/* 设计基础：字体、色板、排版、按钮、表单、页头页脚。全部使用逻辑属性以支持 RTL */
@font-face{font-family:"Inter";font-style:normal;font-weight:100 900;font-display:swap;src:url(../fonts/inter-latin-wght-normal.woff2) format("woff2");unicode-range:U+0000-00FF,U+0131,U+0152-0153,U+02BB-02BC,U+02C6,U+02DA,U+02DC,U+0304,U+0308,U+0329,U+2000-206F,U+20AC,U+2122,U+2191,U+2193,U+2212,U+2215,U+FEFF,U+FFFD}
@font-face{font-family:"Inter";font-style:normal;font-weight:100 900;font-display:swap;src:url(../fonts/inter-latin-ext-wght-normal.woff2) format("woff2");unicode-range:U+0100-02BA,U+02BD-02C5,U+02C7-02CC,U+02CE-02D7,U+02DD-02FF,U+0304,U+0308,U+0329,U+1D00-1DBF,U+1E00-1E9F,U+1EF2-1EFF,U+2020,U+20A0-20AB,U+20AD-20C0,U+2113,U+2C60-2C7F,U+A720-A7FF}
@font-face{font-family:"Inter";font-style:normal;font-weight:100 900;font-display:swap;src:url(../fonts/inter-cyrillic-wght-normal.woff2) format("woff2");unicode-range:U+0301,U+0400-045F,U+0490-0491,U+04B0-04B1,U+2116}
@font-face{font-family:"Inter";font-style:normal;font-weight:100 900;font-display:swap;src:url(../fonts/inter-cyrillic-ext-wght-normal.woff2) format("woff2");unicode-range:U+0460-052F,U+1C80-1C8A,U+20B4,U+2DE0-2DFF,U+A640-A69F,U+FE2E-FE2F}
@font-face{font-family:"IBM Plex Sans Arabic";font-style:normal;font-weight:400;font-display:swap;src:url(../fonts/ibm-plex-sans-arabic-arabic-400-normal.woff2) format("woff2");unicode-range:U+0600-06FF,U+0750-077F,U+0870-088E,U+0890-0891,U+0897-08E1,U+08E3-08FF,U+200C-200E,U+2010-2011,U+204F,U+2E41,U+FB50-FDFF,U+FE70-FE74,U+FE76-FEFC}
@font-face{font-family:"IBM Plex Sans Arabic";font-style:normal;font-weight:500;font-display:swap;src:url(../fonts/ibm-plex-sans-arabic-arabic-500-normal.woff2) format("woff2");unicode-range:U+0600-06FF,U+0750-077F,U+0870-088E,U+0890-0891,U+0897-08E1,U+08E3-08FF,U+200C-200E,U+2010-2011,U+204F,U+2E41,U+FB50-FDFF,U+FE70-FE74,U+FE76-FEFC}
@font-face{font-family:"IBM Plex Sans Arabic";font-style:normal;font-weight:600;font-display:swap;src:url(../fonts/ibm-plex-sans-arabic-arabic-600-normal.woff2) format("woff2");unicode-range:U+0600-06FF,U+0750-077F,U+0870-088E,U+0890-0891,U+0897-08E1,U+08E3-08FF,U+200C-200E,U+2010-2011,U+204F,U+2E41,U+FB50-FDFF,U+FE70-FE74,U+FE76-FEFC}
@font-face{font-family:"IBM Plex Sans Arabic";font-style:normal;font-weight:700;font-display:swap;src:url(../fonts/ibm-plex-sans-arabic-arabic-700-normal.woff2) format("woff2");unicode-range:U+0600-06FF,U+0750-077F,U+0870-088E,U+0890-0891,U+0897-08E1,U+08E3-08FF,U+200C-200E,U+2010-2011,U+204F,U+2E41,U+FB50-FDFF,U+FE70-FE74,U+FE76-FEFC}

:root{
  --ink:#0B1220;--ink-2:#1D2735;--body:#2B3442;--mut:#5E6878;--mut-2:#8A93A3;
  --line:#E4E8EE;--line-2:#CFD5DF;
  --bg:#FFFFFF;--bg-2:#F5F7FA;--bg-3:#ECF0F5;
  --brand:#1530E0;--brand-2:#0F22B8;--brand-soft:#ECEFFF;--brand-glow:#7D8FFF;
  --dark:#0A111D;--dark-2:#121C2C;--on-dark:#E8EDF5;--on-dark-mut:#98A4B7;
  --ok:#0B7A4B;--ok-bg:#E6F4EC;--warn:#8A5200;--warn-bg:#FFF5E2;--err:#C0262D;--err-bg:#FDECEC;
  --r-sm:7px;--r:12px;--r-lg:18px;
  --sh-1:0 1px 2px rgba(11,18,32,.06),0 1px 1px rgba(11,18,32,.04);
  --sh-2:0 18px 40px -18px rgba(11,18,32,.28),0 2px 8px rgba(11,18,32,.06);
  --ai-w:392px;--hdr-h:72px;
  --f:"Inter","PingFang SC","Hiragino Sans GB","Microsoft YaHei","Noto Sans SC",system-ui,-apple-system,"Segoe UI",Roboto,Arial,sans-serif;
  --f-ar:"IBM Plex Sans Arabic","Inter","Segoe UI","Noto Sans Arabic",Tahoma,sans-serif;
  --mono:ui-monospace,"Cascadia Mono",Consolas,monospace;
  /* 供 SVG 示意图使用 */
  --navy:#2A3A55;--acc:var(--brand);
}
*,*::before,*::after{box-sizing:border-box}
html{-webkit-text-size-adjust:100%;scroll-padding-top:140px}
body{margin:0;background:var(--bg);color:var(--body);font:16px/1.65 var(--f);-webkit-font-smoothing:antialiased;-moz-osx-font-smoothing:grayscale;text-rendering:optimizeLegibility}
html:lang(ar) body{font-family:var(--f-ar)}
img,svg{max-width:100%}
h1,h2,h3,h4{color:var(--ink);line-height:1.15;margin:0 0 .5em;font-weight:700;letter-spacing:-.022em}
h1{font-size:clamp(2rem,3.6vw,3rem)}
h2{font-size:clamp(1.5rem,2.4vw,2.1rem)}
h3{font-size:1.1rem;letter-spacing:-.01em}
:lang(zh) h1,:lang(zh) h2,:lang(zh) h3,:lang(zh) h4,:lang(ar) h1,:lang(ar) h2,:lang(ar) h3,:lang(ar) h4{letter-spacing:0}
:lang(zh) h1,:lang(zh) h2{line-height:1.28}
:lang(ar) h1,:lang(ar) h2,:lang(ar) h3{line-height:1.45}
p{margin:0 0 1em}
a{color:var(--brand);text-underline-offset:3px}
a:hover{color:var(--brand-2)}
:focus-visible{outline:2px solid var(--brand);outline-offset:3px;border-radius:4px}
[tabindex="-1"]:focus{outline:none}
::selection{background:var(--brand);color:#fff}
.wrap{max-width:1280px;margin-inline:auto;padding-inline:clamp(18px,4vw,48px)}
.code{font-family:var(--f);font-weight:600;font-size:.76rem;letter-spacing:.06em;color:var(--mut);white-space:nowrap;font-variant-numeric:tabular-nums}
dd .code,.bub .code,.ai-ctx .code{white-space:normal;overflow-wrap:anywhere}
.mono{font-family:var(--mono)}
.mut{color:var(--mut)}
.sr{position:absolute!important;width:1px;height:1px;overflow:hidden;clip:rect(0 0 0 0);white-space:nowrap}
.skip{position:absolute;inset-inline-start:12px;top:-80px;background:var(--brand);color:#fff;padding:10px 16px;border-radius:var(--r-sm);z-index:100}
.skip:focus{top:12px}
.kicker,.eyebrow{display:inline-flex;align-items:center;gap:10px;font-size:.78rem;font-weight:600;letter-spacing:.14em;text-transform:uppercase;color:var(--brand);margin:0 0 14px}
.kicker::before,.eyebrow::before{content:"";width:22px;height:2px;background:currentColor;border-radius:2px}
:lang(zh) .kicker,:lang(zh) .eyebrow{letter-spacing:.18em}
:lang(ar) .kicker,:lang(ar) .eyebrow{letter-spacing:0}
.ic{width:20px;height:20px;flex:none}
[dir=rtl] .ic-arrow{transform:scaleX(-1)}

/* 按钮 */
.btn{display:inline-flex;align-items:center;justify-content:center;gap:9px;min-height:46px;max-width:100%;padding:11px 20px;border:1px solid transparent;border-radius:var(--r-sm);background:var(--ink);color:#fff;font:inherit;font-size:.95rem;font-weight:600;line-height:1.25;text-align:center;text-decoration:none;white-space:normal;cursor:pointer;transition:background-color .16s,border-color .16s,color .16s,box-shadow .16s,transform .16s}
.btn:hover{background:var(--ink-2);color:#fff}
.btn:active{transform:translateY(1px)}
.btn.acc{background:var(--brand)}
.btn.acc:hover{background:var(--brand-2);box-shadow:0 10px 22px -10px rgba(21,48,224,.65)}
.btn.ghost{background:#fff;color:var(--ink);border-color:var(--line-2)}
.btn.ghost:hover{border-color:var(--ink);color:var(--ink);background:#fff}
.btn.added{background:var(--brand-soft);color:var(--brand);border-color:transparent}
.btn.added:hover{background:#DFE4FF;color:var(--brand-2)}
.btn.light{background:#fff;color:var(--ink)}
.btn.light:hover{background:#E9EDF5;color:var(--ink)}
.btn.line-light{background:transparent;color:#fff;border-color:rgba(255,255,255,.34)}
.btn.line-light:hover{border-color:#fff;background:rgba(255,255,255,.06)}
.btn.sm{min-height:38px;padding:7px 14px;font-size:.86rem;gap:7px}
.btn.sm .ic{width:17px;height:17px}
.btn.lg{min-height:52px;padding:13px 26px;font-size:1rem}
.btn[disabled]{opacity:.5;cursor:not-allowed}
.linkbtn{display:inline-flex;align-items:center;gap:6px;background:none;border:0;padding:4px 0;font:inherit;color:var(--brand);font-weight:500;text-decoration:underline;text-underline-offset:3px;cursor:pointer}
.linkbtn:hover{color:var(--brand-2)}
.row{display:flex;flex-wrap:wrap;gap:10px;align-items:center}

/* 标签：类别带色点 */
.tag{display:inline-flex;align-items:center;gap:6px;max-width:100%;font-size:.74rem;font-weight:600;padding:3px 10px;border-radius:999px;line-height:1.45;background:var(--bg-3);color:var(--ink-2)}
.tag::before{content:"";flex:none;width:6px;height:6px;border-radius:50%;background:currentColor}
.tag.cat-gas{background:#ECEFFF;color:#1530E0}
.tag.cat-chem{background:#E3F4F4;color:#0B6B6E}
.tag.cat-abate{background:#FBF1E3;color:#8A5200}
.tag.cat-n2{background:#E6F1FA;color:#145C8F}
.tag.cat-pur{background:#F1ECFA;color:#5B3A99}
.tag.demo{background:transparent;border:1px solid var(--line-2);color:var(--mut)}
.tag.demo::before{display:none}
.tag.soon{background:var(--ink);color:#fff}
.tag.soon::before{background:#7DFFB5}

/* 表单 */
.field{display:flex;flex-direction:column;gap:7px;min-width:0}
.field label,.field .lbl{font-weight:600;font-size:.9rem;color:var(--ink)}
.field .hint{font-size:.8rem;color:var(--mut)}
.req{color:var(--brand);font-weight:500;font-size:.76rem;margin-inline-start:6px}
.opt{color:var(--mut-2);font-weight:400;font-size:.76rem;margin-inline-start:6px}
input[type=text],input[type=email],input[type=tel],input[type=search],input[type=number],select,textarea{
  width:100%;min-height:46px;padding:10px 14px;border:1px solid var(--line-2);border-radius:var(--r-sm);background:#fff;color:var(--ink);font:inherit;font-size:.95rem;transition:border-color .15s,box-shadow .15s}
textarea{min-height:104px;resize:vertical;line-height:1.55}
input::placeholder,textarea::placeholder{color:var(--mut-2)}
input:hover,select:hover,textarea:hover{border-color:#B6BECB}
input:focus,select:focus,textarea:focus{border-color:var(--brand);outline:none;box-shadow:0 0 0 4px rgba(21,48,224,.14)}
input[type=file]{font:inherit;font-size:.88rem;color:var(--mut)}
.field.bad input,.field.bad textarea{border-color:var(--err);box-shadow:0 0 0 4px rgba(192,38,45,.1)}
.errmsg{color:var(--err);font-size:.83rem;margin:0}
.ai-mark{display:inline-block;font-size:.7rem;font-weight:600;color:var(--brand);background:var(--brand-soft);padding:1px 8px;border-radius:999px;margin-inline-start:8px;vertical-align:1px}
.check{display:flex;gap:10px;align-items:flex-start;cursor:pointer}
.check input{width:19px;height:19px;margin:2px 0 0;flex:none;accent-color:var(--brand)}

/* 演示条 */
.demobar{background:var(--dark);color:var(--on-dark-mut);font-size:.76rem;line-height:1.5}
.demobar .wrap{display:flex;flex-wrap:wrap;gap:6px 18px;align-items:center;justify-content:space-between;padding-block:7px}
.demobar .linkbtn{color:#C9D2FF;font-size:.76rem;padding:0}
.demobar .check{align-items:center;gap:7px;color:var(--on-dark-mut)}
.demobar .check input{width:15px;height:15px;margin:0}

/* 页头 */
.hdr{position:sticky;top:0;z-index:30;background:rgba(255,255,255,.9);-webkit-backdrop-filter:saturate(180%) blur(14px);backdrop-filter:saturate(180%) blur(14px);border-bottom:1px solid var(--line)}
.hdr .wrap{display:flex;align-items:center;gap:clamp(16px,2.6vw,40px);min-height:72px}
.brand{display:flex;flex-direction:column;align-items:flex-start;gap:4px;text-decoration:none;flex:none}
.brand img{display:block;height:26px;width:auto}
.brand small{font-size:.68rem;color:var(--mut);line-height:1.2;letter-spacing:.02em}
.nav{display:flex;gap:clamp(4px,1.6vw,26px);flex:1;min-width:0}
.nav a{position:relative;display:inline-flex;align-items:center;padding:24px 4px;color:var(--ink-2);font-weight:500;font-size:.95rem;text-decoration:none;white-space:nowrap}
.nav a:hover{color:var(--ink)}
.nav a[aria-current=page]{color:var(--ink);font-weight:600}
.nav a[aria-current=page]::after{content:"";position:absolute;inset-inline:4px;bottom:-1px;height:2px;background:var(--brand);border-radius:2px}
.tools{display:flex;align-items:center;gap:12px;flex:none}
.langsel{position:relative;display:flex;align-items:center}
.langsel .ic{position:absolute;inset-inline-start:11px;width:17px;height:17px;color:var(--mut);pointer-events:none}
.langsel select{width:auto;min-height:40px;padding-block:6px;padding-inline:36px 30px;border-color:var(--line);background-color:var(--bg-2);font-size:.88rem;font-weight:500;cursor:pointer}
.qlink{display:inline-flex;align-items:center;gap:8px;min-height:40px;padding:7px 14px 7px 12px;border-radius:var(--r-sm);background:var(--ink);color:#fff;font-weight:600;font-size:.88rem;text-decoration:none;white-space:nowrap}
.qlink:hover{background:var(--brand);color:#fff}
.qlink[aria-current=page]{background:var(--brand)}
.qlink .ic{width:18px;height:18px}
.badge{display:inline-grid;place-items:center;min-width:21px;height:21px;padding:0 6px;border-radius:11px;background:var(--brand);color:#fff;font-size:.72rem;font-weight:700;font-variant-numeric:tabular-nums}
.qlink .badge{background:#fff;color:var(--ink)}
.qlink .badge[data-n="0"]{background:rgba(255,255,255,.2);color:#fff}
@media (max-width:980px){
  .hdr .wrap{flex-wrap:wrap;gap:0 14px;padding-block:10px 0;min-height:0}
  .brand{padding-block:4px}
  .brand small{display:none}
  .tools{margin-inline-start:auto}
  .nav{order:3;flex-basis:100%;overflow-x:auto;gap:22px;margin-top:6px;border-top:1px solid var(--line);scrollbar-width:none}
  .nav::-webkit-scrollbar{display:none}
  .nav a{padding:13px 2px}
  .qlink .qtxt{display:none}
  .qlink{padding-inline:11px}
}
@media (max-width:420px){.langsel select{padding-inline:32px 24px;font-size:.84rem}.tools{gap:8px}}

/* 页脚 */
.ftr{background:var(--dark);color:var(--on-dark-mut);font-size:.9rem;padding-block:clamp(56px,7vw,80px) 96px;margin-top:0}
.ftr a{color:var(--on-dark);text-decoration:none}
.ftr a:hover{color:#fff;text-decoration:underline}
.ftr-grid{display:grid;grid-template-columns:minmax(0,1.6fr) repeat(3,minmax(0,1fr));gap:36px clamp(24px,4vw,56px)}
.ftr-brand img{height:26px;width:auto;display:block;margin-bottom:18px}
.ftr-brand p{max-width:36ch;margin:0 0 10px}
.ftr h4{color:#fff;font-size:.8rem;font-weight:600;letter-spacing:.12em;text-transform:uppercase;margin:0 0 16px}
:lang(zh) .ftr h4,:lang(ar) .ftr h4{letter-spacing:.06em}
.ftr ul{list-style:none;margin:0;padding:0;display:grid;gap:10px}
.ftr-bottom{display:flex;flex-wrap:wrap;gap:8px 32px;justify-content:space-between;margin-top:48px;padding-top:22px;border-top:1px solid rgba(255,255,255,.1);font-size:.8rem}
.ftr-bottom p{margin:0}
@media (max-width:860px){.ftr-grid{grid-template-columns:repeat(2,minmax(0,1fr))}.ftr-brand{grid-column:1/-1}}
@media (max-width:480px){.ftr-grid{grid-template-columns:1fr}}