/* overlay background */
.modal-overlay {
  position: fixed;
  top: 0;
  left: 0;
  width: 100vw;
  height: 100vh;
  background: rgba(0, 0, 0, 0.4);
  display: flex;
  align-items: center;
  justify-content: center;
  z-index: 10000;
}

/* modal box */
.modal-box {
  background: #fff;
  border: 4px solid var(--theme-color);
  padding: 20px;
  min-width: 280px;
  max-width: 400px;
  border-radius: 2px;
  box-shadow: 0 8px 24px rgba(0, 0, 0, 0.2);
  text-align: center;
  font-family: sans-serif;
}

/* message text */
.modal-message {
  margin-bottom: 16px;
}

/* button */
.modal-close-btn {
  padding: 6px 12px;
  border: 2px solid var(--theme-color);
  background-color: white;
  color: var(--theme-color);
  cursor: pointer;
  border-radius: 4px;
}

.modal-close-btn:hover {
  background-color: var(--theme-color);
  color: white;
}

#intro-overlay {
  position: fixed;
  top: 106px;
  left: 0;
  right: 0;
  bottom: 0;
  background: rgba(255, 255, 255, 0.75);
  z-index: 9999;
  display: flex;
  align-items: flex-start;
  padding: 1rem;
  box-sizing: border-box;
  justify-content: center;
}

#intro-overlay.hidden {
  display: none;
}

#intro-modal {
  background: #fff;
  border: 1px solid #ddd;
  border-radius: 12px;
  padding: 2rem;
  max-width: 640px;
  max-height: calc(100vh - 106px - 2rem);
  width: calc(100% - rem);
  box-shadow: 0 8px 32px rgba(0,0,0,0.10);
  font-size: small;
  overflow-y: auto;
  margin: auto;
}

#masthead {
  z-index: 10000;
}