/* 上海众燊物联网科技有限公司 — 站点样式
   视觉基调：石墨底 + 蓝图网格 + 火光橙（取自“燊”字的火势） */

:root {
  --ink: #12181f;
  --ink-soft: #3c4854;
  --ink-mute: #6b7987;
  --line: #dfe5ea;
  --line-soft: #eef2f5;
  --paper: #ffffff;
  --wash: #f5f7f9;
  --graphite: #151d25;
  --graphite-2: #1d2731;
  --ember: #e85d26;
  --ember-deep: #c3471a;
  --ember-wash: #fdf0e9;
  --steel: #2f6f8f;
  --radius: 4px;
  --radius-lg: 8px;
  --shadow-sm: 0 1px 2px rgba(18, 24, 31, 0.06), 0 8px 24px -12px rgba(18, 24, 31, 0.18);
  --shadow-lg: 0 2px 4px rgba(18, 24, 31, 0.06), 0 24px 60px -28px rgba(18, 24, 31, 0.35);
  --sans: "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei UI", "Microsoft YaHei",
    system-ui, -apple-system, "Segoe UI", Roboto, "Helvetica Neue", Arial, sans-serif;
  --mono: ui-monospace, SFMono-Regular, "Roboto Mono", "Cascadia Mono", Consolas, monospace;
  --pad: clamp(1rem, 1rem + 2.2vw, 3rem);
  --maxw: 1160px;
}

* { box-sizing: border-box; }

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

body {
  margin: 0;
  font-family: var(--sans);
  font-size: 16.5px;
  line-height: 1.75;
  color: var(--ink);
  background: var(--paper);
  word-break: break-word;
}

h1, h2, h3, h4 { line-height: 1.25; margin: 0 0 0.6em; font-weight: 700; letter-spacing: -0.01em; }
h1 { font-size: clamp(1.9rem, 1.2rem + 3.4vw, 3.1rem); }
h2 { font-size: clamp(1.45rem, 1.1rem + 1.8vw, 2.15rem); }
h3 { font-size: 1.2rem; }
p { margin: 0 0 1em; }
p:last-child { margin-bottom: 0; }

a { color: var(--ember-deep); text-decoration: none; }
a:hover { color: var(--ember); }

ul, ol { margin: 0 0 1em; padding-left: 1.2em; }
li { margin: 0.32em 0; }

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

:focus-visible { outline: 2px solid var(--ember); outline-offset: 3px; border-radius: 2px; }

.skip-link {
  position: absolute; left: -9999px; top: 0; z-index: 100;
  background: var(--graphite); color: #fff; padding: 0.7rem 1.1rem;
}
.skip-link:focus { left: 0.6rem; top: 0.6rem; }

.container { max-width: var(--maxw); margin-inline: auto; padding-inline: var(--pad); }
.band { padding-block: clamp(3rem, 6vw, 5.5rem); }
.band--wash { background: var(--wash); border-block: 1px solid var(--line); }
.band--dark {
  background-color: var(--graphite);
  color: #e9eef3;
  background-image:
    linear-gradient(rgba(255, 255, 255, 0.045) 1px, transparent 1px),
    linear-gradient(90deg, rgba(255, 255, 255, 0.045) 1px, transparent 1px);
  background-size: 56px 56px, 56px 56px;
}
.band--dark h1, .band--dark h2, .band--dark h3 { color: #fff; }
.band--dark a { color: #ffd0b8; }

.eyebrow {
  font-family: var(--mono);
  font-size: 0.8rem;
  letter-spacing: 0.22em;
  text-transform: uppercase;
  color: var(--ember);
  margin: 0 0 0.9rem;
  display: flex;
  align-items: center;
  gap: 0.6rem;
}
.eyebrow::before {
  content: "";
  width: 28px; height: 2px; background: var(--ember); display: inline-block;
}
.band--dark .eyebrow { color: #ff8a52; }

.lede { font-size: clamp(1.02rem, 1rem + 0.35vw, 1.2rem); color: var(--ink-soft); max-width: 62ch; }
.band--dark .lede { color: #b9c6d2; }

.section-head { display: flex; align-items: flex-end; justify-content: space-between; gap: 2rem; margin-bottom: 2.2rem; flex-wrap: wrap; }
.section-head h2 { margin: 0 0 0.35rem; }

/* ---------- 页头 ---------- */
.site-header {
  position: sticky; top: 0; z-index: 50;
  background: rgba(255, 255, 255, 0.94);
  backdrop-filter: blur(10px);
  border-bottom: 1px solid var(--line);
}
.site-header .bar { display: flex; align-items: center; gap: 1.5rem; min-height: 72px; }

.brand { display: flex; align-items: center; gap: 0.7rem; color: var(--ink); }
.brand:hover { color: var(--ink); }
.brand__mark {
  width: 38px; height: 38px; flex: none;
  background: var(--graphite); color: #fff;
  display: grid; place-items: center;
  font-size: 20px; font-weight: 700; letter-spacing: 0;
  border-radius: var(--radius);
  box-shadow: inset 0 -3px 0 var(--ember);
}
.brand__name { font-weight: 700; font-size: 1.02rem; line-height: 1.25; }
.brand__sub { font-size: 0.72rem; color: var(--ink-mute); font-family: var(--mono); letter-spacing: 0.12em; }

.nav { margin-left: auto; }
.nav ul { display: flex; list-style: none; gap: 0.35rem; margin: 0; padding: 0; flex-wrap: wrap; }
.nav a {
  display: block; padding: 0.5rem 0.8rem; border-radius: var(--radius);
  color: var(--ink-soft); font-size: 0.95rem; white-space: nowrap;
}
.nav a:hover { background: var(--wash); color: var(--ink); }
.nav a[aria-current="page"] { color: var(--ember-deep); font-weight: 700; background: var(--ember-wash); }

.nav__item { position: relative; }
.nav__item > .nav__parent::after { content: " ▾"; color: var(--ink-mute); font-size: 0.7em; }
.nav .nav__sub {
  position: absolute; left: 0; top: calc(100% + 6px); min-width: 280px;
  background: var(--paper); border: 1px solid var(--line); border-radius: var(--radius-lg);
  box-shadow: var(--shadow-lg); padding: 0.5rem; display: none; flex-direction: column; gap: 0; z-index: 60;
}
.nav__item:hover .nav__sub, .nav__item:focus-within .nav__sub { display: flex; }
.nav .nav__sub li { margin: 0; }
.nav__sub a { padding: 0.55rem 0.7rem; border-radius: var(--radius); font-size: 0.92rem; }
.nav__sub a:hover { background: var(--ember-wash); color: var(--ember-deep); }
.nav__sub small { display: block; color: var(--ink-mute); font-size: 0.78rem; font-weight: 400; }


.nav-toggle {
  display: none; margin-left: auto;
  background: var(--paper); border: 1px solid var(--line); border-radius: var(--radius);
  font: inherit; font-size: 0.9rem; padding: 0.45rem 0.8rem; cursor: pointer; color: var(--ink);
}

.header-cta { flex: none; }

/* ---------- 按钮 ---------- */
.btn {
  display: inline-flex; align-items: center; justify-content: center; gap: 0.5rem;
  padding: 0.72rem 1.35rem; border-radius: var(--radius);
  font: inherit; font-size: 0.98rem; font-weight: 600; line-height: 1.2;
  border: 1px solid transparent; cursor: pointer; text-align: center;
}
.btn--ember { background: var(--ember); color: #fff; }
.btn--ember:hover { background: var(--ember-deep); color: #fff; }
.btn--dark { background: var(--graphite); color: #fff; }
.btn--dark:hover { background: var(--graphite-2); color: #fff; }
.btn--ghost { border-color: var(--line); color: var(--ink); background: var(--paper); }
.btn--ghost:hover { border-color: var(--ink-mute); color: var(--ink); background: var(--wash); }
.btn--outline-light { border-color: rgba(255, 255, 255, 0.35); color: #fff; background: transparent; }
.btn--outline-light:hover { border-color: #fff; color: #fff; background: rgba(255, 255, 255, 0.08); }
.btn--sm { padding: 0.45rem 0.9rem; font-size: 0.88rem; }
.btn[aria-disabled="true"] {
  background: var(--wash); color: var(--ink-mute); border: 1px dashed var(--line);
  cursor: progress;
}
.btn[aria-disabled="true"]:hover { background: var(--wash); color: var(--ink-mute); border-color: var(--line); }

/* ---------- 网格与卡片 ---------- */
.grid { display: grid; gap: 1.5rem; }
.grid--2 { grid-template-columns: repeat(2, minmax(0, 1fr)); }
.grid--3 { grid-template-columns: repeat(3, minmax(0, 1fr)); }
.grid--4 { grid-template-columns: repeat(4, minmax(0, 1fr)); }

.card {
  background: var(--paper); border: 1px solid var(--line); border-radius: var(--radius-lg);
  padding: 1.6rem; box-shadow: var(--shadow-sm);
  display: flex; flex-direction: column;
}
.card h3 { margin-bottom: 0.4rem; }
.card--link { transition: transform 0.18s ease, box-shadow 0.18s ease, border-color 0.18s ease; }
.card--link:hover { transform: translateY(-3px); box-shadow: var(--shadow-lg); border-color: #c9d4dd; }

.product-card__index {
  font-family: var(--mono); font-size: 0.8rem; letter-spacing: 0.16em;
  color: var(--ember); margin-bottom: 0.9rem;
}
.product-card__tag { color: var(--ink-mute); font-size: 0.9rem; margin: -0.2rem 0 1rem; }
.feature-list { list-style: none; padding: 0; margin: 0 0 1.3rem; }
.feature-list li { position: relative; padding-left: 1.35rem; margin: 0.5rem 0; color: var(--ink-soft); font-size: 0.95rem; }
.feature-list li::before {
  content: ""; position: absolute; left: 0; top: 0.62em;
  width: 8px; height: 8px; border: 2px solid var(--ember); border-radius: 1px;
}
.feature-list--check li::before {
  content: "✓"; border: 0; width: auto; height: auto; top: 0; color: var(--ember-deep); font-weight: 700;
}

.chip {
  display: inline-block; padding: 0.22rem 0.7rem; border-radius: 999px;
  font-size: 0.8rem; background: var(--wash); color: var(--ink-soft);
  border: 1px solid var(--line); margin: 0 0.35rem 0.4rem 0;
}
.chip--ember { background: var(--ember-wash); border-color: #f6cdb8; color: var(--ember-deep); }

/* ---------- 截图占位 ---------- */
.shot {
  aspect-ratio: 16 / 10; width: 100%; margin: 0;
  background-color: var(--wash);
  background-image:
    linear-gradient(45deg, rgba(18, 24, 31, 0.028) 25%, transparent 25%, transparent 75%, rgba(18, 24, 31, 0.028) 75%),
    linear-gradient(45deg, rgba(18, 24, 31, 0.028) 25%, transparent 25%, transparent 75%, rgba(18, 24, 31, 0.028) 75%);
  background-size: 22px 22px; background-position: 0 0, 11px 11px;
  border: 1px dashed #b9c5cf; border-radius: var(--radius-lg);
  display: grid; place-content: center; gap: 0.35rem; text-align: center;
  padding: 1rem;
}
.shot__label { font-weight: 700; color: var(--ink-soft); font-size: 0.95rem; }
.shot__hint { font-family: var(--mono); font-size: 0.75rem; letter-spacing: 0.08em; color: var(--ink-mute); }
.shot--frame { background-color: #fff; border-style: solid; border-color: var(--line); box-shadow: var(--shadow-sm); place-content: start stretch; }
.shot__chrome { display: flex; align-items: center; gap: 0.4rem; padding: 0.6rem 0.8rem; border-bottom: 1px solid var(--line); }
.shot__dot { width: 9px; height: 9px; border-radius: 50%; background: var(--line); }
.shot__title { font-family: var(--mono); font-size: 0.72rem; color: var(--ink-mute); margin-left: 0.4rem; }
.shot__body { flex: 1; display: grid; place-content: center; gap: 0.3rem; text-align: center; padding: 1rem; }

/* ---------- 真实截图 ---------- */
.shot--auto { aspect-ratio: auto; gap: 0; }
.shot__body--media { place-content: stretch; padding: 0; }
.shot__body--media img { display: block; width: 100%; height: auto; }
.shots { display: grid; grid-template-columns: repeat(2, minmax(0, 1fr)); gap: 1.8rem; justify-items: center; }
.phone { width: 100%; max-width: 300px; margin: 0; }
.phone img {
  display: block; width: 100%; height: auto;
  border: 1px solid var(--line); border-radius: 22px; box-shadow: var(--shadow-sm);
}
.phone figcaption { margin-top: .7rem; font-size: .88rem; color: var(--ink-soft); text-align: center; }
@media (max-width: 620px) { .shots { grid-template-columns: 1fr; } }

/* ---------- 功能模块轮播 ---------- */
.carousel__track {
  display: flex; gap: 1.4rem; overflow-x: auto;
  scroll-snap-type: x mandatory; scroll-behavior: smooth;
  scrollbar-width: none; padding-bottom: .4rem;
}
.carousel__track::-webkit-scrollbar { display: none; }
.slide { flex: 0 0 100%; scroll-snap-align: start; margin: 0; }
.slide img {
  display: block; width: 100%; height: auto;
  border: 1px solid var(--line); border-radius: var(--radius-lg); box-shadow: var(--shadow-sm);
}
.slide figcaption { padding-top: 1.1rem; }
.slide figcaption h3 { margin: .1rem 0 .5rem; }
.slide figcaption p:last-child { margin-bottom: 0; color: var(--ink-soft); }
.carousel__bar { display: flex; align-items: center; gap: .9rem; margin-top: 1.2rem; }
.carousel__dots { display: flex; gap: .45rem; margin-inline: auto; }
.carousel__dots button {
  width: 10px; height: 10px; padding: 0; border-radius: 50%; cursor: pointer;
  border: 1px solid var(--line); background: #fff;
}
.carousel__dots button[aria-selected="true"] { background: var(--ember); border-color: var(--ember); }
.carousel__nav {
  width: 2.2rem; height: 2.2rem; border-radius: 50%; cursor: pointer;
  border: 1px solid var(--line); background: #fff; color: var(--ink);
  font-size: 1rem; line-height: 1; display: grid; place-content: center;
}
.carousel__nav:hover:not([disabled]) { border-color: var(--ember); color: var(--ember-deep); }
.carousel__nav[disabled] { opacity: .4; cursor: default; }

/* ---------- 产品页 ---------- */
.crumbs { font-size: 0.85rem; color: var(--ink-mute); padding-block: 1rem 0; }
.crumbs ol { list-style: none; display: flex; flex-wrap: wrap; gap: 0.4rem; margin: 0; padding: 0; }
.crumbs li:not(:last-child)::after { content: "/"; margin-left: 0.45rem; color: #b7c1ca; }
.crumbs a { color: var(--ink-mute); }
.band--dark .crumbs { color: #8b9aa8; }
.band--dark .crumbs a { color: #b9c6d2; }
.band--dark .crumbs li:not(:last-child)::after { color: #55636f; }

.hero-split { display: grid; grid-template-columns: 1.05fr 0.95fr; gap: clamp(2rem, 5vw, 4rem); align-items: center; }
.hero-split .shot { border-color: rgba(255, 255, 255, 0.22); background-color: rgba(255, 255, 255, 0.04); }
.hero-split .shot__label { color: #d7e0e8; }
.hero-split .shot__hint { color: #8b9aa8; }

.spec-row { display: flex; flex-wrap: wrap; gap: 1rem 2.4rem; margin-top: 2rem; padding-top: 1.5rem; border-top: 1px solid rgba(255, 255, 255, 0.14); }
.spec { min-width: 130px; }
.spec__k { font-family: var(--mono); font-size: 0.72rem; letter-spacing: 0.14em; color: #8b9aa8; text-transform: uppercase; }
.spec__v { color: #fff; font-weight: 600; }

.module {
  border: 1px solid var(--line); border-radius: var(--radius-lg); padding: 1.5rem; background: var(--paper);
}
.module__no { font-family: var(--mono); color: var(--ember-deep); font-size: 0.8rem; letter-spacing: 0.14em; }
.module h3 { margin-top: 0.35rem; }
.module p { font-size: 0.95rem; color: var(--ink-soft); }

.steps { list-style: none; padding: 0; margin: 0; display: grid; gap: 1rem; }
.steps:first-child { counter-reset: step; }
.steps li { counter-increment: step; position: relative; padding-left: 3.2rem; }
.steps li::before {
  content: counter(step, decimal-leading-zero);
  position: absolute; left: 0; top: 0.1rem;
  font-family: var(--mono); font-size: 0.9rem; font-weight: 700; color: var(--ember-deep);
  width: 2.3rem; height: 2.3rem; display: grid; place-items: center;
  border: 1px solid var(--line); border-radius: 50%; background: var(--paper);
}
.steps strong { display: block; color: var(--ink); }
.steps span { color: var(--ink-soft); font-size: 0.93rem; }

.faq { border-top: 1px solid var(--line); }
.faq details { border-bottom: 1px solid var(--line); padding: 1.1rem 0; }
.faq summary { cursor: pointer; font-weight: 600; list-style: none; position: relative; padding-right: 2.5rem; }
.faq summary::-webkit-details-marker { display: none; }
.faq summary::after { content: "+"; position: absolute; right: 0.2rem; top: -0.1rem; color: var(--ember); font-size: 1.5rem; line-height: 1.4; }
.faq details[open] summary::after { content: "−"; }
.faq p { margin: 0.8rem 0 0; color: var(--ink-soft); font-size: 0.96rem; }

/* ---------- 表格 ---------- */
.table-wrap { overflow-x: auto; border: 1px solid var(--line); border-radius: var(--radius-lg); }
table { width: 100%; border-collapse: collapse; font-size: 0.94rem; min-width: 640px; background: var(--paper); }
caption { text-align: left; padding: 1.1rem 1.2rem 0.4rem; font-weight: 700; }
th, td { text-align: left; padding: 0.9rem 1.2rem; border-bottom: 1px solid var(--line-soft); vertical-align: top; }
thead th { background: var(--wash); font-size: 0.82rem; letter-spacing: 0.06em; text-transform: uppercase; color: var(--ink-mute); font-weight: 600; }
tbody tr:last-child td { border-bottom: 0; }
.pending { font-family: var(--mono); color: var(--ink-mute); font-size: 0.85rem; }

/* ---------- 页脚 ---------- */
.site-footer { background: var(--graphite); color: #aebbc7; padding-block: 3.2rem 2rem; background-image: linear-gradient(rgba(255,255,255,0.035) 1px, transparent 1px); background-size: 100% 56px; }
.site-footer h3 { color: #fff; font-size: 0.95rem; margin-bottom: 0.9rem; letter-spacing: 0.02em; }
.site-footer a { color: #aebbc7; font-size: 0.92rem; }
.site-footer a:hover { color: #ffb190; }
.footer-grid { display: grid; grid-template-columns: 1.5fr repeat(3, 1fr); gap: 2.5rem; }
.footer-list { list-style: none; padding: 0; margin: 0; }
.footer-list li { margin: 0.45rem 0; }
.footer-brand { display: flex; gap: 0.8rem; align-items: flex-start; margin-bottom: 1rem; }
.footer-brand .brand__mark { box-shadow: inset 0 -3px 0 var(--ember); }
.footer-brand__name { color: #fff; font-weight: 700; }
.footer-note { font-size: 0.88rem; max-width: 34ch; }
.footer-bottom {
  margin-top: 2.6rem; padding-top: 1.4rem; border-top: 1px solid rgba(255, 255, 255, 0.12);
  display: flex; flex-wrap: wrap; gap: 0.6rem 2rem; justify-content: space-between; font-size: 0.84rem; color: #7e8b98;
}
.footer-bottom .mono { font-family: var(--mono); }

.cta-strip { display: flex; flex-wrap: wrap; align-items: center; justify-content: space-between; gap: 1.4rem; }
.cta-strip h2 { margin: 0; }

/* ---------- 响应式 ---------- */
@media (max-width: 1000px) {
  .grid--4 { grid-template-columns: repeat(2, minmax(0, 1fr)); }
  .grid--3 { grid-template-columns: repeat(2, minmax(0, 1fr)); }
  .footer-grid { grid-template-columns: 1fr 1fr; gap: 2rem; }
  .hero-split { grid-template-columns: 1fr; }
}

@media (max-width: 760px) {
  body { font-size: 16px; }
  .nav-toggle { display: inline-flex; }
  .nav {
    display: none; width: 100%; margin: 0; padding-bottom: 1rem; order: 3;
  }
  .nav[data-open="true"] { display: block; }
  .nav ul { flex-direction: column; gap: 0.1rem; }
  .nav a { padding: 0.7rem 0.2rem; border-bottom: 1px solid var(--line-soft); }
  .nav .nav__sub {
    position: static; display: block; min-width: 0; border: 0; border-left: 2px solid var(--line);
    box-shadow: none; border-radius: 0; padding: 0 0 0.4rem 0.8rem; margin-left: 0.4rem; background: transparent;
  }
  .site-header .bar { flex-wrap: wrap; min-height: 0; padding-block: 0.9rem 0; gap: 0.8rem; }
  .header-cta { display: none; }
  .grid--2, .grid--3, .grid--4 { grid-template-columns: 1fr; }
  .footer-grid { grid-template-columns: 1fr; }
  .spec-row { gap: 1rem 1.6rem; }
}

@media (prefers-reduced-motion: reduce) {
  html { scroll-behavior: auto; }
  * { transition: none !important; }
}

@media print {
  .site-header, .site-footer, .btn { display: none !important; }
}