body {
  display: flex;
  justify-content: center;
  align-items: center;
  height: 100vh;
  font-family: Arial, sans-serif;
}

#app {
  text-align: center;
  padding: 40px;
  border-radius: 20px;
}

@media (max-width: 768px) {
  body {
    padding: 20px;
  }

  #app {
    width: 80%;
    box-sizing: border-box;
  }
}

h1 {
  color: #2f3640;
  margin-bottom: 30px;
}

#input-container {
  display: flex;
  justify-content: space-around;
  margin-bottom: 20px;
}

#input-container div {
  flex: 1;
}

input {
  border: 2px solid #2f3640;
  border-radius: 5px;
  height: 30px;
  width: 60px;
  font-size: 16px;
  text-align: center;
  margin-bottom: 20px;
}

#button-container {
  display: flex;
  justify-content: space-evenly;
  margin-bottom: 20px;
}

#start-btn, #reset-btn {
  display: inline-block;
  padding: 10px 20px;
  margin: 20px 0;
  border-radius: 5px;
  border: none;
  cursor: pointer;
  transition: background-color 0.3s ease;
}

#start-btn {
  background-color: #2f3640;
  color: white;
}

#start-btn:hover {
  background-color: #576574;
}

#reset-btn {
  background-color: #ffffff;
  color: #2f3640;
  border: 2px solid #2f3640;
}

#reset-btn:hover {
  background-color: #f0f0f0;
}

#timer-display {
  color: #2f3640;
  font-size: 2em;
  margin-top: 20px;
  border: 2px solid #2f3640;
  padding: 20px;
  border-radius: 10px;
}

.theme-selector-container {
  position:absolute;
  text-align:center;
  top: 90px;
  border-radius: 5px;
  margin-top: 20px;
  padding: 5px;
  z-index: 10;
  background-color: #fff;
  color: #000;
}

.theme-selector-container select {
  border: none;
  background-color: transparent;
  font-size: 16px;
  color: #000;
}

.theme-default {
  background-color: #f8f8f8;
  color: #000;
}

.theme-default #app {
  background: #ffffff;
  color: #000;
  box-shadow: 0px 10px 20px 0px rgba(0, 0, 0, 0.1);
}

.theme-default button:hover {
  background-color: #007B9A; /* Darker blue */
}

.theme-dark, .theme-dark .theme-selector-container, .theme-dark .theme-selector-container select, .theme-dark .theme-selector-container option, .theme-dark #hours-input, .theme-dark #minutes-input, .theme-dark #seconds-input {
  background-color: #000;
  color: #fff;
}

.theme-dark #app, .theme-dark #timer-display {
  background: #111;
  color: #fff;
  box-shadow: 0px 0px 10px 2px #555;
}

.theme-dark h1 {
  color: #fff;
}

.theme-dark #start-btn {
  background-color: rgb(32, 121, 32);
  color: #fff;
}

.theme-dark #start-btn:hover {
  background-color: rgb(21, 80, 21);
}

.theme-dark #reset-btn:hover {
  background-color: #000000; /* Darker blue */
}

.theme-dark #reset-btn {
  background-color: #5c5c5c; /* Darker blue */
  color: white;
}

.theme-dark button:hover {
  background-color: #004461; /* Even darker blue */
}