:root {
  --desk: #151515;
  --desk-2: #20201e;
  --paper: #f6f3ec;
  --paper-edge: #e7e2d6;
  --ink: #1a1a19;
  --ink-2: #5b5a55;
  --ink-3: #8d8b84;
  --accent: #3390ec;
  --highlight: #ffd928;
  --danger: #c8372d;
  --serif: "Songti SC", "STSong", "Noto Serif SC", "Source Han Serif SC", serif;
  --sans: -apple-system, "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei", sans-serif;
  --mono: "SF Mono", ui-monospace, Menlo, monospace;
}

* { box-sizing: border-box; }
html, body { margin: 0; }
body {
  font-family: var(--sans);
  color: var(--paper);
  background:
    radial-gradient(1200px 700px at 50% 30%, #2a2a27 0%, transparent 60%),
    var(--desk);
  min-height: 100dvh;
  display: flex;
  flex-direction: column;
  align-items: center;
  -webkit-font-smoothing: antialiased;
}

/* ---------- top bar ---------- */
.versions {
  margin-top: clamp(20px, 6vh, 64px);
  display: inline-flex;
  gap: 2px;
  padding: 3px;
  border-radius: 999px;
  background: rgba(246, 243, 236, 0.06);
  border: 1px solid rgba(246, 243, 236, 0.1);
  font-size: 13px;
}
.versions button {
  all: unset;
  cursor: pointer;
  padding: 6px 14px;
  border-radius: 999px;
  color: rgba(246, 243, 236, 0.6);
  transition: background 0.15s, color 0.15s;
}
.versions button[aria-pressed="true"] { background: var(--paper); color: var(--ink); }
.versions-hint { margin-top: 8px; font-size: 12px; color: rgba(246, 243, 236, 0.38); }

/* ---------- the card ---------- */
.stage {
  perspective: 1600px;
  margin-top: clamp(32px, 12vh, 110px);
  width: min(600px, 92vw);
  aspect-ratio: 90 / 54;
}
.card {
  position: relative;
  width: 100%;
  height: 100%;
  transform-style: preserve-3d;
  transition: transform 0.7s cubic-bezier(0.2, 0.7, 0.2, 1);
  cursor: pointer;
}
.card.flipped { transform: rotateY(180deg); }
.face {
  position: absolute;
  inset: 0;
  backface-visibility: hidden;
  -webkit-backface-visibility: hidden;
  border-radius: 14px;
  background: var(--paper);
  color: var(--ink);
  box-shadow:
    0 1px 0 rgba(255, 255, 255, 0.7) inset,
    0 0 0 1px var(--paper-edge),
    0 30px 60px -20px rgba(0, 0, 0, 0.7),
    0 12px 24px -12px rgba(0, 0, 0, 0.5);
  overflow: hidden;
}
/* faint paper grain */
.face::before {
  content: "";
  position: absolute;
  inset: 0;
  pointer-events: none;
  opacity: 0.35;
  background-image: url("data:image/svg+xml;utf8,<svg xmlns='http://www.w3.org/2000/svg' width='160' height='160'><filter id='n'><feTurbulence type='fractalNoise' baseFrequency='0.9' numOctaves='2' stitchTiles='stitch'/><feColorMatrix values='0 0 0 0 0.4  0 0 0 0 0.38  0 0 0 0 0.33  0 0 0 0.09 0'/></filter><rect width='100%' height='100%' filter='url(%23n)'/></svg>");
}
.back { transform: rotateY(180deg); }

.front {
  display: grid;
  grid-template-columns: 34% 1fr;
}
.photo {
  position: relative;
  background: #d9d3c4;
  overflow: hidden;
}
.photo img { width: 100%; height: 100%; object-fit: cover; object-position: 50% 18%; display: block; filter: saturate(0.9) contrast(1.02); }
.photo .monogram {
  position: absolute; inset: 0; display: grid; place-items: center;
  font-family: var(--serif); font-size: clamp(56px, 12vw, 96px); color: rgba(26, 26, 25, 0.75);
}
.front-body {
  position: relative;
  padding: 7% 7% 6% 7%;
  display: flex;
  flex-direction: column;
}
.brand {
  position: absolute; top: 7%; right: 7%;
  font-size: 11px; letter-spacing: 0.12em; color: var(--ink-3);
  display: flex; align-items: center; gap: 6px;
}
.brand img { width: 18px; height: 18px; }
.name {
  margin-top: 2%;
  font-family: var(--serif);
  font-weight: 600;
  font-size: clamp(28px, 6vw, 42px);
  letter-spacing: 0.04em;
  line-height: 1.1;
}
.name small {
  font-family: var(--sans); font-weight: 400; font-size: 0.36em;
  letter-spacing: 0.08em; color: var(--ink-3); margin-left: 0.6em;
}
.title { margin-top: 6px; font-size: clamp(12px, 2.2vw, 14px); color: var(--ink-2); }
.line {
  margin-top: auto;
  font-family: var(--serif);
  font-size: clamp(14px, 2.9vw, 18px);
  line-height: 1.55;
  max-width: 21em;
}
.foot {
  margin-top: 6%;
  display: flex; align-items: flex-end; justify-content: space-between; gap: 12px;
}
.tags { display: flex; flex-wrap: wrap; gap: 6px; }
.tag {
  font-size: 11px; padding: 3px 8px; border-radius: 999px;
  border: 1px solid rgba(26, 26, 25, 0.16); color: var(--ink-2);
}
.qr-mini { width: clamp(46px, 10vw, 62px); height: auto; flex: none; opacity: 0.9; }

/* back */
.back {
  display: grid;
  grid-template-columns: 1fr auto;
  gap: 6%;
  padding: 7%;
}
.facts { display: flex; flex-direction: column; gap: 10px; justify-content: center; }
.fact { display: grid; grid-template-columns: 4.6em 1fr; gap: 10px; font-size: clamp(12px, 2.3vw, 14px); line-height: 1.5; }
.fact b { font-weight: 500; color: var(--ink-3); font-size: 0.86em; padding-top: 0.15em; letter-spacing: 0.06em; }
.seeking {
  margin-top: 4px; padding-top: 10px; border-top: 1px dashed rgba(26, 26, 25, 0.18);
  font-family: var(--serif); font-size: clamp(13px, 2.5vw, 15px);
}
.seeking::before { content: "在找 "; font-family: var(--sans); font-size: 0.78em; color: var(--accent); letter-spacing: 0.08em; }
.qr-big { display: flex; flex-direction: column; align-items: center; justify-content: center; gap: 8px; }
.qr-big img { width: clamp(84px, 18vw, 120px); }
.qr-big span { font-size: 11px; color: var(--ink-3); text-align: center; line-height: 1.5; }

.flip-hint { margin-top: 14px; font-size: 12px; color: rgba(246, 243, 236, 0.38); }

/* ---------- actions ---------- */
.actions { margin-top: clamp(20px, 4vh, 36px); display: flex; gap: 10px; flex-wrap: wrap; justify-content: center; }
.btn {
  all: unset; cursor: pointer;
  padding: 11px 20px; border-radius: 999px; font-size: 14px;
  display: inline-flex; align-items: center; gap: 8px;
  transition: transform 0.1s, background 0.15s;
}
.btn:active { transform: scale(0.97); }
.btn-primary { background: var(--paper); color: var(--ink); }
.btn-ghost { color: var(--paper); border: 1px solid rgba(246, 243, 236, 0.22); }
.btn-ghost:hover { background: rgba(246, 243, 236, 0.06); }
.dot { width: 7px; height: 7px; border-radius: 50%; background: #3fbf6f; box-shadow: 0 0 0 3px rgba(63, 191, 111, 0.2); }

.footnote { margin: auto 0 18px; padding-top: 32px; font-size: 11px; color: rgba(246, 243, 236, 0.3); text-align: center; line-height: 1.7; }

/* ---------- mobile: portrait card ---------- */
@media (max-width: 640px) {
  .stage { width: min(360px, 88vw); aspect-ratio: 54 / 90; }
  .front { grid-template-columns: 1fr; grid-template-rows: 47% 1fr; }
  .photo { background: transparent; padding: 9% 9% 0; }
  .photo img { width: auto; height: 100%; border-radius: 10px; box-shadow: 0 0 0 1px var(--paper-edge); }
  .front-body { padding: 6% 9% 9%; position: static; }
  .brand { top: 9%; right: 9%; }
  .name { margin-top: 0; }
  .line { margin-top: 14px; }
  .foot { margin-top: auto; }
  .back { grid-template-columns: 1fr; grid-template-rows: 1fr auto; padding: 10% 9%; gap: 18px; }
  .qr-big { flex-direction: row; justify-content: flex-start; gap: 14px; }
  .qr-big span { text-align: left; }
}

/* ---------- chat drawer ---------- */
.scrim { position: fixed; inset: 0; background: rgba(11, 11, 10, 0.5); opacity: 0; pointer-events: none; transition: opacity 0.2s; }
.scrim.open { opacity: 1; pointer-events: auto; }
.chat {
  position: fixed; z-index: 10;
  background: var(--paper); color: var(--ink);
  display: flex; flex-direction: column;
  transition: transform 0.28s cubic-bezier(0.2, 0.7, 0.2, 1);
  top: 0; right: 0; bottom: 0; width: min(420px, 100vw);
  transform: translateX(105%);
  box-shadow: -20px 0 60px rgba(0, 0, 0, 0.35);
}
.chat.open { transform: none; }
@media (max-width: 640px) {
  .chat { top: auto; left: 0; width: 100%; height: 86dvh; border-radius: 18px 18px 0 0; transform: translateY(105%); }
}
.chat header { padding: 16px 18px 12px; border-bottom: 1px solid var(--paper-edge); display: flex; align-items: center; gap: 12px; }
.chat header .av { width: 36px; height: 36px; border-radius: 50%; overflow: hidden; background: #d9d3c4; flex: none; display: grid; place-items: center; font-family: var(--serif); }
.chat header .av img { width: 100%; height: 100%; object-fit: cover; }
.chat header h2 { margin: 0; font-size: 15px; font-weight: 600; }
.chat header p { margin: 2px 0 0; font-size: 11.5px; color: var(--ink-3); }
.chat header .close { all: unset; cursor: pointer; margin-left: auto; font-size: 22px; color: var(--ink-3); padding: 0 4px; }
.log { flex: 1; overflow-y: auto; padding: 16px 18px; display: flex; flex-direction: column; gap: 10px; }
.msg { max-width: 86%; padding: 9px 13px; border-radius: 14px; font-size: 14px; line-height: 1.6; white-space: pre-wrap; word-break: break-word; }
.msg.bot { align-self: flex-start; background: #fff; border: 1px solid var(--paper-edge); border-bottom-left-radius: 4px; }
.msg.me { align-self: flex-end; background: var(--ink); color: var(--paper); border-bottom-right-radius: 4px; }
.msg.err { align-self: stretch; max-width: none; background: #fbeceb; color: var(--danger); border: 1px solid #f0c9c5; font-size: 12.5px; }
.msg.bot.typing::after { content: "▍"; animation: blink 1s steps(1) infinite; color: var(--ink-3); }
@keyframes blink { 50% { opacity: 0; } }
.suggest { display: flex; flex-wrap: wrap; gap: 6px; padding: 0 18px 10px; }
.suggest button { all: unset; cursor: pointer; font-size: 12.5px; padding: 6px 11px; border-radius: 999px; border: 1px solid rgba(26, 26, 25, 0.16); color: var(--ink-2); background: #fff; }
.suggest button:hover { border-color: var(--ink-2); }
.composer { display: flex; gap: 8px; padding: 10px 14px calc(12px + env(safe-area-inset-bottom)); border-top: 1px solid var(--paper-edge); }
.composer textarea {
  flex: 1; resize: none; border: 1px solid var(--paper-edge); border-radius: 12px; padding: 9px 12px;
  font: inherit; font-size: 14px; line-height: 1.5; background: #fff; color: var(--ink); max-height: 120px; outline: none;
}
.composer textarea:focus { border-color: var(--ink-3); }
.composer button { all: unset; cursor: pointer; padding: 0 16px; border-radius: 12px; background: var(--ink); color: var(--paper); font-size: 14px; }
.composer button:disabled { opacity: 0.4; cursor: default; }

/* ---------- detail page ---------- */
.sheet {
  width: min(680px, 92vw);
  margin: clamp(20px, 5vh, 48px) 0 40px;
  background: var(--paper); color: var(--ink);
  border-radius: 16px;
  box-shadow: 0 30px 60px -20px rgba(0, 0, 0, 0.7);
  padding: clamp(22px, 5vw, 44px);
  position: relative; flex: none;
}
.sheet-head { display: flex; gap: 16px; align-items: center; }
.sheet-head .av { width: 64px; height: 64px; border-radius: 12px; overflow: hidden; background: #d9d3c4; flex: none; display: grid; place-items: center; font-family: var(--serif); font-size: 28px; }
.sheet-head .av img { width: 100%; height: 100%; object-fit: cover; }
.sheet-head h1 { margin: 0; font-family: var(--serif); font-size: 28px; letter-spacing: 0.04em; }
.sheet-head p { margin: 4px 0 0; font-size: 13px; color: var(--ink-2); }
.sheet h3 { margin: 30px 0 10px; font-size: 12px; font-weight: 500; letter-spacing: 0.14em; color: var(--ink-3); }
.intro { font-family: var(--serif); font-size: 16px; line-height: 1.85; margin: 18px 0 0; }
.timeline { list-style: none; margin: 0; padding: 0; border-left: 1px solid var(--paper-edge); }
.timeline li { position: relative; padding: 0 0 12px 18px; font-size: 13.5px; line-height: 1.6; }
.timeline li::before { content: ""; position: absolute; left: -4px; top: 0.55em; width: 7px; height: 7px; border-radius: 50%; background: var(--ink); }
.timeline time { display: block; font-family: var(--mono); font-size: 11.5px; color: var(--ink-3); }
.domains { display: grid; grid-template-columns: repeat(auto-fill, minmax(190px, 1fr)); gap: 10px; }
.domain { border: 1px solid var(--paper-edge); background: #fff; border-radius: 12px; padding: 13px 14px; }
.domain .dn { font-size: 13px; font-weight: 600; display: flex; align-items: center; gap: 6px; }
.domain .dn::before { content: "#"; color: var(--accent); font-weight: 400; }
.domain p { margin: 6px 0 0; font-size: 12.5px; line-height: 1.6; color: var(--ink-2); }
.domain ul { margin: 8px 0 0; padding-left: 16px; font-size: 12px; color: var(--ink-2); line-height: 1.6; }
.sheet .src { margin-top: 26px; font-size: 11px; color: var(--ink-3); line-height: 1.6; }
.back-link { margin-top: 18px; font-size: 13px; color: rgba(246, 243, 236, 0.6); text-decoration: none; }

/* ---------- round share button + sheet ---------- */
.btn-round {
  all: unset; cursor: pointer; width: 42px; height: 42px; border-radius: 50%;
  border: 1px solid rgba(246, 243, 236, 0.22); color: var(--paper);
  display: inline-grid; place-items: center; transition: background 0.15s, transform 0.1s;
}
.btn-round:hover { background: rgba(246, 243, 236, 0.06); }
.btn-round:active { transform: scale(0.95); }
.btn-round svg { width: 18px; height: 18px; stroke: currentColor; fill: none; stroke-width: 1.7; stroke-linecap: round; stroke-linejoin: round; }
.share-pop {
  position: fixed; z-index: 20; left: 50%; bottom: 24px; transform: translate(-50%, 130%);
  width: min(360px, 92vw); background: var(--paper); color: var(--ink); border-radius: 16px;
  padding: 8px; box-shadow: 0 24px 60px rgba(0, 0, 0, 0.5); transition: transform 0.25s cubic-bezier(0.2, 0.7, 0.2, 1);
}
.share-pop.open { transform: translate(-50%, 0); }
.share-pop button {
  all: unset; cursor: pointer; display: flex; align-items: center; gap: 12px; width: calc(100% - 28px);
  padding: 13px 14px; border-radius: 10px; font-size: 15px;
}
.share-pop button:hover { background: rgba(26, 26, 25, 0.05); }
.share-pop svg { width: 18px; height: 18px; stroke: var(--ink-2); fill: none; stroke-width: 1.7; stroke-linecap: round; stroke-linejoin: round; flex: none; }
.share-pop .hint { padding: 6px 14px 10px; font-size: 12px; color: var(--ink-3); }

/* ---------- login dialog ---------- */
.dlg-scrim { position: fixed; inset: 0; z-index: 40; background: rgba(11, 11, 10, 0.6); display: grid; place-items: center; padding: 16px; }
.dlg { position: relative; width: min(360px, 100%); background: var(--paper); color: var(--ink); border-radius: 16px; padding: 24px 22px 20px; display: flex; flex-direction: column; gap: 12px; }
.dlg h2 { margin: 0; font-size: 18px; font-family: var(--serif); }
.dlg-note { margin: 0; font-size: 12.5px; color: var(--ink-3); line-height: 1.6; }
.dlg input { font: inherit; font-size: 15px; padding: 11px 13px; border-radius: 10px; border: 1px solid var(--paper-edge); background: #fff; color: var(--ink); outline: none; min-width: 0; }
.dlg input:focus { border-color: var(--ink-3); }
.dlg-row { display: flex; gap: 8px; }
.dlg-row input { flex: 1; }
.dlg-ghost { all: unset; cursor: pointer; font-size: 13px; padding: 0 12px; border-radius: 10px; border: 1px solid var(--paper-edge); white-space: nowrap; display: grid; place-items: center; }
.dlg-ghost:disabled { opacity: 0.5; cursor: default; }
.dlg-go { all: unset; cursor: pointer; text-align: center; padding: 12px; border-radius: 10px; background: var(--ink); color: var(--paper); font-size: 15px; }
.dlg-go:disabled { opacity: 0.5; }
.dlg-err { min-height: 1.2em; font-size: 12.5px; color: var(--danger); }
.dlg-x { all: unset; cursor: pointer; position: absolute; top: 10px; right: 14px; font-size: 22px; color: var(--ink-3); }

.room-link { margin-top: 18px; font-size: 13px; color: rgba(246, 243, 236, 0.55); text-decoration: none; }
.room-link:hover { color: var(--paper); }