body {
  background-color: #121212;
  color: #ffffff;
  font-family:
    -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, sans-serif;
  line-height: 1.6;
  margin: 0;
  padding: 20px;
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
}

main {
  max-width: 600px;
  width: 100%;
}

header {
  text-align: center;
  border-bottom: 2px solid #333;
  margin-bottom: 30px;
}

section {
  background-color: #1e1e1e;
  padding: 25px;
  margin-bottom: 25px;
  border-radius: 8px;
  border: 1px solid #333;
}

label {
  display: block;
  margin-bottom: 10px;
  font-weight: 700;
  font-size: 1.1rem;
}

select,
input {
  width: 100%;
  padding: 12px;
  margin-bottom: 20px;
  background-color: #000000;
  border: 2px solid #666;
  border-radius: 4px;
  color: #ffffff;
  font-size: 1rem;
  box-sizing: border-box;
}

input[type="date"]::-webkit-calendar-picker-indicator {
  filter: invert(1);
  cursor: pointer;
}

input:focus,
select:focus {
  outline: 2px solid #2196f3;
  border-color: transparent;
}

::placeholder {
  color: #bbb;
  opacity: 1;
}

button {
  width: 100%;
  padding: 15px;
  background-color: #1976d2;
  color: #ffffff;
  border: 2px solid #ffffff;
  border-radius: 4px;
  font-size: 1.1rem;
  font-weight: bold;
  cursor: pointer;
  text-transform: uppercase;
  letter-spacing: 1px;
}

button:hover,
button:focus {
  background-color: #1565c0;
  outline: 3px solid #ffcc00;
}

#agenda-list {
  list-style: none;
  padding: 0;
}

#agenda-list li {
  background-color: #2a2a2a;
  padding: 15px;
  margin-bottom: 10px;
  border-left: 5px solid #2196f3;
  border-radius: 0 4px 4px 0;
  font-size: 1.05rem;
}

#agenda-msg {
  color: #ff8a80;
  font-weight: bold;
  text-align: center;
  padding: 15px;
  border: 2px solid #ff8a80;
  border-radius: 4px;
  background-color: #000000;
  margin-top: 10px;
}

#agenda-msg:empty {
  display: none;
}