:root {
  --brand: #164ca9;
  --brand-d: #103a81;
  --brand-l: #4a78d0;
  --accent: #dfd11d;
  --accent-l: #f0e980;
  --accent-d: #7d6800;
  --ink: #112246;
  --ink-mid: #46587f;
  --paper: #f4f7ff;
  --surface: #ffffff;
  --shadow: 0 20px 44px rgba(17,34,70,.12);
  --radius: 24px;
  --font-head: "Sora", sans-serif;
}

* { box-sizing: border-box; }

html,
body {
  min-width: 0;
  overflow-x: hidden;
}

body {
  margin: 0;
  font-family: "IBM Plex Sans", sans-serif;
  color: var(--ink);
  background: radial-gradient(circle at top right, rgba(223,209,29,.16), transparent 20%), linear-gradient(180deg, #ffffff 0%, var(--paper) 100%);
}

.page {
  width: 100%;
  min-width: 0;
  padding: 24px;
  display: grid;
  gap: 24px;
}

.topbar {
  max-width: 1280px;
  width: 100%;
  min-width: 0;
  margin: 0 auto;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 16px;
  flex-wrap: wrap;
}

.back-link,
.open-direct {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  min-height: 48px;
  padding: 0 18px;
  border-radius: 999px;
  text-decoration: none;
  font-weight: 700;
  transition: transform .25s ease, background .25s ease, color .25s ease;
}

.back-link {
  background: var(--brand);
  color: #fff;
}

.back-link:hover,
.open-direct:hover {
  transform: translateY(-2px);
}

.open-direct {
  color: var(--brand);
  border: 2px solid rgba(22,76,169,.2);
  background: rgba(255,255,255,.85);
}

p {
  margin: 10px 0 0;
  color: var(--ink-mid);
  max-width: 64ch;
}

.content {
  max-width: 1280px;
  width: 100%;
  min-width: 0;
  margin: 0 auto;
  display: grid;
  gap: 2rem;
}

.puzzle-header {
  max-width: 820px;
  min-width: 0;
}

.puzzle-header .label {
  display: inline-block;
  margin-bottom: 16px;
  font-family: var(--font-head);
  font-size: clamp(28px, 5vw, 52px);
  font-weight: 800;
  letter-spacing: -.04em;
  line-height: 1;
  text-transform: none;
  color: var(--ink);
}

.puzzle-header h1 {
  margin: 0;
  font-family: var(--font-head);
  font-size: clamp(28px, 4vw, 48px);
  line-height: 1.08;
  letter-spacing: -.03em;
  overflow-wrap: normal;
  word-break: normal;
}

.puzzle-lead {
  font-size: 1rem;
  color: var(--ink-mid);
  line-height: 1.75;
  max-width: 72ch;
}

.puzzle-wrap {
  display: grid;
  gap: 2.5rem;
  min-width: 0;
}

.puzzle-grid {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 0;
  width: 100%;
  max-width: 980px;
  min-width: 0;
  margin: 0 auto;
  padding: 1.9rem 2rem 2.1rem;
}

.puzzle-piece {
  --piece-chip-bg: rgba(22,76,169,.18);
  --piece-chip-ink: #103a81;
  --piece-panel: linear-gradient(160deg, rgba(16,58,129,.96), rgba(22,76,169,.9));
  --piece-panel-edge: rgba(255,255,255,.16);
  position: relative;
  overflow: visible;
  min-width: 0;
  margin: 0;
  cursor: pointer;
  transition: transform .32s cubic-bezier(.34,1.26,.64,1), filter .28s ease;
  z-index: 1;
}

.puzzle-piece--1 {
  --piece-chip-bg: rgba(22,76,169,.18);
  --piece-chip-ink: #103a81;
  --piece-panel: linear-gradient(160deg, rgba(16,58,129,.97), rgba(29,94,193,.88));
}

.puzzle-piece--2 {
  --piece-chip-bg: rgba(223,209,29,.36);
  --piece-chip-ink: #7d6800;
  --piece-panel: linear-gradient(160deg, rgba(16,58,129,.97), rgba(124,104,9,.9));
  --piece-panel-edge: rgba(240,233,128,.34);
}

.puzzle-piece--3 {
  --piece-chip-bg: rgba(74,120,208,.18);
  --piece-chip-ink: #164ca9;
  --piece-panel: linear-gradient(160deg, rgba(12,46,106,.97), rgba(74,120,208,.84));
}

.puzzle-piece--4 {
  --piece-chip-bg: rgba(240,233,128,.28);
  --piece-chip-ink: #826b00;
  --piece-panel: linear-gradient(160deg, rgba(17,34,70,.96), rgba(22,76,169,.86));
  --piece-panel-edge: rgba(240,233,128,.28);
}

.puzzle-piece:hover,
.puzzle-piece:focus {
  transform: scale(1.02);
  filter: drop-shadow(0 22px 50px rgba(16,58,129,.26));
  z-index: 10;
  outline: none;
}

.puzzle-piece__bg {
  display: block;
  width: 100%;
  height: auto;
}

.puzzle-piece__body {
  position: absolute;
  top: 21%;
  right: 17%;
  bottom: 19%;
  left: 17%;
  min-width: 0;
  padding: 1.95rem 2.05rem 1.8rem;
  display: flex;
  flex-direction: column;
  justify-content: center;
  align-items: center;
  text-align: center;
  pointer-events: none;
  transition: opacity .22s ease, transform .28s ease;
}

.puzzle-piece:hover .puzzle-piece__body,
.puzzle-piece:focus .puzzle-piece__body {
  opacity: .18;
  transform: translateY(5px) scale(.986);
}

.puzzle-piece__id {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  width: 42px;
  height: 42px;
  border-radius: 12px;
  background: var(--piece-chip-bg);
  color: var(--piece-chip-ink);
  box-shadow: inset 0 0 0 1px rgba(255,255,255,.28);
  font-family: var(--font-head);
  font-weight: 800;
  font-size: .83rem;
  margin-bottom: .68rem;
  align-self: center;
}

.puzzle-piece h3 {
  margin: 0 0 .38rem;
  font-family: var(--font-head);
  font-size: .98rem;
  line-height: 1.23;
  color: var(--ink);
  max-width: 100%;
  overflow-wrap: break-word;
}

.puzzle-piece__summary {
  margin: 0;
  max-width: 100%;
  font-size: .8rem;
  color: var(--ink-mid);
  line-height: 1.55;
  overflow-wrap: break-word;
}

.puzzle-piece__overlay {
  position: absolute;
  top: 21%;
  right: 17%;
  bottom: 19%;
  left: 17%;
  min-width: 0;
  padding: 1.95rem 2.05rem 1.8rem;
  display: flex;
  align-items: center;
  justify-content: center;
  opacity: 0;
  pointer-events: none;
  transition: opacity .24s ease;
}

.puzzle-piece:hover .puzzle-piece__overlay,
.puzzle-piece:focus .puzzle-piece__overlay {
  opacity: 1;
}

.puzzle-piece__overlay-inner {
  background: var(--piece-panel);
  backdrop-filter: blur(8px);
  -webkit-backdrop-filter: blur(8px);
  border: 1px solid var(--piece-panel-edge);
  border-radius: 16px;
  padding: 1.15rem 1.25rem;
  width: 100%;
  box-shadow: 0 20px 36px rgba(17,34,70,.24);
  transform: translateY(10px) scale(.95);
  transition: transform .28s cubic-bezier(.34,1.2,.64,1);
}

.puzzle-piece:hover .puzzle-piece__overlay-inner,
.puzzle-piece:focus .puzzle-piece__overlay-inner {
  transform: translateY(0) scale(1);
}

.puzzle-piece__overlay-inner p {
  margin: 0;
  font-size: .92rem;
  color: rgba(255,255,255,.93);
  line-height: 1.72;
}

.puzzle-meta {
  display: grid;
  grid-template-columns: 1fr auto;
  gap: 1.25rem;
  align-items: center;
  width: 100%;
  max-width: 980px;
  min-width: 0;
  margin: 0 auto;
}

.puzzle-note {
  min-width: 0;
  padding: 1.2rem 1.4rem;
  border-radius: 20px;
  background: linear-gradient(160deg, rgba(255,255,255,.98), rgba(234,240,255,.9));
  border: 1px solid rgba(22,76,169,.1);
  box-shadow: 0 2px 12px rgba(17,34,70,.06);
}

.puzzle-note strong {
  display: block;
  font-size: .97rem;
  margin-bottom: .4rem;
}

.puzzle-note p {
  margin: 0;
  font-size: .94rem;
  line-height: 1.7;
}

.cta-link {
  display: inline-flex;
  max-width: 100%;
  align-items: center;
  justify-content: center;
  min-height: 48px;
  padding: 0 18px;
  border-radius: 999px;
  text-decoration: none;
  font-weight: 700;
  color: var(--brand);
  border: 2px solid rgba(22,76,169,.2);
  background: rgba(255,255,255,.85);
  transition: transform .25s ease, background .25s ease, color .25s ease;
}

.cta-link:hover {
  transform: translateY(-2px);
}

@media (max-width: 900px) {
  .puzzle-grid { grid-template-columns: 1fr 1fr; }
  .puzzle-meta { grid-template-columns: 1fr; }
}

@media (max-width: 768px) {
  .page { padding: 16px; }
  .topbar { align-items: flex-start; }
  .content { gap: 1.5rem; }
  .puzzle-grid {
    grid-template-columns: 1fr;
    gap: 1rem;
    width: 100%;
    max-width: 620px;
    padding: .35rem 0 .5rem;
  }
  .puzzle-piece__body {
    top: 17%;
    right: 13%;
    bottom: 14%;
    left: 13%;
    padding: 1.45rem 1.5rem 1.35rem;
  }
  .puzzle-piece__overlay {
    top: 17%;
    right: 13%;
    bottom: 14%;
    left: 13%;
    padding: 1.45rem 1.5rem 1.35rem;
  }
}