/* Reset and base styles */
* {
  margin: 0;
  padding: 0;
  box-sizing: border-box;
  font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, Oxygen, Ubuntu, Cantarell, sans-serif;
}

body {
  background-color: #f5f7fa;
  color: #2d3748;
  line-height: 1.6;
  padding: 20px;
}

/* Header styles */
header {
  text-align: center;
  margin-bottom: 2rem;
}

h1 {
  color: #2c5282;
  font-size: 2.5rem;
  font-weight: 700;
  margin: 1rem 0;
}

/* Main content */
main {
  max-width: 800px;
  margin: 0 auto;
  background: white;
  padding: 2rem;
  border-radius: 12px;
  box-shadow: 0 4px 6px rgba(0, 0, 0, 0.1);
}

section {
  margin-bottom: 2rem;
  padding: 1rem;
  border-bottom: 1px solid #e2e8f0;
}

section:last-child {
  border-bottom: none;
}

/* Total time display */
#h2-total-time {
  font-size: 3rem;
  color: #2c5282;
  text-align: center;
  margin-bottom: 1.5rem;
  font-weight: 700;
}

/* Buttons */
button {
  background-color: #4299e1;
  color: white;
  border: none;
  padding: 0.75rem 1.5rem;
  border-radius: 6px;
  cursor: pointer;
  font-size: 1rem;
  margin: 0.5rem;
  transition: background-color 0.2s;
}

button:hover {
  background-color: #3182ce;
}

#button-start-session {
  background-color: #48bb78;
}

#button-start-session:hover {
  background-color: #38a169;
}

#button-stop-session {
  background-color: #f56565;
}

#button-stop-session:hover {
  background-color: #e53e3e;
}

/* Date navigation */
#input-selected-date {
  padding: 0.5rem;
  border: 1px solid #e2e8f0;
  border-radius: 6px;
  font-size: 1rem;
  margin: 0 0.5rem;
}

/* Session display */
#div-sessions {
  margin-top: 1rem;
}

#div-sessions div {
  background-color: #edf2f7;
  padding: 1rem;
  margin: 0.5rem 0;
  border-radius: 6px;
  transition: transform 0.2s;
}

#div-sessions div:hover {
  transform: translateX(5px);
}

#div-sessions p {
  color: #4a5568;
  font-size: 1.1rem;
}

/* Status messages */
#p-start-session {
  text-align: center;
  color: #4a5568;
  margin: 1rem 0;
  font-size: 1.1rem;
}

#p-missing-session {
  text-align: center;
  color: #718096;
  font-style: italic;
}

#p-session-error-text {
  color: #e53e3e;
  text-align: center;
  margin: 0.5rem 0;
}

/* Responsive design */
@media (max-width: 600px) {
  body {
    padding: 10px;
  }

  main {
    padding: 1rem;
  }

  h1 {
    font-size: 2rem;
  }

  #h2-total-time {
    font-size: 2.5rem;
  }

  button {
    width: 100%;
    margin: 0.5rem 0;
  }

  #input-selected-date {
    width: 100%;
    margin: 0.5rem 0;
  }
}

/* Manual entry form */
.form-group {
  margin-bottom: 1rem;
}

.form-group label {
  display: block;
  margin-bottom: 0.5rem;
  color: #4a5568;
}

.form-group input {
  width: 100%;
  padding: 0.5rem;
  border: 1px solid #e2e8f0;
  border-radius: 6px;
  font-size: 1rem;
}

/* Delete button */
.delete-button {
  background-color: #f56565;
  padding: 0.5rem 1rem;
  font-size: 0.875rem;
  margin-left: 1rem;
}

.delete-button:hover {
  background-color: #e53e3e;
}

/* Session display updates */
#div-sessions div {
  display: flex;
  justify-content: space-between;
  align-items: center;
}

/* Form submit button */
#form-manual-entry button[type="submit"] {
  background-color: #4299e1;
  width: 100%;
  margin-top: 1rem;
}

#form-manual-entry button[type="submit"]:hover {
  background-color: #3182ce;
}