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

/* ===============================
   BASE
=============================== */
body {
  font-family: Arial, sans-serif;
  background: #f4f6f8;
  min-height: 100vh;
}

/* ===============================
   CONTAINER
=============================== */
.container {
  max-width: 420px;
  margin: 80px auto;
  background: #ffffff;
  padding: 30px;
  border-radius: 16px;
  box-shadow: 0 10px 30px rgba(0, 0, 0, 0.1);
}

/* ===============================
   TITLE
=============================== */
h1 {
  text-align: center;
  margin-bottom: 25px;
  font-size: 26px;
}

/* ===============================
   FORM
=============================== */
form {
  display: flex;
  gap: 10px;
  margin-bottom: 20px;
}

form input {
  flex: 1;
  padding: 12px;
  border-radius: 8px;
  border: 1px solid #ccc;
  font-size: 14px;
}

form button {
  padding: 12px 16px;
  background: #2563eb;
  color: #fff;
  border: none;
  border-radius: 8px;
  cursor: pointer;
}

form button:hover {
  background: #1e4fd8;
}

/* ===============================
   FILTERS
=============================== */
.filters {
  display: flex;
  gap: 10px;
  margin-bottom: 15px;
}

.filters button {
  flex: 1;
  padding: 8px;
  border-radius: 8px;
  border: 1px solid #ddd;
  background: #f9f9f9;
  cursor: pointer;
}

.filters button:hover {
  background: #eaeaea;
}

/* ===============================
   COUNTER
=============================== */
#counter {
  margin-bottom: 15px;
  font-size: 14px;
  color: #555;
}

/* ===============================
   TASK LIST
=============================== */
ul {
  list-style: none;
}

/* ===============================
   TASK ITEM
=============================== */
li {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 10px;
  padding: 12px;
  background: #f3f4f6;
  margin-bottom: 10px;
  border-radius: 10px;
}

/* ===============================
   TASK CONTENT
=============================== */
li span {
  flex: 1;
  font-size: 14px;
}

/* ===============================
   CHECKBOX
=============================== */
li input[type="checkbox"] {
  width: 18px;
  height: 18px;
}

/* ===============================
   DELETE BUTTON
=============================== */
li button {
  background: #ef4444;
  color: white;
  border: none;
  padding: 6px 10px;
  border-radius: 6px;
  cursor: pointer;
}

li button:hover {
  background: #dc2626;
}

/* ===============================
   COMPLETED TASK
=============================== */
li.completed {
  opacity: 0.6;
}

li.completed span {
  text-decoration: line-through;
}

/* ===============================
   THEME BUTTON
=============================== */
#themeToggle {
  margin-top: 15px;
  background: #e5e7eb;
  border: none;
  padding: 8px;
  border-radius: 8px;
  cursor: pointer;
}

/* ===============================
   DARK MODE
=============================== */
body.dark {
  background: #121212;
  color: #ffffff;
}

body.dark .container {
  background: #1e1e1e;
}

body.dark li {
  background: #2a2a2a;
}

body.dark input {
  background: #2a2a2a;
  color: white;
  border-color: #444;
}