:root {
  --bg: #0f1115;
  --panel: #151822;
  --text: #e6e9ef;
  --muted: #9aa4b2;
  --accent: #5b8cff;
  --accent-pressed: #3f6df0;
  --success: #36c28a;
  --danger: #ff6b6b;
  --border: #232839;
  --shadow: 0 8px 30px rgba(0, 0, 0, 0.35);
}

* {
  box-sizing: border-box;
}
html,
body {
  height: 100%;
}
body {
  margin: 0;
  background: radial-gradient(
    1200px 800px at 10% 10%,
    #121523 0%,
    var(--bg) 60%
  );
  color: var(--text);
  font: 16px/1.5 ui-sans-serif, system-ui, -apple-system, Segoe UI, Roboto,
    Ubuntu, Cantarell, Noto Sans, Helvetica Neue, Arial, "Apple Color Emoji",
    "Segoe UI Emoji";
  display: grid;
  place-items: center;
  padding: 24px;
}

.app {
  width: 100%;
  max-width: 720px;
  background: linear-gradient(
      180deg,
      rgba(255, 255, 255, 0.02),
      rgba(255, 255, 255, 0)
    ),
    var(--panel);
  border: 1px solid var(--border);
  border-radius: 16px;
  box-shadow: var(--shadow);
  padding: 28px;
}

.header {
  display: flex;
  align-items: baseline;
  gap: 12px;
  margin-bottom: 16px;
}
.title {
  margin: 0;
  font-size: 28px;
  letter-spacing: 0.4px;
}
.subtitle {
  margin: 0;
  color: var(--muted);
  font-size: 14px;
}

.main {
  display: grid;
  gap: 16px;
}

.todo-form {
  display: grid;
  grid-template-columns: 1fr auto;
  grid-template-areas:
    "title submit"
    "desc  desc";
  gap: 8px;
}
.todo-input {
  padding: 12px 14px;
  background: #0e121a;
  border: 1px solid var(--border);
  border-radius: 10px;
  color: var(--text);
  outline: none;
}
.todo-input#todoTitle {
  grid-area: title;
}
.btn[type="submit"] {
  grid-area: submit;
}
.todo-textarea {
  grid-area: desc;
  resize: vertical;
  min-height: 84px;
}
.todo-input::placeholder {
  color: #6b7280;
}
.todo-input:focus {
  border-color: var(--accent);
  box-shadow: 0 0 0 3px rgba(91, 140, 255, 0.15);
}

.btn {
  cursor: pointer;
  border: 1px solid var(--border);
  color: var(--text);
  background: #0e121a;
  border-radius: 10px;
  height: 44px;
  padding: 0 14px;
}
.btn:hover {
  filter: brightness(1.05);
}
.btn:active {
  transform: translateY(1px);
}
.btn-primary {
  background: var(--accent);
  border-color: transparent;
  color: white;
}
.btn-primary:hover {
  background: var(--accent-pressed);
}

.todo-list {
  list-style: none;
  padding: 0;
  margin: 0;
  display: grid;
  gap: 8px;
}
.todo-item {
  display: grid;
  grid-template-columns: 44px 1fr 44px;
  align-items: center;
  gap: 10px;
  padding: 10px;
  background: #0e121a;
  border: 1px solid var(--border);
  border-radius: 12px;
}

.todo-text {
  overflow: hidden;
  white-space: nowrap;
  text-overflow: ellipsis;
}
.todo-content {
  display: grid;
  gap: 4px;
}
.todo-description {
  color: var(--muted);
  font-size: 14px;
  line-height: 1.4;
}
.btn-check {
  background: #0f151f;
  border-color: var(--border);
  color: var(--success);
  font-size: 18px;
}
.btn-remove {
  background: #17131a;
  border-color: var(--border);
  color: var(--danger);
  font-size: 18px;
}

.todo-item.is-completed .todo-text {
  color: var(--muted);
  text-decoration: line-through;
}
.todo-item.is-completed .btn-check {
  filter: brightness(1.2);
}

/* Estado completado - minimalista */
.todo-item.is-completed {
  opacity: 0.6;
  background: rgba(54, 194, 138, 0.08);
  border-color: rgba(54, 194, 138, 0.3);
}

.todo-item.is-completed .todo-text {
  color: var(--muted);
  text-decoration: line-through;
  text-decoration-thickness: 2px;
  text-decoration-color: var(--success);
}

.todo-item.is-completed .todo-description {
  color: var(--muted);
  opacity: 0.7;
}

.todo-item.is-completed .btn-check {
  background: var(--success);
  color: white;
  border-color: var(--success);
  transform: scale(0.95);
}

.todo-item.is-completed .btn-remove {
  opacity: 0.5;
}

.footer {
  margin-top: 8px;
  display: flex;
  justify-content: flex-end;
}
.hint {
  color: var(--muted);
}

@media (max-width: 520px) {
  .app {
    padding: 20px;
  }
  .title {
    font-size: 24px;
  }
  .todo-item {
    grid-template-columns: 40px 1fr 40px;
  }
  .btn,
  .todo-input {
    height: 42px;
  }
}