:root {
  --bg: #0d1117;
  --bg-surface: #161b22;
  --bg-hover: #1c2128;
  --border: #30363d;
  --text: #e6edf3;
  --text-muted: #7d8590;
  --accent: #58a6ff;
  --accent-dim: #388bfd33;
  --complete: #3fb950;
  --urgent: #f85149;
  --warning: #d29922;
}

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

body {
  font-family: var(--font, -apple-system, BlinkMacSystemFont, 'Segoe UI', Helvetica, Arial, sans-serif);
  font-size: var(--font-size, 15px);
  background: var(--bg);
  color: var(--text);
  min-height: 100vh;
  line-height: 1.5;
}

/* Layout */
.app {
  display: flex;
  flex-direction: column;
  height: 100vh;
}

.hidden { display: none !important; }

/* Navigation */
.nav {
  display: flex;
  gap: 0.25rem;
  padding: 0.75rem 1rem;
  border-bottom: 1px solid var(--border);
  background: var(--bg-surface);
}

.nav-btn {
  background: transparent;
  border: none;
  color: var(--text-muted);
  padding: 0.5rem 1rem;
  font-size: 0.9rem;
  border-radius: 4px;
  cursor: pointer;
  font-family: inherit;
}
.nav-btn:hover { color: var(--text); background: var(--bg-hover); }
.nav-btn.active { color: var(--text); background: var(--accent-dim); }
.nav-btn:last-child { margin-left: auto; }

/* Pages */
.page {
  flex: 1;
  display: flex;
  flex-direction: column;
  overflow: hidden;
}

.page-header {
  display: flex;
  justify-content: space-between;
  align-items: center;
  padding: 1rem;
  border-bottom: 1px solid var(--border);
  gap: 1rem;
  flex-wrap: wrap;
}

.page-title {
  font-size: 1rem;
  font-weight: 600;
}

.page-controls { display: flex; gap: 0.5rem; }

.page-body {
  flex: 1;
  overflow-y: auto;
  padding: 1rem;
}

/* Date picker */
.date-picker {
  background: var(--bg-surface);
  border: 1px solid var(--border);
  color: var(--text);
  padding: 0.5rem;
  border-radius: 4px;
  font-family: inherit;
  font-size: 0.9rem;
}
.date-picker:focus { outline: none; border-color: var(--accent); }

/* Buttons */
.btn {
  background: transparent;
  border: 1px solid var(--border);
  color: var(--text-muted);
  padding: 0.3rem 0.6rem;
  font-size: 0.75rem;
  border-radius: 4px;
  cursor: pointer;
  font-family: inherit;
}
.btn:hover { border-color: var(--text-muted); color: var(--text); }
.btn.active { background: var(--accent-dim); border-color: var(--accent); color: var(--accent); }
.btn.primary { background: var(--accent); border-color: var(--accent); color: #fff; }
.btn.primary:hover { filter: brightness(1.1); }

/* Add form */
.add-form { display: flex; gap: 0.5rem; margin-bottom: 1rem; }
.add-input {
  flex: 1;
  background: var(--bg-surface);
  border: 1px solid var(--border);
  color: var(--text);
  padding: 0.5rem;
  font-size: inherit;
  border-radius: 4px;
  font-family: inherit;
}
.add-input:focus { outline: none; border-color: var(--accent); }
.add-input::placeholder { color: var(--text-muted); }

/* Category sections */
.category-section {
  margin-bottom: 1.5rem;
}

.category-header {
  display: flex;
  justify-content: space-between;
  align-items: center;
  padding: 0.5rem 0;
  border-bottom: 1px solid var(--border);
  margin-bottom: 0.5rem;
}

.category-title {
  font-size: 0.85rem;
  font-weight: 600;
  color: var(--accent);
  text-transform: uppercase;
  letter-spacing: 0.05em;
}

.category-count {
  font-size: 0.75rem;
  color: var(--text-muted);
}

/* Task list */
.task-list { list-style: none; }

.task {
  display: flex;
  align-items: flex-start;
  gap: 0.6rem;
  padding: 0.5rem 0;
  border-bottom: 1px solid var(--border);
  cursor: pointer;
}
.task:last-child { border-bottom: none; }
.task:hover { background: var(--bg-hover); margin: 0 -1rem; padding-left: 1rem; padding-right: 1rem; }
.task.selected { background: var(--accent-dim); margin: 0 -1rem; padding-left: 1rem; padding-right: 1rem; }

.task-check {
  width: 16px; height: 16px;
  margin-top: 2px;
  border: 2px solid var(--border);
  border-radius: 3px;
  flex-shrink: 0;
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 10px;
  color: transparent;
}
.task-check:hover { border-color: var(--text-muted); }
.task-check.checked {
  background: var(--check-color, var(--complete));
  border-color: var(--check-color, var(--complete));
  color: #fff;
}

.task-content { flex: 1; min-width: 0; }
.task-main { display: flex; align-items: baseline; gap: 0.5rem; flex-wrap: wrap; }
.task-text { font-size: inherit; }

.task.complete.style-strike .task-text { text-decoration: line-through; }
.task.complete.style-gray .task-text { color: var(--text-muted); }
.task.complete.style-both .task-text { text-decoration: line-through; color: var(--text-muted); }

.task-deadline { font-size: 0.85em; color: var(--text-muted); }
.task-deadline.urgent { color: var(--urgent); }
.task-deadline.soon { color: var(--warning); }
.task-note { font-size: 0.85em; color: var(--text-muted); margin-top: 0.1rem; }
.task-children-indicator { font-size: 0.75em; color: var(--accent); }

.task-actions {
  display: flex;
  gap: 0.25rem;
  opacity: 0;
}
.task:hover .task-actions { opacity: 1; }
.task-action {
  background: none;
  border: none;
  color: var(--text-muted);
  cursor: pointer;
  padding: 0.2rem;
  font-size: 0.9rem;
}
.task-action:hover { color: var(--text); }
.task-action.delete:hover { color: var(--urgent); }

/* Table view */
.task-table {
  width: 100%;
  border-collapse: collapse;
  font-size: inherit;
}
.task-table th {
  text-align: left;
  padding: 0.5rem;
  border-bottom: 2px solid var(--border);
  color: var(--text-muted);
  font-weight: 500;
  font-size: 0.8em;
}
.task-table td {
  padding: 0.5rem;
  border-bottom: 1px solid var(--border);
  vertical-align: top;
}
.task-table tr:hover { background: var(--bg-hover); }
.task-table tr.selected { background: var(--accent-dim); }
.task-table .col-check { width: 30px; }
.task-table .col-task { }
.task-table .col-category { width: 120px; font-size: 0.85em; color: var(--accent); }
.task-table .col-deadline { width: 80px; }
.task-table .col-note { color: var(--text-muted); font-size: 0.9em; }
.task-table .col-actions { width: 50px; text-align: right; }

/* Add task button */
.add-task-btn {
  display: block;
  width: 100%;
  padding: 0.75rem;
  margin-top: 1rem;
  background: var(--bg-surface);
  border: 1px dashed var(--border);
  color: var(--text-muted);
  border-radius: 4px;
  cursor: pointer;
  font-family: inherit;
  font-size: 0.9rem;
}
.add-task-btn:hover {
  border-color: var(--accent);
  color: var(--accent);
}

/* Sublist panel */
.sublist-panel {
  position: fixed;
  top: 0;
  right: 0;
  width: 350px;
  height: 100vh;
  background: var(--bg-surface);
  border-left: 1px solid var(--border);
  display: none;
  flex-direction: column;
  z-index: 50;
  box-shadow: -4px 0 20px rgba(0,0,0,0.3);
}
.sublist-panel.visible { display: flex; }

.panel-header {
  display: flex;
  justify-content: space-between;
  align-items: center;
  padding: 1rem;
  border-bottom: 1px solid var(--border);
}

.panel-title {
  font-size: 0.9rem;
  font-weight: 600;
  white-space: nowrap;
  overflow: hidden;
  text-overflow: ellipsis;
}

.panel-body {
  flex: 1;
  overflow-y: auto;
  padding: 1rem;
}

/* Modals */
.modal-overlay {
  position: fixed;
  top: 0; left: 0; right: 0; bottom: 0;
  background: rgba(0,0,0,0.7);
  display: none;
  align-items: center;
  justify-content: center;
  z-index: 100;
}
.modal-overlay.visible { display: flex; }

.modal-panel {
  background: var(--bg-surface);
  border: 1px solid var(--border);
  border-radius: 8px;
  width: 90%;
  max-width: 500px;
  max-height: 80vh;
  overflow-y: auto;
}
.modal-panel.small { max-width: 400px; }

.modal-header {
  display: flex;
  justify-content: space-between;
  align-items: center;
  padding: 1rem;
  border-bottom: 1px solid var(--border);
}
.modal-title { font-weight: 600; }
.modal-close {
  background: none;
  border: none;
  color: var(--text-muted);
  font-size: 1.5rem;
  cursor: pointer;
  line-height: 1;
}
.modal-close:hover { color: var(--text); }

.modal-body { padding: 1rem; }

.setting-group { margin-bottom: 1rem; }
.setting-label {
  display: block;
  font-size: 0.85rem;
  color: var(--text-muted);
  margin-bottom: 0.3rem;
}

.setting-input {
  background: var(--bg);
  border: 1px solid var(--border);
  color: var(--text);
  padding: 0.4rem 0.6rem;
  border-radius: 4px;
  font-family: inherit;
  font-size: 0.9rem;
}
.setting-input:focus { outline: none; border-color: var(--accent); }
select.setting-input { cursor: pointer; width: 100%; }
.color-input { width: 50px; height: 32px; padding: 2px; cursor: pointer; }

.edit-field { margin-bottom: 1rem; }
.edit-field label {
  display: block;
  font-size: 0.85rem;
  color: var(--text-muted);
  margin-bottom: 0.3rem;
}
.edit-field input, .edit-field textarea, .edit-field select {
  width: 100%;
  background: var(--bg);
  border: 1px solid var(--border);
  color: var(--text);
  padding: 0.5rem;
  border-radius: 4px;
  font-family: inherit;
  font-size: inherit;
}
.edit-field textarea { resize: vertical; min-height: 60px; }
.edit-field input:focus, .edit-field textarea:focus { outline: none; border-color: var(--accent); }

.edit-actions { display: flex; gap: 0.5rem; justify-content: flex-end; }

/* Empty state */
.empty-state {
  text-align: center;
  color: var(--text-muted);
  padding: 2rem;
  font-size: 0.9rem;
}

/* Responsive */
@media (max-width: 600px) {
  .sublist-panel { width: 100%; }
  .page-header { flex-direction: column; align-items: flex-start; }
  .task-actions { opacity: 0.7; }
}