:root {
  --bg: #0f0f0f;
  --surface: #1a1a1a;
  --surface-hover: #242424;
  --border: #2a2a2a;
  --text: #f5f5f5;
  --text-muted: #a3a3a3;
  --accent: #22d3ee;
  --accent-hover: #06b6d4;
  --danger: #f87171;
  --danger-hover: #ef4444;
  --radius: 12px;
  --radius-sm: 8px;
  --shadow: 0 4px 24px rgba(0,0,0,0.4);
}

* { box-sizing: border-box; }
body {
  font-family: 'Plus Jakarta Sans', system-ui, sans-serif;
  background: var(--bg);
  color: var(--text);
  min-height: 100vh;
  margin: 0;
  padding: 2rem 1rem;
  line-height: 1.5;
}

.app {
  max-width: 440px;
  margin: 0 auto;
}

.header {
  margin-bottom: 2rem;
}

.header h1 {
  font-size: 1.75rem;
  font-weight: 700;
  letter-spacing: -0.02em;
  margin: 0 0 0.25rem 0;
}

.header p {
  color: var(--text-muted);
  font-size: 0.9rem;
  margin: 0;
}

.card {
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 1.5rem;
  box-shadow: var(--shadow);
}

.add-row {
  display: flex;
  gap: 0.75rem;
  margin-bottom: 1.5rem;
}

.add-row input {
  flex: 1;
  padding: 0.75rem 1rem;
  font-size: 0.95rem;
  font-family: inherit;
  color: var(--text);
  background: var(--bg);
  border: 1px solid var(--border);
  border-radius: var(--radius-sm);
  outline: none;
  transition: border-color 0.2s, box-shadow 0.2s;
}

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

.add-row input:focus {
  border-color: var(--accent);
  box-shadow: 0 0 0 3px rgba(34, 211, 238, 0.15);
}

.btn {
  font-family: inherit;
  font-size: 0.9rem;
  font-weight: 600;
  padding: 0.75rem 1.25rem;
  border: none;
  border-radius: var(--radius-sm);
  cursor: pointer;
  transition: background 0.2s, transform 0.1s;
}

.btn:active {
  transform: scale(0.98);
}

.btn-primary {
  background: var(--accent);
  color: var(--bg);
}

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

.task-list {
  list-style: none;
  padding: 0;
  margin: 0;
}

.task-list li {
  display: flex;
  align-items: center;
  gap: 0.75rem;
  padding: 0.875rem 1rem;
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: var(--radius-sm);
  margin-bottom: 0.5rem;
  transition: background 0.2s, border-color 0.2s;
}

.task-list li:hover {
  background: var(--surface-hover);
  border-color: var(--border);
}

.task-list li span {
  flex: 1;
  font-size: 0.95rem;
}

.task-list li .btn-delete {
  padding: 0.4rem 0.65rem;
  font-size: 0.8rem;
  font-weight: 500;
  background: transparent;
  color: var(--text-muted);
  border: 1px solid var(--border);
  border-radius: 6px;
  cursor: pointer;
  transition: color 0.2s, background 0.2s, border-color 0.2s;
}

.task-list li .btn-delete:hover {
  color: var(--danger);
  border-color: var(--danger);
  background: rgba(248, 113, 113, 0.08);
}

.empty-state {
  text-align: center;
  padding: 2.5rem 1rem;
  color: var(--text-muted);
}

.empty-state .icon {
  font-size: 2.5rem;
  margin-bottom: 0.75rem;
  opacity: 0.6;
}

.empty-state p {
  margin: 0;
  font-size: 0.95rem;
}

.error {
  color: var(--danger);
  font-size: 0.875rem;
  margin-top: 0.5rem;
  padding: 0.5rem 0;
}

/* Auth (login/register) */
.auth-card .form-row {
  margin-bottom: 1rem;
}
.auth-card .form-row label {
  display: block;
  font-size: 0.85rem;
  color: var(--text-muted);
  margin-bottom: 0.35rem;
}
.auth-card .form-row input {
  width: 100%;
  padding: 0.6rem 0.75rem;
  font-size: 0.95rem;
  font-family: inherit;
  color: var(--text);
  background: var(--bg);
  border: 1px solid var(--border);
  border-radius: var(--radius-sm);
  outline: none;
}
.auth-card .form-row input:focus {
  border-color: var(--accent);
}
.auth-tabs {
  display: flex;
  gap: 0.5rem;
  margin-bottom: 1.25rem;
}
.auth-tabs button {
  flex: 1;
  padding: 0.5rem;
  font-size: 0.9rem;
  font-weight: 500;
  background: transparent;
  color: var(--text-muted);
  border: 1px solid var(--border);
  border-radius: var(--radius-sm);
  cursor: pointer;
}
.auth-tabs button.active {
  background: var(--accent);
  color: var(--bg);
  border-color: var(--accent);
}
.auth-card .btn {
  width: 100%;
  margin-top: 0.5rem;
}
.header-row {
  display: flex;
  justify-content: space-between;
  align-items: center;
  margin-bottom: 2rem;
}
.btn-logout {
  padding: 0.4rem 0.75rem;
  font-size: 0.85rem;
  font-weight: 500;
  background: transparent;
  color: var(--text-muted);
  border: 1px solid var(--border);
  border-radius: var(--radius-sm);
  cursor: pointer;
}
.btn-logout:hover {
  color: var(--danger);
  border-color: var(--danger);
}
.hidden { display: none !important; }