:root{
  --font-display: 'Space Grotesk', sans-serif;
  --font-body: 'Inter', sans-serif;
  --radius-lg: 18px;
  --radius-md: 12px;
  --radius-sm: 8px;
}

.theme-dark{
  --bg: #090c1e;
  --bg-elevated: #10142c;
  --card: #131834;
  --card-back: #131a36;
  --border: #252b52;
  --border-soft: #1c2144;
  --text: #f5f4ff;
  --text-dim: #9296bd;
  --accent-lilac: #d24bff;
  --accent-lilac-soft: #2c1547;
  --accent-purple: #a385ff;
  --accent-purple-soft: #211a45;
  --accent-blue: #7fb4ff;
  --accent-blue-soft: #16213f;
  --accent-pink: #ea6b9b;
  --accent-pink-soft: #33192a;
  --shadow: 0 20px 60px rgba(0,0,0,.45);
  --net-dot: rgba(180, 190, 255, .55);
  --card-dot: rgba(190, 198, 255, .3);
}

.theme-light{
  --bg: #f6f3fc;
  --bg-elevated: #ffffff;
  --card: #ffffff;
  --card-back: #ffffff;
  --border: #e4ddf6;
  --border-soft: #ede6fa;
  --text: #16152b;
  --text-dim: #605e7a;
  --accent-lilac: #9412e6;
  --accent-lilac-soft: #f4e6ff;
  --accent-purple: #6d3fd6;
  --accent-purple-soft: #efe8ff;
  --accent-blue: #3e79e0;
  --accent-blue-soft: #e9f1ff;
  --accent-pink: #ac2973;
  --accent-pink-soft: #fbe9f1;
  --shadow: 0 20px 50px rgba(70,60,120,.12);
  --net-dot: rgba(120, 100, 200, .35);
  --card-dot: rgba(110, 90, 190, .22);
}

*{ box-sizing: border-box; }
[hidden]{ display: none !important; }
html,body{ margin:0; padding:0; }
body{
  background: var(--bg);
  color: var(--text);
  font-family: var(--font-body);
  min-height: 100vh;
  transition: background .35s ease, color .35s ease;
  overflow-x: hidden;
}

.bg-net{
  position: fixed; inset: -6%; z-index: 0; pointer-events: none;
  will-change: transform, opacity;
  animation: netDrift 60s linear infinite;
}
.bg-net svg{ width: 100%; height: 100%; }
.net-dots circle{ fill: var(--net-dot); }
.net-dots line{ stroke: var(--net-dot); stroke-width: .7; opacity: .45; }
.net-dots circle[data-c]{ fill: currentColor; }
.net-dots line[data-c]{
  stroke: currentColor;
  opacity: 0;
  animation-name: linkPulse;
  animation-timing-function: ease-in-out;
  animation-iteration-count: infinite;
}
@keyframes linkPulse{
  0%, 100% { opacity: 0; }
  50%      { opacity: var(--peak, .3); }
}

@keyframes netDrift{
  0%    { transform: translate(0%, 0%) scale(1);       opacity: .68; }
  20%   { transform: translate(3%, -2.2%) scale(1.02);  opacity: .78; }
  40%   { transform: translate(1.2%, 3%) scale(1.04);   opacity: .7; }
  60%   { transform: translate(-3%, 2%) scale(1.02);    opacity: .78; }
  80%   { transform: translate(-1.8%, -3%) scale(1.01); opacity: .72; }
  100%  { transform: translate(0%, 0%) scale(1);        opacity: .68; }
}

@media (prefers-reduced-motion: reduce){
  .bg-net, .net-dots{ animation: none; }
  .net-dots line[data-c]{ animation: none; opacity: var(--peak, .3); }
}

.page{ position: relative; z-index: 1; max-width: 1240px; margin: 0 auto; padding: 28px 32px 60px; }

.topbar{ display:flex; align-items:center; justify-content: space-between; gap: 16px; margin-bottom: 40px; flex-wrap: wrap; }
.logo{ height: 150px; width: auto; display:block; }
.topbar-controls{ display:flex; gap: 8px; }

.pill-btn{
  display:inline-flex; align-items:center; gap:6px;
  background: var(--bg-elevated); color: var(--text);
  border: 1px solid var(--border); border-radius: 999px;
  padding: 8px 16px; font-family: var(--font-body); font-weight: 600; font-size: 13px;
  cursor: pointer; transition: border-color .2s ease, transform .15s ease, background .2s ease;
}
.pill-btn:hover{ border-color: var(--accent-purple); transform: translateY(-1px); }
.pill-btn:focus-visible{ outline: 2px solid var(--accent-purple); outline-offset: 2px; }
.icon-btn{ padding: 8px; width: 34px; height: 34px; justify-content: center; }

.layout{ display:grid; grid-template-columns: 340px 1fr; gap: 56px; align-items: start; }

.headline{
  font-family: var(--font-display); font-weight: 600;
  font-size: clamp(34px, 4vw, 44px); line-height: 1.08; letter-spacing: -0.01em;
  margin: 0 0 18px;
}
.headline .accent{ color: var(--accent-lilac); }
.theme-dark .headline .accent{ text-shadow: 0 0 22px rgba(210, 75, 255, .35); }
.lede{ color: var(--text-dim); font-size: 15px; line-height: 1.5; margin: 0 0 28px; max-width: 30ch; }

.link-row{
  display:flex; align-items:flex-start; gap: 12px; text-decoration:none; color: var(--text);
  background: none; border: none; font-family: var(--font-body); text-align:left; cursor:pointer;
  padding: 10px 0; width: 100%;
}
.link-icon{
  flex: none; width: 34px; height: 34px; border-radius: 999px; display:flex; align-items:center; justify-content:center;
  border: 1px solid var(--accent-lilac); color: var(--accent-lilac);
}
.link-text{ display:flex; flex-direction:column; font-size: 13.5px; line-height: 1.4; }
.link-text strong{ font-size: 14.5px; font-weight: 600; }
.link-text span:not(strong){ color: var(--text-dim); }

.board-wrap{
  position: relative;
  background: var(--bg-elevated); border: 1px solid var(--border-soft); border-radius: var(--radius-lg);
  padding: 26px 28px 30px; box-shadow: var(--shadow);
}
.board-header{ display:flex; align-items:center; justify-content: space-between; margin-bottom: 20px; }
.board-title{ font-family: var(--font-display); font-weight: 600; font-size: 16px; }
.moves-pill{ font-size: 12.5px; font-weight: 600; color: var(--text-dim); border: 1px solid var(--border); border-radius: 999px; padding: 6px 14px; }
.moves-pill #movesCount{ color: var(--text); }

.board{
  display:grid; grid-template-columns: repeat(5, 1fr); gap: 12px;
}

.card{
  position: relative; aspect-ratio: 1 / 1; cursor: pointer; perspective: 900px;
}
.card-inner{
  position:absolute; inset:0; transform-style: preserve-3d; transition: transform .5s cubic-bezier(.2,.8,.2,1);
}
.card.flipped .card-inner, .card.matched .card-inner{ transform: rotateY(180deg); }

.card-face{
  position:absolute; inset:0; backface-visibility: hidden; border-radius: var(--radius-md);
  display:flex; align-items:center; justify-content:center; text-align:center;
  border: 1px solid var(--border);
}
.card-back{
  background: var(--card-back);
  background-image:
    radial-gradient(var(--card-dot) 1.8px, transparent 2.6px);
  background-size: 18px 18px;
  color: var(--text-dim); font-weight: 700; font-size: 11px; letter-spacing: .06em;
}
.card-front{
  background: var(--card); transform: rotateY(180deg);
  flex-direction: column; gap: 8px; padding: 8px;
}
.card-front svg{ width: 26px; height: 26px; }
.card-front .term-label{ font-size: 13px; font-weight: 600; line-height: 1.25; padding: 0 4px; word-break: break-word; }
.card-front .short-label{ display: none; }
.card-back{ font-size: 12px; }

.card:not(.matched):not(.flipped) .card-inner:hover{ transform: translateY(-2px); }

.card.wrong .card-back{ animation: shake .4s ease; }
@keyframes shake{ 25%{ transform: translateX(-4px);} 75%{ transform: translateX(4px);} }

.card.matched[data-color="0"] .card-front{ border-color: var(--accent-purple); background: var(--accent-purple-soft); color: var(--accent-purple); }
.card.matched[data-color="1"] .card-front{ border-color: var(--accent-lilac); background: var(--accent-lilac-soft); color: var(--accent-lilac); }
.card.matched[data-color="2"] .card-front{ border-color: var(--accent-blue); background: var(--accent-blue-soft); color: var(--accent-blue); }
.card.matched[data-color="3"] .card-front{ border-color: var(--accent-pink); background: var(--accent-pink-soft); color: var(--accent-pink); }

.status-msg{ min-height: 20px; margin-top: 16px; font-size: 13px; color: var(--text-dim); text-align: right; transition: color .2s ease; }
.status-msg.wrong{ color: var(--accent-pink); }
.status-msg.success{ color: var(--accent-purple); font-weight: 600; }

.win-panel{ text-align:center; }
.win-flag{
  font-family: var(--font-display);
  font-weight: 400;
  color: var(--accent-lilac);
  font-size: 15px;
  line-height: 1.45;
  margin: 4px 0 22px;
}

.win-grid{ display:grid; grid-template-columns: repeat(5, 1fr); gap: 12px; margin-bottom: 26px; }

.win-item{
  border: 1px solid var(--pc); background: var(--pc-soft); color: var(--pc);
  border-radius: var(--radius-sm); padding: 12px 6px; display:flex; flex-direction:column; align-items:center; gap: 6px;
  font-size: 10px; font-weight: 600; line-height: 1.25;
}
.win-item svg{ width: 20px; height: 20px; }

@media (min-width: 861px){
  html, body{ height: 100%; }
  body{ overflow: hidden; }
  .page{ height: 100vh; display: flex; flex-direction: column; padding-top: 22px; padding-bottom: 22px; }
  .topbar{ flex: 0 0 auto; margin-bottom: 24px; }
  .layout{ flex: 1 1 auto; min-height: 0; align-items: stretch; }
  .intro{ overflow-y: auto; min-height: 0; }
  .board-wrap{ height: 100%; min-height: 0; display: flex; flex-direction: column; }
  .board{
    flex: 1 1 auto; min-height: 0;
    grid-template-columns: repeat(5, 1fr);
    grid-template-rows: repeat(4, 1fr);
  }
  .card{ aspect-ratio: unset; }
  .win-panel{ flex: 1 1 auto; min-height: 0; display: flex; flex-direction: column; justify-content: center; overflow-y: auto; }
}

@media (max-width: 860px){
  .layout{ grid-template-columns: 1fr; gap: 26px; }
  .page{ padding: 16px 12px 36px; }
  .board-wrap{ padding: 16px 14px 20px; border-radius: var(--radius-md); }
  .board{ gap: 8px; grid-template-columns: repeat(4, 1fr); }
  .card-front svg{ width: 24px; height: 24px; }
  .card-front .term-label{ font-size: 12px; line-height: 1.2; }
  .card-back{ font-size: 12px; }
  .win-grid{ grid-template-columns: repeat(3, 1fr); }
  .win-item{ font-size: 12px; padding: 14px 8px; }
  .win-item svg{ width: 24px; height: 24px; }
}
@media (max-width: 560px){
  .logo{ height: 68px; }
  .headline{ font-size: clamp(28px, 8vw, 36px); }
  .card-front .full-label{ display: none; }
  .card-front .short-label{ display: inline; }
}
@media (max-width: 460px){
  .page{ padding: 14px 8px 32px; }
  .board-wrap{ padding: 12px 10px 16px; }
  .board{ gap: 7px; }
  .card-front{ padding: 6px; gap: 5px; }
  .card-front svg{ width: 20px; height: 20px; }
  .card-front .term-label{ font-size: 10.5px; }
  .card-back{ font-size: 10.5px; }
  .board-title{ font-size: 14px; }
  .moves-pill{ font-size: 11px; padding: 5px 12px; }
  .win-grid{ grid-template-columns: repeat(2, 1fr); gap: 10px; }
  .win-item{ font-size: 13.5px; padding: 16px 10px; }
  .win-item svg{ width: 26px; height: 26px; }
  .win-flag{ font-size: 15.5px; }
}

@media (prefers-reduced-motion: reduce){
  .card-inner{ transition: none; }
  .pill-btn{ transition: none; }
}