frontend/src/index.css

:root {
  color: #13231d;
  background:
    radial-gradient(circle at top left, rgba(235, 242, 168, 0.45), transparent 34%),
    radial-gradient(circle at bottom right, rgba(117, 205, 161, 0.28), transparent 28%),
    linear-gradient(180deg, #f7f7f0 0%, #ecf2ea 100%);
  font-family:
    "IBM Plex Sans",
    "Avenir Next",
    "Segoe UI",
    sans-serif;
  line-height: 1.4;
  font-weight: 400;
  font-synthesis: none;
  text-rendering: optimizeLegibility;
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
}

* {
  box-sizing: border-box;
}

body {
  margin: 0;
  min-width: 320px;
  min-height: 100vh;
}

button,
input,
select,
textarea {
  font: inherit;
}

button {
  cursor: pointer;
}

a {
  color: inherit;
}

.shell {
  min-height: 100vh;
  padding: 24px;
}

.panel {
  border: 1px solid rgba(18, 49, 41, 0.14);
  border-radius: 24px;
  background: rgba(255, 255, 255, 0.82);
  box-shadow:
    0 20px 50px rgba(31, 51, 42, 0.08),
    inset 0 1px 0 rgba(255, 255, 255, 0.7);
  backdrop-filter: blur(18px);
}

.home-layout {
  display: grid;
  gap: 24px;
  max-width: 1100px;
  margin: 0 auto;
}

.hero {
  padding: 40px;
  display: grid;
  gap: 16px;
}

.eyebrow {
  font-size: 0.78rem;
  letter-spacing: 0.14em;
  text-transform: uppercase;
  color: #42685a;
}

.hero h1 {
  margin: 0;
  font-family:
    "Iowan Old Style",
    "Palatino Linotype",
    serif;
  font-size: clamp(2.4rem, 6vw, 4.8rem);
  line-height: 0.95;
  max-width: 9ch;
}

.hero p {
  margin: 0;
  max-width: 65ch;
  color: #365145;
  font-size: 1.02rem;
}

.hero-grid {
  display: grid;
  gap: 24px;
}

.card {
  padding: 28px;
}

.form-grid {
  display: grid;
  gap: 18px;
}

.field {
  display: grid;
  gap: 8px;
}

.field label {
  font-size: 0.92rem;
  font-weight: 600;
  color: #29463b;
}

.field input,
.field select,
.ascii-preview {
  width: 100%;
  border: 1px solid rgba(28, 55, 45, 0.16);
  border-radius: 16px;
  background: rgba(255, 255, 255, 0.94);
  padding: 14px 16px;
  color: #13231d;
}

.puzzle-picker {
  display: grid;
  gap: 10px;
  max-height: 360px;
  overflow: auto;
  padding-right: 4px;
}

.puzzle-option {
  display: grid;
  grid-template-columns: auto 44px minmax(0, 1fr);
  gap: 12px;
  align-items: center;
  padding: 14px 16px;
  border: 1px solid rgba(28, 55, 45, 0.12);
  border-radius: 18px;
  background: rgba(255, 255, 255, 0.88);
  transition:
    border-color 140ms ease,
    background 140ms ease,
    transform 140ms ease;
}

.puzzle-option:hover {
  transform: translateY(-1px);
  border-color: rgba(28, 55, 45, 0.22);
}

.puzzle-option.selected {
  border-color: rgba(21, 79, 58, 0.42);
  background: rgba(220, 239, 229, 0.72);
}

.puzzle-option input {
  margin: 0;
}

.puzzle-option-seq {
  font-size: 0.88rem;
  font-weight: 700;
  color: #42685a;
}

.puzzle-option-text {
  display: grid;
  gap: 2px;
}

.puzzle-option-text span {
  color: #46695d;
  font-size: 0.88rem;
}

.primary-button,
.secondary-button,
.ghost-button {
  border: none;
  border-radius: 999px;
  padding: 14px 22px;
  font-weight: 700;
  transition:
    transform 140ms ease,
    box-shadow 140ms ease,
    opacity 140ms ease;
}

.primary-button {
  color: #fcfff8;
  background: linear-gradient(135deg, #154f3a, #2f7f63);
  box-shadow: 0 12px 28px rgba(28, 77, 59, 0.25);
}

.secondary-button {
  color: #12362c;
  background: #dcefe5;
}

.ghost-button {
  color: #285144;
  background: transparent;
  border: 1px solid rgba(40, 81, 68, 0.18);
}

.primary-button:hover,
.secondary-button:hover,
.ghost-button:hover {
  transform: translateY(-1px);
}

.button-row {
  display: flex;
  gap: 12px;
  flex-wrap: wrap;
}

.hint-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(180px, 1fr));
  gap: 14px;
}

.hint-box {
  padding: 18px;
  border-radius: 18px;
  background: rgba(18, 54, 44, 0.05);
}

.hint-box strong {
  display: block;
  margin-bottom: 6px;
}

.admin-button-wrap {
  position: fixed;
  top: 18px;
  right: 18px;
  z-index: 1000;
  display: flex;
  flex-direction: column;
  align-items: flex-end;
  gap: 8px;
}

.admin-button {
  border: 1px solid rgba(18, 49, 41, 0.18);
  background: rgba(255, 255, 255, 0.85);
  color: #2a4a3d;
  padding: 6px 12px;
  border-radius: 999px;
  font-size: 0.82rem;
  font-weight: 500;
  backdrop-filter: blur(10px);
  cursor: pointer;
}

.admin-button:hover {
  border-color: rgba(18, 49, 41, 0.4);
}

.admin-button-on {
  background: rgba(34, 145, 92, 0.18);
  border-color: rgba(34, 145, 92, 0.45);
  color: #145a37;
}

.admin-panel {
  background: rgba(255, 255, 255, 0.96);
  border: 1px solid rgba(18, 49, 41, 0.18);
  border-radius: 14px;
  padding: 14px;
  width: 280px;
  box-shadow: 0 18px 40px rgba(31, 51, 42, 0.16);
  display: grid;
  gap: 10px;
}

.admin-form {
  display: grid;
  gap: 8px;
}

.admin-form label {
  font-size: 0.78em;
  color: #46695d;
  font-weight: 500;
}

.admin-form input {
  padding: 8px 10px;
  border-radius: 8px;
  border: 1px solid rgba(18, 49, 41, 0.18);
  font-size: 0.9rem;
}

.admin-panel-text {
  font-size: 0.88em;
  color: #46695d;
}

.admin-panel-error {
  font-size: 0.85em;
  color: #7f1e1e;
}

.leaderboard-panel {
  margin-top: 18px;
  padding: 20px 24px;
  display: grid;
  gap: 14px;
}

.leaderboard-header {
  display: flex;
  justify-content: space-between;
  align-items: flex-end;
  gap: 12px;
}

.leaderboard-summary {
  font-size: 0.92rem;
  color: #46695d;
  margin-top: 2px;
}

.leaderboard-toggle {
  font-size: 0.82em;
  color: #46695d;
  display: inline-flex;
  align-items: center;
  gap: 6px;
}

.leaderboard-empty {
  font-size: 0.92em;
  color: #5a7568;
  font-style: italic;
}

.leaderboard-table-wrap {
  overflow-x: auto;
}

.leaderboard-table {
  width: 100%;
  border-collapse: collapse;
  font-size: 0.92rem;
}

.leaderboard-table th,
.leaderboard-table td {
  text-align: left;
  padding: 8px 10px;
  border-bottom: 1px solid rgba(18, 49, 41, 0.08);
}

.leaderboard-table th {
  font-size: 0.74em;
  letter-spacing: 0.08em;
  text-transform: uppercase;
  font-weight: 600;
  color: #46695d;
}

.leaderboard-table .row-solved td {
  background: rgba(34, 145, 92, 0.05);
}

.leaderboard-table .row-unsolved td {
  color: #6b7a73;
}

.leaderboard-rank {
  width: 36px;
  font-variant-numeric: tabular-nums;
}

.leaderboard-time {
  font-variant-numeric: tabular-nums;
}

.leaderboard-status {
  font-size: 0.82em;
  text-transform: uppercase;
  letter-spacing: 0.06em;
  color: #46695d;
}

.submit-banner {
  margin-top: 14px;
  padding: 14px 18px;
  border-radius: 14px;
  font-weight: 500;
  font-size: 1.02rem;
  text-align: center;
  border: 1px solid transparent;
  animation: submit-banner-pop 220ms ease-out;
}

.submit-banner-wrong {
  background: rgba(204, 142, 41, 0.12);
  border-color: rgba(204, 142, 41, 0.32);
  color: #8a5a14;
}

.submit-banner-error {
  background: rgba(170, 44, 44, 0.1);
  border-color: rgba(170, 44, 44, 0.32);
  color: #7f1e1e;
}

@keyframes submit-banner-pop {
  0% { transform: translateY(-6px); opacity: 0; }
  100% { transform: translateY(0); opacity: 1; }
}

.field-hint {
  display: block;
  margin-top: 6px;
  font-size: 0.82em;
  color: #5a7568;
  line-height: 1.4;
}

.field-hint code {
  background: rgba(18, 54, 44, 0.08);
  padding: 1px 6px;
  border-radius: 6px;
  font-size: 0.95em;
}

.rules-box strong {
  display: block;
  font-size: 0.78em;
  letter-spacing: 0.08em;
  text-transform: uppercase;
  color: #46695d;
  margin-bottom: 6px;
}

.rules-box p {
  margin: 0;
  line-height: 1.5;
}

.tutorial-link {
  display: inline-block;
  margin-top: 8px;
  font-size: 0.85em;
  color: #2a6151;
  text-decoration: none;
  border-bottom: 1px solid rgba(42, 97, 81, 0.3);
}

.tutorial-link:hover {
  color: #18402f;
  border-bottom-color: rgba(24, 64, 47, 0.65);
}

.play-layout {
  max-width: 1400px;
  margin: 0 auto;
  display: grid;
  gap: 18px;
}

.topbar {
  padding: 20px 24px;
  display: flex;
  gap: 16px;
  justify-content: space-between;
  align-items: center;
  flex-wrap: wrap;
}

.topbar h1 {
  margin: 0;
  font-size: 1.4rem;
}

.meta-line {
  display: flex;
  gap: 10px;
  flex-wrap: wrap;
  color: #46695d;
  font-size: 0.92rem;
}

.meta-pill {
  padding: 8px 12px;
  border-radius: 999px;
  background: rgba(19, 35, 29, 0.06);
}

.play-grid {
  display: grid;
  grid-template-columns: minmax(0, 1fr) 320px;
  gap: 18px;
}

.puzzle-panel {
  padding: 24px;
  overflow: auto;
}

.sidebar {
  padding: 20px;
  display: grid;
  gap: 18px;
  align-content: start;
}

.image-frame {
  border-radius: 18px;
  overflow: hidden;
  border: 1px solid rgba(18, 35, 29, 0.08);
  background: #f4f7f1;
}

.image-frame img {
  display: block;
  width: 100%;
  height: auto;
}

.timer {
  font-size: clamp(2rem, 5vw, 3.2rem);
  font-weight: 800;
  letter-spacing: -0.04em;
}

.status-box {
  padding: 14px 16px;
  border-radius: 18px;
  background: rgba(18, 54, 44, 0.06);
  color: #23463a;
}

.status-box.error {
  background: rgba(170, 44, 44, 0.1);
  color: #7f1e1e;
}

.ascii-preview {
  min-height: 180px;
  font-family:
    "SFMono-Regular",
    "Menlo",
    "Consolas",
    monospace;
  font-size: 0.8rem;
  white-space: pre;
  overflow: auto;
}

.compact-preview {
  min-height: 0;
}

.editor-stack {
  display: grid;
  gap: 16px;
}

.puzzle-note {
  padding: 12px 14px;
  border-radius: 16px;
  background: rgba(18, 54, 44, 0.06);
  color: #2b5446;
  font-size: 0.95rem;
}

.board-grid {
  display: inline-grid;
  gap: 2px;
  padding: 14px;
  border-radius: 18px;
  background: rgba(17, 35, 29, 0.06);
}

.board-cell,
.board-square,
.board-char {
  display: flex;
  align-items: center;
  justify-content: center;
  user-select: none;
}

.board-cell {
  width: 38px;
  height: 38px;
  border-radius: 12px;
  border: none;
  background: rgba(255, 255, 255, 0.92);
  color: #143228;
  font-weight: 700;
}

.board-cell.water {
  background: rgba(255, 255, 255, 0.58);
  color: #4c7567;
}

.board-cell.fixed {
  background: linear-gradient(180deg, #fff3ce, #f2df9b);
}

.board-cell.island-cell {
  border-radius: 50%;
  box-shadow: inset 0 -2px 0 rgba(20, 40, 31, 0.12);
}

.board-cell.bridge-cell {
  font-size: 1.1rem;
}

.board-cell.mirror {
  background: linear-gradient(180deg, #dbe9ff, #b8d1ff);
}

.board-cell.endpoint-cell {
  box-shadow:
    inset 0 -2px 0 rgba(20, 40, 31, 0.12),
    0 0 0 3px rgba(255, 255, 255, 0.4);
}

.board-square {
  width: 44px;
  height: 44px;
  border-radius: 14px;
  border: 1px solid rgba(20, 50, 40, 0.08);
  background: rgba(255, 255, 255, 0.92);
  font-weight: 700;
}

.board-square.fill {
  background: #17352b;
  color: #f7fff6;
}

.board-square.empty {
  background: #eef2ea;
  color: #406257;
}

.board-square.unknown {
  background: rgba(255, 255, 255, 0.92);
  color: #a9b7b0;
}

.char-board {
  display: inline-grid;
  gap: 1px;
  padding: 14px;
  border-radius: 18px;
  background: rgba(17, 35, 29, 0.08);
  font-family:
    "SFMono-Regular",
    "Menlo",
    "Consolas",
    monospace;
}

.board-char {
  width: 24px;
  height: 24px;
  border: none;
  border-radius: 6px;
  background: transparent;
  color: #17362c;
}

.board-char.clickable {
  background: rgba(255, 255, 255, 0.85);
}

.pattern-layout {
  display: grid;
  grid-template-columns: 92px max-content;
  gap: 12px;
  align-items: end;
  width: max-content;
}

.pattern-top-spacer {
  min-height: 1px;
}

.pattern-top-clues {
  display: grid;
  gap: 2px;
  align-items: end;
  justify-content: start;
}

.pattern-row-pair {
  display: contents;
}

.pattern-column-stack {
  display: grid;
  gap: 4px;
  justify-items: center;
  align-content: end;
}

.pattern-board {
  padding: 10px;
  width: max-content;
}

.pattern-clue {
  color: #406257;
}

.pattern-row-clue {
  display: flex;
  justify-content: flex-end;
  gap: 6px;
  flex-wrap: wrap;
  padding-right: 4px;
}

.pattern-clue-pill {
  display: inline-flex;
  min-width: 28px;
  min-height: 22px;
  align-items: center;
  justify-content: center;
  padding: 0 8px;
  border-radius: 999px;
  background: rgba(18, 54, 44, 0.08);
  color: #214338;
  font-family:
    "SFMono-Regular",
    "Menlo",
    "Consolas",
    monospace;
  font-size: 0.86rem;
  font-weight: 700;
}

.palette {
  display: flex;
  gap: 8px;
  flex-wrap: wrap;
}

.palette button {
  width: 38px;
  height: 38px;
  border-radius: 999px;
  border: 2px solid transparent;
  color: #112219;
  font-weight: 800;
}

.palette button.active {
  border-color: #13231d;
  transform: scale(1.05);
}

.erase-swatch {
  width: auto;
  padding: 0 16px;
  background: #eef2ea;
}

.svg-board-shell {
  overflow: auto;
  padding: 10px;
  border-radius: 20px;
  background: rgba(17, 35, 29, 0.05);
}

.svg-board {
  display: block;
  width: min(100%, 760px);
  height: auto;
}

.svg-cell-bg,
.galaxy-cell-bg {
  fill: rgba(255, 255, 255, 0.84);
}

.galaxy-cell-bg {
  stroke: rgba(35, 70, 58, 0.08);
  stroke-width: 1.5;
}

.svg-clue-text {
  fill: #18392e;
  font-size: 22px;
  font-weight: 700;
}

.svg-vertex {
  fill: #1f4d3c;
}

.svg-hit-target {
  cursor: pointer;
}

.svg-hit-line {
  stroke: transparent;
  stroke-width: 22;
  stroke-linecap: round;
}

.svg-line,
.svg-wall {
  stroke-linecap: round;
  transition:
    stroke 120ms ease,
    opacity 120ms ease,
    stroke-width 120ms ease;
}

.svg-line.active {
  stroke: #1f6a4f;
  stroke-width: 7;
}

.svg-line.ghost {
  stroke: rgba(39, 83, 68, 0.16);
  stroke-width: 4;
}

.svg-wall.fixed {
  stroke: #28493d;
  stroke-width: 5;
}

.svg-wall.active {
  stroke: #215b46;
  stroke-width: 6;
}

.svg-wall.ghost {
  stroke: rgba(39, 83, 68, 0.16);
  stroke-width: 4;
}

.svg-xmark {
  fill: #7c8e87;
  font-size: 21px;
  font-weight: 700;
}

.galaxy-dot {
  fill: #17352b;
  stroke: #f7f7f0;
  stroke-width: 3;
}

.undead-legend {
  display: inline-flex;
  width: fit-content;
  padding: 10px 14px;
  border-radius: 999px;
  background: rgba(18, 54, 44, 0.08);
  color: #224639;
  font-weight: 600;
}

.undead-grid-wrap {
  display: grid;
  gap: 10px;
}

.undead-clue-row {
  display: grid;
  grid-template-columns: 40px repeat(4, 38px) 40px;
  gap: 8px;
  align-items: center;
}

.undead-clue-box,
.undead-clue-spacer {
  display: flex;
  align-items: center;
  justify-content: center;
  min-height: 32px;
  color: #46695d;
  font-family:
    "SFMono-Regular",
    "Menlo",
    "Consolas",
    monospace;
}

.undead-clue-box.side {
  font-weight: 700;
}

.undead-cell.monster-cell {
  background: rgba(255, 255, 255, 0.96);
}

.done-layout {
  max-width: 820px;
  margin: 0 auto;
  padding-top: 64px;
  display: grid;
  gap: 18px;
}

.done-card {
  padding: 36px;
  display: grid;
  gap: 16px;
}

.comparison-card {
  padding: 28px;
  display: grid;
  gap: 16px;
}

.comparison-headline {
  margin: 0;
  font-size: 1.15rem;
  font-weight: 600;
  line-height: 1.4;
  color: #18402f;
}

.comparison-grid {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 16px;
}

.comparison-column {
  display: grid;
  gap: 10px;
}

.comparison-column-title {
  font-size: 0.78em;
  letter-spacing: 0.08em;
  text-transform: uppercase;
  font-weight: 600;
}

.comparison-solved {
  color: #1d6b46;
}

.comparison-failed {
  color: #7a3a3a;
}

.comparison-list {
  list-style: none;
  margin: 0;
  padding: 0;
  display: flex;
  flex-wrap: wrap;
  gap: 6px;
}

.comparison-pill {
  display: inline-block;
  padding: 4px 10px;
  border-radius: 999px;
  font-size: 0.88em;
  border: 1px solid transparent;
}

.comparison-pill-solved {
  background: rgba(34, 145, 92, 0.12);
  border-color: rgba(34, 145, 92, 0.28);
  color: #145a37;
}

.comparison-pill-failed {
  background: rgba(170, 70, 70, 0.1);
  border-color: rgba(170, 70, 70, 0.25);
  color: #7a3030;
}

.comparison-empty {
  font-size: 0.9em;
  color: #5a7568;
  font-style: italic;
}

.comparison-footnote {
  margin: 0;
  font-size: 0.82em;
  color: #5a7568;
}

.comparison-footnote code {
  background: rgba(18, 54, 44, 0.08);
  padding: 1px 6px;
  border-radius: 6px;
}

@media (max-width: 640px) {
  .comparison-grid {
    grid-template-columns: 1fr;
  }
}

@media (max-width: 980px) {
  .play-grid {
    grid-template-columns: 1fr;
  }
}

@media (max-width: 640px) {
  .shell {
    padding: 14px;
  }

  .hero,
  .card,
  .puzzle-panel,
  .sidebar,
  .done-card {
    padding: 18px;
  }

  .board-cell {
    width: 32px;
    height: 32px;
  }

  .board-square {
    width: 38px;
    height: 38px;
  }

  .undead-clue-row {
    grid-template-columns: 32px repeat(4, 32px) 32px;
    gap: 6px;
  }

  .board-char {
    width: 20px;
    height: 20px;
    font-size: 0.75rem;
  }
}