/* (A) WRAPPER - POPUP MODE */
.picker-wrap, .picker-wrap * { box-sizing: border-box; }
.picker-wrap.popup {
  /* (A1) FULLSCREEN COVER */
  position: fixed;
  top: 0; left: 0; z-index: 99;
  width: 100vw; height: 100vh;

  /* (A2) BACKGROUND + HIDE BY DEFAULT */
  background: rgba(0, 0, 0, 0.5);
  opacity: 0; visibility: hidden;
  transition: opacity 0.2s;

  /* (A3) CENTER DATE PICKER */
  display: flex;
  align-items: center;
  justify-content: center;
}

/* (A4) SHOW POPUP */
.picker-wrap.show {
  opacity: 1;
  visibility: visible;
}

/* (B) CONTAINER */
.picker {
  max-width: 300px;
  border: 1px solid #000;
  background: #444;
  padding: 10px;
}

/* (C) PERIOD SELECTOR */
.picker-p {
  width: 100%;
  display: flex;
  background: #333;
}
.picker-b, .picker-n {
  font-weight: 700;
  padding: 10px;
  color: #fff;
  background: #1a1a1a;
  cursor: pointer;
}
.picker-m, .picker-y {
  flex-grow: 1;
  padding: 10px;
  border: 0;
  color: #fff;
  background: none;
}
.picker-m:focus, .picker-y:focus { outline: none; }
.picker-m option, .picker-y option { color: #000; }

/* (D) DAYS IN MONTH */
/* (D1) GRID LAYOUT */
.picker-d {
  color: #fff;
  display: grid;
  grid-template-columns: repeat(7, minmax(0, 1fr));
}
.picker-d div { padding: 5px; }

/* (D2) HEADER - DAY NAMES */
.picker-d-h { font-weight: 700; }

/* (D3) BLANK DATES */
.picker-d-b { background: #4e4e4e; }

/* (D4) TODAY */
.picker-d-td { background: #6e1c18; }

/* (D5) PICKABLE DATES */
.picker-d-d:hover {
  cursor: pointer;
  background: #a33c3c;
}

/* (D6) UNPICKABLE DATES */
.picker-d-dd {
  color: #888;
  background: #4e4e4e;
}