:root {
  color-scheme: light;
  --bg-top: #eef4ef;
  --bg-bottom: #fbfaf4;
  --card: rgba(255, 253, 247, 0.95);
  --card-border: rgba(35, 68, 61, 0.16);
  --ink: #24201b;
  --muted: #625f55;
  --accent: #b9462d;
  --accent-strong: #233f3a;
  --accent-warm: #e26f42;
  --panel: #fffaf1;
  --shadow: 0 30px 90px rgba(27, 45, 40, 0.16);
}

* {
  box-sizing: border-box;
}

body {
  margin: 0;
  min-height: 100vh;
  font-family: "Noto Sans Thai", sans-serif;
  color: var(--ink);
  background:
    linear-gradient(rgba(35, 63, 58, 0.035) 1px, transparent 1px),
    linear-gradient(90deg, rgba(35, 63, 58, 0.035) 1px, transparent 1px),
    radial-gradient(circle at 50% 4%, rgba(255, 255, 255, 0.92), transparent 28%),
    linear-gradient(180deg, var(--bg-top), var(--bg-bottom));
  background-size: 28px 28px, 28px 28px, auto, auto;
}

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

.page-shell {
  min-height: 100vh;
  display: grid;
  place-items: center;
  padding: 28px 18px;
}

.hero-card {
  position: relative;
  width: min(100%, 640px);
  padding: 38px;
  border: 1px solid var(--card-border);
  border-radius: 8px;
  background: var(--card);
  box-shadow: var(--shadow);
  backdrop-filter: blur(14px);
  overflow: hidden;
}

.hero-card::before {
  position: absolute;
  inset: 0;
  pointer-events: none;
  content: "";
  background:
    linear-gradient(90deg, rgba(35, 63, 58, 0.08), transparent 22%),
    linear-gradient(rgba(35, 63, 58, 0.026) 1px, transparent 1px);
  background-size: auto, 100% 34px;
  mask-image: linear-gradient(180deg, rgba(0, 0, 0, 0.9), transparent 68%);
}

.eyebrow {
  position: relative;
  margin: 0 0 12px;
  font-size: 0.82rem;
  font-weight: 700;
  letter-spacing: 0;
  text-transform: uppercase;
  color: var(--accent);
}

h1 {
  position: relative;
  margin: 0;
  max-width: 12em;
  font-size: 2.25rem;
  line-height: 1.18;
}

.home-link {
  position: relative;
  display: inline-flex;
  align-items: center;
  gap: 8px;
  margin-bottom: 22px;
  padding: 9px 14px;
  border: 1px solid rgba(35, 68, 61, 0.16);
  border-radius: 999px;
  color: var(--accent-strong);
  background: rgba(255, 255, 255, 0.58);
  font-size: 0.95rem;
  font-weight: 800;
  text-decoration: none;
  transition: transform 140ms ease, border-color 140ms ease, background 140ms ease;
}

.home-link::before {
  content: "<";
  color: var(--accent);
  font-weight: 900;
}

.home-link:hover {
  transform: translateY(-1px);
  border-color: rgba(185, 70, 45, 0.34);
  background: rgba(255, 252, 244, 0.95);
}

.lead {
  margin: 18px 0 0;
  max-width: 56ch;
  font-size: 1rem;
  line-height: 1.75;
  color: var(--muted);
}

.question-panel,
.puzzle-panel,
.setup-panel,
.diagnostic-panel,
.reward-panel,
.answer-panel {
  position: relative;
  margin-top: 24px;
  padding: 22px;
  border-radius: 8px;
  background: rgba(255, 249, 238, 0.78);
  border: 1px solid rgba(106, 81, 52, 0.12);
}

.question-panel {
  display: grid;
  min-height: 280px;
  place-items: center;
  overflow: hidden;
}

.question-image {
  display: block;
  width: 100%;
  height: auto;
  max-height: 520px;
  object-fit: contain;
}

.panel-label {
  margin: 0 0 10px;
  font-size: 0.84rem;
  font-weight: 800;
  letter-spacing: 0;
  text-transform: uppercase;
  color: var(--accent);
}

.panel-head {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 12px;
}

.panel-head .panel-label {
  margin-bottom: 0;
}

.puzzle-copy,
.setup-copy,
.reward-message,
.answer-copy,
.answer-note {
  margin: 0;
  line-height: 1.75;
}

.puzzle-copy {
  font-size: 1.34rem;
  font-weight: 500;
  line-height: 1.9;
}

.setup-copy code {
  padding: 0.14rem 0.35rem;
  border-radius: 8px;
  background: rgba(47, 38, 29, 0.07);
  font-size: 0.92em;
}

.diagnostic-status {
  margin: 0;
  line-height: 1.7;
}

.setup-panel.is-hidden,
.diagnostic-panel.is-hidden {
  display: none;
}

.diagnostic-actions {
  display: flex;
  gap: 8px;
}

.secondary-button {
  border: 1px solid rgba(106, 81, 52, 0.18);
  border-radius: 999px;
  padding: 8px 12px;
  color: var(--ink);
  background: rgba(255, 255, 255, 0.72);
  cursor: pointer;
  transition: background 140ms ease, transform 140ms ease;
}

.secondary-button:hover {
  transform: translateY(-1px);
  background: rgba(255, 255, 255, 0.9);
}

.diagnostic-log {
  margin: 14px 0 0;
  padding: 14px;
  overflow: auto;
  border-radius: 8px;
  background: #2c241c;
  color: #f6efe5;
  font-family: ui-monospace, SFMono-Regular, Menlo, Monaco, Consolas, monospace;
  font-size: 0.84rem;
  line-height: 1.55;
  white-space: pre-wrap;
}

.action-row {
  margin-top: 30px;
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 8px;
}

.question-list {
  display: grid;
  gap: 14px;
  margin-top: 28px;
}

.question-list a {
  display: flex;
  align-items: center;
  justify-content: space-between;
  min-height: 58px;
  padding: 16px 18px;
  border: 1px solid rgba(35, 68, 61, 0.14);
  border-radius: 8px;
  color: var(--ink);
  background: rgba(255, 249, 238, 0.78);
  font-size: 1.1rem;
  font-weight: 800;
  text-decoration: none;
  transition: transform 140ms ease, border-color 140ms ease, background 140ms ease;
}

.question-list a::after {
  color: var(--accent);
  content: ">";
  font-weight: 900;
}

.question-list a:hover {
  transform: translateY(-1px);
  border-color: rgba(185, 70, 45, 0.34);
  background: rgba(255, 252, 244, 0.95);
}

.unlock-button {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 12px;
  border: 0;
  border-radius: 999px;
  min-width: min(100%, 260px);
  padding: 18px 30px;
  font-size: 1.18rem;
  font-weight: 800;
  color: #fffdf8;
  background:
    linear-gradient(135deg, rgba(255, 255, 255, 0.16), transparent 38%),
    linear-gradient(135deg, var(--accent-warm), var(--accent));
  box-shadow: 0 16px 30px rgba(185, 70, 45, 0.28);
  cursor: pointer;
  transition:
    transform 140ms ease,
    box-shadow 140ms ease,
    opacity 140ms ease;
}

.unlock-button:hover {
  transform: translateY(-2px);
  box-shadow: 0 20px 36px rgba(185, 70, 45, 0.32);
}

.button-icon {
  display: grid;
  min-width: 36px;
  height: 30px;
  padding: 0 8px;
  place-items: center;
  border-radius: 999px;
  color: var(--accent-strong);
  background: #fff7e8;
  font-size: 0.82rem;
  font-weight: 900;
  line-height: 1;
}

.unlock-button:disabled {
  opacity: 0.72;
  cursor: wait;
  transform: none;
  box-shadow: 0 8px 18px rgba(187, 90, 42, 0.18);
}

.hint-text {
  margin: 0;
  color: var(--muted);
  font-size: 0.92rem;
}

.reward-panel,
.answer-panel {
  display: none;
}

.reward-panel.is-visible,
.answer-panel.is-visible {
  display: block;
}

.progress-track {
  margin-top: 14px;
  width: 100%;
  height: 10px;
  overflow: hidden;
  border-radius: 999px;
  background: rgba(47, 38, 29, 0.08);
}

.progress-bar {
  display: block;
  width: 0;
  height: 100%;
  border-radius: inherit;
  background: linear-gradient(90deg, #e98c41, #bb5a2a);
  transition: width 220ms ease;
}

.reward-meta {
  margin: 12px 0 0;
  color: var(--muted);
  font-size: 0.92rem;
  line-height: 1.6;
}

.answer-copy strong {
  font-size: 1.34rem;
}

.answer-copy strong:empty {
  display: block;
  min-height: 1.8em;
}

.answer-steps {
  display: grid;
  gap: 8px;
}

.answer-steps p {
  margin: 0;
  font-size: 1.12rem;
  font-weight: 600;
}

.answer-result {
  margin-top: 6px;
  padding: 14px 16px;
  border-radius: 8px;
  color: #fffdf8;
  background: linear-gradient(135deg, var(--accent-strong), #315c52);
  font-size: 1.28rem;
  font-weight: 900;
}

.answer-note {
  margin-top: 10px;
  color: var(--muted);
}

.related-section {
  position: relative;
  margin-top: 34px;
  padding-top: 24px;
  border-top: 1px solid rgba(35, 68, 61, 0.12);
}

.related-header {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 16px;
  margin-bottom: 14px;
}

.related-header .panel-label {
  margin: 0;
}

.related-header a {
  color: var(--accent);
  font-size: 0.94rem;
  font-weight: 800;
  text-decoration: none;
}

.related-grid {
  display: grid;
  grid-template-columns: repeat(3, minmax(0, 1fr));
  gap: 12px;
}

.related-card {
  display: grid;
  overflow: hidden;
  border: 1px solid rgba(35, 68, 61, 0.14);
  border-radius: 8px;
  color: var(--ink);
  background: rgba(255, 249, 238, 0.78);
  text-decoration: none;
  transition: transform 140ms ease, border-color 140ms ease, box-shadow 140ms ease;
}

.related-card:hover {
  transform: translateY(-2px);
  border-color: rgba(185, 70, 45, 0.36);
  box-shadow: 0 14px 24px rgba(35, 63, 58, 0.1);
}

.related-card img {
  width: 100%;
  aspect-ratio: 4 / 3;
  object-fit: cover;
  background: rgba(35, 63, 58, 0.08);
}

.related-card span {
  padding: 12px;
  font-size: 0.98rem;
  font-weight: 900;
}

@media (max-width: 640px) {
  .page-shell {
    padding: 16px;
  }

  .hero-card {
    padding: 24px 20px;
    border-radius: 8px;
  }

  h1 {
    font-size: 1.82rem;
  }

  .puzzle-copy {
    font-size: 1.2rem;
  }

  .question-panel {
    min-height: 220px;
    padding: 14px;
  }

  .unlock-button {
    width: 100%;
    min-width: 0;
  }

  .panel-head {
    align-items: flex-start;
    flex-direction: column;
  }

  .diagnostic-actions {
    width: 100%;
  }

  .secondary-button {
    flex: 1;
  }

  .related-grid {
    grid-template-columns: 1fr;
  }

  .related-card {
    grid-template-columns: 92px 1fr;
    align-items: center;
  }

  .related-card img {
    height: 78px;
    aspect-ratio: auto;
  }
}