body {
  font-family: "Trebuchet MS", Arial, sans-serif;
  background: #f2f2f2;
  margin: 0;
  padding: 40px 20px;
  color: #222;
}

.app {
  max-width: 420px;
  margin: 0 auto;
  background: #ffffff;
  border-radius: 10px;
  box-shadow: 0 4px 16px rgba(0, 0, 0, 0.08);
  overflow: hidden;
}

.app-header {
  background: #1f3864;
  color: #ffffff;
  padding: 24px 26px 20px;
}

.app-header h1 {
  margin: 0 0 4px;
  font-size: 1.4rem;
}

.app-header p {
  margin: 0;
  color: #cfd8ea;
  font-size: 0.9rem;
}

.add-row {
  display: flex;
  gap: 10px;
  padding: 20px 26px 14px;
}

.add-input {
  flex: 1;
  padding: 10px 12px;
  font-family: "Trebuchet MS", Arial, sans-serif;
  font-size: 0.95rem;
  border: 1px solid #ccc;
  border-radius: 6px;
}

.add-button {
  background: #1b6e6e;
  color: #ffffff;
  border: none;
  padding: 10px 20px;
  border-radius: 6px;
  font-size: 0.95rem;
  font-family: "Trebuchet MS", Arial, sans-serif;
  cursor: pointer;
}

.add-button:hover {
  background: #145454;
}

.filters {
  display: flex;
  gap: 8px;
  padding: 0 26px 16px;
}

.filter-tab {
  background: none;
  border: 1px solid #ddd;
  color: #555;
  padding: 6px 14px;
  border-radius: 20px;
  font-size: 0.82rem;
  font-family: "Trebuchet MS", Arial, sans-serif;
  cursor: pointer;
}

.filter-tab.active {
  background: #1f3864;
  border-color: #1f3864;
  color: #ffffff;
}

.task-list {
  list-style: none;
  margin: 0;
  padding: 0 10px;
  border-top: 1px solid #eee;
}

.task {
  display: flex;
  align-items: center;
  gap: 12px;
  padding: 14px 16px;
  border-bottom: 1px solid #eee;
}

.checkbox {
  width: 20px;
  height: 20px;
  flex-shrink: 0;
  border: 2px solid #b8720a;
  border-radius: 5px;
  cursor: pointer;
  position: relative;
}

.checkbox.checked {
  background: #b8720a;
}

.checkbox.checked::after {
  content: "";
  position: absolute;
  left: 5px;
  top: 1px;
  width: 5px;
  height: 10px;
  border: solid #ffffff;
  border-width: 0 2px 2px 0;
  transform: rotate(45deg);
}

.task-text {
  flex: 1;
  font-size: 0.95rem;
  cursor: default;
}

.task.completed .task-text {
  text-decoration: line-through;
  color: #999;
}

.delete-button {
  background: none;
  border: none;
  color: #bbb;
  font-size: 1.2rem;
  line-height: 1;
  cursor: pointer;
  padding: 2px 6px;
}

.delete-button:hover {
  color: #c0392b;
}

.app-footer {
  display: flex;
  justify-content: space-between;
  align-items: center;
  padding: 14px 26px;
  font-size: 0.85rem;
  color: #666;
}

.clear-button {
  background: none;
  border: none;
  color: #1b6e6e;
  font-size: 0.85rem;
  font-family: "Trebuchet MS", Arial, sans-serif;
  cursor: pointer;
  text-decoration: underline;
}

.clear-button:hover {
  color: #145454;
}