@use 'sass:color';

// Colour palette
$primary-blue: #2451a6;
$light-blue: #85bff7;
$green: #12d197;
$text-primary: #23272f;
$text-secondary: #5a6272;
$border-grey: #d1d5db;
$code-bg: #61769a;
$code-text: #e2e8f0;
$white: #fff;
$light-bg: #f8fafc;
$gradient-end: #e0e7ef;

// Function to create selection colour with opacity
@function selection-colour($colour, $opacity: 0.3) {
  @return rgba($colour, $opacity);
}

@function caret-colour($colour, $amount: 20%) {
  @return color.adjust($colour, $lightness: -$amount);
}

* {
  box-sizing: border-box;
  margin: 0;
  user-select: none;
}

html,
body {
  height: 100%;
}

body {
  font-family: 'Segoe UI', Arial, sans-serif;
  color: $text-primary;
}

.scroll-container {
  height: 100vh;
  height: 100dvh;
  overflow-y: auto;
  overflow-x: hidden;
}

.background {
  background: linear-gradient(135deg, $light-bg 0%, $gradient-end 100%);
  position: fixed;
  top: 0;
  left: 0;
  width: 100vw;
  height: 100vh;
  z-index: -1;
}

.page-wrapper {
  display: flex;
  flex-direction: column;
  justify-content: space-between;
  min-height: 100%;
  max-width: 1000px;
  margin: 0 auto;
}

header {
  padding: 32px 32px 0 32px;
}

header > h1 {
  font-size: 2.5rem;
  font-weight: 700;
  color: $primary-blue;
  margin-bottom: 24px;
  text-align: center;
}

h1,
code,
p,
p * {
  user-select: text;
}

code {
  background: $code-bg;
  color: $code-text;
  padding: 2px 6px;
  border-radius: 4px;
  font-family: 'SF Mono', 'Monaco', 'Inconsolata', 'Roboto Mono', 'Consolas', monospace;
  font-size: 0.875em;
  font-weight: 500;
}

header > p {
  color: $text-secondary;
  font-size: 1.1rem;
  margin-bottom: 0;
}

header > p:not(:first-of-type) {
  margin-top: 16px;
}

main {
  display: grid;
  grid-template-rows: min-content min-content min-content;
  grid-template-columns: 1fr 1fr;
  gap: 20px;
  justify-items: center;
  align-items: center;
  padding: 32px;
}

.tokenizer-selector {
  grid-column: 1 / -1;
  grid-row: 1;
  width: 100%;
  margin-bottom: 8px;
}

.radio-group {
  display: flex;
  gap: 16px;
  justify-content: center;
  flex-wrap: wrap;
}

.radio-option {
  display: flex;
  align-items: center;
  gap: 12px;
  padding: 16px 20px;
  background: $white;
  border-radius: 12px;
  box-shadow: 0 2px 8px selection-colour($primary-blue, 0.08);
  cursor: pointer;
  transition: all 0.2s ease;
  border: 2px solid transparent;
  min-width: 180px;
  position: relative;
}

.radio-option:hover {
  box-shadow: 0 4px 16px selection-colour($primary-blue, 0.12);
  transform: translateY(-2px);
}

.radio-option:has(input:checked) {
  background: $gradient-end;
  border-color: $primary-blue;
  box-shadow: 0 4px 16px selection-colour($primary-blue, 0.16);
}

.radio-option input[type='radio'] {
  position: absolute;
  opacity: 0;
  pointer-events: none;
}

.radio-custom {
  width: 20px;
  height: 20px;
  border: 2px solid $border-grey;
  border-radius: 50%;
  position: relative;
  transition: all 0.2s ease;
  flex-shrink: 0;
}

.radio-option:has(input:checked) .radio-custom {
  border-color: $primary-blue;
  background: $primary-blue;
}

.radio-custom::after {
  content: '';
  position: absolute;
  top: 50%;
  left: 50%;
  transform: translate(-50%, -50%) scale(0);
  width: 8px;
  height: 8px;
  border-radius: 50%;
  background: white;
  transition: transform 0.2s ease;
}

.radio-option:has(input:checked) .radio-custom::after {
  transform: translate(-50%, -50%) scale(1);
}

.radio-content {
  display: flex;
  flex-direction: column;
  gap: 2px;
}

.radio-label {
  font-weight: 600;
  color: $primary-blue;
  font-size: 0.95rem;
}

.radio-description {
  font-size: 0.8rem;
  color: $text-primary;
  line-height: 1.2;
}

.diamond-parent {
  grid-column: 1 / -1;
  grid-row: 2;
}

.diamond-left {
  grid-column: 1;
  grid-row: 3;
}

.diamond-right {
  grid-column: 2;
  grid-row: 3;
}

.diamond-result {
  grid-column: 1 / -1;
  grid-row: 4;
}

.diamond-result label {
  display: flex;
  align-items: center;
}

.diamond-result svg {
  width: 20px;
  height: 20px;
  margin-left: 8px;
}

.text-area-card {
  width: 100%;
  height: 100%;
  background: $white;
  border-radius: 10px;
  box-shadow: 0 2px 12px 0 selection-colour($primary-blue, 0.06);
  padding: 18px 20px 16px 20px;
  margin-bottom: 0;
}

label {
  display: inline-block;
  margin-bottom: 8px;
  font-weight: 600;
  color: $primary-blue;
  cursor: help;
}

.box {
  width: 1ch;
  height: 1ch;
  border-radius: 50%;
  margin-left: 6px;
  display: inline-block;
  transform: scale(1.5);
}

textarea {
  width: 100%;
  border: none;
  font-size: 1rem;
  font-family: inherit;
  color: $text-primary;
  box-sizing: border-box;
  resize: none;
  outline: none;
  margin-bottom: 0;
  field-sizing: content; /* Doesn't work in Safari yet */
}

#merged {
  width: 100%;
  user-select: text;

  > * {
    position: relative;
    white-space: pre-wrap;
  }
}

.Unchanged {
  user-select: text;
}

.Left,
.AddedFromLeft,
.RemovedFromLeft {
  user-select: text;
  background: $green;
}

.selection-left::after,
.selection-right::after {
  content: '';
  position: absolute;
  top: 0;
  left: 0;
  width: 100%;
  height: 100%;
}

.selection-left::after {
  background: selection-colour($green);
}

.selection-right::after {
  background: selection-colour($light-blue);
}

.Right,
.AddedFromRight,
.RemovedFromRight {
  user-select: text;
  background: $light-blue;
}

.RemovedFromLeft,
.RemovedFromRight {
  user-select: none;
  text-decoration: line-through;
}

// Selection caret styles
$CARET_WIDTH: 2;
$DOT_RADIUS: 4;

.selection-caret {
  position: relative;
  z-index: 1000;

  &.selection-caret-left {
    background: caret-colour($green);
  }

  &.selection-caret-right {
    background: caret-colour($light-blue);
  }

  > * {
    position: absolute;
    background-color: inherit;
  }

  > .stick {
    left: 0;
    top: 0;
    transform: translateX(-50%);
    width: #{$CARET_WIDTH}px;
    height: 100%;
    display: block;
    border-radius: calc(#{$CARET_WIDTH} / 2 * 1px);
    animation: blink-stick 1s steps(1) infinite;
  }

  > .dot {
    border-radius: 50%;
    width: #{$DOT_RADIUS * 2}px;
    height: #{$DOT_RADIUS * 2}px;
    top: -#{$DOT_RADIUS}px;
    left: -#{$DOT_RADIUS}px;
    transition: opacity 0.3s ease-in-out;
    transform-origin: bottom center;
    box-sizing: border-box;

    &::before {
      content: '';
      position: absolute;
      top: 50%;
      left: 50%;
      transform: translate(-50%, -50%);
      width: 30px;
      height: 30px;
      border-radius: 50%;
    }
  }

  &:hover > .dot {
    opacity: 0;
  }

  > .info {
    top: -1.3em;
    left: calc(-#{$CARET_WIDTH} / 2 * 1px);
    font-size: 0.9em;
    user-select: none;
    color: white;
    padding: 0 2px;
    transition: opacity 0.3s ease-in-out;
    opacity: 0;
    white-space: nowrap;
    border-radius: 3px 3px 3px 0;
  }

  &:hover > .info {
    opacity: 1;
  }
}

@keyframes blink-stick {
  0%,
  100% {
    opacity: 1;
  }
  50% {
    opacity: 0;
  }
}

@media (max-width: 900px) {
  header {
    padding: 32px 18px 0 18px;
  }

  header > h1 {
    margin-bottom: 18px;
  }

  header > p {
    font-size: 1rem;
  }

  main {
    padding: 18px;
  }
}

@media (max-width: 768px) {
  main {
    grid-template-columns: 1fr;
    grid-template-rows: auto auto auto auto auto;
  }

  .tokenizer-selector {
    grid-column: 1;
    grid-row: 1;
  }

  .diamond-parent {
    grid-column: 1;
    grid-row: 2;
  }

  .diamond-left {
    grid-column: 1;
    grid-row: 3;
  }

  .diamond-right {
    grid-column: 1;
    grid-row: 4;
  }

  .radio-group {
    flex-direction: column;
    gap: 12px;
  }

  .radio-option {
    min-width: unset;
    width: 100%;
  }

  .diamond-result {
    grid-column: 1;
    grid-row: 5;
  }
}

footer {
  padding: 16px;
  width: 100%;
  position: relative;
  display: flex;
  justify-content: center;
  align-items: center;
  color: $text-secondary;
}

.github-link > svg {
  position: absolute;
  color: $text-secondary;
  top: 50%;
  right: 36px;
  transform: translateY(-50%);
  width: 32px;
  height: 32px;
  transition: transform 0.2s;
}

.github-link > svg:hover {
  cursor: pointer;
  transform: translateY(-50%) scale(1.15);
}