* {
  box-sizing: border-box;
}

:root {
  --brand-primary: #6366f1;   
  --brand-primary-hover: #4f46e5;
  --success-color: #22c55e;
  --danger-color: #ef4444;
  --icon-muted: #9ca3af;
  --bg-color: rgb(245, 246, 250);
  --container-bg: white;
  --text-color: rgb(51, 51, 51);
  --heading-color: rgb(81, 23, 33);
  --border-color: rgb(238, 238, 238);
  --hover-bg: rgb(230, 230, 230);
  --placeholder-color: rgb(150, 150, 150);
  --input-bg: white;
  --input-border: rgb(221, 221, 221);
  --text-input: rgb(51, 51, 51);
  --checkbox-color: green;
  --completed-text: rgb(153, 153, 153);
  --button-bg: rgb(76, 175, 80);
  --button-hover-bg: rgb(67, 160, 71);
  --button-text: white;
  --delete-color: rgb(255, 77, 77);
  --delete-hover-color: rgb(230, 0, 0);
  --delete-hover-bg: rgba(255, 77, 77, 0.1);
 
}

.dark-mode {
  --brand-primary: #818cf8;
  --success-color: #4ade80;
  --danger-color: #f87171;
  --icon-muted: #6b7280;
  --bg-color: #121212;
  --container-bg: #1e1e1e;
  --text-color: #e0e0e0;
  --heading-color: #ffffff;
  --border-color: #333;
  --hover-bg: #2a2a2a;
  --placeholder-color: rgb(180, 180, 180);
  --input-bg: #2a2a2a;
  --input-border: #444;
  --text-input: #e0e0e0;
  --checkbox-color: #4caf50;
  --completed-text: rgb(100, 100, 100);
  --button-bg: #4caf50;
  --button-hover-bg: #43a047;
  --button-text: white;
  --delete-color: rgb(255, 77, 77);
  --delete-hover-color: rgb(230, 0, 0);
  --delete-hover-bg: rgba(255, 77, 77, 0.1);
  
}

body {
  margin-top: 60px;
  display: flex;
  justify-content: center;
  background-color: var(--bg-color);
}


.container {
  background-color: var(--container-bg);
  box-shadow: 0 8px 20px rgba(0,0,0,0.05);
  width: 100%;
  max-width: 500px;
  border-radius: 12px;
  padding: 20px 25px;
}


.todo-heading {
  color: var(--heading-color);
  font-family: Montserrat;
  font-weight: 600;
  font-size: 2.5rem;
  margin-bottom: 15px;
  text-align: center;
}

.todo-details {
  display: flex;
  gap: 10px;
  margin-bottom: 20px;
 }

.text-input{
  flex: 1;
  padding: 10px;
  font-family: Inter;
  font-size: 18px;
  border: 1px solid var(--input-border);
  border-radius: 5px;
  background-color: var(--input-bg);
  color: var(--text-input)
}

 .text-input::placeholder {
  font-size: 15px;
  color: var(--placeholder-color);
  font-style: italic;
 }

 .text-input:focus {
  outline: none;
  box-shadow: 0 0 0 2px rgba(76, 175, 80, 0.2);
}

 .add-button {
  font-family: Inter;
  padding: 10px 15px;
  border-radius: 6px;
  font-size: 0.9rem;
  border: none;
  cursor: pointer;
  background-color: var(--button-bg);
  color: var(--button-text);
  transition: background-color 0.2s, box-shadow 0.2s;
 }

 .add-button:hover {
  background-color: var(--button-hover-bg);
  box-shadow: 0 6px 18px rgba(0,0,0,0.2);
 }

 .add-button:active {
   transform: scale(0.95);
 }

 .task-list {
  font-family: Montserrat;
  font-weight: 400;
  font-size: 30px;
  margin-bottom: 15px;
  color: var(--heading-color);
  text-align: center;
 }

 .empty-state {
  color: var(--text-color);
  opacity: 0.6;
  font-size: 0.9rem;
}

 .todo-item {
  display: flex;
  justify-content: space-between;
  align-items: center;
  border-bottom: 1px solid var(--border-color);
  padding: 3px 5px;
  gap: 10px;
  cursor: pointer;
  will-change: transform;
  transition: background-color 0.2s, transform 0.2s, border-radius 0.2s, box-shadow 0.2s;
 }



 .todo-item:hover {
  background-color: var(--hover-bg);
  transform: translateY(-2px);
  border-radius: 6px;
  box-shadow: 0 4px 10px rgba(0,0,0,0.08);
 }

.text-container {
  display: flex;
  align-self: flex-start;
  flex: 1;
 }

 .checkbox {
  accent-color: var(--checkbox-color);
  transform: scale(1.1);
  cursor: pointer;
 }

 .todo-text {
  color: var(--text-color);
  font-family: Montserrat;
  font-weight: 400;
  font-size: 16px;
  margin-left: 8px;
  word-wrap: break-word;
  overflow-wrap: break-word;
  outline: none;
 }

 .completed .todo-text {
  text-decoration: line-through;
  color: var(--completed-text);
 }

 .js-buttons {
  display: flex;
  flex-shrink: 0; 
 }
 
 .edit-button, .delete-button, .tick-button {
    display: flex;
    align-items: center;
    justify-content: center;
    border: none;
    cursor: pointer;
    width: 28px;
    height: 28px;
    border-radius: 14px;
    
    background-color: transparent;
    transition: background-color 0.2s;
 }  

 .edit-container, .save-container, .delete-container {
  display: flex;
  justify-content: center;
  align-items: center;
  position: relative;
 }

 .edit-container .tooltip, .save-container .tooltip, 
 .delete-container .tooltip {
   position: absolute;
   bottom: -17px;
   background-color: gray;
   color: white;
   font-size: 11px;
   padding: 2px 4px;
   border-radius: 4px;
   opacity: 0;
   transition: opacity 0.2s ease;
   pointer-events: none;
   white-space: nowrap;
 }

 .edit-container:hover .tooltip, .save-container:hover .tooltip, 
 .delete-container:hover .tooltip {
  opacity: 1;
 }

  .edit-button:hover, .delete-button:hover, .tick-button:hover {
   background-color:  rgba(0,0,0,0.05);
  }

  .edit-icon, .delete-icon, .tick-icon {
    height: 18px;
  }

  .edit-button:hover .edit-icon {
  fill: var(--brand-primary);
  opacity: 1;
 }

 .tick-button:hover .tick-icon{
  filter: brightness(1.1);
  opacity: 1;
 }

 .delete-button:hover .delete-icon {
  filter: brightness(1.1);
  opacity: 1;
 }

 .edit-icon {
  fill: var(--icon-muted);
  opacity: 0.8;
  transition: all 0.2s ease;
 }

 .tick-icon {
  fill: var(--success-color);
  opacity: 0.8;
  transition: all 0.2s ease;
 }

 .delete-icon {
  fill: var(--danger-color);
  opacity: 0.8;
  transition: all 0.2s ease;
 }

 .dark-mode .edit-icon {
  fill: var( --icon-muted);
 }

 .dark-mode .delete-icon {
  fill: var(--danger-color);
 }

 .dark-mode .tick-icon {
  fill: var(--success-color);
 }

 .tick-button {
  display: none;
 }

 .is-editing-item .tick-button {
  display: initial;
 }

 .is-editing-item .edit-button {
  display: none;
 }

 .clear-completed-container {
  display: flex;
  justify-content: flex-end;
  align-items: center;
  margin-top: 10px;
 }

 .clear-completed {
   background-color: transparent;
   color: var(--delete-color);
   border: none;
   font-family: Inter;
   font-size: 0.9rem;
   font-weight: 500;
   cursor: pointer;
   padding: 6px 12px;
   border-radius: 6px;
   transition: color 0.2s ease, background-color 0.2s, all 0.2s ease;;
 }

 .clear-completed:hover {
  background-color: var(--delete-hover-bg);
  color: var(--delete-hover-color);
 }

 .clear-completed:active {
  transform: scale(0.95);
 }

 .clear-completed:disabled {
  color: rgb(204, 204, 204);
  cursor: not-allowed;
 }

 

 @media(max-width: 450px) {
   body {
    margin-top: 40px;
   }

   .container {
    width: 90%;
    padding: 15px;
    margin-top: 20px;
   }

   .todo-heading{
    font-size: 1.3rem;
   }

   .todo-details {
    flex-direction: column;
   }

   .add-button {
    width: 100%;
   }

   .todo-item {
    flex-direction: column;
    align-items: flex-start;
   }

   .todo-text {
    font-size: 0.95rem;
   }
   
   .js-buttons {
    margin-top: 8px;
    gap: 8px;
   }

   .clear-completed-container {
    justify-content: center;
   }
 }