:root {
  --paper: #f2eee4;
  --paper-2: #eae5d8;
  --card: #ffffff;
  --ink: #17181a;
  --ink-2: #4a4842;
  --muted: #7c766c;
  --hair: rgba(23, 24, 26, 0.12);
  --hair-soft: rgba(23, 24, 26, 0.07);
  --accent: #1d5fd6;
  --accent-2: #0f9fb8;
  --stage: #080d14;
  --panel-w: clamp(404px, 37vw, 548px);
}

* { box-sizing: border-box; -webkit-tap-highlight-color: transparent; }

html, body {
  margin: 0;
  height: 100%;
  background: var(--stage);
  color: var(--ink);
  font-family: "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei", "Noto Sans SC", system-ui, -apple-system, sans-serif;
  overflow: hidden;
  -webkit-font-smoothing: antialiased;
  text-rendering: optimizeLegibility;
}

::selection { background: rgba(29, 95, 214, 0.2); }

.app { display: flex; height: 100vh; height: 100dvh; }

/* ============================================================
   LEFT — editorial panel
   ============================================================ */
.panel {
  position: relative;
  flex: 0 0 var(--panel-w);
  width: var(--panel-w);
  display: flex;
  flex-direction: column;
  background: var(--paper);
  background-image:
    radial-gradient(120% 80% at 100% 0%, rgba(255, 255, 255, 0.55), transparent 60%),
    repeating-linear-gradient(0deg, rgba(23, 24, 26, 0.012) 0 1px, transparent 1px 3px);
  border-right: 1px solid rgba(0, 0, 0, 0.28);
  z-index: 3;
}

.topbar {
  flex: 0 0 auto;
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 16px 22px 15px;
  border-bottom: 1px solid var(--hair-soft);
}
.brand { display: flex; align-items: center; gap: 10px; }
.brand .mark {
  width: 30px;
  height: 30px;
  border-radius: 8px;
  background: linear-gradient(145deg, #1d5fd6, #0f9fb8);
  color: #f7f4ec;
  display: grid;
  place-items: center;
}
.brand .mark svg { width: 19px; height: 19px; }
.brand-t { display: flex; flex-direction: column; gap: 2px; }
.brand-t b { font-size: 13.5px; letter-spacing: 0.06em; font-weight: 650; }
.brand-t i {
  font-style: normal;
  font-family: ui-monospace, "SF Mono", Menlo, monospace;
  font-size: 7.5px;
  letter-spacing: 0.2em;
  color: #948e83;
}

.top-right { display: flex; align-items: center; gap: 10px; }
.grade { font-size: 10.5px; color: #8b857a; letter-spacing: 0.05em; }
.lang {
  display: flex;
  border: 1px solid var(--hair);
  border-radius: 6px;
  overflow: hidden;
  background: rgba(255, 255, 255, 0.5);
}
.lang button {
  border: 0;
  background: transparent;
  font-family: inherit;
  font-size: 10px;
  color: #7c766c;
  padding: 4px 8px;
  cursor: pointer;
  transition: background 0.18s, color 0.18s;
}
.lang button.on { background: #17181a; color: #f7f4ec; }

.chapters {
  flex: 0 0 auto;
  display: grid;
  grid-template-columns: repeat(7, 1fr);
  gap: 1px;
  padding: 10px 16px 11px;
  border-bottom: 1px solid var(--hair-soft);
  background: rgba(23, 24, 26, 0.02);
}
.chapter {
  position: relative;
  display: flex;
  flex-direction: column;
  gap: 2px;
  padding: 6px 3px 6px 5px;
  border: 0;
  border-left: 1px solid transparent;
  background: transparent;
  font-family: inherit;
  text-align: left;
  cursor: pointer;
  color: #8b857a;
  border-radius: 4px;
  transition: color 0.16s, background 0.16s;
}
.chapter b {
  font-family: ui-monospace, "SF Mono", Menlo, monospace;
  font-size: 7px;
  font-weight: 500;
  letter-spacing: 0.1em;
  opacity: 0.75;
}
.chapter span {
  font-size: 10.5px;
  line-height: 1.15;
  white-space: nowrap;
  overflow: hidden;
  text-overflow: ellipsis;
}
.chapter:hover { color: #34322d; background: rgba(23, 24, 26, 0.04); }
.chapter.on { color: var(--ink); background: rgba(29, 95, 214, 0.09); }
.chapter.on b { color: var(--accent); opacity: 1; }
.chapter.on::after {
  content: "";
  position: absolute;
  left: 4px;
  right: 4px;
  bottom: 0;
  height: 2px;
  border-radius: 2px;
  background: var(--accent);
}

.scroll {
  flex: 1 1 auto;
  overflow-y: auto;
  overflow-x: hidden;
  padding: 0 30px 20px;
  scrollbar-width: thin;
  scrollbar-color: rgba(23, 24, 26, 0.18) transparent;
}
.scroll::-webkit-scrollbar { width: 6px; }
.scroll::-webkit-scrollbar-thumb { background: rgba(23, 24, 26, 0.15); border-radius: 8px; }

.eyebrow {
  display: flex;
  align-items: center;
  gap: 9px;
  margin-top: 26px;
  font-family: ui-monospace, "SF Mono", Menlo, monospace;
  font-size: 9px;
  letter-spacing: 0.17em;
  color: #8e887d;
  text-transform: uppercase;
}
.eyebrow i { width: 20px; height: 1px; background: var(--accent); display: inline-block; }

.headline {
  margin: 13px 0 9px;
  font-size: clamp(27px, 2.55vw, 37px);
  line-height: 1.24;
  font-weight: 700;
  letter-spacing: 0.01em;
  color: var(--ink);
}
.headline .acc { color: var(--accent); }

.en-line {
  margin: 0 0 17px;
  font-family: "Songti SC", "Times New Roman", Georgia, serif;
  font-style: italic;
  font-size: 14px;
  line-height: 1.5;
  color: #7a746a;
}
.en-line.cn {
  font-family: "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei", system-ui, sans-serif;
  font-style: normal;
  font-size: 12.5px;
  letter-spacing: 0.02em;
}

.lead {
  margin: 0 0 21px;
  font-size: 12.6px;
  line-height: 1.95;
  color: #55524b;
  letter-spacing: 0.01em;
}

/* ---------------- lab card ---------------- */
.lab {
  background: var(--card);
  border: 1px solid rgba(23, 24, 26, 0.09);
  border-radius: 12px;
  padding: 15px 15px 13px;
  box-shadow: 0 1px 2px rgba(23, 24, 26, 0.04), 0 10px 26px rgba(23, 24, 26, 0.05);
}
.lab-head { display: flex; align-items: center; gap: 8px; }
.lab-title { font-size: 11.5px; font-weight: 650; letter-spacing: 0.04em; }
.lab-en {
  font-family: ui-monospace, "SF Mono", Menlo, monospace;
  font-size: 7.5px;
  letter-spacing: 0.16em;
  color: #a29c90;
}
.live {
  margin-left: auto;
  display: flex;
  align-items: center;
  gap: 5px;
  font-size: 9px;
  color: #3e8b62;
  letter-spacing: 0.04em;
}
.live i {
  width: 5px;
  height: 5px;
  border-radius: 50%;
  background: #45b57f;
  box-shadow: 0 0 0 3px rgba(69, 181, 127, 0.14);
  animation: pulse 2.4s ease-in-out infinite;
}
@keyframes pulse { 0%, 100% { opacity: 1; } 50% { opacity: 0.35; } }

.variants {
  display: flex;
  gap: 2px;
  margin: 12px 0 10px;
  padding: 3px;
  border-radius: 8px;
  background: #f4f1e9;
  border: 1px solid rgba(23, 24, 26, 0.05);
}
.variants button {
  flex: 1 1 0;
  border: 0;
  border-radius: 6px;
  background: transparent;
  padding: 6px 2px;
  font-family: inherit;
  font-size: 10.5px;
  color: #7c766c;
  cursor: pointer;
  white-space: nowrap;
  transition: background 0.18s, color 0.18s, box-shadow 0.18s;
}
.variants button:hover { color: #34322d; }
.variants button.on {
  background: #17181a;
  color: #f7f4ec;
  box-shadow: 0 2px 8px rgba(23, 24, 26, 0.18);
}

.mini {
  margin: 0 0 13px;
  padding: 4px 6px;
  border-radius: 8px;
  background: #fbfaf6;
  border: 1px solid rgba(23, 24, 26, 0.055);
}
.mini svg { display: block; width: 100%; height: auto; }

.slider-block { margin-bottom: 12px; }
.slider-row {
  display: flex;
  align-items: baseline;
  justify-content: space-between;
  margin-bottom: 9px;
  font-size: 10.5px;
  color: #7c766c;
  letter-spacing: 0.02em;
}
.slider-row b {
  font-family: ui-monospace, "SF Mono", Menlo, monospace;
  font-size: 11.5px;
  font-weight: 600;
  color: var(--ink);
}
input[type="range"] {
  -webkit-appearance: none;
  appearance: none;
  width: 100%;
  height: 3px;
  border-radius: 3px;
  background: linear-gradient(90deg, var(--accent) 0 var(--p, 50%), #e3ded3 var(--p, 50%) 100%);
  outline: none;
  cursor: pointer;
}
input[type="range"]::-webkit-slider-thumb {
  -webkit-appearance: none;
  width: 14px;
  height: 14px;
  border-radius: 50%;
  background: #fff;
  border: 2.5px solid var(--accent);
  box-shadow: 0 1px 5px rgba(0, 0, 0, 0.18);
  cursor: grab;
}
input[type="range"]::-moz-range-thumb {
  width: 12px;
  height: 12px;
  border-radius: 50%;
  background: #fff;
  border: 2.5px solid var(--accent);
}

.result {
  display: flex;
  align-items: baseline;
  justify-content: space-between;
  gap: 10px;
  padding-top: 11px;
  border-top: 1px solid #efebe1;
}
.res-f {
  font-family: ui-monospace, "SF Mono", Menlo, monospace;
  font-size: 10.5px;
  color: #837d72;
  letter-spacing: 0.01em;
}
.res-v {
  font-family: ui-monospace, "SF Mono", Menlo, monospace;
  font-size: 17px;
  font-weight: 700;
  color: var(--accent);
  letter-spacing: -0.01em;
  white-space: nowrap;
}
.res-note {
  margin: 7px 0 0;
  font-size: 10px;
  line-height: 1.65;
  color: #948e83;
}

/* ---------------- steps ---------------- */
.steps { margin-top: 25px; }
.steps-head {
  display: flex;
  align-items: baseline;
  justify-content: space-between;
  padding-bottom: 7px;
  border-bottom: 1.5px solid var(--ink);
  font-size: 11.5px;
  font-weight: 650;
  letter-spacing: 0.04em;
}
.steps-head .en {
  font-family: ui-monospace, "SF Mono", Menlo, monospace;
  font-size: 7.5px;
  font-weight: 400;
  letter-spacing: 0.18em;
  color: #a29c90;
}
.steps ol { list-style: none; margin: 0; padding: 0; }
.steps li {
  display: grid;
  grid-template-columns: 24px 1fr;
  gap: 4px;
  padding: 12px 0 11px;
  border-bottom: 1px solid var(--hair-soft);
}
.steps li .n {
  font-family: ui-monospace, "SF Mono", Menlo, monospace;
  font-size: 8.5px;
  color: var(--accent);
  padding-top: 3px;
  letter-spacing: 0.06em;
}
.steps li b { display: block; font-size: 11.8px; font-weight: 650; margin-bottom: 4px; color: #26251f; }
.steps li p { margin: 0; font-size: 11.2px; line-height: 1.75; color: #6b6660; }

.foot-note {
  margin: 18px 0 6px;
  text-align: center;
  font-size: 9px;
  letter-spacing: 0.08em;
  color: #a8a296;
}

/* ---------------- pager ---------------- */
.pager {
  flex: 0 0 auto;
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 11px 20px;
  border-top: 1px solid var(--hair-soft);
  background: rgba(242, 238, 228, 0.96);
}
.pager button {
  display: flex;
  align-items: center;
  gap: 5px;
  border: 0;
  background: transparent;
  font-family: inherit;
  font-size: 10.5px;
  color: #5f5a52;
  cursor: pointer;
  padding: 5px 2px;
  transition: color 0.18s;
}
.pager button:hover { color: var(--accent); }
.pager button:disabled { opacity: 0.32; cursor: default; }
.pager svg { width: 13px; height: 13px; fill: none; stroke: currentColor; stroke-width: 1.6; stroke-linecap: round; stroke-linejoin: round; }
#pageNum {
  font-family: ui-monospace, "SF Mono", Menlo, monospace;
  font-size: 9.5px;
  letter-spacing: 0.12em;
  color: #948e83;
}

/* ============================================================
   RIGHT — 3D stage
   ============================================================ */
.stage {
  position: relative;
  flex: 1 1 auto;
  min-width: 0;
  background: var(--stage);
  overflow: hidden;
}
#scene { position: absolute; inset: 0; width: 100%; height: 100%; display: block; cursor: grab; touch-action: none; }
#scene.dragging { cursor: grabbing; }

.stage-veil {
  position: absolute;
  inset: 0;
  pointer-events: none;
  background:
    radial-gradient(80% 60% at 52% 42%, rgba(70, 120, 180, 0.1), transparent 62%),
    radial-gradient(110% 80% at 50% 118%, rgba(0, 0, 0, 0.62), transparent 62%),
    linear-gradient(180deg, rgba(6, 9, 14, 0.55) 0%, transparent 18%, transparent 78%, rgba(6, 9, 14, 0.5) 100%);
}

.stage-badge {
  position: absolute;
  top: 20px;
  left: 24px;
  display: flex;
  align-items: center;
  gap: 8px;
  padding: 7px 13px;
  border-radius: 20px;
  background: rgba(11, 15, 21, 0.66);
  border: 1px solid rgba(255, 255, 255, 0.08);
  backdrop-filter: blur(14px);
  -webkit-backdrop-filter: blur(14px);
  font-size: 9.5px;
  letter-spacing: 0.06em;
  color: #c3cdda;
  z-index: 4;
}
.stage-badge i {
  width: 5px; height: 5px; border-radius: 50%;
  background: #4ade80;
  box-shadow: 0 0 9px rgba(74, 222, 128, 0.85);
  animation: pulse 2.4s ease-in-out infinite;
}

.watermark {
  position: absolute;
  top: 56px;
  right: 16px;
  font-size: 152px;
  font-weight: 800;
  line-height: 1;
  letter-spacing: -0.055em;
  color: rgba(255, 255, 255, 0.035);
  pointer-events: none;
  user-select: none;
  z-index: 1;
  font-family: ui-monospace, "SF Mono", Menlo, monospace;
}

.stage-tools {
  position: absolute;
  top: 18px;
  right: 22px;
  display: flex;
  gap: 6px;
  z-index: 6;
}
.icobtn {
  width: 32px;
  height: 32px;
  display: grid;
  place-items: center;
  border-radius: 8px;
  border: 1px solid rgba(255, 255, 255, 0.08);
  background: rgba(11, 15, 21, 0.66);
  color: #a6b3c4;
  cursor: pointer;
  backdrop-filter: blur(12px);
  -webkit-backdrop-filter: blur(12px);
  transition: color 0.18s, border-color 0.18s, background 0.18s;
}
.icobtn svg { width: 15px; height: 15px; fill: none; stroke: currentColor; stroke-width: 1.6; stroke-linecap: round; stroke-linejoin: round; }
.icobtn:hover { color: #eaf2fb; border-color: rgba(255, 255, 255, 0.22); }
.icobtn.on { color: #3fd6f2; border-color: rgba(63, 214, 242, 0.45); background: rgba(18, 40, 52, 0.7); }
.icobtn .lbl { display: none; }

.chip-layer { position: absolute; inset: 0; overflow: hidden; pointer-events: none; z-index: 5; }

.fchip {
  position: absolute;
  top: 0;
  left: 0;
  padding: 5px 9px 6px 8px;
  border-radius: 7px;
  background: rgba(10, 14, 20, 0.86);
  border: 1px solid rgba(255, 255, 255, 0.09);
  border-left: 2px solid var(--c);
  backdrop-filter: blur(9px);
  -webkit-backdrop-filter: blur(9px);
  box-shadow: 0 8px 24px rgba(0, 0, 0, 0.45);
  white-space: nowrap;
  will-change: transform, opacity;
  transition: opacity 0.2s linear;
}
.fchip-top { display: flex; align-items: center; gap: 5px; }
.fchip .dot {
  width: 5px; height: 5px; border-radius: 50%;
  background: var(--c);
  box-shadow: 0 0 8px var(--c);
  flex: 0 0 auto;
}
.fchip-name { font-size: 9.5px; letter-spacing: 0.03em; color: #b9c4d3; }
.fchip-v {
  margin-top: 2px;
  padding-left: 10px;
  font-family: ui-monospace, "SF Mono", Menlo, monospace;
  font-size: 12.5px;
  font-weight: 600;
  color: var(--c);
  letter-spacing: 0.01em;
}
.fchip.sm { padding: 3px 7px 4px 6px; }
.fchip.sm .fchip-v { font-size: 10.5px; padding-left: 9px; margin-top: 1px; }
.fchip.sm .fchip-name { font-size: 8.5px; }

.fchip.title {
  padding: 1px 0 1px 8px;
  background: transparent;
  border: 0;
  border-left: 2px solid var(--c);
  border-radius: 0;
  box-shadow: none;
  backdrop-filter: none;
}
.fchip.title .fchip-name { font-size: 10.5px; color: #e4ecf6; letter-spacing: 0.05em; }
.fchip.title .fchip-s {
  margin-top: 1px;
  font-family: ui-monospace, "SF Mono", Menlo, monospace;
  font-size: 7.5px;
  letter-spacing: 0.16em;
  color: #7e8b9d;
}

.telemetry {
  position: absolute;
  left: 24px;
  bottom: 22px;
  display: flex;
  gap: 8px;
  z-index: 4;
}
.tstat {
  min-width: 82px;
  padding: 7px 11px 8px;
  border-radius: 7px;
  background: rgba(10, 14, 20, 0.7);
  border: 1px solid rgba(255, 255, 255, 0.07);
  backdrop-filter: blur(12px);
  -webkit-backdrop-filter: blur(12px);
}
.tstat .k {
  font-size: 8px;
  letter-spacing: 0.12em;
  color: #7f8b9c;
  text-transform: uppercase;
  font-family: ui-monospace, "SF Mono", Menlo, monospace;
}
.tstat .v {
  margin-top: 3px;
  font-family: ui-monospace, "SF Mono", Menlo, monospace;
  font-size: 13.5px;
  color: #e9f1fa;
  letter-spacing: 0.01em;
}
.tstat .v u { text-decoration: none; font-size: 9px; color: #7f8b9c; margin-left: 2px; }

.stage-legend {
  position: absolute;
  right: 24px;
  bottom: 26px;
  display: flex;
  gap: 13px;
  font-size: 9px;
  color: #8d99aa;
  z-index: 4;
}
.stage-legend span { display: flex; align-items: center; gap: 5px; }
.stage-legend i { width: 5px; height: 5px; border-radius: 50%; background: currentColor; box-shadow: 0 0 7px currentColor; }

.stage-hint {
  position: absolute;
  left: 50%;
  bottom: 26px;
  transform: translateX(-50%);
  font-size: 9px;
  letter-spacing: 0.1em;
  color: rgba(140, 155, 175, 0.5);
  z-index: 4;
  pointer-events: none;
  white-space: nowrap;
}

/* ---------------- boot ---------------- */
#boot {
  position: fixed;
  inset: 0;
  display: grid;
  place-items: center;
  background: #090c12;
  z-index: 60;
  transition: opacity 0.65s ease;
}
#boot.hide { opacity: 0; pointer-events: none; }
.boot-ring {
  width: 38px;
  height: 38px;
  margin: 0 auto 16px;
  border-radius: 50%;
  border: 2px solid rgba(29, 95, 214, 0.18);
  border-top-color: var(--accent);
  animation: spin 0.9s linear infinite;
}
@keyframes spin { to { transform: rotate(360deg); } }
.boot-inner p {
  margin: 0;
  font-family: ui-monospace, "SF Mono", Menlo, monospace;
  font-size: 10px;
  letter-spacing: 0.24em;
  color: #6d7789;
}
.boot-fail { text-align: center; max-width: 320px; padding: 0 24px; }
.boot-fail b { display: block; margin-bottom: 10px; font-size: 14px; color: #d7e1ee; letter-spacing: 0.03em; }
.boot-fail p { font-size: 11.5px; line-height: 1.9; color: #7d8899; letter-spacing: 0.01em; }

/* ---------------- responsive ---------------- */
@media (max-width: 1180px) {
  :root { --panel-w: 392px; }
  .chapter span { font-size: 9.8px; }
  .chapters { padding: 8px 12px 9px; }
  .headline { font-size: 27px; }
  .scroll { padding: 0 24px 18px; }
  .watermark { font-size: 132px; }
}

@media (max-width: 900px) {
  .app { flex-direction: column; }
  .stage { order: -1; flex: 0 0 42vh; height: 42vh; }
  .panel { flex: 1 1 auto; width: 100%; border-right: 0; border-top: 1px solid rgba(0, 0, 0, 0.3); }
  .scroll { padding: 0 20px 16px; }
  .eyebrow { margin-top: 18px; }
  .headline { font-size: 24px; margin: 10px 0 7px; }
  .en-line { font-size: 12.5px; margin-bottom: 12px; }
  .lead { font-size: 11.8px; line-height: 1.8; margin-bottom: 15px; }
  .watermark { font-size: 92px; top: 2px; }
  .telemetry { left: 14px; bottom: 12px; gap: 6px; }
  .tstat { min-width: 64px; padding: 5px 8px; }
  .tstat .v { font-size: 11.5px; }
  .stage-legend, .stage-hint { display: none; }
  .stage-badge { top: 12px; left: 14px; font-size: 8.5px; padding: 5px 10px; }
  .fchip.sm { display: none; }
  .fchip { padding: 4px 7px 5px 6px; }
  .fchip-v { font-size: 11px; }
  .fchip-name { font-size: 8.5px; }
  .fchip.sm { display: none; }
  .fchip { padding: 4px 7px 5px 6px; }
  .fchip-v { font-size: 11px; }
  .fchip-name { font-size: 8.5px; }
  .steps li p { font-size: 10.8px; }
}

@media (max-width: 900px) {
  .chapters { grid-template-columns: repeat(7, 1fr); padding: 8px 12px; }
  .chapter { padding: 5px 2px 5px 4px; }
  .chapter span { font-size: 9px; }
}

@media (max-width: 520px) {
  .brand-t i { display: none; }
  .grade { display: none; }
  .variants button { font-size: 9.5px; }
  .res-v { font-size: 15px; }
}