/* ============================================
   CSS VARIABLES & RESET
   ============================================ */
:root {
  --bg: #f0f2f8;
  --bg-card: #ffffff;
  --bg-column: #f7f8fc;
  --sidebar-bg: #1e1e2e;
  --sidebar-text: #a0a0c0;
  --sidebar-active: #ffffff;
  --sidebar-active-bg: rgba(139,92,246,0.2);
  --sidebar-hover: rgba(255,255,255,0.07);
  --topbar-bg: #ffffff;
  --text-primary: #1a1a2e;
  --text-secondary: #6b7280;
  --text-muted: #9ca3af;
  --border: #e5e7eb;
  --border-hover: #d1d5db;
  --accent-purple: #8b5cf6;
  --accent-purple-light: #ede9fe;
  --accent-blue: #3b82f6;
  --accent-amber: #f59e0b;
  --accent-green: #10b981;
  --accent-red: #ef4444;
  --shadow-sm: 0 1px 3px rgba(0,0,0,0.08);
  --shadow-md: 0 4px 16px rgba(0,0,0,0.10);
  --shadow-lg: 0 12px 40px rgba(0,0,0,0.15);
  --sidebar-width: 260px;
  --topbar-height: 70px;
  --radius-sm: 8px;
  --radius-md: 12px;
  --radius-lg: 16px;
  --transition: 0.2s ease;
}

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

html { font-size: 16px; }

body {
  font-family: 'Segoe UI', system-ui, -apple-system, sans-serif;
  background: var(--bg);
  color: var(--text-primary);
  display: flex;
  min-height: 100vh;
  overflow-x: hidden;
}

/* ============================================
   SIDEBAR
   ============================================ */
.sidebar {
  width: var(--sidebar-width);
  background: var(--sidebar-bg);
  display: flex;
  flex-direction: column;
  position: fixed;
  top: 0; left: 0;
  height: 100vh;
  z-index: 100;
  transition: transform var(--transition);
  overflow-y: auto;
}

.sidebar-header {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 24px 20px 20px;
  border-bottom: 1px solid rgba(255,255,255,0.07);
}

.logo {
  display: flex;
  align-items: center;
  gap: 10px;
}

.logo-icon {
  font-size: 1.5rem;
  filter: drop-shadow(0 0 8px #8b5cf6);
}

.logo-text {
  font-size: 1.3rem;
  font-weight: 700;
  color: #fff;
  letter-spacing: -0.5px;
}

.sidebar-toggle {
  display: none;
  background: none;
  border: none;
  color: var(--sidebar-text);
  font-size: 1.2rem;
  cursor: pointer;
  padding: 4px 8px;
  border-radius: var(--radius-sm);
  transition: background var(--transition);
}

.sidebar-toggle:hover { background: var(--sidebar-hover); }

.sidebar-nav {
  flex: 1;
  padding: 20px 12px;
}

.nav-label {
  font-size: 0.7rem;
  text-transform: uppercase;
  letter-spacing: 1.5px;
  color: var(--sidebar-text);
  padding: 12px 8px 6px;
  font-weight: 600;
}

.sidebar-nav ul { list-style: none; }

.nav-item {
  display: flex;
  align-items: center;
  gap: 12px;
  padding: 10px 12px;
  border-radius: var(--radius-sm);
  color: var(--sidebar-text);
  cursor: pointer;
  font-size: 0.9rem;
  font-weight: 500;
  transition: all var(--transition);
  margin-bottom: 2px;
}

.nav-item:hover {
  background: var(--sidebar-hover);
  color: #fff;
}

.nav-item.active {
  background: var(--sidebar-active-bg);
  color: var(--sidebar-active);
  border-left: 3px solid var(--accent-purple);
  padding-left: 9px;
}

.nav-icon { font-size: 1rem; }

.sidebar-footer {
  padding: 16px 20px;
  border-top: 1px solid rgba(255,255,255,0.07);
  display: flex;
  align-items: center;
  gap: 12px;
}

.user-avatar {
  width: 38px; height: 38px;
  border-radius: 50%;
  background: linear-gradient(135deg, var(--accent-purple), #a78bfa);
  display: flex; align-items: center; justify-content: center;
  color: #fff;
  font-weight: 700;
  font-size: 0.85rem;
  flex-shrink: 0;
}

.user-info { flex: 1; }
.user-name { font-size: 0.85rem; color: #fff; font-weight: 600; }
.user-role { font-size: 0.72rem; color: var(--sidebar-text); margin-top: 1px; }

.settings-btn {
  background: none;
  border: none;
  cursor: pointer;
  font-size: 1.1rem;
  opacity: 0.6;
  transition: opacity var(--transition);
}
.settings-btn:hover { opacity: 1; }

/* ============================================
   MAIN
   ============================================ */
.main {
  flex: 1;
  margin-left: var(--sidebar-width);
  display: flex;
  flex-direction: column;
  min-height: 100vh;
  transition: margin-left var(--transition);
}

/* ============================================
   TOPBAR
   ============================================ */
.topbar {
  position: sticky;
  top: 0;
  z-index: 50;
  background: var(--topbar-bg);
  border-bottom: 1px solid var(--border);
  height: var(--topbar-height);
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 0 28px;
  gap: 16px;
  box-shadow: var(--shadow-sm);
}

.topbar-left, .topbar-right {
  display: flex;
  align-items: center;
  gap: 14px;
}

.menu-btn {
  display: none;
  background: none;
  border: none;
  font-size: 1.4rem;
  cursor: pointer;
  color: var(--text-secondary);
  padding: 6px;
  border-radius: var(--radius-sm);
  transition: background var(--transition);
}
.menu-btn:hover { background: var(--bg); }

.search-box {
  display: flex;
  align-items: center;
  gap: 10px;
  background: var(--bg);
  border: 1.5px solid var(--border);
  border-radius: 50px;
  padding: 8px 16px;
  transition: border-color var(--transition);
}
.search-box:focus-within { border-color: var(--accent-purple); }
.search-icon { color: var(--text-muted); font-size: 0.9rem; }
.search-box input {
  border: none;
  background: transparent;
  outline: none;
  font-size: 0.9rem;
  color: var(--text-primary);
  width: 220px;
}
.search-box input::placeholder { color: var(--text-muted); }

.notif-btn {
  position: relative;
  font-size: 1.3rem;
  cursor: pointer;
  padding: 8px;
  border-radius: var(--radius-sm);
  transition: background var(--transition);
}
.notif-btn:hover { background: var(--bg); }
.notif-badge {
  position: absolute;
  top: 4px; right: 4px;
  background: var(--accent-red);
  color: #fff;
  font-size: 0.6rem;
  font-weight: 700;
  min-width: 16px;
  height: 16px;
  border-radius: 8px;
  display: flex; align-items: center; justify-content: center;
  padding: 0 3px;
}

/* ============================================
   BUTTONS
   ============================================ */
.btn {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  padding: 10px 20px;
  border-radius: 50px;
  font-size: 0.875rem;
  font-weight: 600;
  cursor: pointer;
  border: none;
  transition: all var(--transition);
}

.btn-primary {
  background: linear-gradient(135deg, var(--accent-purple), #7c3aed);
  color: #fff;
  box-shadow: 0 4px 14px rgba(139,92,246,0.4);
}
.btn-primary:hover {
  transform: translateY(-1px);
  box-shadow: 0 6px 20px rgba(139,92,246,0.5);
}

.btn-ghost {
  background: var(--bg);
  color: var(--text-secondary);
  border: 1.5px solid var(--border);
}
.btn-ghost:hover { border-color: var(--border-hover); background: var(--border); }

.btn-danger {
  background: var(--accent-red);
  color: #fff;
}
.btn-danger:hover { background: #dc2626; transform: translateY(-1px); }

/* ============================================
   STATS ROW
   ============================================ */
.stats-row {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 16px;
  padding: 24px 28px 0;
}

.stat-card {
  background: var(--bg-card);
  border-radius: var(--radius-md);
  padding: 18px 20px;
  display: flex;
  align-items: center;
  gap: 16px;
  box-shadow: var(--shadow-sm);
  border: 1px solid var(--border);
  transition: transform var(--transition), box-shadow var(--transition);
}
.stat-card:hover {
  transform: translateY(-2px);
  box-shadow: var(--shadow-md);
}

.stat-icon {
  width: 46px; height: 46px;
  border-radius: var(--radius-sm);
  display: flex; align-items: center; justify-content: center;
  font-size: 1.3rem;
  flex-shrink: 0;
}

.stat-info { display: flex; flex-direction: column; }
.stat-value {
  font-size: 1.6rem;
  font-weight: 700;
  color: var(--text-primary);
  line-height: 1;
}
.stat-label {
  font-size: 0.78rem;
  color: var(--text-muted);
  margin-top: 4px;
  font-weight: 500;
}

/* ============================================
   BOARD
   ============================================ */
.board {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 20px;
  padding: 24px 28px 40px;
  flex: 1;
  align-items: start;
}

/* ============================================
   COLUMN
   ============================================ */
.column {
  background: var(--bg-column);
  border-radius: var(--radius-lg);
  border: 1px solid var(--border);
  display: flex;
  flex-direction: column;
  min-height: 300px;
  transition: box-shadow var(--transition);
}

.column.drag-over {
  box-shadow: 0 0 0 2px var(--accent-purple);
  background: rgba(139,92,246,0.04);
}

.column-header {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 16px 16px 12px;
  border-bottom: 1px solid var(--border);
}

.column-title {
  display: flex;
  align-items: center;
  gap: 8px;
}

.column-dot {
  width: 10px; height: 10px;
  border-radius: 50%;
  flex-shrink: 0;
}

.column-title h2 {
  font-size: 0.9rem;
  font-weight: 700;
  color: var(--text-primary);
}

.column-count {
  background: var(--bg-card);
  border: 1px solid var(--border);
  color: var(--text-secondary);
  font-size: 0.72rem;
  font-weight: 700;
  padding: 2px 8px;
  border-radius: 20px;
  min-width: 24px;
  text-align: center;
}

.col-add-btn {
  background: none;
  border: 1.5px solid var(--border);
  color: var(--text-muted);
  width: 28px; height: 28px;
  border-radius: 8px;
  cursor: pointer;
  font-size: 1rem;
  line-height: 1;
  display: flex; align-items: center; justify-content: center;
  transition: all var(--transition);
}
.col-add-btn:hover {
  border-color: var(--accent-purple);
  color: var(--accent-purple);
  background: var(--accent-purple-light);
}

/* TASK LIST */
.task-list {
  padding: 12px 10px;
  display: flex;
  flex-direction: column;
  gap: 10px;
  min-height: 60px;
  flex: 1;
}

.task-list.drag-over-list {
  background: rgba(139,92,246,0.06);
  border-radius: var(--radius-md);
}

/* ============================================
   TASK CARD
   ============================================ */
.task-card {
  background: var(--bg-card);
  border-radius: var(--radius-md);
  padding: 14px 14px 12px;
  box-shadow: var(--shadow-sm);
  border: 1.5px solid var(--border);
  cursor: grab;
  transition: all var(--transition);
  position: relative;
  user-select: none;
}

.task-card:hover {
  border-color: var(--border-hover);
  box-shadow: var(--shadow-md);
  transform: translateY(-1px);
}

.task-card.dragging {
  opacity: 0.45;
  cursor: grabbing;
  transform: rotate(2deg) scale(1.02);
  box-shadow: var(--shadow-lg);
}

.task-card.done-card {
  opacity: 0.75;
}

.task-card.done-card .task-title {
  text-decoration: line-through;
  color: var(--text-muted);
}

/* Card top row */
.card-top {
  display: flex;
  align-items: flex-start;
  justify-content: space-between;
  gap: 8px;
  margin-bottom: 8px;
}

.card-badges {
  display: flex;
  align-items: center;
  gap: 6px;
  flex-wrap: wrap;
}

.badge {
  font-size: 0.68rem;
  font-weight: 600;
  padding: 3px 8px;
  border-radius: 20px;
  text-transform: uppercase;
  letter-spacing: 0.5px;
}

.badge-cat-personal { background:#e8f4fd; color:#3b82f6; }
.badge-cat-work { background:#fef3c7; color:#d97706; }
.badge-cat-study { background:#ede9fe; color:#7c3aed; }
.badge-cat-health { background:#fce7f3; color:#db2777; }

.badge-prio-high { background:#fee2e2; color:#dc2626; }
.badge-prio-medium { background:#fef9c3; color:#b45309; }
.badge-prio-low { background:#dcfce7; color:#15803d; }

.card-actions {
  display: flex;
  gap: 4px;
  opacity: 0;
  transition: opacity var(--transition);
}
.task-card:hover .card-actions { opacity: 1; }

.action-btn {
  background: none;
  border: none;
  cursor: pointer;
  font-size: 0.9rem;
  padding: 3px 5px;
  border-radius: 6px;
  transition: background var(--transition);
  line-height: 1;
}
.action-btn:hover { background: var(--bg); }

/* Task title */
.task-title {
  font-size: 0.9rem;
  font-weight: 600;
  color: var(--text-primary);
  line-height: 1.35;
  margin-bottom: 6px;
}

/* Task description */
.task-desc {
  font-size: 0.78rem;
  color: var(--text-secondary);
  line-height: 1.45;
  margin-bottom: 10px;
  display: -webkit-box;
  -webkit-line-clamp: 2;
  -webkit-box-orient: vertical;
  overflow: hidden;
}

/* Tags */
.task-tags {
  display: flex;
  flex-wrap: wrap;
  gap: 5px;
  margin-bottom: 10px;
}

.tag {
  background: var(--bg);
  border: 1px solid var(--border);
  color: var(--text-secondary);
  font-size: 0.68rem;
  padding: 2px 7px;
  border-radius: 20px;
}

/* Card footer */
.card-footer {
  display: flex;
  align-items: center;
  justify-content: space-between;
  margin-top: 6px;
  border-top: 1px solid var(--border);
  padding-top: 8px;
}

.card-due {
  font-size: 0.72rem;
  color: var(--text-muted);
  display: flex;
  align-items: center;
  gap: 4px;
}

.card-due.overdue { color: var(--accent-red); font-weight: 600; }
.card-due.today { color: var(--accent-amber); font-weight: 600; }

.card-grip {
  color: var(--text-muted);
  font-size: 0.7rem;
  cursor: grab;
}

/* Empty state */
.empty-state {
  text-align: center;
  padding: 30px 16px;
  color: var(--text-muted);
  font-size: 0.8rem;
}
.empty-icon { font-size: 2rem; display: block; margin-bottom: 8px; }

/* ============================================
   MODAL
   ============================================ */
.modal-overlay {
  position: fixed;
  inset: 0;
  background: rgba(10,10,30,0.55);
  backdrop-filter: blur(4px);
  z-index: 200;
  display: none;
  align-items: center;
  justify-content: center;
  padding: 20px;
}
.modal-overlay.active { display: flex; }

.modal {
  background: var(--bg-card);
  border-radius: var(--radius-lg);
  width: 100%;
  max-width: 540px;
  box-shadow: var(--shadow-lg);
  animation: slideUp 0.25s ease;
}

.modal-sm { max-width: 380px; }

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

.modal-header {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 20px 24px;
  border-bottom: 1px solid var(--border);
}
.modal-header h2 { font-size: 1.1rem; font-weight: 700; }

.modal-close {
  background: none;
  border: none;
  color: var(--text-muted);
  font-size: 1rem;
  cursor: pointer;
  padding: 6px 9px;
  border-radius: var(--radius-sm);
  transition: all var(--transition);
}
.modal-close:hover { background: var(--bg); color: var(--text-primary); }

.modal-body {
  padding: 20px 24px;
  display: flex;
  flex-direction: column;
  gap: 14px;
}

.modal-body p {
  color: var(--text-secondary);
  font-size: 0.9rem;
  line-height: 1.5;
}

.form-row {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 14px;
}

.form-group {
  display: flex;
  flex-direction: column;
  gap: 6px;
}

.form-group label {
  font-size: 0.8rem;
  font-weight: 600;
  color: var(--text-secondary);
}

.form-group input,
.form-group textarea,
.form-group select {
  padding: 10px 13px;
  border: 1.5px solid var(--border);
  border-radius: var(--radius-sm);
  font-size: 0.88rem;
  color: var(--text-primary);
  background: var(--bg-card);
  outline: none;
  transition: border-color var(--transition);
  font-family: inherit;
  resize: none;
}

.form-group input:focus,
.form-group textarea:focus,
.form-group select:focus {
  border-color: var(--accent-purple);
  box-shadow: 0 0 0 3px rgba(139,92,246,0.12);
}

.modal-footer {
  display: flex;
  justify-content: flex-end;
  gap: 10px;
  padding: 16px 24px;
  border-top: 1px solid var(--border);
}

/* ============================================
   TOAST
   ============================================ */
.toast-container {
  position: fixed;
  bottom: 28px;
  right: 28px;
  z-index: 999;
  display: flex;
  flex-direction: column;
  gap: 10px;
  pointer-events: none;
}

.toast {
  background: var(--sidebar-bg);
  color: #fff;
  padding: 13px 20px;
  border-radius: var(--radius-md);
  font-size: 0.85rem;
  display: flex;
  align-items: center;
  gap: 10px;
  box-shadow: var(--shadow-lg);
  animation: toastIn 0.3s ease;
  min-width: 240px;
  pointer-events: auto;
  border-left: 4px solid var(--accent-purple);
}

.toast.success { border-left-color: var(--accent-green); }
.toast.danger  { border-left-color: var(--accent-red);   }
.toast.info    { border-left-color: var(--accent-blue);  }

@keyframes toastIn {
  from { opacity: 0; transform: translateX(40px); }
  to   { opacity: 1; transform: translateX(0);    }
}

@keyframes toastOut {
  from { opacity: 1; transform: translateX(0); }
  to   { opacity: 0; transform: translateX(40px); }
}

/* ============================================
   OVERLAY (mobile)
   ============================================ */
.sidebar-overlay {
  display: none;
  position: fixed;
  inset: 0;
  background: rgba(0,0,0,0.4);
  z-index: 90;
}

/* ============================================
   RESPONSIVE
   ============================================ */
@media (max-width: 1200px) {
  .stats-row { grid-template-columns: repeat(2, 1fr); }
  .board { grid-template-columns: repeat(2, 1fr); }
}

@media (max-width: 768px) {
  :root { --sidebar-width: 260px; }

  .sidebar {
    transform: translateX(-100%);
  }
  .sidebar.open {
    transform: translateX(0);
    box-shadow: var(--shadow-lg);
  }
  .sidebar-toggle { display: block; }
  .sidebar-overlay { display: block; }
  .sidebar-overlay.active { display: block; }
  .sidebar-overlay:not(.active) { display: none; }

  .main { margin-left: 0; }
  .menu-btn { display: flex; }

  .topbar { padding: 0 16px; }
  .search-box input { width: 140px; }

  .stats-row { padding: 16px 16px 0; gap: 12px; }
  .board { grid-template-columns: 1fr; padding: 16px 16px 40px; }

  .stat-value { font-size: 1.3rem; }
}

@media (max-width: 480px) {
  .stats-row { grid-template-columns: repeat(2, 1fr); }
  .search-box input { width: 100px; }
  .form-row { grid-template-columns: 1fr; }
  .topbar-right .notif-btn { display: none; }
}