:root {
  --bg: #0f172a;
  --panel: rgba(15, 23, 42, 0.72);
  --card: rgba(30, 41, 59, 0.88);
  --line: rgba(148, 163, 184, 0.18);
  --text: #e2e8f0;
  --muted: #94a3b8;
  --accent: #38bdf8;
  --accent-strong: #0ea5e9;
  --success: #34d399;
  --danger: #f87171;
  --shadow: 0 24px 80px rgba(15, 23, 42, 0.45);
}

* {
  box-sizing: border-box;
}

body {
  margin: 0;
  min-height: 100vh;
  font-family: Inter, "Segoe UI", system-ui, sans-serif;
  color: var(--text);
  background:
    radial-gradient(circle at top left, rgba(56, 189, 248, 0.18), transparent 28%),
    radial-gradient(circle at bottom right, rgba(52, 211, 153, 0.12), transparent 24%),
    linear-gradient(160deg, #020617 0%, #0f172a 45%, #111827 100%);
}

.app {
  width: min(760px, calc(100% - 32px));
  margin: 48px auto;
}

.header,
.main {
  backdrop-filter: blur(18px);
  background: var(--panel);
  border: 1px solid var(--line);
  box-shadow: var(--shadow);
}

.header {
  display: flex;
  justify-content: space-between;
  gap: 24px;
  padding: 28px 28px 24px;
  border-radius: 24px 24px 0 0;
}

.eyebrow {
  margin: 0 0 8px;
  color: var(--accent);
  font-size: 0.82rem;
  letter-spacing: 0.08em;
  text-transform: uppercase;
}

.header h1 {
  margin: 0;
  font-size: clamp(1.8rem, 4vw, 2.4rem);
}

.subtitle {
  margin: 10px 0 0;
  color: var(--muted);
}

.stats {
  display: grid;
  grid-template-columns: repeat(3, minmax(72px, 1fr));
  gap: 12px;
}

.stat {
  padding: 14px 16px;
  border-radius: 16px;
  background: var(--card);
  border: 1px solid var(--line);
  text-align: center;
}

.stat span {
  display: block;
  font-size: 1.5rem;
  font-weight: 700;
}

.stat small {
  color: var(--muted);
}

.main {
  padding: 24px 28px 28px;
  border-top: none;
  border-radius: 0 0 24px 24px;
}

.task-form {
  display: grid;
  grid-template-columns: 1fr auto;
  gap: 12px;
}

.task-form input,
.task-form button,
.filter,
.ghost {
  border: 1px solid var(--line);
  border-radius: 14px;
  font: inherit;
}

.task-form input {
  width: 100%;
  padding: 14px 16px;
  color: var(--text);
  background: rgba(15, 23, 42, 0.65);
}

.task-form input:focus {
  outline: 2px solid rgba(56, 189, 248, 0.35);
  border-color: rgba(56, 189, 248, 0.55);
}

.task-form button,
.filter.active {
  background: linear-gradient(135deg, var(--accent), var(--accent-strong));
  color: #082f49;
  font-weight: 700;
}

.task-form button {
  padding: 0 20px;
  cursor: pointer;
}

.toolbar {
  display: flex;
  flex-wrap: wrap;
  gap: 10px;
  margin: 18px 0;
}

.filter,
.ghost {
  padding: 10px 14px;
  color: var(--text);
  background: rgba(15, 23, 42, 0.55);
  cursor: pointer;
}

.ghost {
  margin-left: auto;
  color: var(--danger);
}

.task-list {
  list-style: none;
  margin: 0;
  padding: 0;
  display: grid;
  gap: 12px;
}

.task-item {
  display: grid;
  grid-template-columns: auto 1fr auto;
  align-items: center;
  gap: 14px;
  padding: 16px 18px;
  border-radius: 16px;
  background: var(--card);
  border: 1px solid var(--line);
  animation: fadeIn 0.25s ease;
}

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

.task-title {
  margin: 0;
  word-break: break-word;
}

.task-meta {
  margin: 4px 0 0;
  color: var(--muted);
  font-size: 0.82rem;
}

.checkbox {
  width: 22px;
  height: 22px;
  accent-color: var(--success);
  cursor: pointer;
}

.delete-btn {
  border: none;
  background: transparent;
  color: var(--danger);
  cursor: pointer;
  padding: 6px 10px;
  border-radius: 10px;
}

.delete-btn:hover {
  background: rgba(248, 113, 113, 0.12);
}

.empty-state {
  margin: 0;
  padding: 28px 12px;
  text-align: center;
  color: var(--muted);
}

.empty-state.hidden {
  display: none;
}

@keyframes fadeIn {
  from {
    opacity: 0;
    transform: translateY(6px);
  }
  to {
    opacity: 1;
    transform: translateY(0);
  }
}

@media (max-width: 640px) {
  .header {
    flex-direction: column;
  }

  .toolbar {
    align-items: stretch;
  }

  .ghost {
    margin-left: 0;
  }
}