:root {
  --bg: #0b0f14;
  --panel: #111722;
  --text: #e6eef8;
  --muted: #a7b3c2;
  --primary: #4ea1ff;
  --accent: #7bd389;
  --danger: #ff6b6b;
  --border: #1b2432;
  --shadow: 0 10px 30px rgba(0, 0, 0, 0.35);
}

* {
  box-sizing: border-box;
}
html,
body {
  height: 100%;
}
body {
  margin: 0;
  font-family: ui-sans-serif, system-ui, -apple-system, Segoe UI, Roboto,
    Helvetica, Arial, "Apple Color Emoji", "Segoe UI Emoji";
  background: linear-gradient(160deg, #0b0f14, #0e1622 60%, #0b0f14);
  color: var(--text);
  display: grid;
  place-items: center;
}

.app {
  width: min(680px, calc(100% - 32px));
  background: var(--panel);
  border: 1px solid var(--border);
  border-radius: 14px;
  box-shadow: var(--shadow);
  padding: 24px;
}

h1 {
  margin: 0 0 12px;
  font-size: 22px;
  letter-spacing: 0.4px;
}

/* Form */
#todo-form {
  display: grid;
  grid-template-columns: 1fr auto;
  gap: 10px;
  margin-bottom: 16px;
}
#todo-input {
  padding: 12px 14px;
  border-radius: 10px;
  border: 1px solid var(--border);
  background: #0d1420;
  color: var(--text);
  outline: none;
}
#todo-input::placeholder {
  color: #70819b;
}
#todo-form button[type="submit"] {
  padding: 0 14px;
  border-radius: 10px;
  border: 1px solid transparent;
  background: var(--primary);
  color: #001025;
  font-weight: 600;
  cursor: pointer;
}

/* Controls */
.controls {
  display: grid;
  grid-template-columns: 1fr auto 1fr;
  align-items: center;
  gap: 8px;
  padding: 10px 12px;
  border: 1px solid var(--border);
  border-radius: 10px;
  background: #0d1420;
  margin-bottom: 12px;
}
.controls .left {
  color: var(--muted);
  font-size: 14px;
}
.controls .right {
  text-align: right;
}
.controls .muted {
  color: var(--muted);
  background: transparent;
  border: 1px solid var(--border);
  padding: 6px 10px;
  border-radius: 8px;
  cursor: pointer;
}
.filters {
  display: inline-flex;
  gap: 6px;
}
.filters .filter {
  border: 1px solid var(--border);
  background: #0b1220;
  color: var(--muted);
  padding: 6px 10px;
  border-radius: 999px;
  cursor: pointer;
}
.filters .filter.is-active {
  color: var(--text);
  border-color: var(--primary);
  box-shadow: 0 0 0 3px rgba(78, 161, 255, 0.2) inset;
}

/* List */
.todo-list {
  list-style: none;
  margin: 0;
  padding: 0;
  display: grid;
  gap: 8px;
}
.todo-item {
  display: grid;
  grid-template-columns: auto 1fr auto;
  gap: 10px;
  align-items: center;
  padding: 12px;
  border-radius: 12px;
  background: #0d1420;
  border: 1px solid var(--border);
}
.todo-item .checkbox {
  width: 18px;
  height: 18px;
  border-radius: 5px;
  border: 1px solid var(--border);
  appearance: none;
  background: #0a111b;
  cursor: pointer;
  display: grid;
  place-items: center;
}
.todo-item .checkbox:checked {
  background: var(--accent);
  border-color: #1e2a22;
}
.todo-item .checkbox:checked::after {
  content: "✓";
  color: #082312;
  font-weight: 900;
  font-size: 14px;
}
.todo-item .title {
  line-height: 1.4;
}
.todo-item.completed .title {
  color: #7d8ba1;
  text-decoration: line-through;
}
.todo-item .actions {
  display: inline-flex;
  gap: 6px;
}
.todo-item .icon-btn {
  border: 1px solid var(--border);
  background: #0b1220;
  color: var(--muted);
  padding: 6px 8px;
  border-radius: 8px;
  cursor: pointer;
}
.todo-item .icon-btn.delete {
  color: #ffd5d5;
  border-color: #3e1f24;
  background: #1a0f12;
}

.edit-input {
  width: 100%;
  padding: 8px 10px;
  border: 1px solid var(--border);
  border-radius: 8px;
  background: #0a111b;
  color: var(--text);
}

.footer {
  margin-top: 14px;
  color: var(--muted);
  text-align: center;
  font-size: 12px;
}

@media (max-width: 480px) {
  .controls {
    grid-template-columns: 1fr;
    gap: 10px;
  }
  .controls .right {
    text-align: left;
  }
}