/* Shixia Semiconductor — 石峡半导体
   Palette and type are derived from the name: 石峡, a stone gorge — a narrow pass
   that gathers a river and lets it through, which is what a bandpass filter does
   to the spectrum. Jade for the pass, stone for everything around it. */

:root {
  --ink:        #0E1A16;
  --ink-2:      #16261F;
  --jade-deep:  #123C2E;
  --jade:       #1E8A63;
  --jade-glow:  #4ECB9C;
  --stone:      #E7EAE4;
  --stone-2:    #D6DBD3;
  --paper:      #F7F8F4;
  --mute:       #5C665F;
  --line:       #C9CFC7;

  --disp: 'Space Grotesk', ui-sans-serif, system-ui, sans-serif;
  --body: 'IBM Plex Sans', ui-sans-serif, system-ui, -apple-system, sans-serif;
  --mono: 'IBM Plex Mono', ui-monospace, 'SF Mono', Menlo, monospace;

  --maxw: 1180px;
  --gut: 28px;
}
html[lang="zh"] {
  --body: 'Noto Sans SC', ui-sans-serif, system-ui, sans-serif;
  --disp: 'Noto Sans SC', 'Space Grotesk', sans-serif;
}

* { box-sizing: border-box; margin: 0; padding: 0; }
html { scroll-behavior: smooth; }
body {
  font-family: var(--body); color: var(--ink); background: var(--paper);
  -webkit-font-smoothing: antialiased; line-height: 1.6; font-size: 17px;
}
a { color: inherit; text-decoration: none; }
img, svg { display: block; max-width: 100%; }
.wrap { max-width: var(--maxw); margin: 0 auto; padding: 0 var(--gut); }
.mono { font-family: var(--mono); }
h1, h2, h3, h4 { font-family: var(--disp); font-weight: 600; line-height: 1.08; letter-spacing: -.012em; }
html[lang="zh"] h1, html[lang="zh"] h2, html[lang="zh"] h3 { letter-spacing: 0; }

.eyebrow {
  font-family: var(--mono); font-size: 12px; letter-spacing: .17em;
  text-transform: uppercase; color: var(--jade); font-weight: 500;
}
html[lang="zh"] .eyebrow { letter-spacing: .08em; }

.btn {
  display: inline-flex; align-items: center; gap: .5em;
  font-family: var(--mono); font-size: 13.5px; letter-spacing: .02em;
  padding: 12px 20px; border-radius: 2px; border: 1px solid var(--jade-deep);
  transition: background .18s, color .18s, border-color .18s; cursor: pointer; background: none;
}
html[lang="zh"] .btn { font-family: var(--body); }
.btn-primary { background: var(--jade-deep); color: #EAF4EE; }
.btn-primary:hover { background: var(--jade); border-color: var(--jade); }
.btn-ghost { color: var(--jade-deep); }
.btn-ghost:hover { background: var(--jade-deep); color: #EAF4EE; }
.btn-dark { border-color: #3C5C4E; color: #EAF4EE; }
.btn-dark:hover { background: var(--jade); border-color: var(--jade); }
:focus-visible { outline: 2px solid var(--jade-glow); outline-offset: 3px; }

/* ---------- header ---------- */
.nav {
  position: sticky; top: 0; z-index: 60;
  background: rgba(247,248,244,.88); backdrop-filter: saturate(150%) blur(10px);
  border-bottom: 1px solid var(--line);
}
.nav-in { display: flex; align-items: center; gap: 22px; height: 64px; }
.brand { display: flex; align-items: baseline; gap: 9px; }
.brand .mark {
  font-family: 'Space Grotesk', sans-serif; font-weight: 700; font-size: 21px;
  letter-spacing: .15em; color: var(--ink);
}
.brand .cn { font-family: 'Noto Sans SC', sans-serif; font-size: 14px; color: var(--mute); }
.nav-links { display: flex; gap: 24px; margin-left: auto; }
.nav-links a { font-size: 14.5px; opacity: .82; }
.nav-links a:hover, .nav-links a[aria-current="page"] { opacity: 1; color: var(--jade-deep); }
.nav-right { display: flex; align-items: center; gap: 14px; }
.lang { display: flex; border: 1px solid var(--line); border-radius: 2px; overflow: hidden; }
.lang button {
  font-family: var(--mono); font-size: 12.5px; padding: 6px 10px;
  background: none; border: none; cursor: pointer; color: var(--mute);
}
.lang button.on { background: var(--jade-deep); color: #EAF4EE; }
.menu-btn { display: none; font-family: var(--mono); font-size: 13px; background: none; color: var(--ink); -webkit-appearance: none; appearance: none;
  border: 1px solid var(--line); padding: 7px 11px; border-radius: 2px; cursor: pointer; }

/* ---------- hero: the coverage map ---------- */
.hero { background: var(--ink); color: #E7EDE9; padding: 60px 0 0; overflow: hidden; }
.hero h1 { font-size: clamp(34px, 5vw, 58px); color: #F2F6F3; margin: 16px 0 18px; max-width: 17ch; }
.hero h1 .accent { color: var(--jade-glow); }
.hero .lead { font-size: 18.5px; color: #A9BBB2; max-width: 46ch; margin-bottom: 26px; }
.hero .cta { display: flex; gap: 13px; flex-wrap: wrap; margin-bottom: 42px; }

.spectrum { position: relative; padding-bottom: 26px; }
.spectrum svg { width: 100%; height: auto; }
.spec-cap {
  font-family: var(--mono); font-size: 12px; color: #7E958A; margin-top: 10px;
  display: flex; justify-content: space-between; gap: 16px; flex-wrap: wrap;
}
html[lang="zh"] .spec-cap { font-family: var(--body); }
.band { cursor: pointer; }
.band:hover .band-bar, .band.on .band-bar { fill: var(--jade-glow); }
.band:hover .band-name, .band.on .band-name { fill: #FFFFFF; }

.trust { border-top: 1px solid #24352D; background: var(--ink); }
.trust-in { display: flex; flex-wrap: wrap; gap: 8px 30px; padding: 14px 0;
  font-family: var(--mono); font-size: 12.5px; color: #8AA093; }
.trust b { color: var(--jade-glow); font-weight: 500; }
.trust .sep { color: #3C5C4E; }
html[lang="zh"] .trust-in { font-family: var(--body); }

/* ---------- sections ---------- */
section { padding: 82px 0; }
.sec-head { max-width: 62ch; margin-bottom: 44px; }
.sec-head h2 { font-size: clamp(27px, 3.4vw, 40px); margin: 12px 0 14px; }
.sec-head p { color: var(--mute); font-size: 18px; }

.two { display: grid; grid-template-columns: 1fr 1fr; gap: 24px; }
.card {
  border: 1px solid var(--line); border-radius: 3px; padding: 30px 28px; background: var(--paper);
  transition: border-color .2s, transform .2s, box-shadow .2s; display: flex; flex-direction: column;
}
.card:hover { border-color: var(--jade); transform: translateY(-3px);
  box-shadow: 0 18px 40px -28px rgba(18,60,46,.5); }
.card .k { font-family: var(--mono); font-size: 12px; color: var(--jade);
  letter-spacing: .13em; text-transform: uppercase; }
html[lang="zh"] .card .k { font-family: var(--body); letter-spacing: .04em; }
.card h3 { font-size: 23px; margin: 12px 0 10px; }
.card p { color: var(--mute); font-size: 16px; }

/* product table */
.ptable { width: 100%; border-collapse: collapse; font-size: 15px; }
.ptable thead th {
  font-family: var(--mono); font-size: 11px; letter-spacing: .08em; text-transform: uppercase;
  color: var(--mute); font-weight: 500; text-align: left; padding: 11px 13px;
  border-bottom: 1px solid var(--jade-deep);
}
html[lang="zh"] .ptable thead th { font-family: var(--body); letter-spacing: .03em; }
.ptable td { padding: 14px 13px; border-bottom: 1px solid var(--line); vertical-align: middle; }
.ptable tr:hover td { background: var(--stone); }
.ptable .pn { font-family: var(--mono); font-weight: 500; }
.ptable .pn a:hover { color: var(--jade); }
.ptable .num { font-family: var(--mono); font-size: 13.5px; color: var(--mute); }
.ptable .doc a {
  font-family: var(--mono); font-size: 12.5px; color: var(--jade-deep);
  border: 1px solid var(--jade-deep); border-radius: 2px; padding: 5px 10px; white-space: nowrap;
}
.ptable .doc a:hover { background: var(--jade-deep); color: #EAF4EE; }

/* process */
.steps { display: grid; grid-template-columns: repeat(5, 1fr); border-top: 1px solid var(--line); }
.step { padding: 24px 20px 4px 0; border-right: 1px solid var(--line); }
.step:last-child { border-right: none; padding-right: 0; }
.step .no { font-family: var(--mono); font-size: 12px; color: var(--jade); letter-spacing: .1em; }
.step h4 { font-size: 18px; margin: 10px 0 7px; }
.step p { color: var(--mute); font-size: 14.5px; }

/* dark strip */
.strip { background: var(--ink); color: #DCE6E0; }
.strip h2 { color: #EFF4F1; }
.strip p { color: #A7B9B0; }
.her { display: grid; grid-template-columns: auto 1fr; gap: 48px; align-items: center; }
.her .cn { font-family: 'Noto Sans SC', sans-serif; font-weight: 700;
  font-size: clamp(76px, 11vw, 130px); color: var(--jade-glow); line-height: .92; }
.her .en { font-family: var(--mono); font-size: 12.5px; letter-spacing: .2em;
  color: #7E958A; text-transform: uppercase; margin-top: 8px; }

/* ---------- product page ---------- */
.crumb { font-family: var(--mono); font-size: 12.5px; color: var(--mute); margin-bottom: 22px; }
.crumb a { color: var(--jade-deep); }
.crumb a:hover { text-decoration: underline; }
html[lang="zh"] .crumb { font-family: var(--body); }
.phead h1 { font-size: clamp(32px, 4.6vw, 50px); margin: 6px 0 10px; }
.phead .sub { color: var(--mute); font-size: 18.5px; max-width: 56ch; }
.chips { display: flex; flex-wrap: wrap; gap: 9px; margin: 20px 0 26px; }
.chip { font-family: var(--mono); font-size: 12.5px; color: var(--jade-deep);
  background: var(--stone); border: 1px solid var(--line); border-radius: 2px; padding: 6px 11px; }
.pcta { display: flex; gap: 13px; flex-wrap: wrap; }

.demo { background: var(--ink); border-radius: 4px; padding: 26px 26px 22px; margin: 30px 0 38px; color: #E7EDE9; }
.demo-head { display: flex; justify-content: space-between; align-items: baseline; gap: 10px; flex-wrap: wrap; }
.demo-head h3 { font-size: 20px; color: #F2F6F3; }
.demo-head .hint { font-family: var(--mono); font-size: 12px; color: #8AA093; }
html[lang="zh"] .demo-head .hint { font-family: var(--body); }
.readout { display: flex; gap: 26px; flex-wrap: wrap; font-family: var(--mono);
  font-size: 13px; color: #AFC0B8; margin: 10px 0 6px; }
.readout b { color: var(--jade-glow); font-weight: 500; font-size: 15px; }
html[lang="zh"] .readout { font-family: var(--body); }
.demo svg { width: 100%; height: auto; }
.slider { display: flex; align-items: center; gap: 14px; margin-top: 6px; }
.slider label { font-family: var(--mono); font-size: 12px; color: #8AA093; white-space: nowrap; }
input[type=range] {
  -webkit-appearance: none; appearance: none; height: 3px; background: #2C463C;
  border-radius: 3px; flex: 1; outline: none;
}
input[type=range]::-webkit-slider-thumb {
  -webkit-appearance: none; appearance: none; width: 17px; height: 17px; border-radius: 50%;
  background: var(--jade-glow); cursor: pointer; border: 3px solid #0B1512;
}
input[type=range]::-moz-range-thumb {
  width: 15px; height: 15px; border-radius: 50%; background: var(--jade-glow);
  cursor: pointer; border: 3px solid #0B1512;
}
.demo .note { font-family: var(--mono); font-size: 11.5px; color: #6E8579; margin-top: 12px; }
html[lang="zh"] .demo .note { font-family: var(--body); }

.cols { display: grid; grid-template-columns: 1.12fr .88fr; gap: 42px; align-items: start; }
table.spec { width: 100%; border-collapse: collapse; font-size: 15px; }
table.spec caption { text-align: left; font-family: var(--mono); font-size: 12px;
  letter-spacing: .13em; text-transform: uppercase; color: var(--jade); margin-bottom: 12px; }
html[lang="zh"] table.spec caption { font-family: var(--body); letter-spacing: .04em; }
table.spec th, table.spec td { text-align: left; padding: 10px 12px; border-bottom: 1px solid var(--line); }
table.spec thead th { font-family: var(--mono); font-size: 11px; letter-spacing: .07em;
  text-transform: uppercase; color: var(--mute); font-weight: 500; }
table.spec td.n { font-family: var(--mono); color: var(--jade-deep); }
.applist { list-style: none; }
.applist li { padding: 11px 0 11px 20px; border-bottom: 1px solid var(--line);
  position: relative; color: var(--mute); font-size: 15.5px; }
.applist li::before { content: ""; position: absolute; left: 0; top: 18px;
  width: 7px; height: 7px; background: var(--jade); border-radius: 1px; }
.aptitle { font-family: var(--mono); font-size: 12px; letter-spacing: .13em;
  text-transform: uppercase; color: var(--jade); margin-bottom: 8px; }
html[lang="zh"] .aptitle { font-family: var(--body); letter-spacing: .04em; }

/* ---------- forms ---------- */
.form { display: flex; flex-direction: column; gap: 15px; }
.form .row { display: grid; grid-template-columns: 1fr 1fr; gap: 15px; }
.form label { font-family: var(--mono); font-size: 11px; letter-spacing: .07em;
  text-transform: uppercase; color: var(--mute); display: block; margin-bottom: 5px; }
html[lang="zh"] .form label { font-family: var(--body); letter-spacing: .03em; }
.form input, .form select, .form textarea {
  width: 100%; background: var(--paper); border: 1px solid var(--line); border-radius: 2px;
  padding: 10px 12px; font-family: var(--body); font-size: 15px; color: var(--ink);
}
.form input:focus, .form select:focus, .form textarea:focus { border-color: var(--jade); outline: none; }
.form textarea { resize: vertical; min-height: 96px; }
.fmsg { font-family: var(--mono); font-size: 13px; min-height: 20px; }
.fmsg.ok { color: var(--jade); }
.fmsg.err { color: #9C0006; }

/* ---------- footer ---------- */
.ft { background: var(--ink); color: #8AA093; padding: 40px 0 36px; }
.ft-in { display: flex; flex-wrap: wrap; gap: 18px 40px; justify-content: space-between; align-items: flex-start; }
.ft .fb { display: flex; align-items: baseline; gap: 9px; }
.ft .fb .mark { font-family: 'Space Grotesk', sans-serif; font-weight: 700;
  letter-spacing: .15em; color: #E7EDE9; font-size: 18px; }
.ft .fb .cn { font-family: 'Noto Sans SC', sans-serif; color: #7E958A; }
.ft .tag { font-family: var(--mono); font-size: 12px; margin-top: 10px; max-width: 36ch; line-height: 1.9; }
html[lang="zh"] .ft .tag { font-family: var(--body); }
.ft .legal { font-family: var(--mono); font-size: 12px; line-height: 2; text-align: right; }
.ft .legal .cn { font-family: 'Noto Sans SC', sans-serif; color: #9CB2A6; }
.ft a:hover { color: var(--jade-glow); }

/* ---------- responsive ---------- */
@media (max-width: 900px) {
  .nav-links { display: none; }
  .nav-links.open { display: flex; position: absolute; top: 64px; left: 0; right: 0;
    background: var(--paper); border-bottom: 1px solid var(--line);
    flex-direction: column; gap: 0; padding: 8px var(--gut) 14px; }
  .nav-links.open a { padding: 10px 0; border-bottom: 1px solid var(--line); }
  .menu-btn { display: inline-block; }
  .two, .cols, .form .row { grid-template-columns: 1fr; }
  .steps { grid-template-columns: 1fr 1fr; }
  .step { border-right: none; border-bottom: 1px solid var(--line); padding: 18px 0; }
  .her { grid-template-columns: 1fr; gap: 20px; }
  section { padding: 60px 0; }
  .ft-in { flex-direction: column; }
  .ft .legal { text-align: left; }
  .ptable td:nth-child(4), .ptable th:nth-child(4) { display: none; }
}
@media (prefers-reduced-motion: reduce) {
  html { scroll-behavior: auto; }
  * { animation: none !important; transition: none !important; }
}


/* ---------- brand lockup, Rev C ---------- */
.brand .wm { height: 16px; width: auto; display: block; }
.brand { align-items: center; }
.ft .fb { align-items: center; }
.ft .fb .wm { height: 13px; width: auto; display: block; }
@media (max-width: 560px) { .brand .cn { display: none; } .brand .wm { height: 15px; } }

/* ---------- gated data sheets ---------- */
td.doc a.req { color: var(--jade); }
td.doc a.req::before { content: "\2192\00a0"; }
.dsnote { margin: 14px 0 0; font-size: 13.5px; color: var(--mute); max-width: 78ch; line-height: 1.75; }
.docreq {
  border: 1px solid var(--line); border-left: 3px solid var(--jade);
  background: #EFF4F0; padding: 13px 16px; margin: 0 0 20px; font-size: 14px; line-height: 1.7;
}
.docreq b { font-family: var(--mono); color: var(--jade-deep); }

/* ---------- tuning-state rail: дискретные состояния должны быть видны ---------- */
.vhidden { position: absolute; width: 1px; height: 1px; overflow: hidden;
           clip: rect(0 0 0 0); white-space: nowrap; }
.vrail { position: relative; flex: 1; display: flex; align-items: center;
         justify-content: space-between; min-height: 22px; padding: 4px 0 26px; }
.vline, .vfill { position: absolute; top: 14px; height: 2px; pointer-events: none; }
.vline { left: 11px; right: 11px; background: #2A3F35; }
.vfill { left: 11px; width: 0; background: var(--jade); transition: width .16s ease; }
.vstep {
  position: relative; z-index: 1; width: 22px; height: 22px; padding: 0;
  border-radius: 50%; border: 2px solid #4ECB9C; background: #0E1A16;
  cursor: pointer; transition: transform .12s ease, background .12s ease, box-shadow .12s ease;
}
.vstep::after {
  content: attr(data-v); position: absolute; top: 25px; left: 50%;
  transform: translateX(-50%); font-family: var(--mono); font-size: 11px;
  color: #8AA093; white-space: nowrap;
}
.vstep:hover { transform: scale(1.18); background: #16302690; }
.vstep:focus-visible { outline: 2px solid #EAFBF4; outline-offset: 3px; }
.vstep[aria-checked="true"] {
  background: #EAFBF4; border-color: #EAFBF4;
  box-shadow: 0 0 0 5px rgba(78, 203, 156, .22);
}
.vstep[aria-checked="true"]::after { color: #EAFBF4; font-weight: 600; }
@media (max-width: 560px) {
  .vstep { width: 18px; height: 18px; }
  .vstep::after { font-size: 10px; top: 21px; }
  .vline, .vfill { top: 12px; }
}
@media (max-width: 700px) {
  .slider { flex-wrap: wrap; row-gap: 6px; }
  .vrail { flex: 1 0 100%; padding-left: 2px; padding-right: 2px; }
}

/* ---------- шапка на телефоне ---------- */
/* Английское «Request a sample» вдвое длиннее китайского «索取样品»: в узкой
   шапке оно переносилось, раздувало строку и сминало переключатель языка. */
.nav-in > * { flex-shrink: 0; }
.lang button, .menu-btn, .nav-right .btn, .brand .cn { white-space: nowrap; }
.lang button { min-width: 44px; text-align: center; }
.menu-cta { display: none; }   /* копия кнопки живёт только в мобильном меню */

@media (max-width: 700px) {
  .nav-in { gap: 12px; }
  .nav-right { margin-left: auto; gap: 10px; }
  .nav-right .btn { display: none; }          /* кнопка переезжает в меню */
  .nav-links.open .menu-cta {
    display: block; order: -1; text-align: center;
    background: var(--jade-deep); color: #EAF4EE;
    padding: 13px 0; margin: 4px 0 10px; border-radius: 2px;
    font-family: var(--mono); font-size: 14px; border-bottom: none;
  }
  .nav-links.open .menu-cta:hover { color: #EAF4EE; }
}
@media (max-width: 380px) {
  .brand .wm { height: 14px; }
  .lang button { padding: 6px 8px; min-width: 40px; }
}

/* ---------- состояние отправки и подтверждение ---------- */
/* Отправка через SMTP занимает пару секунд. Раньше единственным откликом было
   многоточие под кнопками — далеко от того места, куда смотрит человек. */
.btn.loading { opacity: .9; cursor: progress; }
.btn.loading::before {
  content: ""; width: 13px; height: 13px; flex: 0 0 13px; border-radius: 50%;
  border: 2px solid currentColor; border-top-color: transparent;
  animation: spin .7s linear infinite;
}
@keyframes spin { to { transform: rotate(360deg); } }

.fdone {
  display: flex; gap: 16px; align-items: flex-start;
  border: 1px solid var(--line); border-left: 3px solid var(--jade);
  background: #EFF4F0; padding: 22px 24px; margin: 0 0 8px;
  animation: fdone-in .28s ease both;
}
@keyframes fdone-in { from { opacity: 0; transform: translateY(6px); } }
.fdone-i {
  flex: 0 0 26px; width: 26px; height: 26px; border-radius: 50%;
  background: var(--jade); position: relative; margin-top: 2px;
}
.fdone-i::after {
  content: ""; position: absolute; left: 9px; top: 5px; width: 6px; height: 12px;
  border: solid #fff; border-width: 0 2px 2px 0; transform: rotate(45deg);
  animation: tick .3s .18s ease both;
}
@keyframes tick { from { opacity: 0; transform: rotate(45deg) scale(.4); } }
.fdone h3 { margin: 0 0 6px; font-size: 17px; }
.fdone p { margin: 0 0 14px; font-size: 14.5px; line-height: 1.65; color: var(--mute); max-width: 52ch; }
.fdone-a {
  font-family: var(--mono); font-size: 13px; background: none; cursor: pointer;
  border: 1px solid var(--line); padding: 9px 14px; border-radius: 2px; color: var(--ink);
  -webkit-appearance: none; appearance: none;
}
.fdone-a:hover { border-color: var(--jade); color: var(--jade-deep); }
@media (prefers-reduced-motion: reduce) {
  .btn.loading::before, .fdone, .fdone-i::after { animation: none; }
}

/* Авторское display у .form перебивало браузерное [hidden] — форма не пряталась
   после отправки, данные оставались, и заявку можно было отправить повторно. */
[hidden] { display: none !important; }