/* ============================================================
   comcomAI · 云管端平台 — base
   ============================================================ */

:root {
  --green-900: #073A27;
  --green-800: #0B4F35;
  --green-700: #106847;
  --green-600: #1C8158;
  --green-500: #3F9D7A;
  --green-400: #71BB9D;
  --green-300: #A6D5C0;
  --green-100: #D3EADF;
  --green-50: #ECF6F1;

  --orange: #F08200;
  --orange-deep: #CC6C00;

  --n0: #FFFFFF;
  --n1: #FBFCFB;
  --n2: #F6F8F7;
  --n3: #EDF1EF;
  --n4: #DEE5E1;
  --n5: #C6D0CB;
  --n6: #A3AFAA;
  --n7: #898989;
  --n8: #666F6B;
  --n9: #4A514D;
  --n10: #2F3531;
  --n11: #171A18;
  --n12: #0B0D0C;

  --ink-line: rgba(236, 246, 241, 0.14);
  --ink-line-soft: rgba(236, 246, 241, 0.08);
  --light-line: rgba(47, 53, 49, 0.13);

  --wrap: 1280px;
  --gutter: clamp(20px, 4vw, 56px);
  --ease: cubic-bezier(0.22, 0.61, 0.36, 1);

  --f-sans: "Noto Sans SC", "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei", sans-serif;
  --f-disp: "Barlow Condensed", "Noto Sans SC", sans-serif;
  --f-mono: "IBM Plex Mono", "SFMono-Regular", Consolas, "Noto Sans SC", monospace;
}

*,
*::before,
*::after {
  box-sizing: border-box;
}

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

body {
  margin: 0;
  background: var(--n1);
  color: var(--n10);
  font-family: var(--f-sans);
  font-size: 16px;
  line-height: 1.75;
  font-weight: 400;
  -webkit-font-smoothing: antialiased;
  overflow-x: hidden;
  text-wrap: pretty;
}

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

h1, h2, h3, h4, p, ul, ol, figure {
  margin: 0;
}

ul, ol {
  padding: 0;
  list-style: none;
}

a {
  color: inherit;
  text-decoration: none;
}

button {
  font: inherit;
  color: inherit;
  border: 0;
  background: none;
  cursor: pointer;
}

::selection {
  background: var(--green-700);
  color: var(--green-50);
}

.wrap {
  width: 100%;
  max-width: calc(var(--wrap) + var(--gutter) * 2);
  margin: 0 auto;
  padding-inline: var(--gutter);
}

.skip {
  position: fixed;
  top: 10px;
  left: 10px;
  z-index: 200;
  padding: 10px 16px;
  background: var(--green-50);
  color: var(--green-900);
  font-size: 13px;
  transform: translateY(-160%);
  transition: transform 0.2s var(--ease);
}

.skip:focus {
  transform: none;
}

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

/* ---------- typography ---------- */

.eyebrow {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 8px 10px;
  font-family: var(--f-mono);
  font-size: 11px;
  line-height: 1;
  letter-spacing: 0.16em;
  text-transform: uppercase;
  color: var(--green-600);
  margin-bottom: 26px;
}

.eyebrow__dash {
  width: 26px;
  height: 1px;
  background: var(--orange);
  flex: none;
}

.eyebrow__cn {
  font-family: var(--f-sans);
  font-size: 11px;
  letter-spacing: 0.06em;
  color: var(--n8);
  padding-left: 10px;
  border-left: 1px solid var(--light-line);
}

.eyebrow--dark {
  color: var(--green-300);
}

.eyebrow--dark .eyebrow__cn {
  color: rgba(236, 246, 241, 0.52);
  border-left-color: var(--ink-line);
}

.sec-title {
  font-size: clamp(38px, 4.6vw, 66px);
  line-height: 1.14;
  font-weight: 800;
  letter-spacing: -0.025em;
  color: var(--n11);
  text-wrap: balance;
}

.sec-title--wide {
  max-width: 14ch;
}

.section--ink .sec-title,
.section--deep .sec-title {
  color: var(--green-50);
}

.section {
  position: relative;
  padding-block: clamp(88px, 9vw, 148px);
  scroll-margin-top: 84px;
}

.section--light {
  background: var(--n1);
}

.section--soft {
  background: var(--n2);
}

.section--ink {
  background: var(--n11);
  color: var(--green-50);
}

.section--deep {
  background: var(--green-900);
  color: var(--green-50);
}

/* subtle top hairline between sections */
.section--light::before {
  content: "";
  position: absolute;
  inset: 0 var(--gutter) auto;
  height: 1px;
  background: var(--light-line);
  opacity: 0.65;
}

/* ---------- section head ---------- */

.sec-head {
  display: grid;
  grid-template-columns: minmax(0, 1.35fr) minmax(280px, 0.65fr);
  gap: clamp(32px, 6vw, 96px);
  align-items: end;
  margin-bottom: clamp(52px, 6vw, 86px);
}

.sec-head__aside {
  padding-bottom: 8px;
}

.sec-head__aside p {
  font-size: 15px;
  line-height: 1.9;
  color: var(--n8);
  max-width: 42ch;
}

.sec-head--dark .sec-head__aside p {
  color: rgba(236, 246, 241, 0.66);
}

/* ---------- buttons ---------- */

.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 12px;
  height: 52px;
  padding-inline: 26px;
  border-radius: 2px;
  font-size: 15px;
  font-weight: 500;
  letter-spacing: 0.02em;
  line-height: 1;
  transition: background 0.28s var(--ease), color 0.28s var(--ease),
    border-color 0.28s var(--ease), transform 0.28s var(--ease);
}

.btn svg {
  width: 15px;
  height: 15px;
  fill: none;
  stroke: currentColor;
  stroke-width: 1.4;
  transition: transform 0.28s var(--ease);
}

.btn:hover svg {
  transform: translateX(3px);
}

.btn--solid {
  background: var(--green-50);
  color: var(--green-900);
}

.btn--solid:hover {
  background: var(--n0);
}

.btn--ghost {
  color: var(--green-50);
  border: 1px solid rgba(236, 246, 241, 0.3);
}

.btn--ghost:hover {
  border-color: var(--green-300);
  background: rgba(236, 246, 241, 0.06);
}

/* ---------- nav ---------- */

.nav {
  position: fixed;
  inset: 0 0 auto;
  z-index: 90;
  height: 68px;
  background: rgba(7, 58, 39, 0.72);
  border-bottom: 1px solid rgba(236, 246, 241, 0.1);
  backdrop-filter: blur(14px) saturate(1.25);
  -webkit-backdrop-filter: blur(14px) saturate(1.25);
  transition: background 0.3s var(--ease), border-color 0.3s var(--ease);
}

.nav.is-scrolled {
  background: rgba(7, 58, 39, 0.94);
}

.nav__inner {
  height: 68px;
  display: flex;
  align-items: center;
  gap: 18px;
}

.brand {
  display: inline-flex;
  align-items: center;
  gap: 10px;
  flex: none;
}

.brand__mark {
  width: 22px;
  height: 22px;
  fill: none;
  stroke: var(--green-300);
  stroke-width: 1.2;
}

.brand__mark rect {
  fill: rgba(166, 213, 192, 0.16);
  stroke: var(--green-300);
}

.brand__word {
  font-family: var(--f-disp);
  font-size: 23px;
  font-weight: 600;
  letter-spacing: 0.01em;
  color: var(--green-50);
  line-height: 1;
}

.brand__word span {
  color: var(--green-300);
  font-weight: 400;
}

.nav__divider {
  width: 1px;
  height: 18px;
  background: rgba(236, 246, 241, 0.22);
  flex: none;
}

.nav__product {
  font-size: 12px;
  letter-spacing: 0.04em;
  color: rgba(236, 246, 241, 0.62);
  white-space: nowrap;
}

.nav__links {
  display: flex;
  align-items: center;
  gap: clamp(14px, 2vw, 30px);
  margin-left: auto;
}

.nav__links a {
  position: relative;
  font-size: 13px;
  letter-spacing: 0.03em;
  color: rgba(236, 246, 241, 0.72);
  padding-block: 6px;
  transition: color 0.2s var(--ease);
}

.nav__links a::after {
  content: "";
  position: absolute;
  left: 0;
  bottom: 0;
  width: 100%;
  height: 1px;
  background: var(--green-300);
  transform: scaleX(0);
  transform-origin: left;
  transition: transform 0.28s var(--ease);
}

.nav__links a:hover,
.nav__links a.is-current {
  color: var(--green-50);
}

.nav__links a:hover::after,
.nav__links a.is-current::after {
  transform: scaleX(1);
}

.nav__cta {
  display: inline-flex;
  align-items: center;
  gap: 9px;
  height: 36px;
  padding-inline: 16px;
  margin-left: 10px;
  border: 1px solid rgba(236, 246, 241, 0.26);
  border-radius: 2px;
  font-size: 12.5px;
  letter-spacing: 0.06em;
  color: var(--green-50);
  flex: none;
  transition: border-color 0.24s var(--ease), background 0.24s var(--ease);
}

.nav__cta:hover {
  border-color: var(--green-300);
  background: rgba(236, 246, 241, 0.08);
}

.nav__dot {
  width: 5px;
  height: 5px;
  border-radius: 50%;
  background: var(--orange);
  box-shadow: 0 0 0 3px rgba(240, 130, 0, 0.18);
}

/* ---------- chain rail ---------- */

.rail {
  position: fixed;
  right: 26px;
  top: 50%;
  transform: translateY(-50%);
  z-index: 40;
  height: 190px;
  width: 22px;
  display: none;
}

.rail__track {
  position: absolute;
  left: 50%;
  top: 0;
  bottom: 0;
  width: 1px;
  background: rgba(166, 213, 192, 0.4);
  transform: translateX(-50%);
}

.rail__fill {
  position: absolute;
  inset: 0 0 auto;
  height: 100%;
  background: var(--green-600);
  transform: scaleY(0);
  transform-origin: top;
  transition: transform 0.12s linear;
}

.rail__mark {
  position: absolute;
  left: 50%;
  transform: translate(-50%, -50%);
  display: grid;
  place-items: center;
  width: 21px;
  height: 21px;
  border-radius: 50%;
  font-family: var(--f-sans);
  font-size: 9px;
  line-height: 1;
  color: var(--green-300);
  background: var(--green-900);
  border: 1px solid rgba(166, 213, 192, 0.36);
  transition: color 0.3s var(--ease), background 0.3s var(--ease), border-color 0.3s var(--ease);
}

.rail__mark--cloud { top: 0; }
.rail__mark--pipe { top: 50%; }
.rail__mark--device { top: 100%; }

.rail__mark.is-on {
  color: var(--n11);
  background: var(--orange);
  border-color: var(--orange);
}

/* ---------- reveal ---------- */

.js .reveal {
  opacity: 0;
  transform: translateY(22px);
  transition: opacity 0.8s var(--ease), transform 0.8s var(--ease);
}

.js .reveal.is-in {
  opacity: 1;
  transform: none;
}

@media (min-width: 1280px) {
  .rail {
    display: block;
  }
}

@media (max-width: 900px) {
  .nav__product,
  .nav__divider {
    display: none;
  }
  .nav__links {
    display: none;
  }
  .nav__cta {
    margin-left: auto;
  }
  .sec-head {
    grid-template-columns: 1fr;
    align-items: start;
    gap: 24px;
  }
  .sec-head__aside {
    padding-bottom: 0;
  }
}

@media (prefers-reduced-motion: reduce) {
  html {
    scroll-behavior: auto;
  }
  *,
  *::before,
  *::after {
    animation-duration: 0.001ms !important;
    animation-iteration-count: 1 !important;
    transition-duration: 0.001ms !important;
  }
  .js .reveal {
    opacity: 1;
    transform: none;
  }
}