/* ── CSS Variables & Reset ── */
:root {
  --bg: #f0f2f7;
  --surface: #ffffff;
  --surface-2: #f7f8fc;
  --border: #e2e6f0;
  --text: #1a1d2e;
  --text-muted: #7a839e;
  --primary: #6c63ff;
  --primary-dark: #574fd6;
  --danger: #ff5c6a;
  --danger-dark: #e0394a;
  --success: #22c55e;
  --shadow-sm: 0 2px 8px rgba(108,99,255,0.08);
  --shadow-md: 0 6px 24px rgba(108,99,255,0.13);
  --radius: 14px;
  --radius-sm: 8px;
  --transition: 0.22s ease;
}

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

body {
  font-family: 'Segoe UI', system-ui, -apple-system, sans-serif;
  background: var(--bg);
  color: var(--text);
  min-height: 100vh;
  display: flex;
  align-items: flex-start;
  justify-content: center;
  padding: 40px 16px 60px;
  transition: background var(--transition), color var(--transition);
}

/* ── Background gradient orbs ── */
body::before, body::after {
  content: '';
  position: fixed;
  border-radius: 50%;
  filter: blur(80px);
  opacity: 0.35;
  pointer-events: none;
  z-index: 0;
}
body::before {
  width: 420px; height: 420px;
  background: radial-gradient(circle, #6c63ff 0%, transparent 70%);
  top: -100px; left: -100px;
}
body::after {
  width: 320px; height: 320px;
  background: radial-gradient(circle, #ff5c6a 0%, transparent 70%);
  bottom: -80px; right: -80px;
}

/* ── Container ── */
.container {
  position: relative;
  z-index: 1;
  width: 100%;
  max-width: 560px;
  background: var(--surface);
  border-radius: var(--radius);
  box-shadow: var(--shadow-md);
  padding: 32px 32px 24px;
  transition: background var(--transition), box-shadow var(--transition);
}

/* ── Header ── */
header {
  margin-bottom: 28px;
}

.logo-text {
  font-size: 1.5rem;
  font-weight: 800;
  letter-spacing: -0.5px;
  color: var(--primary);
}

/* ── Form ── */
#task-form {
  margin-bottom: 20px;
}

.input-wrapper {
  position: relative;
  display: flex;
  align-items: center;
  background: var(--surface-2);
  border: 1.5px solid var(--border);
  border-radius: 12px;
  transition: border-color var(--transition), box-shadow var(--transition);
}
.input-wrapper:focus-within {
  border-color: var(--primary);
  box-shadow: 0 0 0 3px rgba(108,99,255,0.12);
  background: var(--surface);
}

#task-input {
  flex: 1;
  padding: 14px 52px 14px 18px;
  border: none;
  background: transparent;
  color: var(--text);
  font-size: 0.95rem;
  outline: none;
}
#task-input::placeholder { color: var(--text-muted); }

#add-btn {
  position: absolute;
  right: 8px;
  width: 34px; height: 34px;
  display: flex; align-items: center; justify-content: center;
  background: var(--primary);
  color: #fff;
  border: none;
  border-radius: 8px;
  font-size: 0.9rem;
  cursor: pointer;
  box-shadow: 0 2px 8px rgba(108,99,255,0.35);
  transition: background var(--transition), transform var(--transition), box-shadow var(--transition);
}
#add-btn:hover {
  background: var(--primary-dark);
  transform: scale(1.08);
  box-shadow: 0 4px 14px rgba(108,99,255,0.45);
}
#add-btn:active { transform: scale(0.96); }

/* ── Filters ── */
.filters {
  display: flex;
  gap: 4px;
  margin-bottom: 20px;
  background: var(--surface-2);
  border: 1px solid var(--border);
  border-radius: 10px;
  padding: 4px;
}

.filter-btn {
  flex: 1;
  padding: 7px 10px;
  border: none;
  border-radius: 7px;
  background: transparent;
  color: var(--text-muted);
  font-size: 0.82rem;
  font-weight: 500;
  cursor: pointer;
  transition: all var(--transition);
}
.filter-btn:hover {
  color: var(--primary);
  background: rgba(108,99,255,0.07);
}
.filter-btn.active {
  background: var(--surface);
  color: var(--primary);
  font-weight: 700;
  box-shadow: 0 1px 4px rgba(108,99,255,0.12);
}

/* ── Task List ── */
#task-list {
  list-style: none;
  display: flex;
  flex-direction: column;
  gap: 10px;
  min-height: 0;
}

/* ── Group Headers ── */
.group-header {
  font-size: 0.72rem;
  font-weight: 700;
  text-transform: uppercase;
  letter-spacing: 0.7px;
  color: var(--text-muted);
  padding: 6px 2px 2px;
  margin-top: 4px;
  list-style: none;
  display: flex;
  align-items: center;
  gap: 6px;
}
.group-header:first-child { margin-top: 0; }
.group-header::after {
  content: '';
  flex: 1;
  height: 1px;
  background: var(--border);
}
.group-header--overdue  { color: var(--danger); }
.group-header--today    { color: #f59e0b; }
.group-header--completed { color: var(--success); opacity: 0.7; }

/* ── Empty State ── */
.empty-state {
  display: flex;
  flex-direction: column;
  align-items: center;
  padding: 32px 0 20px;
  gap: 8px;
  animation: fadeInUp 0.35s ease;
}
.empty-state[hidden] { display: none; }

.empty-illustration {
  position: relative;
  width: 72px; height: 72px;
  background: linear-gradient(135deg, rgba(108,99,255,0.12), rgba(255,92,106,0.08));
  border-radius: 20px;
  display: flex; align-items: center; justify-content: center;
  margin-bottom: 6px;
}
.empty-illustration > i {
  font-size: 2rem;
  background: linear-gradient(135deg, #6c63ff, #ff5c6a);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
}

.empty-title {
  font-size: 1rem;
  font-weight: 700;
  color: var(--text);
  margin-top: 6px;
}
.empty-sub {
  font-size: 0.82rem;
  color: var(--text-muted);
}

/* ── Toast ── */
.toast {
  position: fixed;
  bottom: 28px;
  left: 50%;
  transform: translateX(-50%) translateY(20px);
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: var(--radius-sm);
  box-shadow: var(--shadow-md);
  padding: 12px 18px;
  display: flex;
  align-items: center;
  gap: 12px;
  font-size: 0.88rem;
  color: var(--text);
  opacity: 0;
  pointer-events: none;
  transition: opacity 0.25s ease, transform 0.25s ease;
  z-index: 100;
  white-space: nowrap;
}
.toast.show {
  opacity: 1;
  transform: translateX(-50%) translateY(0);
  pointer-events: auto;
}
.toast-undo {
  background: none;
  border: none;
  color: var(--primary);
  font-size: 0.88rem;
  font-weight: 700;
  cursor: pointer;
  padding: 0;
  text-decoration: underline;
  text-underline-offset: 2px;
}

/* ── Task Item ── */
.task-item {
  display: flex;
  align-items: center;
  gap: 14px;
  padding: 14px 16px;
  background: var(--surface-2);
  border: 1.5px solid var(--border);
  border-radius: var(--radius-sm);
  transition: box-shadow var(--transition), border-color var(--transition), background var(--transition), opacity var(--transition), transform var(--transition);
  animation: slideIn 0.25s cubic-bezier(0.34, 1.56, 0.64, 1);
  cursor: grab;
}
.task-item:active { cursor: grabbing; }
.task-item:hover {
  box-shadow: 0 4px 16px rgba(108,99,255,0.10);
  border-color: rgba(108,99,255,0.4);
  transform: translateY(-1px);
}
/* Drop indicator line */
.drop-line {
  height: 2px;
  background: var(--primary);
  border-radius: 2px;
  box-shadow: 0 0 8px rgba(108,99,255,0.55);
  pointer-events: none;
  margin: 0;
}
.task-item.dragging {
  opacity: 0.4;
  cursor: grabbing;
}

@keyframes slideIn {
  from { opacity: 0; transform: translateY(-12px) scale(0.97); }
  to   { opacity: 1; transform: translateY(0) scale(1); }
}

@keyframes fadeInUp {
  from { opacity: 0; transform: translateY(10px); }
  to   { opacity: 1; transform: translateY(0); }
}

@keyframes fadeOut {
  from { opacity: 1; transform: translateX(0); }
  to   { opacity: 0; transform: translateX(30px); }
}

@keyframes bounceIn {
  0%   { transform: scale(0.85); opacity: 0; }
  60%  { transform: scale(1.06); opacity: 1; }
  100% { transform: scale(1); }
}

.task-item.bounce {
  animation: bounceIn 0.32s cubic-bezier(0.34, 1.56, 0.64, 1);
}

.task-item.removing {
  animation: fadeOut 0.22s ease forwards;
}

/* Completed task visual treatment */
.task-item.completed {
  background: rgba(34, 197, 94, 0.04);
  border-color: rgba(34, 197, 94, 0.18);
}
.task-item.completed .task-text {
  text-decoration: line-through;
  text-decoration-color: var(--text-muted);
  color: var(--text-muted);
  transition: color var(--transition), text-decoration-color var(--transition);
}

/* ── Checkbox ── */
.task-checkbox {
  appearance: none;
  -webkit-appearance: none;
  width: 22px; height: 22px;
  border: 2px solid var(--border);
  border-radius: 7px;
  cursor: pointer;
  flex-shrink: 0;
  display: flex;
  align-items: center;
  justify-content: center;
  transition: all var(--transition);
  position: relative;
  background: var(--surface);
}
.task-checkbox:checked {
  background: linear-gradient(135deg, #6c63ff, #574fd6);
  border-color: transparent;
}
.task-checkbox:checked::after {
  content: '\f00c';
  font-family: 'Font Awesome 6 Free';
  font-weight: 900;
  font-size: 0.65rem;
  color: #fff;
  position: absolute;
}
.task-checkbox:hover:not(:checked) {
  border-color: var(--primary);
}

/* ── Task Text ── */
.task-text {
  flex: 1;
  font-size: 0.95rem;
  color: var(--text);
  word-break: break-word;
  transition: color var(--transition);
}

/* ── Due Date ── */
.task-meta {
  display: flex;
  flex-direction: column;
  gap: 3px;
  flex: 1;
  min-width: 0;
}
/* Read-only due badge (normal view) */
.task-due {
  font-size: 0.72rem;
  color: var(--text-muted);
  display: flex;
  align-items: center;
  gap: 4px;
}
.task-due.overdue  { color: var(--danger); font-weight: 600; }
.task-due.due-today { color: #f59e0b; font-weight: 600; }

/* Edit-mode due date row */
.task-meta-edit-row {
  margin-top: 6px;
}
.due-pick-btn {
  display: inline-flex;
  align-items: center;
  gap: 5px;
  background: var(--surface-2);
  border: 1px solid var(--border);
  border-radius: 20px;
  color: var(--text-muted);
  font-size: 0.75rem;
  font-family: inherit;
  padding: 3px 10px 3px 8px;
  cursor: pointer;
  transition: border-color var(--transition), color var(--transition), background var(--transition);
}
.due-pick-btn i { font-size: 0.7rem; }
.due-pick-btn:hover {
  border-color: var(--primary);
  color: var(--primary);
  background: rgba(108,99,255,0.06);
}
.due-pick-btn.overdue   { color: var(--danger); border-color: rgba(255,92,106,0.4); }
.due-pick-btn.due-today { color: #f59e0b; border-color: rgba(245,158,11,0.4); }

/* ── Date Modal ── */
.date-modal-overlay {
  position: fixed;
  inset: 0;
  background: rgba(0,0,0,0.4);
  display: flex;
  align-items: center;
  justify-content: center;
  z-index: 200;
  animation: fadeInUp 0.18s ease;
}
.date-modal {
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  box-shadow: var(--shadow-md);
  padding: 24px 28px 20px;
  display: flex;
  flex-direction: column;
  gap: 16px;
  min-width: 260px;
}
.date-modal-title {
  font-size: 0.95rem;
  font-weight: 700;
  color: var(--text);
}
.date-modal-input {
  width: 100%;
  padding: 9px 12px;
  border: 1.5px solid var(--border);
  border-radius: var(--radius-sm);
  background: var(--surface-2);
  color: var(--text);
  font-size: 0.92rem;
  font-family: inherit;
  outline: none;
  transition: border-color var(--transition);
}
.date-modal-input:focus { border-color: var(--primary); }
.date-modal-input.empty { color: var(--text-muted); }
.date-modal-btns {
  display: flex;
  gap: 8px;
  justify-content: flex-end;
}
.date-modal-btn {
  padding: 7px 18px;
  border-radius: var(--radius-sm);
  font-size: 0.85rem;
  font-weight: 600;
  cursor: pointer;
  border: none;
  transition: opacity 0.15s;
}
.date-modal-btn:hover { opacity: 0.85; }
.date-modal-clear {
  background: var(--surface-2);
  border: 1px solid var(--border);
  color: var(--text-muted);
}
.date-modal-confirm {
  background: linear-gradient(135deg, #6c63ff, #574fd6);
  color: #fff;
  box-shadow: 0 3px 10px rgba(108,99,255,0.3);
}

/* ── Edit Input ── */
.task-edit-input {
  flex: 1;
  border: 1.5px solid var(--border);
  border-radius: 6px;
  background: var(--surface-2);
  color: var(--text);
  font-size: 0.95rem;
  font-weight: 500;
  outline: none;
  padding: 6px 10px;
  width: 100%;
  transition: border-color var(--transition);
}
.task-edit-input:focus {
  border-color: var(--primary);
  background: var(--surface);
}

/* ── Action Buttons ── */
.task-actions {
  display: flex;
  gap: 4px;
  opacity: 0;
  transition: opacity var(--transition);
  flex-shrink: 0;
}
.task-item:hover .task-actions {
  opacity: 1;
}

.btn-icon {
  background: none;
  border: none;
  cursor: pointer;
  width: 34px; height: 34px;
  border-radius: 8px;
  display: flex; align-items: center; justify-content: center;
  font-size: 0.88rem;
  transition: background var(--transition), color var(--transition), transform var(--transition);
  color: var(--text-muted);
  -webkit-tap-highlight-color: transparent;
  touch-action: manipulation;
}
.btn-icon:hover { transform: scale(1.1); }
.btn-edit:hover { background: rgba(108,99,255,0.1); color: var(--primary); }
.btn-delete:hover { background: rgba(255,92,106,0.1); color: var(--danger); }

/* Save button — same idle style as other icon buttons */
.btn-save {
  background: none;
  color: var(--text-muted);
  width: 34px; height: 34px;
}
.btn-save:hover { background: rgba(34,197,94,0.12); color: var(--success); transform: scale(1.1); }

/* ── Footer ── */
.app-footer {
  display: flex;
  align-items: center;
  justify-content: space-between;
  margin-top: 24px;
  padding-top: 14px;
  border-top: 1px solid var(--border);
}

#task-count {
  font-size: 0.8rem;
  color: var(--text-muted);
  font-weight: 500;
}

#clear-completed {
  background: none;
  border: none;
  color: var(--text-muted);
  font-size: 0.8rem;
  padding: 0;
  cursor: pointer;
  display: flex; align-items: center; gap: 5px;
  transition: color var(--transition);
}
#clear-completed:hover {
  color: var(--danger);
}

/* ── Edit mode card ── */
.task-item.editing {
  border-color: var(--primary);
  background: var(--surface);
  box-shadow: 0 0 0 3px rgba(108,99,255,0.12), 0 4px 16px rgba(108,99,255,0.08);
  cursor: default;
  align-items: center;
}
.task-item.editing:hover {
  transform: none;
  border-color: var(--primary);
}
.task-item.editing .task-actions {
  opacity: 1;
  align-self: flex-start;
}
.task-item.editing .task-meta {
  align-self: stretch;
}

/* Save button in editing state — green on hover only */
.task-item.editing .btn-save {
  background: none;
  color: var(--text-muted);
  border-radius: 8px;
  width: 34px; height: 34px;
  box-shadow: none;
}
.task-item.editing .btn-save:hover {
  background: rgba(34,197,94,0.12);
  color: var(--success);
  transform: scale(1.06);
}

/* Hide checkbox in edit mode */
.task-item.editing .task-checkbox {
  display: none;
}

/* ── Mobile ── */
@media (max-width: 500px) {
  .container { padding: 22px 16px 18px; }
  .logo-text { font-size: 1.25rem; }
  .task-actions { opacity: 1; }
  .btn-icon { width: 40px; height: 40px; font-size: 1rem; }
}