* {
  margin: 0;
  padding: 0;
  box-sizing: border-box;
}

body {
  font-family: 'Poppins', sans-serif;
  background: linear-gradient(135deg, #e0f7fa, #f3e5f5);
  min-height: 100vh;
  padding: 2rem;
  display: flex;
  justify-content: center;
  align-items: flex-start;
  flex-direction: column;
}

.logo-header {
  width: 100%;
  text-align: center;
  margin-bottom: 2rem;
  padding: 0 1rem;
}

.logo {
  display: inline-block;
  padding: 1rem 2rem;
  background: linear-gradient(to right, #7e57c2, #64b5f6);
  border-radius: 12px;
  color: white;
  box-shadow: 0 8px 16px rgba(126, 87, 194, 0.2);
  cursor: default;
  transition: transform 0.3s;
  user-select: none;
}

.logo:hover {
  transform: scale(1.05);
}

.logo-big {
  font-size: 2.2rem;
  font-weight: bold;
  letter-spacing: 0.2rem;
  display: block;
}

.logo-small {
  font-size: 1rem;
  font-weight: 400;
  text-transform: uppercase;
  letter-spacing: 0.1rem;
}

.container {
  background: #ffffff;
  padding: 2rem;
  border-radius: 16px;
  box-shadow: 0 12px 30px rgba(0, 0, 0, 0.1);
  width: 100%;
  max-width: 900px;
  animation: fadeIn 0.6s ease;
  box-sizing: border-box;
}

h1 {
  text-align: center;
  font-weight: 600;
  color: #4527a0;
  margin-bottom: 2rem;
}

h2 {
  color: #5e35b1;
  margin-bottom: 0.8rem;
  font-weight: 600;
}

.input-container {
  display: flex;
  flex-direction: column;
  gap: 0.8rem;
  margin-bottom: 2rem;
}

.input-container input {
  padding: 0.9rem 1rem;
  border: 2px solid #ce93d8;
  border-radius: 10px;
  font-size: 1rem;
  transition: 0.3s;
  outline: none;
  width: 100%;
  box-sizing: border-box;
}

.input-container input:focus {
  border-color: #8e24aa;
}

.input-container button {
  padding: 0.9rem;
  background-color: #7e57c2;
  color: #fff;
  border: none;
  border-radius: 10px;
  font-size: 1rem;
  cursor: pointer;
  font-weight: bold;
  transition: background-color 0.3s, transform 0.2s;
  width: 100%;
  box-sizing: border-box;
}

.input-container button:hover {
  background-color: #5e35b1;
  transform: translateY(-2px);
}

.task-section {
  display: flex;
  flex-direction: column;
  gap: 2rem;
}

ul {
  list-style: none;
  padding: 0;
}

li {
  background-color: #ede7f6;
  padding: 1rem;
  margin-bottom: 0.7rem;
  border-radius: 8px;
  display: flex;
  justify-content: space-between;
  align-items: center;
  transition: 0.3s;
  animation: popIn 0.3s ease-in-out;
}

li input[type="checkbox"] {
  margin-right: 0.8rem;
  transform: scale(1.3);
  cursor: pointer;
}

li button {
  background-color: #d32f2f;
  color: white;
  border: none;
  padding: 0.5rem 0.8rem;
  border-radius: 6px;
  cursor: pointer;
  font-weight: 600;
  transition: background-color 0.3s;
}

li button:hover {
  background-color: #b71c1c;
}

@keyframes fadeIn {
  from {
    opacity: 0;
    transform: translateY(20px);
  }
  to {
    opacity: 1;
    transform: translateY(0);
  }
}

@keyframes popIn {
  from {
    opacity: 0;
    transform: scale(0.95);
  }
  to {
    opacity: 1;
    transform: scale(1);
  }
}

@media (min-width: 768px) {
  .input-container {
    flex-direction: row;
    gap: 1rem;
  }

  .input-container input {
    flex: 1;
  }

  .input-container button {
    width: auto;
  }

  .task-section {
    flex-direction: row;
    justify-content: space-between;
  }

  .task-list,
  .completed-task {
    width: 48%;
  }
}

@media (max-width: 480px) {
  .logo {
    padding: 0.8rem 1.2rem;
  }

  .logo-big {
    font-size: 1.8rem;
  }

  .logo-small {
    font-size: 0.85rem;
  }
}

@media (min-width: 1024px) {
  .container {
    max-width: 1200px;
    padding: 3rem 4rem;
  }

  .task-section {
    gap: 3rem;
  }
}