/* 陈晞澈的国际象棋小站 · 巧克力棋风 */
:root {
  --choc: #2a1713;
  --choc-soft: #4a2e22;
  --crimson: #8b000c;
  --crimson-deep: #6d0009;
  --cream: #f4ebdd;
  --sand: #e5d0b5;
  --paper: #faf6ec;
  --card: #fffdf8;
  --ink: #2a1713;
  --muted: #8d7c68;
  --line: #e7dcc8;
  --gold: #c9a227;
  --win: #2e7d4f;
  --draw: #b07d1e;
  --loss: #8b000c;
}
* { box-sizing: border-box; margin: 0; padding: 0; }
html { scroll-behavior: smooth; }
body {
  font-family: "Inter", -apple-system, "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei", sans-serif;
  color: var(--ink);
  background: var(--paper);
  line-height: 1.8;
}
.wrap { max-width: 840px; margin: 0 auto; padding: 0 1.5rem; }
a { color: var(--crimson); text-decoration: none; }
a:hover { text-decoration: underline; }

/* ---------- header ---------- */
.site-header {
  background: rgba(244, 235, 221, .94);
  backdrop-filter: blur(10px);
  border-bottom: 1px solid var(--line);
  position: sticky; top: 0; z-index: 50;
}
.site-header .wrap { display: flex; align-items: center; justify-content: space-between; height: 62px; }
.logo { font-weight: 800; font-size: 1.02rem; color: var(--ink); letter-spacing: .12em; }
.logo:hover { text-decoration: none; color: var(--crimson); }
.site-header nav { display: flex; gap: 1.5rem; }
.site-header nav a { color: var(--muted); font-size: .9rem; letter-spacing: .06em; transition: color .2s; }
.site-header nav a:hover { text-decoration: none; color: var(--ink); }
.site-header nav a.active { color: var(--crimson); font-weight: 700; }

/* ---------- hero ---------- */
.hero {
  position: relative; overflow: hidden; text-align: center;
  background:
    radial-gradient(900px 420px at 50% -8%, rgba(139, 0, 12, .55), transparent 62%),
    linear-gradient(180deg, #1d0f0c 0%, var(--choc) 100%);
  color: var(--cream);
  padding: 5.5rem 0 5rem;
}
.hero::before {
  content: "CHESS"; position: absolute; left: 50%; top: 52%;
  transform: translate(-50%, -50%);
  font-size: clamp(6rem, 22vw, 15rem); font-weight: 800; letter-spacing: .08em;
  color: transparent; -webkit-text-stroke: 1px rgba(244, 235, 221, .14);
  pointer-events: none; white-space: nowrap; line-height: 1;
}
.hero-inner { position: relative; }
.hero-kicker {
  color: var(--sand); letter-spacing: .42em; text-indent: .42em;
  font-size: .78rem; font-weight: 700;
}
.hero h1 {
  font-size: clamp(2.8rem, 9vw, 4.2rem); font-weight: 800;
  letter-spacing: .24em; text-indent: .24em; margin: .9rem 0 .3rem; color: var(--cream);
}
.hero-slogan { color: var(--sand); font-size: .95rem; letter-spacing: .3em; text-indent: .3em; opacity: .85; }
.hero-sub { color: rgba(244, 235, 221, .72); margin-top: 1rem; font-size: .95rem; }
.hero-badges { margin-top: 1.6rem; display: flex; gap: .7rem; justify-content: center; flex-wrap: wrap; }
.hero-badges span {
  font-size: .86rem; letter-spacing: .04em; color: var(--cream);
  border: 1px solid rgba(244, 235, 221, .35); border-radius: 999px; padding: .34rem 1.05rem;
  background: rgba(244, 235, 221, .06);
}
.cta {
  display: inline-block; margin-top: 2.1rem; padding: .72rem 2.4rem; border-radius: 999px;
  background: var(--crimson); color: var(--cream); font-weight: 700; letter-spacing: .14em; font-size: .95rem;
  transition: background .25s, transform .25s;
}
.cta:hover { background: var(--crimson-deep); color: var(--cream); text-decoration: none; transform: translateY(-2px); }
.cta.small { margin-top: 0; padding: .55rem 1.5rem; font-size: .9rem; }
.cta.ghost { background: transparent; border: 1px solid var(--crimson); color: var(--crimson); }
.cta.ghost:hover { background: var(--crimson); color: var(--cream); }

/* ---------- sections ---------- */
section.wrap { padding-top: 3.5rem; }
.band { background: var(--cream); border-top: 1px solid var(--line); border-bottom: 1px solid var(--line); }
.band .wrap { padding-top: 3rem; padding-bottom: 3rem; }
h2 { font-size: 1.3rem; font-weight: 800; letter-spacing: .14em; margin-bottom: 1.5rem; display: flex; align-items: center; gap: .8rem; }
h2::before { content: ""; width: 26px; height: 3px; background: var(--crimson); flex: none; }
h2 small { font-size: .78rem; color: var(--muted); font-weight: 400; letter-spacing: .02em; }
.page-head { padding-top: 3rem; }
.page-head h1 { font-size: 1.9rem; font-weight: 800; letter-spacing: .12em; margin-bottom: .4rem; }
.muted { color: var(--muted); font-size: .93rem; }
.more { margin-top: 1.2rem; }

/* reveal */
.reveal { opacity: 0; transform: translateY(18px); transition: opacity .5s ease, transform .5s ease; }
.reveal.visible { opacity: 1; transform: none; }

/* ---------- stat cards（胶囊卡片） ---------- */
.cards { display: grid; grid-template-columns: repeat(auto-fit, minmax(200px, 1fr)); gap: 1.1rem; }
.card {
  background: var(--card); border: 1px solid var(--line); border-radius: 22px;
  padding: 1.7rem 1.4rem; text-align: center;
  transition: transform .25s, box-shadow .25s;
}
.card:hover { transform: translateY(-4px); box-shadow: 0 16px 34px rgba(42, 23, 19, .1); }
.card-num { font-size: 2.7rem; font-weight: 800; font-variant-numeric: tabular-nums; color: var(--choc); letter-spacing: .02em; }
.card-num em { font-style: normal; font-size: .95rem; color: var(--muted); font-weight: 400; margin-left: .25rem; }
.card p { font-size: .87rem; color: var(--muted); margin-top: .5rem; }

/* ---------- timeline ---------- */
.timeline { list-style: none; }
.timeline li {
  display: flex; gap: 1.1rem; align-items: flex-start;
  padding: 1.15rem .4rem; border-bottom: 1px solid var(--line);
  cursor: pointer; transition: background .2s;
}
.timeline li:hover { background: var(--card); }
.timeline .r {
  flex: none; width: 3rem; text-align: center; font-weight: 800; font-size: .84rem;
  color: var(--crimson); padding-top: .25rem; letter-spacing: .06em;
}
.timeline strong { font-size: 1.02rem; font-weight: 700; }
.timeline strong::before { content: "● "; font-size: .78em; }
.timeline li.win strong::before { color: var(--win); }
.timeline li.draw strong::before { color: var(--draw); }
.timeline li.loss strong::before { color: var(--loss); }
.timeline p { color: var(--muted); font-size: .9rem; margin-top: .1rem; }
.timeline .tap { margin-left: auto; flex: none; color: var(--muted); font-size: 1.05rem; font-weight: 300; transition: transform .25s; }
.timeline li.open .tap { transform: rotate(45deg); color: var(--crimson); }
.timeline .detail { display: none; margin-top: .6rem; font-size: .9rem; color: var(--ink); border-left: 2px solid var(--crimson); padding-left: .9rem; }
.timeline li.open .detail { display: block; animation: fadein .25s ease; }
@keyframes fadein { from { opacity: 0; } to { opacity: 1; } }

/* ---------- quiz（深色卡片） ---------- */
.quiz-card {
  background: linear-gradient(150deg, var(--choc-soft), var(--choc));
  color: var(--cream); border-radius: 24px; padding: 2.2rem;
}
.quiz-q { font-size: 1.1rem; font-weight: 700; margin-bottom: 1.1rem; letter-spacing: .02em; }
.quiz-opts { display: grid; gap: .6rem; }
.quiz-opts button {
  text-align: left; padding: .72rem 1.15rem; border-radius: 999px;
  border: 1px solid rgba(244, 235, 221, .28); background: rgba(244, 235, 221, .07);
  color: var(--cream); font-size: .95rem; cursor: pointer; transition: all .18s; font-family: inherit;
}
.quiz-opts button:hover:not(:disabled) { border-color: var(--cream); background: rgba(244, 235, 221, .14); }
.quiz-opts button:disabled { cursor: default; }
.quiz-opts button.correct { border-color: var(--win); background: rgba(46, 125, 79, .35); }
.quiz-opts button.wrong { border-color: var(--crimson); background: rgba(139, 0, 12, .5); }
.quiz-feedback { min-height: 1.8em; margin-top: .9rem; font-size: .93rem; color: var(--sand); }
.quiz-next {
  margin-top: .3rem; padding: .55rem 1.7rem; border-radius: 999px;
  border: none; background: var(--crimson); color: var(--cream);
  font-weight: 700; cursor: pointer; font-size: .92rem; font-family: inherit; letter-spacing: .08em;
}
.quiz-next:hover { background: var(--crimson-deep); }
.quiz-score { margin-top: .9rem; color: rgba(244, 235, 221, .6); font-size: .87rem; }

/* ---------- profile ---------- */
.profile { background: var(--card); border: 1px solid var(--line); border-radius: 20px; padding: 1.7rem 1.9rem; }
.profile h3 { font-size: 1.05rem; margin-bottom: .3rem; letter-spacing: .06em; }
.profile ul { list-style: none; }
.profile li { padding: .55rem 0; border-bottom: 1px solid var(--line); font-size: .94rem; }
.profile li:last-child { border-bottom: none; }
.profile strong { display: inline-block; min-width: 6em; color: var(--muted); font-weight: 400; }

/* ---------- games ---------- */
.filters { display: flex; gap: .55rem; margin-top: 1.3rem; flex-wrap: wrap; align-items: center; }
.chip {
  padding: .42rem 1.2rem; border-radius: 999px; border: 1px solid var(--line);
  background: var(--card); font-size: .89rem; cursor: pointer; color: var(--ink);
  transition: all .18s; font-family: inherit; letter-spacing: .04em;
}
.chip:hover { border-color: var(--choc); }
.chip.active { background: var(--choc); border-color: var(--choc); color: var(--cream); }
.game-list { display: grid; gap: .9rem; margin-top: 1.5rem; }
.game {
  background: var(--card); border: 1px solid var(--line); border-radius: 16px;
  padding: 1.2rem 1.4rem 1.2rem 1.7rem; position: relative;
  transition: box-shadow .25s, transform .25s;
}
.game::before { content: ""; position: absolute; left: 0; top: 1.15rem; bottom: 1.15rem; width: 3px; border-radius: 2px; }
.game.win::before { background: var(--win); }
.game.draw::before { background: var(--draw); }
.game.loss::before { background: var(--loss); }
.game:hover { box-shadow: 0 12px 28px rgba(42, 23, 19, .08); transform: translateY(-2px); }
.game.hide { display: none; }
.game-head { display: flex; justify-content: space-between; align-items: baseline; margin-bottom: .2rem; }
.round { font-size: .8rem; color: var(--muted); letter-spacing: .12em; font-weight: 700; }
.result { font-weight: 800; font-size: 1.18rem; letter-spacing: .06em; }
.game.win .result { color: var(--win); }
.game.draw .result { color: var(--draw); }
.game.loss .result { color: var(--loss); }
.game h3 { font-size: 1.04rem; font-weight: 700; margin-bottom: .25rem; }
.vs { font-size: .8rem; color: var(--muted); font-weight: 400; }
.tag { font-size: .76rem; color: var(--muted); border: 1px solid var(--line); border-radius: 999px; padding: .1rem .6rem; font-weight: 400; }
.game p { color: var(--muted); font-size: .9rem; }

/* ---------- photos（描金细边框） ---------- */
.photo-grid { display: grid; grid-template-columns: repeat(auto-fit, minmax(220px, 1fr)); gap: 1.4rem; }
.photo-slot { background: var(--card); border: 1px solid var(--gold); border-radius: 6px; padding: 10px; transition: transform .3s, box-shadow .3s; }
.photo-slot:hover { transform: translateY(-4px); box-shadow: 0 18px 36px rgba(42, 23, 19, .12); }
.photo-slot img { width: 100%; aspect-ratio: 4/3; object-fit: cover; cursor: zoom-in; display: block; border-radius: 2px; }
.photo-slot .slot {
  aspect-ratio: 4/3; border: 1px dashed var(--line); border-radius: 2px;
  display: flex; flex-direction: column; align-items: center; justify-content: center;
  font-size: 2rem; color: var(--muted); background: var(--paper);
}
.photo-slot .slot p { font-size: .82rem; margin-top: .4rem; }
.photo-slot figcaption { font-size: .8rem; color: var(--muted); margin-top: .7rem; text-align: center; letter-spacing: .08em; }
.lightbox {
  position: fixed; inset: 0; background: rgba(29, 15, 12, .94); z-index: 100;
  display: flex; align-items: center; justify-content: center; padding: 1.5rem;
}
.lightbox[hidden] { display: none; }
.lightbox img { max-width: 100%; max-height: 88vh; border: 1px solid var(--gold); padding: 10px; background: var(--choc); }
.lightbox-close { position: absolute; top: 1.2rem; right: 1.4rem; color: var(--cream); font-size: 1.6rem; cursor: pointer; opacity: .75; }
.lightbox-close:hover { opacity: 1; }

/* ---------- 在线下棋 ---------- */
.play-area { display: grid; grid-template-columns: minmax(0, 560px) 300px; gap: 1.6rem; align-items: start; justify-content: center; }
.board-frame { background: var(--card); border: 1px solid var(--line); border-radius: 20px; padding: 1.3rem; }
.player-card { display: flex; align-items: center; gap: .8rem; padding: .5rem .2rem; }
.player-card.you { padding-top: .8rem; }
.player-card .who { flex: 1; }
.player-card .who strong { font-size: .96rem; letter-spacing: .04em; }
.player-card .who p { font-size: .82rem; color: var(--muted); margin: 0; }
.captured { font-size: 1.25rem; letter-spacing: .04em; min-height: 1.7em; }
.score-diff { color: var(--win); font-weight: 700; }
.thinking::after { content: ""; animation: dots 1.1s steps(1) infinite; }
@keyframes dots { 0% { content: ""; } 25% { content: "."; } 50% { content: ".."; } 75% { content: "..."; } }
.board {
  display: grid; grid-template-columns: repeat(8, 1fr);
  border: 1px solid var(--choc); border-radius: 10px; overflow: hidden;
  aspect-ratio: 1; width: 100%;
}
.sq { position: relative; display: flex; align-items: center; justify-content: center; cursor: pointer; user-select: none; -webkit-tap-highlight-color: transparent; }
.sq.light { background: var(--cream); }
.sq.dark { background: #a0714f; }
.sq .piece { font-size: clamp(1.9rem, 7vw, 2.9rem); line-height: 1; pointer-events: none; }
.sq .piece.w { color: #fffdf6; text-shadow: 0 1px 0 var(--choc), 1px 0 0 var(--choc), -1px 0 0 var(--choc), 0 -1px 0 var(--choc); }
.sq .piece.b { color: var(--choc); }
.sq.selected { box-shadow: inset 0 0 0 3px var(--crimson); }
.sq.lastmove::after { content: ""; position: absolute; inset: 0; background: rgba(139, 0, 12, .13); pointer-events: none; }
.sq .dot { position: absolute; width: 26%; height: 26%; border-radius: 50%; background: rgba(139, 0, 12, .4); pointer-events: none; }
.sq .dot.capture { width: 84%; height: 84%; background: transparent; border: 3px solid rgba(139, 0, 12, .6); }
.sq .coord { position: absolute; font-size: .62rem; font-weight: 700; opacity: .45; pointer-events: none; }
.sq .coord.rank { top: 2px; left: 4px; }
.sq .coord.file { bottom: 2px; right: 5px; }
.sq.light .coord { color: #8a6a45; }
.sq.dark .coord { color: var(--cream); }
.panel { display: grid; gap: 1rem; align-content: start; }
.status-card {
  background: var(--card); border: 1px solid var(--line); border-left: 3px solid var(--crimson);
  border-radius: 14px; padding: 1rem 1.2rem; font-size: .94rem; min-height: 4em;
}
.control-card { background: var(--card); border: 1px solid var(--line); border-radius: 14px; padding: 1rem 1.2rem; display: grid; gap: .9rem; }
.seg-row { display: flex; align-items: center; justify-content: space-between; gap: .8rem; }
.seg-label { font-size: .88rem; color: var(--muted); }
.seg { display: inline-flex; border: 1px solid var(--line); border-radius: 999px; overflow: hidden; }
.seg .diff { border: none; background: transparent; padding: .42rem 1.3rem; font-size: .9rem; cursor: pointer; color: var(--muted); font-family: inherit; transition: all .18s; }
.seg .diff.active { background: var(--choc); color: var(--cream); font-weight: 700; }
.btn-row { display: flex; gap: .55rem; }
.btn-row .cta.small { flex: 1; text-align: center; white-space: nowrap; }
.btn-row .chip { white-space: nowrap; }
.moves-card { background: var(--card); border: 1px solid var(--line); border-radius: 14px; padding: 1rem 1.2rem; }
.moves-card h3 { font-size: .95rem; margin-bottom: .5rem; letter-spacing: .1em; }
.movelist { max-height: 220px; overflow-y: auto; list-style: none; font-size: .9rem; color: var(--muted); font-variant-numeric: tabular-nums; }
.movelist li { padding: .22rem .4rem; border-radius: 6px; }
.movelist li:nth-child(odd) { background: var(--paper); }

/* ---------- footer（深红） ---------- */
.site-footer { margin-top: 4.5rem; background: var(--crimson); color: var(--cream); padding: 2.6rem 0; text-align: center; }
.site-footer .foot-title { font-size: 1.5rem; font-weight: 800; letter-spacing: .3em; text-indent: .3em; margin-bottom: .5rem; }
.site-footer p { font-size: .85rem; color: rgba(244, 235, 221, .75); letter-spacing: .08em; }
.site-footer .tiny { font-size: .76rem; margin-top: .35rem; opacity: .7; }

@media (max-width: 760px) {
  .play-area { grid-template-columns: minmax(0, 560px); justify-content: center; }
  .hero h1 { font-size: 2.5rem; }
  .site-header .wrap { flex-wrap: wrap; height: auto; padding-top: .55rem; padding-bottom: .55rem; row-gap: .35rem; }
  .site-header nav { width: 100%; justify-content: space-between; gap: 0; }
  .site-header nav a { font-size: .85rem; padding: .2rem 0; }
  .board-frame { padding: .8rem; border-radius: 14px; }
}