/* ── Reset & Base ────────────────────────────────────────── */
*, *::before, *::after { box-sizing: border-box; margin: 0; padding: 0; }

:root {
  --primary: #4F46E5;
  --primary-light: #EEF2FF;
  --primary-dark: #4338CA;
  --bg: #F9FAFB;
  --surface: #FFFFFF;
  --border: #E5E7EB;
  --text: #111827;
  --text-secondary: #6B7280;
  --text-tertiary: #9CA3AF;
  --error: #DC2626;
  --error-light: #FEF2F2;
  --success: #059669;
  --warning: #D97706;
  --radius: 10px;
  --shadow: 0 1px 3px rgba(0,0,0,0.08);

  /* Tag color palette (12 hues) */
  --tag-0-bg: #DBEAFE; --tag-0-fg: #1E40AF;
  --tag-1-bg: #D1FAE5; --tag-1-fg: #065F46;
  --tag-2-bg: #FDE68A; --tag-2-fg: #92400E;
  --tag-3-bg: #E0E7FF; --tag-3-fg: #3730A3;
  --tag-4-bg: #FCE7F3; --tag-4-fg: #9D174D;
  --tag-5-bg: #FED7AA; --tag-5-fg: #9A3412;
  --tag-6-bg: #CCFBF1; --tag-6-fg: #115E59;
  --tag-7-bg: #EDE9FE; --tag-7-fg: #5B21B6;
  --tag-8-bg: #FEE2E2; --tag-8-fg: #991B1B;
  --tag-9-bg: #D9F99D; --tag-9-fg: #3F6212;
  --tag-10-bg: #E0F2FE; --tag-10-fg: #075985;
  --tag-11-bg: #FECDD3; --tag-11-fg: #9F1239;
}

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

.hidden { display: none !important; }

/* ── Buttons ─────────────────────────────────────────────── */
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  padding: 10px 20px;
  border: none;
  border-radius: var(--radius);
  font-size: 14px;
  font-weight: 600;
  cursor: pointer;
  transition: opacity 0.15s;
}
.btn:hover { opacity: 0.85; }
.btn:disabled { opacity: 0.5; cursor: not-allowed; }
.btn-primary { background: var(--primary); color: #fff; }
.btn-ghost { background: none; color: var(--text-secondary); }
.btn-ghost:hover { color: var(--text); }
.btn-sm { padding: 7px 14px; font-size: 13px; }
.btn-danger { background: none; color: var(--error); border: 1px solid var(--error); padding: 6px 12px; font-size: 12px; }
.btn-danger:hover { background: var(--error-light); }

/* ── Auth View ───────────────────────────────────────────── */
.auth-view {
  display: flex;
  align-items: center;
  justify-content: center;
  min-height: 100vh;
  padding: 20px;
}
.auth-card {
  background: var(--surface);
  border-radius: 16px;
  padding: 40px;
  width: 100%;
  max-width: 400px;
  box-shadow: var(--shadow);
}
.auth-logo {
  text-align: center;
  font-size: 28px;
  font-weight: 700;
  color: var(--primary);
  margin-bottom: 4px;
}
.auth-subtitle {
  text-align: center;
  color: var(--text-secondary);
  font-size: 15px;
  margin-bottom: 24px;
}
.tabs {
  display: flex;
  gap: 4px;
  background: var(--bg);
  border-radius: 8px;
  padding: 4px;
  margin-bottom: 20px;
}
.tab {
  flex: 1;
  padding: 8px;
  border: none;
  background: none;
  border-radius: 6px;
  font-size: 14px;
  font-weight: 600;
  color: var(--text-secondary);
  cursor: pointer;
  transition: all 0.15s;
}
.tab.active {
  background: var(--surface);
  color: var(--primary);
  box-shadow: 0 1px 2px rgba(0,0,0,0.06);
}
.auth-card label {
  display: block;
  font-size: 14px;
  font-weight: 600;
  color: var(--text);
  margin-bottom: 14px;
}
.auth-card input {
  display: block;
  width: 100%;
  margin-top: 6px;
  padding: 10px 14px;
  border: 1px solid var(--border);
  border-radius: var(--radius);
  font-size: 15px;
  color: var(--text);
  outline: none;
  transition: border-color 0.15s;
}
.auth-card input:focus { border-color: var(--primary); }
.auth-card .btn { width: 100%; margin-top: 8px; }
.error-text {
  color: var(--error);
  font-size: 14px;
  text-align: center;
  margin-top: 12px;
}

/* ── Header ──────────────────────────────────────────────── */
.header {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 12px 24px;
  background: var(--surface);
  border-bottom: 1px solid var(--border);
}
.header-logo {
  font-size: 20px;
  font-weight: 700;
  color: var(--primary);
}
.header-right {
  display: flex;
  align-items: center;
  gap: 12px;
}
.user-email {
  font-size: 13px;
  color: var(--text-secondary);
}

/* ── Toolbar ─────────────────────────────────────────────── */
.toolbar {
  display: flex;
  align-items: center;
  justify-content: space-between;
  flex-wrap: wrap;
  gap: 12px;
  padding: 16px 24px;
  max-width: 900px;
  margin: 0 auto;
}
.filters {
  display: flex;
  gap: 4px;
  background: var(--surface);
  border-radius: 8px;
  padding: 4px;
  border: 1px solid var(--border);
}
.filter {
  padding: 6px 14px;
  border: none;
  background: none;
  border-radius: 6px;
  font-size: 13px;
  font-weight: 600;
  color: var(--text-secondary);
  cursor: pointer;
  transition: all 0.15s;
}
.filter.active {
  background: var(--primary);
  color: #fff;
}
.toolbar-right {
  display: flex;
  align-items: center;
  gap: 10px;
}
.sort-select {
  padding: 7px 12px;
  border: 1px solid var(--border);
  border-radius: var(--radius);
  font-size: 13px;
  color: var(--text-secondary);
  background: var(--surface);
  cursor: pointer;
  outline: none;
}
.task-meta {
  max-width: 900px;
  margin: 0 auto;
  padding: 0 24px 8px;
  font-size: 13px;
  color: var(--text-tertiary);
}

/* ── Task List ───────────────────────────────────────────── */
.task-list {
  max-width: 900px;
  margin: 0 auto;
  padding: 0 24px 40px;
  display: flex;
  flex-direction: column;
  gap: 8px;
}
.task-card {
  display: flex;
  align-items: flex-start;
  gap: 12px;
  background: var(--surface);
  border-radius: var(--radius);
  padding: 14px 16px;
  box-shadow: var(--shadow);
  transition: box-shadow 0.15s;
}
.task-card:hover { box-shadow: 0 2px 8px rgba(0,0,0,0.1); }
.task-card.completed { opacity: 0.6; }

.task-checkbox {
  width: 22px;
  height: 22px;
  border-radius: 50%;
  border: 2px solid var(--border);
  cursor: pointer;
  flex-shrink: 0;
  margin-top: 1px;
  display: flex;
  align-items: center;
  justify-content: center;
  transition: all 0.15s;
  background: none;
  padding: 0;
}
.task-checkbox:hover { border-color: var(--primary); }
.task-checkbox.checked {
  background: var(--primary);
  border-color: var(--primary);
  color: #fff;
  font-size: 12px;
  font-weight: 700;
}

.task-body { flex: 1; min-width: 0; }
.task-title {
  font-size: 15px;
  font-weight: 600;
  color: var(--text);
  word-break: break-word;
}
.task-card.completed .task-title {
  text-decoration: line-through;
  color: var(--text-tertiary);
}
.task-notes {
  font-size: 13px;
  color: var(--text-secondary);
  margin-top: 4px;
  overflow: hidden;
  text-overflow: ellipsis;
  white-space: nowrap;
}
.task-tags {
  display: flex;
  flex-wrap: wrap;
  gap: 4px;
  margin-top: 6px;
}
.task-tag {
  font-size: 11px;
  font-weight: 600;
  padding: 2px 8px;
  border-radius: 12px;
  background: #DBEAFE;
  color: #1E40AF;
  cursor: pointer;
  transition: all 0.15s ease;
  border: 1.5px solid transparent;
}
.task-tag:hover {
  filter: brightness(0.92);
  transform: translateY(-1px);
}
.task-tag.active-filter {
  border-color: currentColor;
  box-shadow: 0 1px 4px rgba(0,0,0,0.12);
}
.task-meta-row {
  display: flex;
  align-items: center;
  gap: 10px;
  margin-top: 6px;
  flex-wrap: wrap;
}
.task-badge {
  font-size: 11px;
  font-weight: 600;
  padding: 2px 8px;
  border-radius: 6px;
  background: var(--primary-light);
  color: var(--primary);
}
.task-due {
  font-size: 12px;
  color: var(--warning);
  font-weight: 500;
}
.task-due.overdue { color: var(--error); }
.task-time {
  font-size: 12px;
  color: var(--text-tertiary);
}
.task-actions {
  display: flex;
  gap: 6px;
  flex-shrink: 0;
  align-items: flex-start;
}
.task-action-btn {
  padding: 5px 10px;
  border-radius: 6px;
  border: 1px solid var(--border);
  background: none;
  font-size: 12px;
  font-weight: 600;
  color: var(--text-secondary);
  cursor: pointer;
  transition: all 0.15s;
}
.task-action-btn:hover { border-color: var(--primary); color: var(--primary); }
.task-action-btn.delete { color: var(--error); border-color: transparent; }
.task-action-btn.delete:hover { border-color: var(--error); background: var(--error-light); }

/* ── Empty State ─────────────────────────────────────────── */
.empty-state {
  text-align: center;
  padding: 60px 24px;
  max-width: 400px;
  margin: 0 auto;
}
.empty-title { font-size: 18px; font-weight: 600; color: var(--text); margin-bottom: 8px; }
.empty-sub { font-size: 14px; color: var(--text-secondary); line-height: 1.6; }

/* ── Loading ─────────────────────────────────────────────── */
.loading {
  display: flex;
  justify-content: center;
  padding: 40px;
}
.spinner {
  width: 32px;
  height: 32px;
  border: 3px solid var(--border);
  border-top-color: var(--primary);
  border-radius: 50%;
  animation: spin 0.6s linear infinite;
}
@keyframes spin { to { transform: rotate(360deg); } }

/* ── Modal ───────────────────────────────────────────────── */
.modal-overlay {
  position: fixed;
  inset: 0;
  background: rgba(0,0,0,0.4);
  display: flex;
  align-items: center;
  justify-content: center;
  z-index: 100;
  padding: 20px;
}
.modal {
  background: var(--surface);
  border-radius: 16px;
  width: 100%;
  max-width: 480px;
  box-shadow: 0 20px 60px rgba(0,0,0,0.15);
}
.modal-header {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 20px 24px 0;
}
.modal-header h2 { font-size: 18px; font-weight: 700; }
.modal-close {
  width: 32px;
  height: 32px;
  border: none;
  background: var(--bg);
  border-radius: 8px;
  font-size: 20px;
  color: var(--text-secondary);
  cursor: pointer;
  display: flex;
  align-items: center;
  justify-content: center;
}
.modal-close:hover { background: var(--border); }
#task-form {
  padding: 20px 24px 24px;
}
#task-form label {
  display: block;
  font-size: 13px;
  font-weight: 600;
  color: var(--text-secondary);
  text-transform: uppercase;
  letter-spacing: 0.3px;
  margin-bottom: 14px;
}
#task-form input, #task-form textarea {
  display: block;
  width: 100%;
  margin-top: 6px;
  padding: 10px 14px;
  border: 1px solid var(--border);
  border-radius: var(--radius);
  font-size: 15px;
  font-family: inherit;
  color: var(--text);
  outline: none;
  resize: vertical;
}
#task-form input:focus, #task-form textarea:focus { border-color: var(--primary); }
.modal-actions {
  display: flex;
  justify-content: flex-end;
  gap: 8px;
  margin-top: 8px;
}

/* ── Tags Toggle Button ──────────────────────────────────── */
.tags-toggle-btn {
  display: inline-flex;
  align-items: center;
  gap: 4px;
  border: 1px solid var(--border);
  border-radius: var(--radius);
}
.tags-toggle-btn.active {
  background: var(--primary-light);
  color: var(--primary);
  border-color: var(--primary);
}

/* ── Tag Filter Bar ─────────────────────────────────────── */
.tag-filter-bar {
  max-width: 900px;
  margin: 0 auto;
  padding: 0 24px;
  animation: tagSlideIn 0.2s ease-out;
}
@keyframes tagSlideIn {
  from { opacity: 0; transform: translateY(-8px); }
  to   { opacity: 1; transform: translateY(0); }
}
.tag-filter-bar-inner {
  display: flex;
  align-items: center;
  gap: 10px;
  padding: 10px 0;
  border-bottom: 1px solid var(--border);
}
.tag-filter-pills {
  display: flex;
  flex-wrap: wrap;
  gap: 6px;
  flex: 1;
  min-width: 0;
}
.tag-pill {
  display: inline-flex;
  align-items: center;
  gap: 5px;
  padding: 5px 12px;
  border-radius: 16px;
  font-size: 12px;
  font-weight: 600;
  cursor: pointer;
  border: 2px solid transparent;
  transition: all 0.15s ease;
  user-select: none;
  white-space: nowrap;
}
.tag-pill:hover {
  filter: brightness(0.93);
  transform: translateY(-1px);
}
.tag-pill.active {
  border-color: currentColor;
  box-shadow: 0 2px 8px rgba(0,0,0,0.12);
  transform: translateY(-1px);
}
.tag-pill-count {
  font-size: 10px;
  font-weight: 700;
  opacity: 0.65;
  background: rgba(0,0,0,0.08);
  border-radius: 8px;
  padding: 1px 6px;
  min-width: 18px;
  text-align: center;
}
.tag-filter-controls {
  display: flex;
  align-items: center;
  gap: 6px;
  flex-shrink: 0;
}
.tag-mode-btn {
  padding: 4px 10px;
  border: 1px solid var(--border);
  border-radius: 6px;
  background: var(--surface);
  font-size: 11px;
  font-weight: 700;
  color: var(--text-secondary);
  cursor: pointer;
  transition: all 0.15s;
  text-transform: uppercase;
  letter-spacing: 0.5px;
}
.tag-mode-btn:hover { border-color: var(--primary); color: var(--primary); }
.tag-mode-btn.active-and { background: var(--primary); color: #fff; border-color: var(--primary); }
.tag-clear-btn {
  padding: 4px 10px;
  border: none;
  border-radius: 6px;
  background: var(--error-light);
  font-size: 11px;
  font-weight: 600;
  color: var(--error);
  cursor: pointer;
  transition: all 0.15s;
}
.tag-clear-btn:hover { background: var(--error); color: #fff; }

/* ── Tag Overview Panel ─────────────────────────────────── */
.tag-overview {
  max-width: 900px;
  margin: 0 auto;
  padding: 0 24px;
  animation: tagSlideIn 0.2s ease-out;
}
.tag-overview-inner {
  padding: 16px 0 12px;
  border-bottom: 1px solid var(--border);
}
.tag-overview-header {
  display: flex;
  align-items: center;
  justify-content: space-between;
  margin-bottom: 12px;
}
.tag-overview-title {
  font-size: 15px;
  font-weight: 700;
  color: var(--text);
}
.tag-overview-count {
  font-size: 12px;
  color: var(--text-tertiary);
}
.tag-overview-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(200px, 1fr));
  gap: 10px;
}
.tag-card {
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 14px;
  cursor: pointer;
  transition: all 0.2s ease;
  position: relative;
  overflow: hidden;
}
.tag-card:hover {
  box-shadow: 0 4px 12px rgba(0,0,0,0.08);
  transform: translateY(-2px);
}
.tag-card.active {
  border-color: var(--primary);
  box-shadow: 0 0 0 1px var(--primary), 0 4px 12px rgba(79,70,229,0.15);
}
.tag-card-accent {
  position: absolute;
  top: 0;
  left: 0;
  right: 0;
  height: 3px;
}
.tag-card-name {
  font-size: 14px;
  font-weight: 700;
  margin-bottom: 8px;
}
.tag-card-stats {
  display: flex;
  align-items: center;
  gap: 12px;
  font-size: 12px;
  color: var(--text-secondary);
}
.tag-card-progress {
  width: 100%;
  height: 4px;
  background: var(--bg);
  border-radius: 2px;
  margin-top: 10px;
  overflow: hidden;
}
.tag-card-progress-fill {
  height: 100%;
  border-radius: 2px;
  transition: width 0.3s ease;
}

/* ── Responsive ──────────────────────────────────────────── */
@media (max-width: 600px) {
  .toolbar { padding: 12px 16px; }
  .task-list { padding: 0 16px 40px; }
  .header { padding: 12px 16px; }
  .task-actions { flex-direction: column; }
  .tag-filter-bar { padding: 0 16px; }
  .tag-overview { padding: 0 16px; }
  .tag-overview-grid { grid-template-columns: repeat(auto-fill, minmax(150px, 1fr)); }
  .tag-filter-bar-inner { flex-wrap: wrap; }
  .tag-filter-controls { width: 100%; justify-content: flex-end; padding-top: 6px; border-top: 1px solid var(--border); }
}