/* src/styles.css */
* {
  box-sizing: border-box;
}

body {
  background: #000;
  margin: 0;
  padding: 0;
}

.app-root {
  color: #fff;
  display: flex;
  background: #000;
  flex-direction: column;
  justify-content: center;
  align-items:  center;
  min-height: 100vh;
  font-family: system-ui, -apple-system, BlinkMacSystemFont, Segoe UI, Roboto, Noto Sans, Ubuntu, Cantarell, Helvetica Neue, sans-serif;
}

.pi-title {
  position: absolute;
  color: #0000;
  opacity: 1;
  background-color: #0000;
  background-image: radial-gradient(circle at 0%, #ffffffe6 2%, #ffffff1a 55%), linear-gradient(-120deg, #0000 45%, #fff6 50%, #0000 60%);
  background-position: 0 0, 0 0;
  background-repeat: repeat, repeat;
  background-size: auto, auto;
  background-attachment: scroll, scroll;
  background-origin: padding-box, padding-box;
  -webkit-background-clip: text;
  background-clip: text;
  font-size: 5em;
  top: 0;
}

.calculator {
  background: #000;
  width: 100%;
  max-width: 420px;
  padding: 24px 32px 32px;
}

.screen {
  position: relative;
  overflow: hidden;
  border-left: 1px dotted #666;
  border-right: 1px dotted #666;
  margin-bottom: 28px;
  padding: 16px 20px;
  font-family: SF Mono, Menlo, Roboto Mono, ui-monospace, monospace;
  font-size: 1.8rem;
}

.screen-left, .screen-right {
  color: #777;
  white-space: nowrap;
  overflow: hidden;
  text-overflow: ellipsis;
  flex: 1;
}

.screen-left {
  text-align: left;
}

.screen-right {
  text-align: right;
}

.screen-middle {
  text-align: center;
  border: 2px solid #fff;
  border-radius: 6px;
  min-width: 2ch;
  padding: 4px 10px;
  font-weight: 600;
}

.screen-middle--wrong {
  color: #ff4d4d;
  border-color: #ff4d4d;
}

.screen-middle--highlight {
  color: #000;
  background: #fff;
}

.screen-line {
  white-space: nowrap;
  font-variant-numeric: tabular-nums;
  transition: transform .12s ease-out;
}

.screen-prefix {
  color: #ddd;
}

.screen-suffix {
  color: #777;
}

.numpad {
  display: grid;
  grid-template-columns: repeat(3, 72px);
  grid-auto-rows: 72px;
  justify-content: center;
  gap: 12px;
}

.numpad-key {
  color: #fff;
  display: flex;
  cursor: pointer;
  user-select: none;
  background: #000;
  border: 2px solid #fff;
  justify-content: center;
  align-items:  center;
  transition: background 80ms ease-out, color 80ms ease-out, transform 50ms ease-out, box-shadow 80ms ease-out;
  font-size: 1.6rem;
}

.numpad-key--active {
  color: #000;
  background: #fff;
  transform: translateY(2px);
}

.numpad-key--empty {
  cursor: default;
  pointer-events: none;
  border-color: #0000;
}

.helper-text {
  text-align: center;
  color: #777;
  margin-top: 16px;
  font-size: .8rem;
}

@media (max-width: 480px) {
  .calculator {
    margin: 0 12px;
    padding: 18px 16px 24px;
  }

  .screen {
    padding: 12px 14px;
    font-size: 1.4rem;
  }

  .numpad {
    grid-template-columns: repeat(3, 64px);
    grid-auto-rows: 64px;
    gap: 10px;
  }
}

.settings-button {
  position: fixed;
  display: flex;
  cursor: pointer;
  z-index: 100;
  background: none;
  border: none;
  border-radius: 50%;
  justify-content: center;
  align-items:  center;
  width: 36px;
  height: 36px;
  padding: 0;
  transition: color .12s ease-out, border-color .12s ease-out, box-shadow .12s ease-out, transform 80ms ease-out, background .15s ease-out;
  font-size: 1.3rem;
  top: 12px;
  left: 12px;
}

.settings-button:hover {
  transform: translateX(1px)scale(1.05)rotate(45deg);
}

.settings-backdrop {
  position: fixed;
  display: flex;
  z-index: 90;
  background: #000000b3;
  justify-content: center;
  align-items:  center;
  inset: 0;
}

.settings-modal {
  position: relative;
  color: #fff;
  background: #050505;
  border: 1px solid #444;
  border-radius: 10px;
  width: calc(100% - 40px);
  max-width: 360px;
  padding: 20px 24px 18px;
  font-family: system-ui, -apple-system, BlinkMacSystemFont, Segoe UI, Roboto, Noto Sans, Ubuntu, Cantarell, Helvetica Neue, sans-serif;
}

.settings-close {
  position: absolute;
  color: #888;
  cursor: pointer;
  background: none;
  border: none;
  padding: 2px 4px;
  transition: color .12s ease-out, transform 80ms ease-out;
  font-size: 1.4rem;
  line-height: 1;
  top: 8px;
  right: 10px;
}

.settings-close:hover {
  color: #fff;
  transform: scale(1.05);
}

.settings-title {
  margin: 0 0 12px;
  font-size: 1.1rem;
  font-weight: 600;
}

.settings-body {
  color: #bbb;
  font-size: .9rem;
}

.settings-option {
  display: flex;
  justify-content: space-between;
  align-items:  center;
  gap: 12px;
  margin-top: 8px;
}

.settings-option--stack {
  align-items:  flex-start;
  margin-top: 16px;
}

.settings-option-text {
  flex: 1;
  min-width: 0;
}

.settings-option-label {
  color: #fff;
  font-size: .95rem;
  font-weight: 500;
}

.settings-option-sub {
  color: #777;
  margin-top: 2px;
  font-size: .8rem;
}

.toggle {
  position: relative;
  flex-shrink: 0;
  width: 42px;
  height: 22px;
}

.toggle input {
  opacity: 0;
  position: absolute;
  width: 0;
  height: 0;
}

.toggle-slider {
  position: absolute;
  cursor: pointer;
  background-color: #333;
  border-radius: 999px;
  transition: background-color .15s ease-out;
  inset: 0;
}

.toggle-slider:before {
  content: "";
  position: absolute;
  background-color: #bbb;
  border-radius: 50%;
  width: 18px;
  height: 18px;
  transition: transform .15s ease-out, background-color .15s ease-out;
  top: 2px;
  left: 2px;
}

.toggle input:checked + .toggle-slider {
  background-color: #0a7b2c;
}

.toggle input:checked + .toggle-slider:before {
  background-color: #fff;
  transform: translateX(20px);
}

.settings-start-controls {
  display: flex;
  flex-shrink: 0;
  align-items:  center;
  gap: 8px;
}

.settings-start-input {
  color: #fff;
  outline: none;
  background: #000;
  border: 1px solid #444;
  border-radius: 6px;
  width: 72px;
  padding: 4px 6px;
  font-family: inherit;
  font-size: .85rem;
}

.settings-start-input:focus {
  border-color: #888;
}

.settings-apply {
  color: #eee;
  cursor: pointer;
  background: #111;
  border: 1px solid #555;
  border-radius: 6px;
  padding: 4px 10px;
  transition: background .12s ease-out, border-color .12s ease-out, transform 80ms ease-out;
  font-family: inherit;
  font-size: .85rem;
}

.settings-apply:hover {
  background: #222;
  border-color: #888;
  transform: translateY(-1px);
}

.settings-apply:active {
  transform: translateY(0);
}

.digit-checkpoint {
  color: #7cff7c !important;
}

.controls-row {
  display: flex;
  justify-content: center;
  align-items:  flex-start;
  gap: 12px;
  margin-top: 8px;
}

.side-controls {
  display: flex;
  flex-direction: column;
  align-items: stretch;
  gap: 6px;
}

.side-index {
  text-align: center;
  color: #aaa;
  border: 1px solid #333;
  border-radius: 6px;
  min-width: 40px;
  padding: 4px 6px;
  font-family: SF Mono, Menlo, Roboto Mono, ui-monospace, monospace;
  font-size: .85rem;
}

.side-button {
  color: #eee;
  cursor: pointer;
  background: #050505;
  border: 1px solid #444;
  border-radius: 6px;
  padding: 4px 0;
  transition: background .12s ease-out, border-color .12s ease-out, transform 80ms ease-out;
  font-family: inherit;
  font-size: .9rem;
}

.side-button:hover {
  background: #151515;
  border-color: #777;
  transform: translateY(-1px);
}

.side-button:active {
  transform: translateY(0);
}

@media (max-width: 480px) {
  .controls-row {
    gap: 8px;
  }

  .side-index {
    font-size: .75rem;
  }

  .side-button {
    font-size: .8rem;
  }
}

.screen-middle--checkpoint {
  color: #7cff7c;
  background: none;
  border-color: #7cff7c;
}