@import url('https://fonts.googleapis.com/css2?family=Inter:wght@300;400;500;600;700&display=swap');

/* ── Design tokens ─────────────────────────────────── */
:root {
  --bg:            #0f172a;
  --surface:       #1e293b;
  --surface-2:     #263348;
  --border:        #334155;
  --border-hover:  #475569;
  --accent:        #6366f1;
  --accent-hover:  #4f46e5;
  --accent-muted:  rgba(99,102,241,0.15);
  --text-primary:  #f1f5f9;
  --text-secondary:#94a3b8;
  --text-muted:    #64748b;
  --priority-high:   #ef4444;
  --priority-medium: #f59e0b;
  --priority-low:    #22c55e;
  --danger:        #ef4444;
  --danger-muted:  rgba(239,68,68,0.12);
  --success:       #22c55e;
  --success-muted: rgba(34,197,94,0.12);
  --radius-sm:     6px;
  --radius:        10px;
  --radius-lg:     16px;
  --shadow:        0 4px 24px rgba(0,0,0,0.4);
}

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

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

a { color: inherit; text-decoration: none; }

/* ── Navbar ────────────────────────────────────────── */
.navbar {
  position: sticky;
  top: 0;
  z-index: 100;
  background: var(--surface);
  border-bottom: 1px solid var(--border);
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 0 24px;
  height: 60px;
}

.navbar-brand {
  font-size: 20px;
  font-weight: 700;
  background: linear-gradient(135deg, #6366f1, #8b5cf6);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
  display: flex;
  align-items: center;
  gap: 8px;
}

.navbar-brand::before {
  content: "✓";
  display: inline-flex;
  align-items: center;
  justify-content: center;
  width: 32px;
  height: 32px;
  background: linear-gradient(135deg, #6366f1, #8b5cf6);
  border-radius: 8px;
  color: white;
  font-size: 16px;
  -webkit-text-fill-color: white;
}

.navbar-right {
  display: flex;
  align-items: center;
  gap: 14px;
}

.navbar-username {
  color: var(--text-secondary);
  font-size: 14px;
}

.navbar-logout {
  padding: 6px 14px;
  background: transparent;
  border: 1px solid var(--border);
  border-radius: var(--radius-sm);
  color: var(--text-secondary);
  font-size: 13px;
  font-weight: 500;
  cursor: pointer;
  transition: all 0.2s;
}

.navbar-logout:hover {
  border-color: var(--border-hover);
  color: var(--text-primary);
  background: var(--surface-2);
}

/* ── Flash messages ────────────────────────────────── */
.flash-container {
  max-width: 900px;
  margin: 16px auto 0;
  padding: 0 20px;
  display: flex;
  flex-direction: column;
  gap: 8px;
}

.alert {
  padding: 12px 16px;
  border-radius: var(--radius-sm);
  font-size: 14px;
  border: 1px solid;
  animation: slideDown 0.25s ease;
}

@keyframes slideDown {
  from { opacity: 0; transform: translateY(-8px); }
  to   { opacity: 1; transform: translateY(0); }
}

.alert.success {
  background: var(--success-muted);
  border-color: rgba(34,197,94,0.3);
  color: #86efac;
}

.alert.error {
  background: var(--danger-muted);
  border-color: rgba(239,68,68,0.3);
  color: #fca5a5;
}

/* ── Main layout ───────────────────────────────────── */
.main-content {
  max-width: 900px;
  margin: 24px auto 60px;
  padding: 0 20px;
}

/* ── Stats row ─────────────────────────────────────── */
.stats-row {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 12px;
  margin-bottom: 20px;
}

.stat-card {
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 16px 20px;
  display: flex;
  flex-direction: column;
  gap: 4px;
}

.stat-label {
  font-size: 12px;
  font-weight: 500;
  text-transform: uppercase;
  letter-spacing: 0.06em;
  color: var(--text-muted);
}

.stat-value {
  font-size: 28px;
  font-weight: 700;
  color: var(--text-primary);
  line-height: 1;
}

.stat-card.stat-active .stat-value   { color: var(--accent); }
.stat-card.stat-done  .stat-value    { color: var(--success); }

/* ── Control bar ───────────────────────────────────── */
.control-bar {
  display: flex;
  align-items: center;
  gap: 10px;
  margin-bottom: 16px;
  flex-wrap: wrap;
}

/* Search */
.search-wrap {
  position: relative;
  flex: 1;
  min-width: 180px;
}

.search-icon {
  position: absolute;
  left: 11px;
  top: 50%;
  transform: translateY(-50%);
  color: var(--text-muted);
  pointer-events: none;
  font-size: 14px;
}

.search-input {
  width: 100%;
  padding: 9px 12px 9px 34px;
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: var(--radius-sm);
  color: var(--text-primary);
  font-size: 14px;
  font-family: inherit;
  transition: border-color 0.2s, box-shadow 0.2s;
}

.search-input::placeholder { color: var(--text-muted); }

.search-input:focus {
  outline: none;
  border-color: var(--accent);
  box-shadow: 0 0 0 3px var(--accent-muted);
}

/* Filter tabs */
.filter-tabs {
  display: flex;
  gap: 4px;
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: var(--radius-sm);
  padding: 3px;
}

.filter-tab {
  padding: 6px 14px;
  border-radius: 4px;
  font-size: 13px;
  font-weight: 500;
  color: var(--text-secondary);
  transition: all 0.2s;
  white-space: nowrap;
}

.filter-tab:hover { color: var(--text-primary); background: var(--surface-2); }

.filter-tab.active {
  background: var(--accent);
  color: #fff;
}

/* Sort select */
.sort-select {
  padding: 9px 12px;
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: var(--radius-sm);
  color: var(--text-primary);
  font-size: 13px;
  font-family: inherit;
  cursor: pointer;
  appearance: none;
  -webkit-appearance: none;
  background-image: url("data:image/svg+xml,%3Csvg xmlns='http://www.w3.org/2000/svg' width='12' height='12' viewBox='0 0 12 12'%3E%3Cpath fill='%2394a3b8' d='M6 8L1 3h10z'/%3E%3C/svg%3E");
  background-repeat: no-repeat;
  background-position: right 10px center;
  padding-right: 30px;
  transition: border-color 0.2s;
}

.sort-select:focus {
  outline: none;
  border-color: var(--accent);
  box-shadow: 0 0 0 3px var(--accent-muted);
}

.sort-select option { background: var(--surface); }

/* Export button */
.btn-export {
  padding: 9px 16px;
  background: transparent;
  border: 1px solid var(--border);
  border-radius: var(--radius-sm);
  color: var(--text-secondary);
  font-size: 13px;
  font-weight: 500;
  white-space: nowrap;
  transition: all 0.2s;
  display: flex;
  align-items: center;
  gap: 6px;
}

.btn-export:hover {
  border-color: var(--accent);
  color: var(--accent);
  background: var(--accent-muted);
}

/* ── Add-task card ─────────────────────────────────── */
.add-task-card {
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 16px 20px;
  margin-bottom: 20px;
}

.add-task-form {
  display: flex;
  gap: 10px;
  flex-wrap: wrap;
  align-items: center;
}

.add-task-input {
  flex: 1;
  min-width: 200px;
  padding: 9px 14px;
  background: var(--bg);
  border: 1px solid var(--border);
  border-radius: var(--radius-sm);
  color: var(--text-primary);
  font-size: 14px;
  font-family: inherit;
  transition: border-color 0.2s, box-shadow 0.2s;
}

.add-task-input::placeholder { color: var(--text-muted); }

.add-task-input:focus {
  outline: none;
  border-color: var(--accent);
  box-shadow: 0 0 0 3px var(--accent-muted);
}

.add-task-date,
.add-task-priority {
  padding: 9px 12px;
  background: var(--bg);
  border: 1px solid var(--border);
  border-radius: var(--radius-sm);
  color: var(--text-primary);
  font-size: 14px;
  font-family: inherit;
  transition: border-color 0.2s;
}

.add-task-date:focus,
.add-task-priority:focus {
  outline: none;
  border-color: var(--accent);
  box-shadow: 0 0 0 3px var(--accent-muted);
}

.add-task-priority { cursor: pointer; }
.add-task-priority option { background: var(--surface); }

.btn-add {
  padding: 9px 20px;
  background: var(--accent);
  border: none;
  border-radius: var(--radius-sm);
  color: #fff;
  font-size: 14px;
  font-weight: 600;
  font-family: inherit;
  cursor: pointer;
  transition: background 0.2s;
  white-space: nowrap;
}

.btn-add:hover { background: var(--accent-hover); }

/* ── Task cards ────────────────────────────────────── */
.task-list {
  display: flex;
  flex-direction: column;
  gap: 8px;
}

.task-card {
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  display: flex;
  align-items: center;
  gap: 14px;
  padding: 14px 16px;
  border-left: 3px solid var(--border);
  transition: border-color 0.2s, background 0.2s;
}

.task-card:hover { background: var(--surface-2); border-color: var(--border-hover); }

.task-card.priority-high   { border-left-color: var(--priority-high); }
.task-card.priority-medium { border-left-color: var(--priority-medium); }
.task-card.priority-low    { border-left-color: var(--priority-low); }
.task-card.overdue         { background: rgba(239,68,68,0.05); }
.task-card.completed-card  { opacity: 0.65; }

/* Circle checkbox */
.task-check {
  width: 22px;
  height: 22px;
  border-radius: 50%;
  border: 2px solid var(--border-hover);
  display: flex;
  align-items: center;
  justify-content: center;
  flex-shrink: 0;
  transition: all 0.2s;
  color: transparent;
  font-size: 12px;
}

.task-check:hover {
  border-color: var(--accent);
  background: var(--accent-muted);
  color: var(--accent);
}

.task-card.completed-card .task-check {
  background: var(--success);
  border-color: var(--success);
  color: #fff;
}

/* Task body */
.task-body {
  flex: 1;
  min-width: 0;
}

.task-content {
  font-size: 15px;
  color: var(--text-primary);
  word-break: break-word;
}

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

.task-meta {
  display: flex;
  align-items: center;
  gap: 8px;
  margin-top: 4px;
  flex-wrap: wrap;
}

.badge {
  display: inline-flex;
  align-items: center;
  padding: 2px 8px;
  border-radius: 20px;
  font-size: 11px;
  font-weight: 600;
  text-transform: uppercase;
  letter-spacing: 0.05em;
}

.badge-high   { background: rgba(239,68,68,0.15);   color: #fca5a5; }
.badge-medium { background: rgba(245,158,11,0.15);  color: #fcd34d; }
.badge-low    { background: rgba(34,197,94,0.15);   color: #86efac; }
.badge-overdue{ background: var(--danger-muted);    color: #fca5a5; }

.task-date {
  font-size: 12px;
  color: var(--text-muted);
}

/* Task actions */
.task-actions {
  display: flex;
  align-items: center;
  gap: 4px;
  flex-shrink: 0;
}

.action-btn {
  width: 32px;
  height: 32px;
  border-radius: var(--radius-sm);
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 15px;
  transition: all 0.2s;
  color: var(--text-muted);
  border: none;
  background: none;
  cursor: pointer;
  padding: 0;
}

.action-btn:hover { background: var(--surface-2); color: var(--text-primary); }
.action-btn.delete:hover { background: var(--danger-muted); color: var(--danger); }

/* ── Empty state ───────────────────────────────────── */
.empty-state {
  text-align: center;
  padding: 60px 20px;
  color: var(--text-muted);
}

.empty-icon {
  font-size: 48px;
  margin-bottom: 16px;
  opacity: 0.4;
}

.empty-title {
  font-size: 18px;
  font-weight: 600;
  color: var(--text-secondary);
  margin-bottom: 8px;
}

.empty-sub {
  font-size: 14px;
}

/* ── Auth pages ────────────────────────────────────── */
.auth-page {
  min-height: 100vh;
  background: linear-gradient(135deg, #0f172a 0%, #1e1b4b 50%, #0f172a 100%);
  display: flex;
  align-items: center;
  justify-content: center;
  padding: 20px;
}

.auth-card {
  width: 100%;
  max-width: 420px;
  background: rgba(30,41,59,0.8);
  backdrop-filter: blur(20px);
  -webkit-backdrop-filter: blur(20px);
  border: 1px solid rgba(99,102,241,0.2);
  border-radius: var(--radius-lg);
  padding: 40px;
  box-shadow: 0 8px 48px rgba(0,0,0,0.5), 0 0 0 1px rgba(255,255,255,0.04);
}

.auth-brand {
  text-align: center;
  margin-bottom: 8px;
}

.auth-brand-text {
  font-size: 28px;
  font-weight: 800;
  background: linear-gradient(135deg, #6366f1, #8b5cf6, #a78bfa);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
  display: flex;
  align-items: center;
  justify-content: center;
  gap: 8px;
}

.auth-brand-icon {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  width: 36px;
  height: 36px;
  background: linear-gradient(135deg, #6366f1, #8b5cf6);
  border-radius: 10px;
  color: white;
  font-size: 18px;
  -webkit-text-fill-color: white;
}

.auth-subtitle {
  text-align: center;
  color: var(--text-muted);
  font-size: 14px;
  margin-bottom: 28px;
}

.auth-flash {
  margin-bottom: 16px;
  display: flex;
  flex-direction: column;
  gap: 8px;
}

.form-group {
  margin-bottom: 18px;
}

.form-group label {
  display: block;
  margin-bottom: 6px;
  font-size: 13px;
  font-weight: 500;
  color: var(--text-secondary);
}

.form-group input {
  width: 100%;
  padding: 10px 14px;
  background: var(--bg);
  border: 1px solid var(--border);
  border-radius: var(--radius-sm);
  color: var(--text-primary);
  font-size: 14px;
  font-family: inherit;
  transition: border-color 0.2s, box-shadow 0.2s;
}

.form-group input::placeholder { color: var(--text-muted); }

.form-group input:focus {
  outline: none;
  border-color: var(--accent);
  box-shadow: 0 0 0 3px var(--accent-muted);
}

.auth-btn {
  width: 100%;
  padding: 12px;
  background: linear-gradient(135deg, var(--accent), #8b5cf6);
  border: none;
  border-radius: var(--radius-sm);
  color: #fff;
  font-size: 15px;
  font-weight: 600;
  font-family: inherit;
  cursor: pointer;
  transition: opacity 0.2s, transform 0.1s;
  margin-top: 4px;
}

.auth-btn:hover  { opacity: 0.9; }
.auth-btn:active { transform: scale(0.99); }

.auth-footer {
  text-align: center;
  margin-top: 24px;
  font-size: 14px;
  color: var(--text-muted);
}

.auth-footer a {
  color: var(--accent);
  font-weight: 500;
  transition: color 0.2s;
}

.auth-footer a:hover { color: #a5b4fc; }

/* ── Update page ───────────────────────────────────── */
.update-page {
  min-height: calc(100vh - 60px);
  display: flex;
  align-items: flex-start;
  justify-content: center;
  padding: 40px 20px;
}

.update-card {
  width: 100%;
  max-width: 560px;
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: var(--radius-lg);
  padding: 36px 40px;
}

.update-title {
  font-size: 20px;
  font-weight: 700;
  color: var(--text-primary);
  margin-bottom: 24px;
}

.update-content-input {
  width: 100%;
  padding: 10px 14px;
  background: var(--bg);
  border: 1px solid var(--border);
  border-radius: var(--radius-sm);
  color: var(--text-primary);
  font-size: 15px;
  font-family: inherit;
  margin-bottom: 16px;
  transition: border-color 0.2s, box-shadow 0.2s;
}

.update-content-input:focus {
  outline: none;
  border-color: var(--accent);
  box-shadow: 0 0 0 3px var(--accent-muted);
}

.update-row {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 12px;
  margin-bottom: 24px;
}

.update-field label {
  display: block;
  font-size: 13px;
  font-weight: 500;
  color: var(--text-secondary);
  margin-bottom: 6px;
}

.update-field input,
.update-field select {
  width: 100%;
  padding: 9px 12px;
  background: var(--bg);
  border: 1px solid var(--border);
  border-radius: var(--radius-sm);
  color: var(--text-primary);
  font-size: 14px;
  font-family: inherit;
  transition: border-color 0.2s, box-shadow 0.2s;
}

.update-field input:focus,
.update-field select:focus {
  outline: none;
  border-color: var(--accent);
  box-shadow: 0 0 0 3px var(--accent-muted);
}

.update-field select { cursor: pointer; }
.update-field select option { background: var(--surface); }

.update-actions {
  display: flex;
  align-items: center;
  gap: 14px;
}

.btn-save {
  padding: 10px 24px;
  background: var(--accent);
  border: none;
  border-radius: var(--radius-sm);
  color: #fff;
  font-size: 14px;
  font-weight: 600;
  font-family: inherit;
  cursor: pointer;
  transition: background 0.2s;
}

.btn-save:hover { background: var(--accent-hover); }

.btn-back {
  font-size: 14px;
  color: var(--text-secondary);
  transition: color 0.2s;
}

.btn-back:hover { color: var(--text-primary); }

/* ── Responsive ────────────────────────────────────── */
@media (max-width: 640px) {
  .navbar { padding: 0 16px; }

  .stats-row { grid-template-columns: repeat(3, 1fr); gap: 8px; }
  .stat-card { padding: 12px 14px; }
  .stat-value { font-size: 22px; }

  .control-bar { gap: 8px; }
  .filter-tabs { order: 2; width: 100%; }
  .filter-tab  { flex: 1; text-align: center; }

  .add-task-form { flex-direction: column; align-items: stretch; }
  .add-task-input { min-width: 0; }

  .update-row { grid-template-columns: 1fr; }
  .update-card { padding: 24px 20px; }
}