:root {
  --screen-bg: radial-gradient(circle at center, #1c2e4a 0%, #040915 60%);
  --panel: rgba(10, 26, 50, 0.9);
  --panel-border: rgba(20, 240, 180, 0.35);
  --accent: #3affd4;
  --accent-strong: #ff7be1;
  --tile-bg: #0c1628;
  --tile-border: #5ef1ff;
  --text-main: #e2ffe7;
  --text-dim: #7bdadb;
  --font-headline: "Press Start 2P", system-ui;
  --font-body: "Space Grotesk", system-ui;
  font-size: 62.5%;
}

@media (max-width: 480px) {
  :root {
    font-size: 56%;
  }
}

*,
*::before,
*::after {
  box-sizing: border-box;
}

body {
  margin: 0;
  min-height: 100vh;
  font-family: var(--font-body);
  font-size: 1.6rem;
  color: var(--text-main);
  background: var(--screen-bg);
  display: flex;
  align-items: stretch;
  justify-content: center;
  padding: clamp(0.8rem, 3vw, 2.6rem);
  overflow-y: auto;
}

.crt-overlay {
  position: fixed;
  inset: 0;
  pointer-events: none;
  background-image: linear-gradient(
      rgba(0, 0, 0, 0),
      rgba(0, 0, 0, 0.3)
    ),
    repeating-linear-gradient(
      0deg,
      rgba(255, 255, 255, 0.08) 0,
      rgba(255, 255, 255, 0.02) 2px,
      transparent 3px,
      transparent 4px
    );
  mix-blend-mode: screen;
  animation: scan 6s linear infinite;
}

@keyframes scan {
  0% {
    opacity: 0.4;
  }
  50% {
    opacity: 0.65;
  }
  100% {
    opacity: 0.4;
  }
}

.shell {
  width: min(110rem, calc(100vw - clamp(1rem, 4vw, 4rem)));
  background: var(--panel);
  box-shadow: 0 3rem 4rem rgba(0, 0, 0, 0.6), 0 0 3rem rgba(61, 255, 213, 0.25);
  border: 2px solid var(--panel-border);
  border-radius: 1.6rem;
  padding: clamp(1.8rem, 4vw, 3rem);
  display: flex;
  flex-direction: column;
  gap: 2rem;
  position: relative;
  overflow: hidden;
  margin: 0 auto;
}

.shell::after {
  content: "";
  position: absolute;
  inset: 0;
  border: 1px solid rgba(58, 255, 212, 0.25);
  pointer-events: none;
  mix-blend-mode: screen;
}

.hud {
  display: flex;
  justify-content: space-between;
  gap: 2rem;
  align-items: flex-end;
  border-bottom: 1px solid rgba(58, 255, 212, 0.3);
  padding-bottom: 1.5rem;
  flex-wrap: wrap;
}

.hud h1 {
  font-family: var(--font-headline);
  font-size: 2rem;
  letter-spacing: 0.2rem;
  margin: 0 0 0.5rem;
  text-shadow: 0 0 0.8rem rgba(255, 255, 255, 0.4);
}

.hud p {
  margin: 0;
  color: var(--text-dim);
}

.stats {
  display: flex;
  flex-wrap: wrap;
  gap: 2rem;
}

.stat span {
  text-transform: uppercase;
  font-size: 1.2rem;
  letter-spacing: 0.2rem;
  color: var(--text-dim);
}

.stat strong {
  display: block;
  margin-top: 0.4rem;
  font-size: 2.4rem;
  font-family: var(--font-headline);
}

.game-area {
  display: grid;
  grid-template-columns: minmax(0, 2fr) minmax(18rem, 1fr);
  gap: clamp(2rem, 3vw, 3rem);
  align-items: start;
}

.board {
  --board-max: min(
    calc(100vh - 22rem),
    calc(100vw - clamp(2rem, 6vw, 7rem))
  );
  width: min(100%, var(--board-max));
  aspect-ratio: 1 / 1;
  background: rgba(4, 9, 21, 0.8);
  border: 2px solid var(--panel-border);
  border-radius: 1.6rem;
  display: grid;
  grid-template-columns: repeat(var(--size, 4), 1fr);
  gap: clamp(0.7rem, 1vw, 1rem);
  padding: clamp(0.7rem, 1vw + 0.2rem, 1rem);
  position: relative;
  box-shadow: inset 0 0 2rem rgba(0, 0, 0, 0.6);
  margin-inline: auto;
}

.board::after {
  content: "";
  position: absolute;
  inset: 1rem;
  border: 1px dashed rgba(58, 255, 212, 0.35);
  pointer-events: none;
}

.controls {
  display: flex;
  flex-direction: column;
  gap: 1rem;
  background: rgba(13, 31, 52, 0.85);
  border: 1px solid rgba(58, 255, 212, 0.35);
  border-radius: 1.2rem;
  padding: 1.5rem;
  min-width: 0;
  max-width: min(28rem, calc(100vw - 4rem));
  width: 100%;
  box-shadow: inset 0 0 1rem rgba(0, 0, 0, 0.6);
}

.btn {
  border: 0;
  padding: 1.2rem 1.6rem;
  border-radius: 0.8rem;
  font-family: var(--font-body);
  font-weight: 600;
  letter-spacing: 0.1rem;
  text-transform: uppercase;
  cursor: pointer;
  color: #04111f;
  transition: transform 0.1s ease, box-shadow 0.2s ease;
}

.btn.primary {
  background: linear-gradient(135deg, #3affd4, #40c4ff);
  box-shadow: 0 0.6rem 2rem rgba(58, 255, 212, 0.35);
}

.btn.ghost {
  background: rgba(255, 255, 255, 0.1);
  color: var(--text-main);
  border: 1px dashed rgba(58, 255, 212, 0.7);
}

.btn:active {
  transform: translateY(2px);
  box-shadow: none;
}

.btn.full-width {
  width: 100%;
}

.tip {
  font-size: 1.2rem;
  color: var(--text-dim);
  margin: 0.5rem 0 0;
}

.timer {
  margin-top: 1rem;
  padding: 1rem;
  border: 1px solid rgba(58, 255, 212, 0.35);
  border-radius: 0.8rem;
  background: rgba(4, 9, 21, 0.6);
  text-align: center;
}

.timer span {
  display: block;
  font-size: 1.2rem;
  color: var(--text-dim);
}

.timer strong {
  font-size: 3.2rem;
  font-family: var(--font-headline);
}

.tile {
  border: 0;
  border-radius: 1rem;
  background: radial-gradient(circle at 20% 20%, #ffffff20, transparent 60%),
    linear-gradient(135deg, #072039, #0b2d4f);
  color: var(--accent);
  font-family: var(--font-headline);
  font-size: clamp(1.4rem, 1vw + 1rem, 2rem);
  letter-spacing: 0.2rem;
  text-shadow: 0 0 0.8rem rgba(58, 255, 212, 0.6);
  cursor: pointer;
  display: flex;
  align-items: center;
  justify-content: center;
  position: relative;
  transition: transform 0.2s cubic-bezier(0.2, 0.8, 0.2, 1),
    background 0.3s ease;
  box-shadow: inset 0 0 0 1px rgba(94, 241, 255, 0.5),
    0 0.7rem 1.4rem rgba(0, 0, 0, 0.5);
  will-change: transform;
}

.tile::after {
  content: "";
  position: absolute;
  inset: 0;
  border-radius: inherit;
  border: 1px solid rgba(255, 255, 255, 0.08);
  mix-blend-mode: screen;
}

.tile.correct {
  color: #04111f;
  background: linear-gradient(135deg, #b1ffe7, #68f6ff);
  box-shadow: inset 0 0 0 1px rgba(255, 255, 255, 0.45),
    0 1rem 2.4rem rgba(76, 255, 214, 0.45);
}

.tile.correct::after {
  border-color: rgba(255, 255, 255, 0.35);
}

.tile.marked {
  background: linear-gradient(135deg, #2c1235, #613a9a);
  color: #ffe5ff;
  box-shadow: inset 0 0 0 1px rgba(255, 255, 255, 0.25),
    0 1rem 2.4rem rgba(105, 73, 255, 0.45);
}

.tile.marked::after {
  border-color: rgba(255, 255, 255, 0.4);
}

.tile.is-moving {
  z-index: 3;
}

.tile:focus-visible {
  outline: 2px solid var(--accent-strong);
  outline-offset: -4px;
}

.tile.empty {
  opacity: 0.1;
  cursor: default;
  box-shadow: none;
}

.ticker {
  border-top: 1px solid rgba(58, 255, 212, 0.3);
  padding-top: 1rem;
  overflow: hidden;
  font-family: var(--font-headline);
  font-size: 1.1rem;
  letter-spacing: 0.3rem;
  color: var(--accent);
}

.ticker span {
  display: inline-block;
  animation: ticker 20s linear infinite;
}

@keyframes ticker {
  0% {
    transform: translateX(0);
  }
  100% {
    transform: translateX(-50%);
  }
}

.toast {
  position: fixed;
  bottom: 3rem;
  left: 50%;
  transform: translateX(-50%);
  background: rgba(3, 12, 24, 0.8);
  border: 1px solid rgba(58, 255, 212, 0.6);
  padding: 1.6rem 2.4rem;
  border-radius: 0.8rem;
  font-family: var(--font-headline);
  letter-spacing: 0.1rem;
  text-align: center;
  box-shadow: 0 0 2rem rgba(58, 255, 212, 0.5);
  transition: opacity 0.3s ease, transform 0.3s ease;
}

.toast.hidden {
  opacity: 0;
  pointer-events: none;
  transform: translate(-50%, 2rem);
}

@media (max-width: 900px) {
  .shell {
    width: 100%;
    min-height: calc(100vh - 2rem);
    border-radius: 1.2rem;
  }

  .game-area {
    grid-template-columns: 1fr;
    gap: 2rem;
  }

  .controls {
    flex-direction: row;
    flex-wrap: wrap;
    justify-content: center;
    max-width: none;
  }

  .controls .btn {
    flex: 1 1 12rem;
  }
}

@media (max-width: 600px) {
  body {
    padding: 1rem;
  }

  .shell {
    border-radius: 1rem;
  }

  .hud {
    flex-direction: column;
    align-items: flex-start;
    gap: 1rem;
  }

  .board {
    gap: 0.8rem;
    padding: 0.8rem;
  }

  .tile {
    font-size: 1.6rem;
  }

  .controls {
    flex-direction: column;
    align-items: stretch;
  }

  .controls .btn {
    flex: 1 1 auto;
    width: 100%;
  }

  .board {
    --board-max: min(calc(100vh - 20rem), calc(100vw - 3rem));
  }
}

@media (max-width: 720px) {
  body {
    padding: 1.2rem;
  }

  .game-area {
    gap: 1.6rem;
  }

  .board {
    gap: 0.8rem;
    padding: 0.8rem;
    --board-max: min(calc(100vh - 18rem), calc(100vw - 4rem));
  }

  .controls {
    padding: 1.3rem;
    gap: 0.8rem;
  }
}

.start-screen {
  position: fixed;
  inset: 0;
  background: rgba(4, 9, 21, 0.82);
  backdrop-filter: blur(6px);
  display: flex;
  align-items: center;
  justify-content: center;
  padding: clamp(1.6rem, 4vw, 3.2rem);
  opacity: 0;
  pointer-events: none;
  transition: opacity 0.35s ease;
  z-index: 30;
}

.start-screen::after {
  content: "";
  position: absolute;
  inset: 0;
  background-image: radial-gradient(
      circle at 20% 20%,
      rgba(58, 255, 212, 0.08),
      transparent 50%
    ),
    linear-gradient(
      115deg,
      rgba(0, 255, 189, 0.05) 0%,
      rgba(0, 0, 0, 0) 50%,
      rgba(123, 218, 219, 0.08) 100%
    );
  pointer-events: none;
}

.start-screen.is-visible {
  opacity: 1;
  pointer-events: auto;
}

.start-panel {
  width: min(60rem, 100%);
  background: linear-gradient(145deg, rgba(7, 16, 34, 0.95), rgba(8, 26, 46, 0.95));
  border: 1px solid rgba(58, 255, 212, 0.5);
  border-radius: 1.6rem;
  padding: clamp(1.8rem, 5vw, 3rem);
  text-align: left;
  box-shadow: 0 3rem 4rem rgba(0, 0, 0, 0.65), 0 0 3rem rgba(61, 255, 213, 0.25);
  position: relative;
  overflow: hidden;
  max-height: min(90vh, 76rem);
  overflow-y: auto;
}

.start-panel::before {
  content: "";
  position: absolute;
  inset: 1rem;
  border: 1px dashed rgba(58, 255, 212, 0.35);
  border-radius: 1.2rem;
  pointer-events: none;
}

.start-panel h2 {
  font-family: var(--font-headline);
  font-size: 1.9rem;
  margin: 0 0 0.8rem;
  letter-spacing: 0.2rem;
}

.start-panel p {
  margin: 0 0 1.6rem;
  color: var(--text-dim);
}

.start-header {
  display: flex;
  align-items: stretch;
  gap: 2rem;
  margin-bottom: 2rem;
}

.start-copy {
  flex: 2;
}

.eyebrow {
  text-transform: uppercase;
  font-size: 1.1rem;
  letter-spacing: 0.5rem;
  color: var(--accent);
  margin-bottom: 0.8rem;
}

.start-preview {
  flex: 1;
  border: 1px solid rgba(58, 255, 212, 0.45);
  border-radius: 1.2rem;
  padding: 1.2rem;
  background: rgba(3, 10, 24, 0.9);
  display: flex;
  flex-direction: column;
  gap: 0.8rem;
  box-shadow: inset 0 0 1.5rem rgba(0, 0, 0, 0.6);
}

.preview-grid {
  --preview-size: 4;
  display: grid;
  grid-template-columns: repeat(var(--preview-size), 1fr);
  gap: 0.4rem;
  aspect-ratio: 1 / 1;
}

.preview-cell {
  border-radius: 0.6rem;
  border: 1px solid rgba(58, 255, 212, 0.4);
  background: rgba(8, 26, 46, 0.7);
  box-shadow: inset 0 0 0.6rem rgba(0, 0, 0, 0.7);
}

.preview-cell.is-empty {
  border-style: dashed;
  border-color: rgba(255, 255, 255, 0.35);
  background: rgba(255, 255, 255, 0.08);
}

.preview-label {
  text-transform: uppercase;
  font-size: 1.1rem;
  letter-spacing: 0.3rem;
  color: var(--text-dim);
}

.start-form {
  display: flex;
  flex-direction: column;
  gap: 1.6rem;
  position: relative;
  z-index: 1;
}

.size-picker {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(14rem, 1fr));
  gap: 1.2rem;
}

.size-option {
  border: 0;
  border-radius: 1rem;
  background: rgba(7, 18, 35, 0.9);
  color: var(--text-main);
  padding: 1.4rem;
  text-align: left;
  display: flex;
  flex-direction: column;
  gap: 0.6rem;
  cursor: pointer;
  font-family: var(--font-body);
  letter-spacing: 0.1rem;
  box-shadow: inset 0 0 0 1px rgba(58, 255, 212, 0.3),
    0 1rem 2rem rgba(0, 0, 0, 0.45);
  transition: transform 0.2s ease, box-shadow 0.2s ease, background 0.2s ease;
  position: relative;
  overflow: hidden;
}

.size-option::after {
  content: "";
  position: absolute;
  inset: 0;
  border-radius: inherit;
  background: radial-gradient(
    circle at top,
    rgba(255, 255, 255, 0.15),
    transparent 65%
  );
  opacity: 0;
  transition: opacity 0.3s ease;
  pointer-events: none;
}

.size-option:hover {
  background: rgba(12, 30, 54, 0.95);
  box-shadow: inset 0 0 0 1px rgba(58, 255, 212, 0.5),
    0 1.4rem 2.6rem rgba(0, 0, 0, 0.55);
}

.size-option:hover::after {
  opacity: 1;
}

.size-option:focus-visible {
  outline: 2px solid var(--accent-strong);
  outline-offset: 3px;
}

.size-option .label {
  font-family: var(--font-headline);
  font-size: 1.4rem;
  letter-spacing: 0.3rem;
}

.size-option .best-time {
  font-size: 1.2rem;
  color: var(--text-dim);
  text-transform: uppercase;
  letter-spacing: 0.2rem;
}

.size-option.is-active {
  background: linear-gradient(140deg, rgba(61, 255, 213, 0.15), rgba(64, 196, 255, 0.2));
  box-shadow: inset 0 0 0 1px rgba(58, 255, 212, 0.8),
    0 1.2rem 2.4rem rgba(58, 255, 212, 0.35);
}

.size-option.is-active::after {
  opacity: 0.8;
}

.size-option:active {
  transform: translateY(2px);
}

.start-note {
  font-size: 1.3rem;
  color: var(--text-dim);
  text-transform: uppercase;
  letter-spacing: 0.3rem;
}

.start-actions {
  display: flex;
  gap: 1rem;
}

.start-actions .btn {
  flex: 1 1 50%;
}

@media (max-width: 640px) {
  .start-header {
    flex-direction: column;
  }

  .start-preview {
    flex-direction: row;
    align-items: center;
  }

  .preview-grid {
    width: 8rem;
  }
}

@media (max-width: 520px) {
  .shell {
    padding: 1.6rem;
    gap: 1.4rem;
  }

  .hud {
    gap: 1.2rem;
  }

  .board {
    --board-max: min(calc(100vh - 16rem), calc(100vw - 3rem));
  }

  .start-actions {
    flex-direction: column;
  }

  .start-actions .btn {
    flex: 1 1 auto;
    width: 100%;
  }
}

.start-screen {
  position: fixed;
  inset: 0;
  background: rgba(4, 9, 21, 0.82);
  backdrop-filter: blur(6px);
  display: flex;
  align-items: center;
  justify-content: center;
  padding: clamp(1.6rem, 4vw, 3.2rem);
  opacity: 0;
  pointer-events: none;
  transition: opacity 0.35s ease;
  z-index: 30;
}

.start-screen.is-visible {
  opacity: 1;
  pointer-events: auto;
}

.start-panel {
  width: min(44rem, 100%);
  background: linear-gradient(145deg, rgba(7, 16, 34, 0.95), rgba(8, 26, 46, 0.95));
  border: 1px solid rgba(58, 255, 212, 0.5);
  border-radius: 1.6rem;
  padding: clamp(2rem, 5vw, 3rem);
  text-align: left;
  box-shadow: 0 3rem 4rem rgba(0, 0, 0, 0.65), 0 0 3rem rgba(61, 255, 213, 0.25);
  position: relative;
  overflow: hidden;
}

.start-panel::before {
  content: "";
  position: absolute;
  inset: 1rem;
  border: 1px dashed rgba(58, 255, 212, 0.35);
  border-radius: 1.2rem;
  pointer-events: none;
}

.start-panel h2 {
  font-family: var(--font-headline);
  font-size: 1.9rem;
  margin: 0 0 0.8rem;
  letter-spacing: 0.2rem;
}

.start-panel p {
  margin: 0 0 1.6rem;
  color: var(--text-dim);
}

.start-form {
  display: flex;
  flex-direction: column;
  gap: 1.6rem;
  position: relative;
  z-index: 1;
}

.size-picker {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(14rem, 1fr));
  gap: 1rem;
}

.size-option {
  border: 0;
  border-radius: 1rem;
  background: rgba(7, 18, 35, 0.9);
  color: var(--text-main);
  padding: 1.4rem;
  text-align: left;
  display: flex;
  flex-direction: column;
  gap: 0.6rem;
  cursor: pointer;
  font-family: var(--font-body);
  letter-spacing: 0.1rem;
  box-shadow: inset 0 0 0 1px rgba(58, 255, 212, 0.3),
    0 1rem 2rem rgba(0, 0, 0, 0.45);
  transition: transform 0.2s ease, box-shadow 0.2s ease, background 0.2s ease;
}

.size-option:hover {
  background: rgba(12, 30, 54, 0.95);
}

.size-option:focus-visible {
  outline: 2px solid var(--accent-strong);
  outline-offset: 3px;
}

.size-option .label {
  font-family: var(--font-headline);
  font-size: 1.4rem;
  letter-spacing: 0.3rem;
}

.size-option .best-time {
  font-size: 1.2rem;
  color: var(--text-dim);
  text-transform: uppercase;
  letter-spacing: 0.2rem;
}

.size-option.is-active {
  background: linear-gradient(140deg, rgba(61, 255, 213, 0.15), rgba(64, 196, 255, 0.2));
  box-shadow: inset 0 0 0 1px rgba(58, 255, 212, 0.8),
    0 1.2rem 2.4rem rgba(58, 255, 212, 0.35);
}

.size-option:active {
  transform: translateY(2px);
}

.start-note {
  font-size: 1.3rem;
  color: var(--text-dim);
  text-transform: uppercase;
  letter-spacing: 0.3rem;
}

.start-actions {
  display: flex;
  gap: 1rem;
}

.start-actions .btn {
  flex: 1 1 50%;
}

@media (max-width: 520px) {
  .start-actions {
    flex-direction: column;
  }

  .start-actions .btn {
    flex: 1 1 auto;
    width: 100%;
  }
}

@media (max-width: 420px) {
  .hud h1 {
    font-size: 1.6rem;
  }

  .stat strong {
    font-size: 2rem;
  }

  .game-area {
    gap: 1.5rem;
  }

  .controls {
    padding: 1.2rem;
    gap: 0.8rem;
  }

  .timer strong {
    font-size: 2.4rem;
  }

  .board {
    gap: 0.6rem;
    padding: 0.7rem;
    --board-max: min(calc(100vh - 14rem), calc(100vw - 2.4rem));
  }

  .start-panel {
    padding: 1.6rem;
  }
}

@media (max-width: 360px) {
  body {
    padding: 0.8rem;
  }

  .shell {
    padding: 1.4rem;
    gap: 1.2rem;
  }

  .board {
    --board-max: min(calc(100vh - 12rem), calc(100vw - 2rem));
  }

  .controls {
    padding: 1.1rem;
  }
}

@media (max-height: 640px) {
  body {
    padding: clamp(0.8rem, 2vw, 1.8rem);
  }

  .shell {
    gap: 1.4rem;
    padding: clamp(1.4rem, 3vw, 2.2rem);
  }

  .board {
    --board-max: min(calc(100vh - 10rem), calc(100vw - 5rem));
  }

  .start-screen {
    padding: clamp(1.2rem, 3vw, 2.4rem);
  }

  .start-panel {
    max-height: 88vh;
  }
}

@media (max-height: 720px) {
  .shell {
    gap: 1.6rem;
  }

  .game-area {
    gap: 1.4rem;
  }

  .board {
    --board-max: min(calc(100vh - 14rem), calc(100vw - 4rem));
  }

  .start-screen {
    align-items: flex-start;
    overflow-y: auto;
  }

  .start-panel {
    margin: 1.5rem auto;
  }
}

@media (max-height: 600px) {
  .start-panel {
    margin: 2rem auto;
  }

  .start-header {
    flex-direction: column;
  }

  .preview-grid {
    max-width: 9rem;
  }
}