shadow var(--transition), transform var(--transition), opacity var(--transition);
  position: relative;
  overflow: hidden;
}

.card:hover {
  box-shadow: 0 2px 8px var(--color-shadow);
}

.card:focus {
  outline: 2px solid var(--color-primary);
}

.card.dragging {
  opacity: 0.4;
  transform: scale(0.97);
}

.card.dimmed {
  opacity: 0.3;
}

.card-color-bar {
  width: 4px;
  flex-shrink: 0;
  border-radius: var(--radius-sm) 0 0 var(--radius-sm);
}

.card-body {
  flex: 1;
  padding: 8px 10px;
  min-width: 0;
}

.card-title {
  font-weight: 600;
  font-size: 13px;
  overflow-wrap: break-word;
}

.card-desc {
  font-size: 12px;
  color: var(--color-text-muted);
  margin-top: 3px;
  overflow-wrap: break-word;
  white-space: pre-wrap;
}

.card-meta {
  font-size: 11px;
  color: var(--color-text-muted);
  margin-top: 4px;
}

.card-actions {
  display: none;
  flex-direction: column;
  gap: 2px;
  padding: 4px;
  align-items: center;
  justify-content: center;
}

.card:hover .card-actions {
  display: flex;
}

.btn-edit-card,
.btn-delete-card {
  width: 22px;
  height: 22px;
  border-radius: var(--radius-sm);
  font-size: 13px;
  display: flex;
  align-items: center;
  justify-content: center;
  color: var(--color-text-muted);
}

.btn-edit-card:hover { background: var(--color-primary); color: #fff; }
.btn-delete-card:hover { background: var(--color-danger); color: #fff; }

/* Drop target slot */
.card-drop-target {
  height: 4px;
  border-radius: 2px;
  transition: height var(--transition), background var(--transition);
}

.card-drop-target.drop-active {
  height: 32px;
  background: var(--color-drop);
  border: 2px dashed var(--color-primary);
  border-radius: var(--radius-sm);
}

/* ─── Add Card Button ─────────────────────────────────────────────────────── */

.btn-add-card {
  padding: 7px 12px;
  border-top: 1px solid var(--color-border);
  width: 100%;
  text-align: left;
  font-size: 12px;
  color: var(--color-text-muted);
  border-radius: 0 0 var(--radius) var(--radius);
}

.btn-add-card:hover {
  background: var(--color-bg);
  color: var(--color-text);
}

/* ─── Add Column Placeholder ─────────────────────────────────────────────── */

.column-add-placeholder {
  flex-shrink: 0;
  width: var(--col-width);
  display: flex;
  align-items: flex-start;
}

.btn-add-col-inline {
  width: 100%;
  padding: 10px;
  background: transparent;
  border: 2px dashed var(--color-border);
  border-radius: var(--radius);
  color: var(--color-text-muted);
  font-size: 13px;
  transition: border-color var(--transition), color var(--transition);
}

.btn-add-col-inline:hover {
  border-color: var(--color-primary);
  color: var(--color-primary);
}

/* ─── Dialog ─────────────────────────────────────────────────────────────── */

.dialog-overlay {
  position: fixed;
  inset: 0;
  background: var(--color-overlay);
  display: flex;
  align-items: center;
  justify-content: center;
  z-index: 1000;
  padding: 16px;
}

.dialog {
  background: var(--color-surface);
  border-radius: var(--radius);
  box-shadow: 0 8px 32px var(--color-shadow);
  width: 100%;
  max-width: 420px;
  max-height: 90vh;
  overflow-y: auto;
  animation: dialog-in 0.15s ease;
}

.dialog-sm {
  max-width: 300px;
}

@keyframes dialog-in {
  from { transform: scale(0.95); opacity: 0; }
  to { transform: scale(1); opacity: 1; }
}

.dialog-header {
  display: flex;
  align-items: center;
  padding: 16px 20px 12px;
  border-bottom: 1px solid var(--color-border);
}

.dialog-title {
  flex: 1;
  font-size: 16px;
  font-weight: 600;
}

.dialog-close {
  width: 28px;
  height: 28px;
  border-radius: var(--radius-sm);
  font-size: 14px;
  display: flex;
  align-items: center;
  justify-content: center;
  color: var(--color-text-muted);
}

.dialog-close:hover {
  background: var(--color-bg);
}

.dialog-body {
  padding: 16px 20px;
  display: flex;
  flex-direction: column;
  gap: 14px;
}

.dialog-body p {
  color: var(--color-text);
}

.dialog-label {
  display: flex;
  flex-direction: column;
  gap: 5px;
  font-size: 13px;
  font-weight: 500;
  color: var(--color-text-muted);
}

.dialog-input {
  padding: 8px 10px;
  border: 1px solid var(--color-border);
  border-radius: var(--radius-sm);
  background: var(--color-bg);
  font-size: 14px;
  width: 100%;
  resize: vertical;
}

.dialog-input:focus {
  outline: 2px solid var(--color-primary);
  border-color: transparent;
}

.dialog-footer {
  display: flex;
  gap: 8px;
  justify-content: flex-end;
  padding: 12px 20px 16px;
  border-top: 1px solid var(--color-border);
}

/* ─── Color Picker ───────────────────────────────────────────────────────── */

.color-picker-row {
  display: flex;
  gap: 8px;
  flex-wrap: wrap;
  padding: 4px 0;
}

.color-option {
  cursor: pointer;
}

.color-option input[type="radio"] {
  position: absolute;
  opacity: 0;
  width: 0;
  height: 0;
}

.color-swatch {
  display: block;
  width: 26px;
  height: 26px;
  border-radius: 50%;
  border: 2px solid var(--color-border);
  transition: transform var(--transition), border-color var(--transition);
}

.swatch-none {
  background: var(--color-bg) !important;
  border-style: dashed;
}

.color-option input[type="radio"]:checked + .color-swatch {
  border-color: var(--color-text);
  transform: scale(1.2);
}

/* ─── Mobile Responsive ─────────────────────────────────────────────────── */

@media (max-width: 640px) {
  #top-bar {
    padding: 8px 12px;
    gap: 8px;
  }

  .app-title {
    font-size: 15px;
  }

  #search-input {
    width: 120px;
  }

  #search-input:focus {
    width: 150px;
  }

  #btn-add-col,
  #btn-export,
  #btn-import-label {
    font-size: 12px;
    padding: 4px 8px;
  }

  .columns-container {
    flex-direction: column;
    align-items: stretch;
    padding: 12px;
    gap: 12px;
    overflow-x: hidden;
    overflow-y: auto;
  }

  .column {
    width: 100%;
    max-height: none;
  }

  .column-add-placeholder {
    width: 100%;
  }
}

@media (max-width: 400px) {
  .top-bar-right {
    width: 100%;
    justify-content: flex-end;
  }
}