/* =============================================================================
   化工深度助手 — 官方页面样式
   设计令牌沿用 DeepSeek 品牌体系（颜色/圆角/间距/字体族），页面为深色主题。
   ========================================================================== */

:root {
  /* 品牌与背景 */
  --brand: #4d6bfe;
  --brand-deep: #3a65c2;
  --bg: #0a0a0a;
  --bg-alt: #0d0d0f;
  --panel: #151517;
  --panel-2: #1c1c20;
  --hero-blue: #2a5180;
  --hero-blue-deep: #183254;

  /* 文字 */
  --text: #ffffff;
  --text-2: rgba(255, 255, 255, .66);
  --text-3: rgba(255, 255, 255, .42);

  /* 描边 */
  --border: rgba(255, 255, 255, .08);
  --border-2: rgba(255, 255, 255, .14);

  /* 圆角（对齐 --ds-radius-*） */
  --r-card: 24px;
  --r-panel: 16px;
  --r-media: 12px;
  --r-sm: 8px;
  --r-pill: 100px;

  /* 间距 */
  --sp-2: 8px; --sp-3: 12px; --sp-4: 16px; --sp-5: 24px;
  --sp-6: 32px; --sp-7: 40px; --sp-8: 56px; --sp-9: 80px; --sp-10: 120px;

  /* 字体：不引外链字体，避免部署环境（尤其国内网络）加载失败 */
  --font: "DM Sans", system-ui, -apple-system, BlinkMacSystemFont, "Segoe UI",
          Roboto, "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei",
          "Noto Sans SC", sans-serif;
  --mono: "Fragment Mono", "Roboto Mono", ui-monospace, SFMono-Regular,
          Menlo, Consolas, monospace;

  --wrap: 1200px;
  --shadow-card: 0 1px 2px rgba(0, 0, 0, .4), 0 24px 48px -24px rgba(0, 0, 0, .8);

  /* 「待回填」后缀，英文模式下由下方的 [data-lang="en"] 覆盖 */
  --field-pending: " · 待回填";
}

* { box-sizing: border-box; }

html { scroll-behavior: smooth; }

body {
  margin: 0;
  background: var(--bg);
  color: var(--text);
  font-family: var(--font);
  font-size: 16px;
  line-height: 1.65;
  -webkit-font-smoothing: antialiased;
  text-rendering: optimizeLegibility;
  overflow-x: hidden;
}

h1, h2, h3 { margin: 0; font-weight: 600; letter-spacing: -.02em; line-height: 1.2; }
p { margin: 0; }
a { color: inherit; text-decoration: none; }
code, .mono { font-family: var(--mono); }

.wrap { width: 100%; max-width: var(--wrap); margin: 0 auto; padding: 0 var(--sp-6); }
.wrap-narrow { max-width: 860px; }

/* 元素默认可见；由 JS 打开挂载动画，避免无 JS / 无头渲染时整页空白 */
.reveal { opacity: 1; transform: none; }
html.js-reveal .reveal { opacity: 0; transform: translateY(18px); }
html.js-reveal .reveal.in { opacity: 1; transform: none; transition: opacity .6s ease, transform .6s cubic-bezier(.2, .7, .3, 1); }

/* ------------------------------- 顶部导航 ------------------------------- */
.nav {
  position: fixed; inset: 0 0 auto 0; z-index: 50;
  transition: background .3s ease, border-color .3s ease, backdrop-filter .3s ease;
  border-bottom: 1px solid transparent;
}
.nav.scrolled {
  background: rgba(10, 10, 10, .78);
  -webkit-backdrop-filter: blur(14px);
  backdrop-filter: blur(14px);
  border-bottom-color: var(--border);
}
.nav-inner {
  max-width: 1440px; margin: 0 auto; height: 68px;
  padding: 0 var(--sp-6);
  display: flex; align-items: center; gap: var(--sp-5);
}
.nav-brand { display: flex; align-items: center; gap: 10px; font-weight: 600; letter-spacing: -.02em; }
.mark { display: inline-flex; color: var(--text); }
.mark-sm { opacity: .95; }
.nav-name { font-size: 15px; white-space: nowrap; }
.nav-links { display: flex; gap: var(--sp-5); margin-left: var(--sp-6); }
.nav-links a {
  font-size: 14px; color: var(--text-2); transition: color .2s ease;
}
.nav-links a:hover { color: var(--text); }
.nav-right { margin-left: auto; display: flex; align-items: center; gap: var(--sp-4); }

.lang {
  display: inline-flex; gap: 6px; align-items: center;
  background: none; border: 0; cursor: pointer;
  font: inherit; font-size: 14px; color: var(--text-3);
  padding: 6px 8px; border-radius: var(--r-sm);
  transition: color .2s ease, background .2s ease;
}
.lang:hover { background: rgba(255, 255, 255, .06); }
.lang-zh, .lang-en { transition: color .2s ease; }
html[data-lang="zh"] .lang-zh { color: var(--text); }
html[data-lang="en"] .lang-en { color: var(--text); }
.lang-sep { opacity: .35; }

/* --------------------------------- 按钮 --------------------------------- */
.btn {
  display: inline-flex; align-items: center; justify-content: center; gap: 8px;
  border: 1px solid transparent; border-radius: var(--r-pill);
  font: inherit; font-weight: 500; cursor: pointer;
  white-space: nowrap; transition: transform .18s ease, background .2s ease,
    border-color .2s ease, box-shadow .2s ease;
}
.btn:active { transform: translateY(1px); }
.btn-sm { height: 36px; padding: 0 16px; font-size: 14px; }
.btn-lg { height: 48px; padding: 0 26px; font-size: 15.5px; }
.btn-white { background: #fff; color: #16171a; }
.btn-white:hover { background: rgba(255, 255, 255, .88); }
.btn-brand {
  background: var(--brand); color: #fff;
  box-shadow: 0 8px 24px -8px rgba(77, 107, 254, .7);
}
.btn-brand:hover { background: #5f7bff; }

.pill {
  display: inline-flex; align-items: center;
  border: 1px solid var(--border-2); border-radius: var(--r-pill);
  color: var(--text-2); font-size: 12.5px; font-weight: 500;
  padding: 5px 12px; white-space: nowrap;
}
.pill-sm { padding: 2px 9px; font-size: 11.5px; opacity: .8; }

/* ---------------------------------- Hero -------------------------------- */
.hero { position: relative; padding: calc(68px + var(--sp-8)) 0 var(--sp-9); overflow: hidden; }
.hero-glow {
  position: absolute; left: 50%; top: -260px; z-index: 0;
  width: 2000px; height: 1240px; transform: translateX(-50%);
  pointer-events: none;
  background:
    radial-gradient(1000px 780px at 50% 32%, rgba(51, 102, 162, .92) 0%, rgba(51, 102, 162, 0) 100%),
    radial-gradient(820px 600px at 14% 22%, rgba(26, 58, 98, .85) 0%, rgba(26, 58, 98, 0) 100%),
    radial-gradient(820px 600px at 86% 20%, rgba(32, 70, 116, .85) 0%, rgba(32, 70, 116, 0) 100%),
    linear-gradient(180deg, rgba(30, 64, 106, .5) 0%, rgba(30, 64, 106, 0) 62%);
}
.hero-wrap { position: relative; z-index: 1; text-align: center; }
.hero-badge { margin-bottom: var(--sp-5); }
.hero-title { display: flex; flex-direction: column; gap: 6px; }
.hero-title > span:first-child { font-size: 40px; color: rgba(255, 255, 255, .82); font-weight: 600; }
.hero-title-2 {
  font-size: 62px; font-weight: 600; letter-spacing: -.035em;
  background: linear-gradient(180deg, #fff 30%, rgba(255, 255, 255, .74) 100%);
  -webkit-background-clip: text; background-clip: text; color: transparent;
}
.hero-sub {
  max-width: 720px; margin: var(--sp-5) auto 0;
  color: var(--text-2); font-size: 16.5px; line-height: 1.8;
}
.hero-sub strong { color: rgba(255, 255, 255, .92); font-weight: 600; }
.hero-cta {
  margin-top: var(--sp-7);
  display: flex; flex-direction: column; align-items: center; gap: var(--sp-3);
}
.hero-note { color: var(--text-3); font-size: 13.5px; }

/* ------------------------- 产品界面示意（App mock） ---------------------- */
.app {
  margin: var(--sp-9) auto 0;
  background: var(--panel);
  border: 1px solid var(--border);
  border-radius: var(--r-panel);
  box-shadow: var(--shadow-card);
  overflow: hidden; text-align: left;
}
.app-bar {
  height: 44px; display: flex; align-items: center; gap: var(--sp-4);
  padding: 0 var(--sp-4);
  border-bottom: 1px solid var(--border);
  background: rgba(255, 255, 255, .02);
}
.dots { display: inline-flex; gap: 7px; }
.dots i { width: 11px; height: 11px; border-radius: 50%; background: rgba(255, 255, 255, .16); }
.dots i:nth-child(1) { background: #ff5f57; }
.dots i:nth-child(2) { background: #febc2e; }
.dots i:nth-child(3) { background: #28c840; }
.app-title { font-size: 12.5px; color: var(--text-3); }

.app-body { display: grid; grid-template-columns: 214px 1fr 236px; min-height: 520px; }

.app-side {
  border-right: 1px solid var(--border);
  padding: var(--sp-4) var(--sp-3);
  background: rgba(255, 255, 255, .012);
}
.side-brand {
  display: flex; align-items: center; gap: 8px;
  font-size: 13.5px; font-weight: 600; padding: 4px 8px 14px;
}
.side-new {
  width: 100%; height: 34px; border-radius: var(--r-sm);
  background: rgba(255, 255, 255, .07); border: 1px solid var(--border);
  color: var(--text); font: inherit; font-size: 13px; cursor: default;
}
.side-list, .side-ws { list-style: none; margin: 14px 0 0; padding: 0; }
.side-list li {
  font-size: 13px; color: var(--text-2); padding: 7px 8px; border-radius: var(--r-sm);
}
.side-cap {
  font-size: 11px; color: var(--text-3); text-transform: uppercase;
  letter-spacing: .08em; margin: 18px 0 0; padding: 0 8px;
}
.side-ws li {
  font-size: 13px; color: var(--text-2); padding: 7px 8px;
  border-radius: var(--r-sm); overflow: hidden; text-overflow: ellipsis; white-space: nowrap;
}
.side-ws li.active { background: rgba(255, 255, 255, .07); color: var(--text); }

.app-chat { display: flex; flex-direction: column; min-width: 0; }
.chat-head {
  height: 46px; display: flex; align-items: center; padding: 0 var(--sp-5);
  border-bottom: 1px solid var(--border); font-size: 13.5px; color: var(--text-2);
}
.chat-scroll { padding: var(--sp-5); display: flex; flex-direction: column; gap: var(--sp-5); flex: 1; }
.msg { font-size: 13.5px; line-height: 1.75; }
.msg.user { display: flex; justify-content: flex-end; }
.msg.user p {
  max-width: 78%; background: rgba(77, 107, 254, .16);
  border: 1px solid rgba(77, 107, 254, .3);
  padding: 10px 14px; border-radius: 14px 14px 4px 14px; color: rgba(255, 255, 255, .92);
}
.msg.bot { display: flex; flex-direction: column; gap: 10px; color: var(--text-2); max-width: 92%; }
.msg.bot code {
  background: rgba(255, 255, 255, .09); padding: 1px 6px; border-radius: 5px;
  font-size: 12px; color: #ffd479;
}
.think { font-size: 12.5px; color: var(--text-3); }
.tool {
  display: flex; align-items: center; gap: 10px; flex-wrap: wrap;
  border: 1px solid var(--border); border-radius: var(--r-media);
  background: rgba(255, 255, 255, .025);
  padding: 9px 12px; font-family: var(--mono); font-size: 12px;
}
.tool-name { color: #8ab4ff; }
.tool-arg { color: var(--text-2); }
.tool-note { font-size: 12.5px; color: var(--text-3); }

.chat-input {
  margin: 0 var(--sp-5) var(--sp-5);
  border: 1px solid var(--border); border-radius: 14px;
  padding: 12px 44px 12px 14px; position: relative;
  font-size: 13px; color: var(--text-3); background: rgba(255, 255, 255, .02);
}
.send {
  position: absolute; right: 10px; bottom: 10px;
  width: 26px; height: 26px; border-radius: 50%; background: rgba(255, 255, 255, .12);
}

.app-ledger { border-left: 1px solid var(--border); padding: var(--sp-4) var(--sp-3); }
.ledger-head {
  display: flex; align-items: center; justify-content: space-between;
  font-size: 12.5px; color: var(--text-2); padding: 0 8px 12px;
  border-bottom: 1px solid var(--border);
}
.ledger-count {
  font-family: var(--mono); font-size: 11px; color: var(--text-3);
  border: 1px solid var(--border); border-radius: var(--r-pill); padding: 0 7px;
}
.ledger-row {
  display: grid; grid-template-columns: 1fr auto; gap: 4px 8px;
  padding: 12px 8px; border-bottom: 1px solid rgba(255, 255, 255, .05);
}
.ledger-label { font-size: 12.5px; color: var(--text-2); }
.ledger-val { font-family: var(--mono); font-size: 12px; color: var(--text); justify-self: end; }
.ledger-row .chip { grid-column: 1 / -1; justify-self: start; }
.ledger-foot { font-size: 11.5px; color: #ffb27a; padding: 14px 8px 0; line-height: 1.6; }

/* --------------------------------- 状态片 -------------------------------- */
.chip {
  display: inline-flex; align-items: center;
  font-size: 11px; font-family: var(--mono); font-weight: 500;
  padding: 2px 9px; border-radius: var(--r-pill);
  border: 1px solid transparent; white-space: nowrap;
}
.chip-ok { color: #6ee7a8; background: rgba(52, 211, 153, .12); border-color: rgba(52, 211, 153, .28); }
.chip-pending { color: #ffd479; background: rgba(250, 204, 21, .1); border-color: rgba(250, 204, 21, .26); }
.chip-mismatch { color: #ff9d9d; background: rgba(248, 113, 113, .12); border-color: rgba(248, 113, 113, .28); }
.chip-warn { color: #ffb27a; background: rgba(251, 146, 60, .12); border-color: rgba(251, 146, 60, .28); }
.chip-info { color: #9dc0ff; background: rgba(96, 165, 250, .12); border-color: rgba(96, 165, 250, .26); }

/* --------------------------------- 章节 --------------------------------- */
.section { padding: var(--sp-10) 0; scroll-margin-top: 84px; }
.section-alt { background: var(--bg-alt); border-block: 1px solid var(--border); }
.h2 { font-size: 38px; text-align: center; letter-spacing: -.03em; }
.lead {
  text-align: center; color: var(--text-2); font-size: 16px;
  max-width: 680px; margin: var(--sp-4) auto 0;
}

.grid { display: grid; gap: var(--sp-5); margin-top: var(--sp-8); }
.grid-2 { grid-template-columns: repeat(2, minmax(0, 1fr)); }
.grid-3 { grid-template-columns: repeat(3, minmax(0, 1fr)); }

.card {
  background: linear-gradient(180deg, rgba(255, 255, 255, .035), rgba(255, 255, 255, .012));
  border: 1px solid var(--border); border-radius: var(--r-card);
  padding: var(--sp-6); display: flex; flex-direction: column; gap: var(--sp-4);
  transition: border-color .25s ease, transform .25s ease;
}
.card:hover { border-color: var(--border-2); transform: translateY(-2px); }
.card h3 { font-size: 19px; }
.card > p { color: var(--text-2); font-size: 14.5px; line-height: 1.8; }
.card code {
  background: rgba(255, 255, 255, .08); padding: 1px 6px;
  border-radius: 5px; font-size: 13px; color: #ffd479;
}
.card b { color: rgba(255, 255, 255, .92); font-weight: 600; }

/* 卡片内嵌示意面板 */
.mock-panel {
  margin-top: auto;
  background: rgba(0, 0, 0, .38);
  border: 1px solid var(--border); border-radius: var(--r-panel);
  padding: var(--sp-4); font-size: 13px;
}
.mock-panel p { margin: 0 0 7px; color: var(--text-2); }
.mock-panel p:last-of-type { margin-bottom: 0; }
.mock-panel.mono { font-family: var(--mono); font-size: 12.2px; line-height: 1.85; }
.mock-foot { color: var(--text-3) !important; font-size: 11.8px; margin-top: 12px !important; line-height: 1.6; }
.mock-panel .ok { color: #6ee7a8; }
.mock-panel .dim { color: var(--text-3); }
.tag {
  display: inline-block; min-width: 74px; color: #8ab4ff;
}
.tree { color: var(--text-2); }
.tree.l1 { padding-left: 16px; color: var(--text-3); }

.row {
  display: flex; align-items: center; gap: 10px;
  padding: 8px 0; border-bottom: 1px solid rgba(255, 255, 255, .05);
  font-size: 12.8px;
}
.row:last-of-type { border-bottom: 0; }
.row-wrap { flex-wrap: wrap; }
.row-k { color: var(--text-2); flex: 1; min-width: 0; }
.row-v { font-family: var(--mono); font-size: 12.2px; color: var(--text); }

.fields { display: grid; grid-template-columns: repeat(2, 1fr); gap: 8px; }
.field {
  border: 1px dashed rgba(255, 255, 255, .18); border-radius: var(--r-sm);
  padding: 8px 10px; font-size: 12.2px; color: var(--text-3);
}
/* 「待回填」后缀随语言切换（文案来自 CSS 变量，避免 JS 逐格改写） */
.field::after { content: var(--field-pending); color: #ffb27a; }
html[data-lang="en"] { --field-pending: " · to be filled"; }

/* 工作纪律 / 工具链 三列 */
.col { padding: var(--sp-6); border-top: 1px solid var(--border-2); }
.col h3 { font-size: 17px; margin-bottom: 10px; }
.col p { color: var(--text-2); font-size: 14.5px; line-height: 1.8; }
.col .num {
  font-family: var(--mono); font-size: 12px; color: var(--brand);
  letter-spacing: .1em; display: block; margin-bottom: var(--sp-4);
}
.col-quiet { border-top-color: var(--border); }

/* 快速开始 */
.steps { display: grid; grid-template-columns: repeat(3, 1fr); gap: var(--sp-5); margin-top: var(--sp-8); }
.step {
  background: linear-gradient(180deg, rgba(255, 255, 255, .035), rgba(255, 255, 255, .01));
  border: 1px solid var(--border); border-radius: var(--r-card); padding: var(--sp-6);
}
.step-n {
  display: inline-flex; align-items: center; justify-content: center;
  width: 28px; height: 28px; border-radius: 50%;
  background: rgba(77, 107, 254, .18); border: 1px solid rgba(77, 107, 254, .4);
  color: #a9beff; font-size: 13px; font-family: var(--mono); margin-bottom: var(--sp-4);
}
.step h3 { font-size: 17px; margin-bottom: 8px; }
.step p { color: var(--text-2); font-size: 14.5px; }

/* 下载 */
.dl-card {
  margin-top: var(--sp-8);
  background: linear-gradient(180deg, rgba(77, 107, 254, .1), rgba(255, 255, 255, .02));
  border: 1px solid rgba(77, 107, 254, .28);
  border-radius: var(--r-card); padding: var(--sp-7);
}
.dl-info { display: flex; align-items: center; justify-content: space-between; gap: var(--sp-5); flex-wrap: wrap; }
.dl-os { display: flex; align-items: center; gap: 14px; color: var(--text); }
.dl-os svg { color: rgba(255, 255, 255, .8); }
.dl-os strong { display: block; font-size: 16.5px; font-weight: 600; }
.dl-meta { display: block; font-size: 12.5px; color: var(--text-3); font-family: var(--mono); margin-top: 3px; }
.dl-list {
  list-style: none; margin: var(--sp-6) 0 0; padding: var(--sp-5) 0 0;
  border-top: 1px solid rgba(255, 255, 255, .09);
  display: grid; gap: 10px;
}
.dl-list li { color: var(--text-2); font-size: 14px; padding-left: 20px; position: relative; }
.dl-list li::before {
  content: ""; position: absolute; left: 4px; top: .62em;
  width: 6px; height: 6px; border-radius: 50%; background: rgba(255, 255, 255, .3);
}
.dl-other { text-align: center; color: var(--text-3); font-size: 13.5px; margin-top: var(--sp-5); }

/* FAQ */
.faq { margin-top: var(--sp-8); border-top: 1px solid var(--border); }
.faq details { border-bottom: 1px solid var(--border); }
.faq summary {
  cursor: pointer; list-style: none; padding: var(--sp-5) 34px var(--sp-5) 0;
  font-size: 16.5px; font-weight: 500; position: relative;
}
.faq summary::-webkit-details-marker { display: none; }
.faq summary::after {
  content: "+"; position: absolute; right: 6px; top: 50%; transform: translateY(-50%);
  color: var(--text-3); font-size: 20px; font-weight: 400; transition: transform .2s ease;
}
.faq details[open] summary::after { content: "\2013"; }
.faq details p { color: var(--text-2); font-size: 14.5px; line-height: 1.85; padding: 0 40px var(--sp-5) 0; }

/* 页脚 */
.foot { border-top: 1px solid var(--border); padding: var(--sp-8) 0; background: var(--bg); }
.foot-inner { display: flex; flex-direction: column; align-items: center; gap: 10px; text-align: center; }
.foot-brand { display: flex; align-items: center; gap: 9px; font-weight: 600; font-size: 15px; }
.foot-note { color: var(--text-3); font-size: 12.5px; max-width: 720px; }

/* ------------------------------- 响应式 -------------------------------- */
@media (max-width: 1180px) {
  .app-body { grid-template-columns: 200px 1fr; }
  .app-ledger { display: none; }
}
@media (max-width: 980px) {
  .nav-links { display: none; }
  .hero-title > span:first-child { font-size: 32px; }
  .hero-title-2 { font-size: 46px; }
  .h2 { font-size: 30px; }
  .grid-2, .grid-3, .steps { grid-template-columns: 1fr; }
  .section { padding: var(--sp-9) 0; }
  .col { padding: var(--sp-5) 0; }
}
@media (max-width: 760px) {
  .wrap { padding: 0 var(--sp-5); }
  .app-body { grid-template-columns: 1fr; min-height: 0; }
  .app-side { display: none; }
  .hero { padding-top: calc(68px + var(--sp-6)); }
  .hero-title > span:first-child { font-size: 26px; }
  .hero-title-2 { font-size: 34px; }
  .hero-sub { font-size: 15px; }
  .app { margin-top: var(--sp-8); }
  .chat-scroll { padding: var(--sp-4); gap: var(--sp-4); }
  .chat-input { margin: 0 var(--sp-4) var(--sp-4); }
  .dl-card { padding: var(--sp-6); }
  .dl-info { flex-direction: column; align-items: stretch; }
  .btn-lg { width: 100%; }
  .nav-inner { padding: 0 var(--sp-4); gap: var(--sp-3); }
  .nav-dl span { display: none; }
  .nav-dl { padding: 0 12px; }
}

@media (prefers-reduced-motion: reduce) {
  html { scroll-behavior: auto; }
  html.js-reveal .reveal { opacity: 1; transform: none; transition: none; }
  .card:hover { transform: none; }
}

/* ── 使用方式表（#access）──────────────────────────────────────────────
   与深色底一致：表头弱化、行间 1px 分隔、窄屏横向滚动不换行挤压。 */
.tbl-wrap {
  margin-top: 30px;
  border: 1px solid var(--border);
  border-radius: 16px;
  overflow-x: auto;
  background: rgba(255, 255, 255, .02);
}
.tbl {
  width: 100%;
  min-width: 620px;
  border-collapse: collapse;
  font-size: 14.5px;
}
.tbl th,
.tbl td {
  padding: 15px 18px;
  text-align: left;
  vertical-align: top;
}
.tbl thead th {
  font-size: 12.5px;
  letter-spacing: .04em;
  color: var(--text-3);
  font-weight: 600;
  border-bottom: 1px solid var(--border);
}
.tbl tbody tr + tr td { border-top: 1px solid var(--border); }
.tbl td { color: var(--text-2); }
.tbl td:first-child { color: var(--text); white-space: nowrap; }
.tbl td b { font-weight: 600; }
@media (max-width: 760px) {
  .tbl { min-width: 520px; font-size: 13.5px; }
  .tbl th, .tbl td { padding: 12px 14px; }
}