* {
  margin: 0;
  padding: 0;
  box-sizing: border-box;
}

body {
  background: #111;
  display: flex;
  justify-content: center;
  align-items: center;
  min-height: 100vh;
  font-family: Arial, Helvetica, sans-serif;
  user-select: none;
  -webkit-user-select: none;
}

/*
      All sizing is relative via em units.
      The calculator's font-size scales to fill 90% of the viewport
      while preserving the ~1.6:1 aspect ratio.
      Base: 1em ≈ 1% of calculator width at reference size.
    */
.calculator {
  /* 90vw / 45em = 2vw per em; 90vh / 28.215em = 3.19vh per em */
  font-size: min(2vw, 3.19vh);
  width: 99dvw;
  max-height: 97dvh;
  aspect-ratio: 16 / 9;
  display: flex;
  flex-direction: column;
  background: linear-gradient(
    180deg,
    #b8b0a0 0%,
    #a89c8c 5%,
    #8c8478 50%,
    #6e685e 100%
  );
  border-radius: 0.6em;
  /* padding: 1em 1.2em 1em; */
  box-shadow:
    0 0.3em 1.5em rgba(0, 0, 0, 0.6),
    inset 0 0.08em 0 rgba(255, 255, 255, 0.15);
}

/* === DISPLAY === */
.display-frame {
  flex: none;
  background: linear-gradient(180deg, #777 0%, #999 0.15em, #bbb 0.3em);
  border-radius: 0.3em;
  padding: 0.2em 0.3em 0.25em;
  margin-bottom: 1em;
}

.display-screen {
  background: linear-gradient(180deg, #c8c4b0 0%, #b8b4a2 40%, #aca894 100%);
  border-radius: 0.2em;
  height: 4.2em;
  position: relative;
  overflow: hidden;
}

#pointer_div {
  position: relative;
  width: 100%;
  height: 100%;
}

.display-text {
  z-index: 1;
  position: absolute;
  font-weight: bold;
  font-size: 1.9em;
  font-family: sans-serif;
  left: 3%;
  top: 15%;
}

.display-indicator {
  z-index: 1;
  position: absolute;
  font-size: 0.84em;
  font-family: sans-serif;
  top: 70%;
}

#modifier {
  left: 3%;
}
#pgrm {
  left: 16%;
}
#begin {
  left: 28%;
}
#dmyc {
  left: 38%;
}

/* === KEY ROW === */
.key-row {
  display: flex;
  flex: 1;
  padding: 0 0.15em;
  margin-bottom: 0.4em;
  gap: 0.1em;
}

.key-row:last-child {
  margin-bottom: 0;
}

/* === KEY STRUCTURE === */
.key {
  flex: 1;
  min-width: 0;
  border: none;
  border-radius: 0.3em 0.3em 0.25em 0.25em;
  cursor: pointer;
  display: flex;
  flex-direction: column;
  margin-right: 0.28em;
  padding: 0;
  overflow: visible;
  position: relative;
  font-family: Arial, Helvetica, sans-serif;
  container-type: size;
  background-color: transparent;
}

.key:last-child {
  margin-right: 0;
}
.key:active {
  transform: translateY(0.07em);
  filter: brightness(0.85);
}

.key-face {
  display: flex;
  flex: 1;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  border-radius: 0.3em 0.3em 0 0;
  padding: 0.1em 0.15em 0;
  line-height: 1.15;
}

.key-label {
  font-size: 30cqh;
  font-weight: bold;
}

.key-f {
  font-size: 14cqh;
  font-weight: bold;
  color: #e89030;
  letter-spacing: 0.03em;
  line-height: 1;
}

.key-light .key-face .key-f {
  color: #71400b;
}

/* Angled front-face pad */
.key-pad {
  flex: none;
  height: 22cqh;
  font-size: 14cqh;
  font-weight: bold;
  line-height: 1.5;
  text-align: center;
  letter-spacing: 0.02em;
  padding-bottom: 4cqh;
  border-radius: 0 0 0.5em 0.5em;
  transform-origin: top center;
}

/* === DARK KEYS === */
.key-dark .key-face {
  background: linear-gradient(180deg, #4a4540 0%, #3a3530 60%, #302c28 100%);
  color: #e8e4dc;
  box-shadow: inset 0 0.08em 0 rgba(255, 255, 255, 0.08);
}

.key-dark .key-pad {
  background: linear-gradient(180deg, #47423e 0%, #222 100%);
  color: #5898c8;
}

/* === LIGHT KEYS === */
.key-light .key-face {
  background: linear-gradient(180deg, #ccc4b4 0%, #b4ac9c 60%, #a8a090 100%);
  color: #2a2520;
  box-shadow: inset 0 0.08em 0 rgba(255, 255, 255, 0.25);
}

.key-light .key-pad {
  background: linear-gradient(180deg, #908880 0%, #807870 100%);
  color: #143b58;
}

/* === ORANGE KEY === */
.key-orange .key-face {
  background: linear-gradient(180deg, #e89030 0%, #d07020 60%, #c06018 100%);
  color: #fff;
  box-shadow: inset 0 0.08em 0 rgba(255, 255, 255, 0.2);
}

.key-orange .key-pad {
  background: linear-gradient(180deg, #a04810 0%, #903808 100%);
  color: #fff;
}

/* === BLUE KEY === */
.key-blue .key-face {
  background: linear-gradient(180deg, #4898d0 0%, #3878b0 60%, #2868a0 100%);
  color: #fff;
  box-shadow: inset 0 0.08em 0 rgba(255, 255, 255, 0.2);
}

.key-blue .key-pad {
  background: linear-gradient(180deg, #1c4870 0%, #143858 100%);
  color: #80c0f0;
}

/* === F KEY (gold text on dark) === */
.key-f-mod .key-face {
  background: linear-gradient(180deg, #4a4540 0%, #3a3530 60%, #302c28 100%);
  color: #e89030;
  box-shadow: inset 0 0.08em 0 rgba(255, 255, 255, 0.08);
}

.key-f-mod .key-pad {
  background: linear-gradient(180deg, #2a2622 0%, #222 100%);
}

/* === WIDE ZERO KEY === */
.key-zero {
  flex: 2.1;
}

/* === SMALL TEXT VARIANTS === */
.key-label.small {
  font-size: 24cqh;
}
.key-label.tiny {
  font-size: 19cqh;
}

/* === CLEAR prefix on f-labels === */
.key-f-clear {
  display: block;
  font-size: 0.4em;
  letter-spacing: 0.08em;
}

.arrow-down {
  font-size: 1.2em;
}