/* ============================================================
   阳光新材 · 鎏彩装饰 —— 产品资料在线版
   设计基调：印刷级技术资料。细规则线、编号体系、衬线标题、
   零渐变 / 零阴影 / 零大圆角 / 零 emoji。
   ============================================================ */

:root {
  --ink:      #15181C;
  --ink-2:    #4A5158;
  --ink-3:    #878D94;
  --rule:     #E5E5E1;
  --rule-2:   #D2D2CC;
  --paper:    #FFFFFF;
  --paper-2:  #F7F7F4;
  --brand:    #1A4C7C;
  --brand-dk: #123A5E;
  --accent:   #0E7A52;

  --serif: "Songti SC", "Noto Serif SC", "Source Han Serif SC", "Source Han Serif CN", "SimSun", Georgia, serif;
  --sans: -apple-system, BlinkMacSystemFont, "Segoe UI", "PingFang SC", "Hiragino Sans GB",
          "Microsoft YaHei", "Source Han Sans SC", "Noto Sans CJK SC", sans-serif;
  --mono: ui-monospace, "SF Mono", "Cascadia Mono", "Consolas", "Liberation Mono", Menlo, monospace;
}

* { box-sizing: border-box; }

html { -webkit-text-size-adjust: 100%; scroll-behavior: smooth; }

body {
  margin: 0;
  background: var(--paper);
  color: var(--ink);
  font-family: var(--sans);
  font-size: 16px;
  line-height: 1.75;
  overflow-wrap: break-word;
  -webkit-font-smoothing: antialiased;
}

img { max-width: 100%; height: auto; display: block; }

.container {
  width: 100%;
  max-width: 1240px;
  margin: 0 auto;
  padding: 0 32px;
}

.skip {
  position: absolute; left: -9999px; top: 0;
  background: var(--brand); color: #fff; padding: 10px 16px; z-index: 99;
}
.skip:focus { left: 0; }

/* ---------------- masthead ---------------- */
.masthead { border-bottom: 1px solid var(--rule); }

.masthead-grid {
  display: grid;
  grid-template-columns: minmax(0, 1fr) minmax(0, 46%);
  gap: 56px;
  align-items: center;
  padding: 64px 0 60px;
}

.kicker {
  margin: 0 0 26px;
  font-family: var(--mono);
  font-size: 11.5px;
  letter-spacing: .17em;
  text-transform: uppercase;
  color: var(--brand);
}
.kicker-sep { color: var(--rule-2); margin: 0 10px; }

.masthead h1 {
  margin: 0 0 20px;
  font-family: var(--serif);
  font-size: 44px;
  line-height: 1.26;
  font-weight: 600;
  letter-spacing: .01em;
}

.tagline {
  margin: 0 0 22px;
  padding-top: 18px;
  border-top: 1px solid var(--rule);
  font-size: 15px;
  letter-spacing: .28em;
  color: var(--accent);
}

.abstract {
  margin: 0 0 30px;
  max-width: 44ch;
  color: var(--ink-2);
  font-size: 14.5px;
  line-height: 1.9;
}

/* facts strip */
.facts {
  margin: 0 0 32px;
  padding: 16px 0;
  border-top: 1px solid var(--rule);
  border-bottom: 1px solid var(--rule);
  display: flex;
  flex-wrap: wrap;
  gap: 0;
}
.fact {
  padding: 0 26px 0 0;
  margin-right: 26px;
  border-right: 1px solid var(--rule);
}
.fact:last-child { border-right: 0; margin-right: 0; padding-right: 0; }
.fact dt {
  font-family: var(--mono);
  font-size: 10.5px;
  letter-spacing: .14em;
  text-transform: uppercase;
  color: var(--ink-3);
  margin: 0 0 3px;
}
.fact dd {
  margin: 0;
  font-size: 19px;
  font-weight: 600;
  letter-spacing: .01em;
  font-variant-numeric: tabular-nums;
}

/* buttons */
.actions { display: flex; flex-wrap: wrap; gap: 10px; }
.btn {
  display: inline-block;
  padding: 11px 22px;
  border: 1px solid var(--rule-2);
  border-radius: 2px;
  background: #fff;
  color: var(--ink);
  font-size: 13px;
  font-weight: 600;
  letter-spacing: .02em;
  text-decoration: none;
  cursor: pointer;
  white-space: nowrap;
  transition: border-color .15s, color .15s, background .15s;
}
.btn:hover { border-color: var(--ink); }
.btn-solid {
  background: var(--brand); border-color: var(--brand); color: #fff;
}
.btn-solid:hover { background: var(--brand-dk); border-color: var(--brand-dk); }

/* hero media */
.masthead-media { margin: 0; }
.masthead-media img {
  width: 100%;
  aspect-ratio: 4 / 3;
  object-fit: cover;
  border: 1px solid var(--rule);
  background: var(--paper-2);
}
.masthead-media figcaption {
  margin-top: 10px;
  font-family: var(--mono);
  font-size: 11px;
  letter-spacing: .06em;
  color: var(--ink-3);
}

/* ---------------- sticky chapter bar ---------------- */
.tocbar {
  position: sticky; top: 0; z-index: 30;
  background: var(--paper);
  border-bottom: 1px solid var(--rule);
}
.tocbar-list {
  list-style: none; margin: 0; padding: 0;
  display: flex; flex-wrap: wrap;
  gap: 0 4px;
}
.tocbar-list li { display: flex; }
.tocbar-list a {
  display: inline-flex; align-items: baseline; gap: 7px;
  padding: 13px 11px;
  font-size: 13px;
  color: var(--ink-2);
  text-decoration: none;
  border-bottom: 2px solid transparent;
}
.tocbar-list a .n {
  font-family: var(--mono);
  font-size: 11px;
  color: var(--ink-3);
  letter-spacing: .04em;
}
.tocbar-list a:hover { color: var(--ink); }
.tocbar-list a.active { color: var(--brand); border-bottom-color: var(--brand); }
.tocbar-list a.active .n { color: var(--brand); }

/* ---------------- usage note ---------------- */
.usage {
  margin: 40px 0 0;
  padding: 22px 26px;
  border: 1px solid var(--rule);
  background: var(--paper-2);
}
.usage-label {
  margin: 0 0 14px;
  font-family: var(--mono);
  font-size: 11px;
  letter-spacing: .15em;
  text-transform: uppercase;
  color: var(--brand);
}
.usage-list { margin: 0; padding: 0; list-style: none; }
.usage-list li {
  display: flex; gap: 14px; flex-wrap: wrap;
  padding: 6px 0;
  font-size: 14px;
  color: var(--ink-2);
}
.usage-key {
  flex: 0 0 76px;
  font-family: var(--mono);
  font-size: 11.5px;
  letter-spacing: .06em;
  color: var(--ink);
  padding-top: 2px;
}

/* ---------------- section heads ---------------- */
.block { padding: 62px 0 0; }
.sec-head {
  display: flex; align-items: baseline; gap: 16px;
  padding-bottom: 14px;
  border-bottom: 1px solid var(--rule-2);
  margin-bottom: 26px;
}
.sec-num {
  margin: 0;
  font-family: var(--mono);
  font-size: 12px;
  letter-spacing: .12em;
  color: var(--brand);
}
.sec-head h2 {
  margin: 0;
  font-family: var(--serif);
  font-size: 26px;
  font-weight: 600;
  letter-spacing: .02em;
}
.sec-note {
  margin: 0 0 0 auto;
  font-family: var(--mono);
  font-size: 11.5px;
  letter-spacing: .08em;
  color: var(--ink-3);
}

/* ---------------- index table ---------------- */
.idx { border-top: 1px solid var(--rule); }
.idx-row {
  display: grid;
  grid-template-columns: 58px minmax(0, 1fr) 128px 152px;
  gap: 20px;
  align-items: center;
  padding: 15px 10px 15px 0;
  border-bottom: 1px solid var(--rule);
  text-decoration: none;
  color: inherit;
  transition: background .15s;
}
.idx-row:hover { background: var(--paper-2); }
.idx-num {
  font-family: var(--mono);
  font-size: 13px;
  letter-spacing: .06em;
  color: var(--ink-3);
  font-variant-numeric: tabular-nums;
}
.idx-row:hover .idx-num { color: var(--brand); }
.idx-name {
  font-size: 16px;
  font-weight: 600;
  letter-spacing: .01em;
}
.idx-en {
  display: block;
  font-family: var(--mono);
  font-size: 10.5px;
  font-weight: 400;
  letter-spacing: .12em;
  color: var(--ink-3);
  margin-top: 3px;
}
.idx-range {
  font-family: var(--mono);
  font-size: 12px;
  color: var(--ink-2);
  letter-spacing: .04em;
  font-variant-numeric: tabular-nums;
}
.idx-thumb img {
  width: 152px;
  aspect-ratio: 16 / 9;
  object-fit: cover;
  border: 1px solid var(--rule);
  background: var(--paper-2);
}

/* ---------------- document pages ---------------- */
.pages { padding-bottom: 20px; }
.pg {
  display: grid;
  grid-template-columns: 152px minmax(0, 1fr);
  gap: 34px;
  padding: 34px 0 42px;
  border-bottom: 1px solid var(--rule);
}
.pg:last-child { border-bottom: 0; }
.pg-rail { padding-top: 2px; }
.pg-num {
  display: block;
  font-family: var(--mono);
  font-size: 34px;
  line-height: 1;
  letter-spacing: -.01em;
  color: var(--ink);
  font-variant-numeric: tabular-nums;
}
.pg-label {
  display: block;
  margin-top: 8px;
  font-family: var(--mono);
  font-size: 10.5px;
  letter-spacing: .13em;
  text-transform: uppercase;
  color: var(--brand);
}
.pg-main { min-width: 0; }
.pg-main figure { margin: 0; }
.pg-img {
  width: 100%;
  aspect-ratio: 16 / 9;
  object-fit: contain;
  border: 1px solid var(--rule);
  background: var(--paper-2);
  cursor: zoom-in;
}
.txt { margin-top: 12px; }
.txt summary {
  display: inline-flex; align-items: center; gap: 8px;
  cursor: pointer; list-style: none;
  font-family: var(--mono);
  font-size: 11.5px;
  letter-spacing: .1em;
  text-transform: uppercase;
  color: var(--ink-3);
  padding: 6px 0;
  border-bottom: 1px solid var(--rule);
}
.txt summary::-webkit-details-marker { display: none; }
.txt summary::before { content: "+"; font-weight: 700; color: var(--brand); }
.txt[open] summary::before { content: "–"; }
.txt summary:hover { color: var(--ink); }
.txt pre {
  margin: 14px 0 0;
  padding: 18px 20px;
  background: var(--paper-2);
  border-left: 2px solid var(--rule-2);
  font-family: var(--sans);
  font-size: 14px;
  line-height: 1.95;
  color: var(--ink-2);
  white-space: pre-wrap;
  word-break: break-word;
}

/* ---------------- footer ---------------- */
.foot {
  margin-top: 70px;
  border-top: 1px solid var(--rule-2);
  background: var(--paper-2);
  padding: 38px 0 44px;
}
.foot-grid {
  display: grid;
  grid-template-columns: minmax(0, 1fr) minmax(0, 1.3fr) minmax(0, .8fr);
  gap: 36px;
}
.foot-name {
  margin: 0 0 4px;
  font-size: 14.5px;
  font-weight: 600;
  letter-spacing: .02em;
}
.foot-note {
  margin: 0 0 6px;
  font-size: 12.5px;
  line-height: 1.85;
  color: var(--ink-3);
}
.foot-meta { text-align: right; }

/* ---------------- floating ---------------- */
.to-top {
  position: fixed; right: 20px; bottom: 20px; z-index: 40;
  width: 38px; height: 38px;
  border: 1px solid var(--rule-2); border-radius: 2px;
  background: #fff; color: var(--ink);
  font-size: 16px; cursor: pointer;
  opacity: 0; pointer-events: none; transition: opacity .18s;
}
.to-top.show { opacity: 1; pointer-events: auto; }
.to-top:hover { border-color: var(--ink); }

.lightbox {
  position: fixed; inset: 0; z-index: 60;
  background: rgba(14,17,20,.94);
  display: flex; align-items: center; justify-content: center;
  padding: 28px; overflow: auto;
}
.lightbox[hidden] { display: none; }
.lightbox img {
  max-width: 100%; max-height: 92vh; width: auto; height: auto;
  border: 1px solid #2a2f34;
}
.lb-close {
  position: fixed; top: 14px; right: 16px; z-index: 61;
  width: 36px; height: 36px; border: 1px solid #3a4046; border-radius: 2px;
  background: transparent; color: #fff; font-size: 22px; cursor: pointer; line-height: 1;
}
.lb-close:hover { border-color: #fff; }

/* ---------------- responsive ---------------- */
@media (max-width: 1080px) {
  .masthead-grid { grid-template-columns: minmax(0, 1fr) minmax(0, 40%); gap: 36px; }
  .masthead h1 { font-size: 36px; }
  .idx-row { grid-template-columns: 48px minmax(0, 1fr) 104px 112px; gap: 14px; }
  .idx-thumb img { width: 112px; }
  .pg { grid-template-columns: 110px minmax(0, 1fr); gap: 22px; }
  .foot-grid { grid-template-columns: minmax(0, 1fr) minmax(0, 1fr); }
  .foot-meta { text-align: left; }
}

@media (max-width: 760px) {
  .container { padding: 0 18px; }
  .tocbar { position: static; }
  .tocbar-list { gap: 0; }
  .tocbar-list a { padding: 9px 9px; font-size: 12.5px; }
  .masthead-grid {
    grid-template-columns: minmax(0, 1fr);
    gap: 30px;
    padding: 38px 0 40px;
  }
  .masthead h1 { font-size: 29px; }
  .kicker { margin-bottom: 18px; font-size: 10.5px; }
  .abstract { font-size: 14px; }
  .fact { padding-right: 16px; margin-right: 16px; }
  .fact dd { font-size: 16px; }
  .actions .btn { flex: 1 1 auto; text-align: center; padding: 11px 14px; }
  .usage { padding: 18px; }
  .usage-list li { display: block; }
  .usage-key { display: block; flex: none; margin-bottom: 2px; }
  .block { padding-top: 44px; }
  .sec-head h2 { font-size: 21px; }
  .idx-row {
    grid-template-columns: 34px minmax(0, 1fr) 76px;
    gap: 10px; padding: 13px 0;
  }
  .idx-range { display: none; }
  .idx-thumb img { width: 76px; }
  .idx-name { font-size: 15px; }
  .pg { grid-template-columns: minmax(0, 1fr); gap: 12px; padding: 26px 0 32px; }
  .pg-rail { display: flex; align-items: baseline; gap: 12px; }
  .pg-num { font-size: 24px; }
  .pg-label { margin-top: 0; }
  .foot-grid { grid-template-columns: minmax(0, 1fr); gap: 18px; }
}

/* ---------------- print ---------------- */
@media print {
  .masthead, .tocbar, .usage, .foot, .to-top, .lightbox, .idx, .sec-head, .txt { display: none !important; }
  .container { max-width: none; padding: 0; }
  .block { padding: 0; }
  .pg { border: 0; padding: 0; break-after: page; page-break-after: always; }
  .pg:last-child { break-after: auto; page-break-after: auto; }
  .pg-rail { display: none; }
  .pg-img { border: 0; width: 100%; }
  body { font-size: 12pt; }
}