/* Reset default styles */
* {
  margin: 0;
  padding: 0;
  box-sizing: border-box;
}

body {
  font-family: 'Segoe UI', Tahoma, Geneva, Verdana, sans-serif;
  background: linear-gradient(135deg, #e0eafc 0%, #cfdef3 100%);
  color: #22223b;
  display: flex;
  justify-content: center;
  align-items: center;
  height: 100vh;
}

/* Main container card */
.container {
  background-color: #fff;
  padding: 40px 30px;
  border-radius: 18px;
  box-shadow: 0 8px 32px rgba(44, 62, 80, 0.15);
  width: 100%;
  max-width: 420px;
  text-align: center;
}

/* Header */
.container h1 {
  font-size: 2.5rem;
  text-transform: uppercase;
  color: #3a86ff;
  letter-spacing: 2px;
  margin-bottom: 10px;
}

.h1 {
  border-bottom: 3px solid #3a86ff;
  margin-bottom: 24px;
}

/* Todo list container */
.todos-group {
  padding: 10px;
  border-radius: 10px;
  max-height: 320px;
  overflow-y: auto;
  background: #f7faff;
  box-shadow: 0 2px 8px rgba(44, 62, 80, 0.07);
}

.todos {
  display: flex;
  flex-direction: column;
}

/* Individual todo item */
.todo-item {
  font-size: 1rem;
  padding: 12px;
  color: #22223b;
  background-color: #e9f5ff;
  margin: 8px 0;
  border-radius: 10px;
  text-align: left;
  box-shadow: 0 1px 4px rgba(44, 62, 80, 0.05);
  display: flex;
  justify-content: space-between;
  align-items: center;
  gap: 10px;
  transition: background 0.2s;
}

.todo-item:hover {
  background: #d0ebff;
}

/* Edit button */
.edit-btn {
  background: transparent;
  border: none;
  cursor: pointer;
  font-size: 1.3rem;
  color: #3a86ff;
  transition: color 0.2s;
}

.edit-btn:hover {
  color: #ffbe0b;
}

/* Delete button */
.delete-btn {
  background: transparent;
  border: none;
  cursor: pointer;
  font-size: 1.3rem;
  color: #ef233c;
  transition: color 0.2s;
}

.delete-btn:hover {
  color: #d90429;
}

.todo-text {
  flex: 1;
  font-weight: 500;
}

/* Input and button */
.input-group {
  margin-top: 22px;
  display: flex;
  gap: 10px;
}

input[type="text"] {
  flex: 1;
  padding: 12px 14px;
  border: 2px solid #bdbdbd;
  border-radius: 10px;
  font-size: 1rem;
  transition: border-color 0.3s ease, box-shadow 0.2s;
  background: #f7faff;
}

input[type="text"]:focus {
  border-color: #3a86ff;
  outline: none;
  box-shadow: 0 0 0 2px #a0c4ff;
}

#addBtn {
  padding: 12px 18px;
  background-color: #3a86ff;
  color: white;
  border: none;
  border-radius: 10px;
  font-size: 1rem;
  cursor: pointer;
  font-weight: 600;
  transition: background-color 0.3s, transform 0.2s;
  box-shadow: 0 2px 8px rgba(44, 62, 80, 0.07);
}

#addBtn:hover {
  background-color: #4361ee;
  transform: translateY(-2px) scale(1.04);
}

#addBtn:active {
  background-color: #3a86ff;
  transform: translateY(0) scale(1);
}

/* Dark mode styles */
body.dark-mode {
  background: linear-gradient(135deg, #232526 0%, #393e46 100%);
  color: #e0eafc;
}

body.dark-mode .container {
  background-color: #23243a;
  box-shadow: 0 8px 32px rgba(44, 62, 80, 0.35);
}

body.dark-mode .todos-group {
  background: #23243a;
  box-shadow: 0 2px 8px rgba(44, 62, 80, 0.18);
}

body.dark-mode .todo-item {
  background-color: #2d3142;
  color: #e0eafc;
}

body.dark-mode .todo-item:hover {
  background: #393e46;
}

body.dark-mode input[type="text"] {
  background: #23243a;
  color: #e0eafc;
  border-color: #393e46;
}

body.dark-mode input[type="text"]:focus {
  border-color: #3a86ff;
  box-shadow: 0 0 0 2px #3a86ff44;
}

body.dark-mode #addBtn {
  background-color: #3a86ff;
  color: #fff;
}

body.dark-mode #addBtn:hover {
  background-color: #4361ee;
}

body.dark-mode .edit-btn {
  color: #ffd166;
}

body.dark-mode .edit-btn:hover {
  color: #ffbe0b;
}

body.dark-mode .delete-btn {
  color: #ef476f;
}

body.dark-mode .delete-btn:hover {
  color: #d90429;
}

/* -------------------- */
/* Responsive styles start here */
/* -------------------- */

/* Mobile devices (up to 600px) */
@media (max-width: 600px) {
  body {
    height: auto;
    min-height: 100vh;
    padding: 0;
    display: flex;
    justify-content: center;
    align-items: center;
  }
  .container {
    padding: 16px 4vw;
    border-radius: 10px;
    max-width: 100vw;
    width: 100vw;
    box-shadow: 0 2px 8px rgba(44, 62, 80, 0.10);
    margin: 0 10px; /* Added margin for left and right */
    display: flex;
    flex-direction: column;
    align-items: center;
  }
  .container h1 {
    font-size: 1.3rem;
    margin-bottom: 4px;
  }
  .h1 {
    margin-bottom: 10px;
    border-bottom-width: 2px;
  }
  .todos-group {
    max-height: 180px;
    padding: 4px;
  }
  .todo-item {
    font-size: 0.9rem;
    padding: 6px;
    gap: 4px;
    margin: 6px 0;
  }
  .input-group {
    margin-top: 10px;
    gap: 4px;
    flex-direction: column;
    align-items: stretch;
  }
  input[type="text"] {
    padding: 7px 8px;
    font-size: 0.9rem;
    border-radius: 7px;
    margin-bottom: 6px;
  }
  #addBtn {
    padding: 9px 0;
    font-size: 0.95rem;
    border-radius: 7px;
    width: 100%;
  }
  #darkModeBtn {
    position: fixed !important;
    top: 10px !important;
    right: 10px !important;
    padding: 7px 12px !important;
    font-size: 0.95rem !important;
    border-radius: 7px !important;
    z-index: 1000 !important;
  }
}

/* Tablets (601px to 900px) */
@media (min-width: 601px) and (max-width: 900px) {
  .container {
    padding: 32px 18px;
    border-radius: 16px;
    max-width: 80vw;
  }
  .container h1 {
    font-size: 2rem;
  }
  .todos-group {
    max-height: 260px;
    padding: 8px;
  }
  .todo-item {
    font-size: 1rem;
    padding: 10px;
    gap: 8px;
  }
  .input-group {
    margin-top: 18px;
    gap: 8px;
  }
  input[type="text"] {
    padding: 10px 12px;
    font-size: 1rem;
    border-radius: 9px;
  }
  #addBtn {
    padding: 10px 15px;
    font-size: 1rem;
    border-radius: 9px;
  }
}

/* Large screens (above 1200px) */
@media (min-width: 1200px) {
  .container {
    max-width: 540px;
    padding: 48px 40px;
  }
  .container h1 {
    font-size: 2.8rem;
  }
  .todos-group {
    max-height: 400px;
    padding: 16px;
  }
  .todo-item {
    font-size: 1.1rem;
    padding: 16px;
    gap: 14px;
  }
  .input-group {
    margin-top: 32px;
    gap: 14px;
  }
  input[type="text"] {
    padding: 16px 18px;
    font-size: 1.1rem;
    border-radius: 12px;
  }
  #addBtn {
    padding: 16px 24px;
    font-size: 1.1rem;
    border-radius: 12px;
  }
}

/* Ensure dark mode styles remain responsive */
@media (max-width: 600px) {
  body.dark-mode .container,
  body.dark-mode .todos-group,
  body.dark-mode input[type="text"] {
    border-radius: 8px;
  }
}