:root {
  --ink: #14202a;
  --muted: #64717d;
  --line: #d6dde3;
  --paper: #f3f5f6;
  --white: #ffffff;
  --steel: #425c70;
  --deep: #17232d;
  --blue: #1f6f94;
  --orange: #c65b32;
  --green: #217065;
  --shadow: 0 18px 44px rgba(20, 32, 42, .14);
}

* {
  box-sizing: border-box;
}

html {
  scroll-behavior: smooth;
}

body {
  margin: 0;
  color: var(--ink);
  font-family: "Microsoft YaHei", "PingFang SC", Arial, sans-serif;
  line-height: 1.72;
  background: var(--paper);
}

a {
  color: inherit;
}

button,
input {
  font: inherit;
}

.hero {
  min-height: 80vh;
  color: #fff;
  background:
    linear-gradient(90deg, rgba(14, 24, 32, .94), rgba(14, 24, 32, .73) 48%, rgba(14, 24, 32, .22)),
    url("data:image/svg+xml,%3Csvg xmlns='http://www.w3.org/2000/svg' width='1600' height='900' viewBox='0 0 1600 900'%3E%3Crect width='1600' height='900' fill='%238d9aa2'/%3E%3Cpath d='M0 690h1600v210H0z' fill='%23303a42'/%3E%3Cpath d='M165 600h1220v68H165z' fill='%23222d35'/%3E%3Cpath d='M280 430h560v180H280z' fill='%23566975'/%3E%3Cpath d='M340 360h320v95H340z' fill='%232d3a43'/%3E%3Cpath d='M710 330h95v280h-95z' fill='%233d4d56'/%3E%3Cpath d='M850 470h380v125H850z' fill='%23c65b32'/%3E%3Cpath d='M930 390h260v96H930z' fill='%232a343c'/%3E%3Cpath d='M1000 280h90v112h-90z' fill='%23425c70'/%3E%3Cpath d='M965 245h160v48H965z' fill='%23d6dde3'/%3E%3Ccircle cx='450' cy='662' r='64' fill='%23171d22'/%3E%3Ccircle cx='450' cy='662' r='28' fill='%2388949b'/%3E%3Ccircle cx='1120' cy='662' r='64' fill='%23171d22'/%3E%3Ccircle cx='1120' cy='662' r='28' fill='%2388949b'/%3E%3Cpath d='M1040 512h130l58 52h-188z' fill='%23dce9ee' opacity='.82'/%3E%3Cpath d='M1270 330h70v285h-70z' fill='%232c3840'/%3E%3Cpath d='M1240 290h130v50h-130z' fill='%23546671'/%3E%3Cpath d='M885 442h120v30H885z' fill='%23d6dde3'/%3E%3Ccircle cx='964' cy='458' r='16' fill='%23131a1f'/%3E%3Cpath d='M120 220h520v8H120zm800 506h560v10H920z' fill='%23fff' opacity='.28'/%3E%3C/svg%3E");
  background-size: cover;
  background-position: center;
}

.nav {
  width: min(1120px, calc(100% - 40px));
  margin: 0 auto;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 20px;
  padding: 24px 0;
}

.brand {
  display: inline-flex;
  align-items: center;
  gap: 10px;
  text-decoration: none;
  font-weight: 800;
  font-size: 22px;
}

.brand-mark {
  width: 34px;
  height: 34px;
  border: 2px solid rgba(255, 255, 255, .86);
  border-radius: 8px;
  position: relative;
}

.brand-mark::before,
.brand-mark::after {
  content: "";
  position: absolute;
  background: var(--orange);
}

.brand-mark::before {
  width: 18px;
  height: 3px;
  left: 6px;
  top: 10px;
}

.brand-mark::after {
  width: 3px;
  height: 16px;
  left: 15px;
  top: 8px;
}

.nav-links {
  display: flex;
  flex-wrap: wrap;
  justify-content: flex-end;
  gap: 17px;
  font-size: 14px;
}

.nav-links a {
  color: rgba(255, 255, 255, .82);
  text-decoration: none;
}

.nav-links a:hover,
.nav-links a.active {
  color: #fff;
}

.hero-inner {
  width: min(1120px, calc(100% - 40px));
  margin: 0 auto;
  padding: 72px 0 96px;
}

.eyebrow {
  margin: 0 0 12px;
  color: #d7ebf1;
  font-weight: 700;
}

h1 {
  max-width: 760px;
  margin: 0;
  color: #fff;
  font-size: 76px;
  line-height: 1.04;
  letter-spacing: 0;
}

.hero p {
  max-width: 760px;
  margin: 24px 0 0;
  color: rgba(255, 255, 255, .9);
  font-size: 20px;
}

.hero-actions {
  display: flex;
  flex-wrap: wrap;
  gap: 14px;
  margin-top: 34px;
}

.button {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  min-height: 46px;
  padding: 11px 18px;
  border: 1px solid rgba(255, 255, 255, .35);
  border-radius: 6px;
  color: #fff;
  text-decoration: none;
  font-weight: 700;
  background: rgba(255, 255, 255, .1);
}

.button.primary {
  border-color: var(--orange);
  background: var(--orange);
}

main {
  width: min(1120px, calc(100% - 40px));
  margin: 0 auto;
  padding: 42px 0 72px;
}

section {
  padding: 42px 0;
  border-top: 1px solid var(--line);
}

.intro-grid,
.split,
.section-head {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 32px;
  align-items: start;
}

.section-head {
  align-items: end;
  margin-bottom: 20px;
}

h2 {
  margin: 0 0 16px;
  font-size: 34px;
  line-height: 1.24;
  letter-spacing: 0;
}

h3 {
  margin: 0 0 8px;
  font-size: 20px;
  letter-spacing: 0;
}

p {
  margin: 0 0 14px;
}

.lead {
  font-size: 24px;
  line-height: 1.58;
}

.muted {
  color: var(--muted);
}

.fact-grid {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 12px;
}

.fact,
.machine-card,
.calculator,
.accordion-body {
  border: 1px solid var(--line);
  border-radius: 8px;
  background: var(--white);
}

.fact {
  min-height: 126px;
  padding: 18px;
}

.fact span {
  display: block;
  color: var(--muted);
  font-size: 13px;
}

.fact strong {
  display: block;
  margin-top: 7px;
  font-size: 19px;
  line-height: 1.35;
}

.filter-group {
  display: flex;
  flex-wrap: wrap;
  justify-content: flex-end;
  gap: 8px;
}

.filter {
  min-height: 38px;
  padding: 8px 13px;
  border: 1px solid var(--line);
  border-radius: 6px;
  color: var(--ink);
  background: var(--white);
  cursor: pointer;
}

.filter.active {
  color: #fff;
  border-color: var(--blue);
  background: var(--blue);
}

.machine-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 16px;
}

.machine-card {
  overflow: hidden;
  transition: transform .18s ease, box-shadow .18s ease;
}

.machine-card:hover {
  transform: translateY(-2px);
  box-shadow: var(--shadow);
}

.machine-card.hidden {
  display: none;
}

.machine-visual {
  height: 150px;
  background:
    linear-gradient(180deg, rgba(255, 255, 255, .16), rgba(255, 255, 255, 0)),
    linear-gradient(135deg, #3e596b, #1d2a34);
  position: relative;
  overflow: hidden;
}

.machine-visual::before,
.machine-visual::after {
  content: "";
  position: absolute;
  border-radius: 4px;
}

.machine-visual::before {
  left: 24px;
  right: 24px;
  bottom: 28px;
  height: 26px;
  background: #d9e1e6;
}

.machine-visual::after {
  width: 92px;
  height: 58px;
  left: 58px;
  bottom: 54px;
  background: var(--orange);
  box-shadow: 112px 10px 0 #687b86;
}

.machine-visual.mill::after {
  width: 54px;
  height: 94px;
  left: 118px;
  bottom: 48px;
  background: #607988;
  box-shadow: -60px 54px 0 var(--orange);
}

.machine-visual.center::after {
  width: 145px;
  height: 88px;
  left: 70px;
  bottom: 45px;
  background: #607988;
  box-shadow: 110px 18px 0 var(--orange);
}

.machine-visual.grinder::after {
  width: 70px;
  height: 70px;
  left: 70px;
  bottom: 48px;
  border-radius: 50%;
  background: #d9e1e6;
  box-shadow: 120px 28px 0 var(--orange);
}

.machine-visual.gantry::after {
  width: 220px;
  height: 74px;
  left: 48px;
  bottom: 58px;
  background: transparent;
  border: 18px solid #d9e1e6;
  border-bottom: 0;
  box-shadow: 92px 52px 0 var(--orange);
}

.machine-visual.boring::after {
  width: 72px;
  height: 72px;
  left: 88px;
  bottom: 55px;
  background: #d9e1e6;
  box-shadow: 86px 24px 0 var(--orange), 160px 48px 0 #607988;
}

.machine-body {
  padding: 18px;
}

.tag {
  display: inline-flex;
  margin-bottom: 8px;
  padding: 3px 8px;
  border-radius: 999px;
  color: #fff;
  font-size: 12px;
  background: var(--green);
}

.empty {
  display: none;
  margin-top: 16px;
  padding: 20px;
  border: 1px solid var(--line);
  border-radius: 8px;
  color: var(--muted);
  text-align: center;
  background: var(--white);
}

.machine-scene {
  min-height: 430px;
  border-radius: 8px;
  box-shadow: var(--shadow);
  background:
    linear-gradient(135deg, rgba(23, 35, 45, .08), rgba(198, 91, 50, .12)),
    url("data:image/svg+xml,%3Csvg xmlns='http://www.w3.org/2000/svg' width='900' height='1050' viewBox='0 0 900 1050'%3E%3Crect width='900' height='1050' fill='%23d8dee2'/%3E%3Cpath d='M80 760h740v98H80z' fill='%2323323d'/%3E%3Cpath d='M140 330h460v330H140z' fill='%235f747f'/%3E%3Cpath d='M195 245h300v110H195z' fill='%232a3741'/%3E%3Cpath d='M555 210h90v450h-90z' fill='%23374751'/%3E%3Cpath d='M635 455h140v120H635z' fill='%23c65b32'/%3E%3Cpath d='M675 320h75v146h-75z' fill='%23425c70'/%3E%3Cpath d='M650 286h126v45H650z' fill='%23eff4f7'/%3E%3Ccircle cx='245' cy='742' r='62' fill='%23151c22'/%3E%3Ccircle cx='245' cy='742' r='26' fill='%2388949b'/%3E%3Ccircle cx='640' cy='742' r='62' fill='%23151c22'/%3E%3Ccircle cx='640' cy='742' r='26' fill='%2388949b'/%3E%3Cpath d='M250 612h280v34H250z' fill='%23eff4f7'/%3E%3Ccircle cx='470' cy='630' r='20' fill='%23141b20'/%3E%3Cpath d='M122 875h650v16H122z' fill='%23c65b32'/%3E%3Cpath d='M90 135h720v10H90zM100 922h700v8H100z' fill='%23fff' opacity='.5'/%3E%3C/svg%3E");
  background-size: cover;
  background-position: center;
}

.feature-list {
  display: grid;
  gap: 16px;
}

.feature {
  padding: 18px 0;
  border-bottom: 1px solid var(--line);
}

.feature:last-child {
  border-bottom: 0;
}

.table-wrap {
  margin-top: 20px;
  overflow-x: auto;
  border: 1px solid var(--line);
  border-radius: 8px;
  background: var(--white);
}

table {
  width: 100%;
  min-width: 760px;
  border-collapse: collapse;
}

th,
td {
  padding: 14px 16px;
  border-bottom: 1px solid var(--line);
  text-align: left;
  vertical-align: top;
}

th {
  color: #fff;
  background: var(--deep);
}

tr:last-child td {
  border-bottom: 0;
}

.calculator {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 14px;
  padding: 20px;
}

.calculator label {
  display: grid;
  gap: 8px;
}

.calculator span {
  color: var(--muted);
  font-size: 13px;
}

.calculator input {
  width: 100%;
  min-height: 44px;
  padding: 10px 12px;
  border: 1px solid var(--line);
  border-radius: 6px;
}

.result {
  display: grid;
  align-content: center;
  min-height: 86px;
  padding: 14px;
  border-radius: 8px;
  color: #fff;
  background: linear-gradient(135deg, var(--blue), var(--green));
}

.result strong {
  display: block;
  margin-top: 4px;
  font-size: 24px;
}

.accordion {
  display: grid;
  gap: 10px;
}

.accordion-head {
  width: 100%;
  min-height: 48px;
  padding: 12px 16px;
  border: 1px solid var(--line);
  border-radius: 8px;
  color: var(--ink);
  text-align: left;
  font-weight: 800;
  background: var(--white);
  cursor: pointer;
}

.accordion-head.active {
  color: #fff;
  border-color: var(--steel);
  background: var(--steel);
}

.accordion-body {
  display: none;
  padding: 16px;
}

.accordion-body.open {
  display: block;
}

.top-button {
  position: fixed;
  right: 18px;
  bottom: 18px;
  z-index: 10;
  width: 46px;
  height: 46px;
  border: 0;
  border-radius: 6px;
  color: #fff;
  font-size: 20px;
  font-weight: 800;
  background: var(--deep);
  cursor: pointer;
  opacity: 0;
  pointer-events: none;
  transition: opacity .18s ease;
}

.top-button.visible {
  opacity: 1;
  pointer-events: auto;
}

footer {
  padding: 26px 20px 38px;
  color: var(--muted);
  text-align: center;
  font-size: 14px;
}

@media (max-width: 920px) {
  h1 {
    font-size: 56px;
  }

  .intro-grid,
  .split,
  .section-head,
  .calculator {
    grid-template-columns: 1fr;
  }

  .machine-grid {
    grid-template-columns: 1fr 1fr;
  }

  .filter-group {
    justify-content: flex-start;
  }
}

@media (max-width: 620px) {
  .nav,
  .hero-inner,
  main {
    width: min(100% - 28px, 1120px);
  }

  .nav {
    align-items: flex-start;
    flex-direction: column;
  }

  .nav-links {
    justify-content: flex-start;
    gap: 12px 16px;
  }

  h1 {
    font-size: 42px;
  }

  h2 {
    font-size: 28px;
  }

  .hero-inner {
    padding: 52px 0 72px;
  }

  .hero p,
  .lead {
    font-size: 18px;
  }

  .fact-grid,
  .machine-grid {
    grid-template-columns: 1fr;
  }

  .button {
    width: 100%;
  }
}