/* ==========================================================
   自然之力 ziranzhili.com — 站点主样式
   ========================================================== */

:root {
  --navy: #0b2b45;
  --navy-2: #123f6b;
  --navy-3: #1a5a92;
  --teal: #12a594;
  --teal-light: #4fd1c5;
  --gold: #f5a623;
  --ink: #1c2b36;
  --gray: #5b6b78;
  --gray-light: #8a99a5;
  --bg: #ffffff;
  --bg-soft: #f4f8fa;
  --border: #e3ecf1;
  --radius: 14px;
  --shadow-sm: 0 2px 10px rgba(11, 43, 69, .06);
  --shadow: 0 10px 34px rgba(11, 43, 69, .10);
  --shadow-lg: 0 22px 60px rgba(11, 43, 69, .16);
  --maxw: 1200px;
  --nav-h: 72px;
}

* { margin: 0; padding: 0; box-sizing: border-box; }

html { scroll-behavior: smooth; }

body {
  font-family: "PingFang SC", "Microsoft YaHei", "Hiragino Sans GB",
               "Source Han Sans CN", "Noto Sans CJK SC", system-ui, sans-serif;
  color: var(--ink);
  background: var(--bg);
  line-height: 1.75;
  -webkit-font-smoothing: antialiased;
  overflow-x: hidden;
}

img { max-width: 100%; display: block; }
a { color: inherit; text-decoration: none; }
ul { list-style: none; }

.wrap { width: 100%; max-width: var(--maxw); margin: 0 auto; padding: 0 24px; }

/* ---------- 通用组件 ---------- */
.section { padding: 96px 0; }
.section--soft { background: var(--bg-soft); }

.sec-head { text-align: center; max-width: 760px; margin: 0 auto 56px; }
.sec-tag {
  display: inline-block;
  font-size: 13px;
  letter-spacing: .18em;
  color: var(--teal);
  font-weight: 700;
  margin-bottom: 14px;
  text-transform: uppercase;
}
.sec-title {
  font-size: 34px;
  font-weight: 800;
  color: var(--navy);
  letter-spacing: -.01em;
  line-height: 1.35;
}
.sec-desc { margin-top: 16px; color: var(--gray); font-size: 16px; }
.sec-title::after {
  content: "";
  display: block;
  width: 56px;
  height: 4px;
  border-radius: 4px;
  background: linear-gradient(90deg, var(--teal), var(--gold));
  margin: 20px auto 0;
}

.btn {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  padding: 13px 30px;
  border-radius: 999px;
  font-size: 15px;
  font-weight: 600;
  cursor: pointer;
  border: 1.5px solid transparent;
  transition: all .25s ease;
}
.btn--primary { background: var(--teal); color: #fff; box-shadow: 0 8px 22px rgba(18,165,148,.28); }
.btn--primary:hover { background: #0e8d80; transform: translateY(-2px); box-shadow: 0 12px 28px rgba(18,165,148,.36); }
.btn--ghost { border-color: rgba(255,255,255,.45); color: #fff; }
.btn--ghost:hover { background: rgba(255,255,255,.12); border-color: #fff; }
.btn--outline { border-color: var(--navy); color: var(--navy); }
.btn--outline:hover { background: var(--navy); color: #fff; }

/* ---------- 顶部导航 ---------- */
.nav {
  position: fixed;
  top: 0; left: 0; right: 0;
  height: var(--nav-h);
  z-index: 100;
  display: flex;
  align-items: center;
  transition: background .3s, box-shadow .3s, backdrop-filter .3s;
}
.nav.scrolled {
  background: rgba(255,255,255,.94);
  backdrop-filter: blur(12px);
  box-shadow: 0 2px 20px rgba(11,43,69,.08);
}
.nav__inner { display: flex; align-items: center; justify-content: space-between; width: 100%; max-width: var(--maxw); margin: 0 auto; padding: 0 24px; }

.logo { display: flex; align-items: center; gap: 11px; }
.logo__mark {
  width: 38px; height: 38px;
  border-radius: 10px;
  background: linear-gradient(135deg, var(--teal), var(--navy-3));
  display: grid; place-items: center;
  flex-shrink: 0;
}
.logo__mark svg { width: 22px; height: 22px; }
.logo__text { display: flex; flex-direction: column; line-height: 1.15; }
.logo__cn { font-size: 18px; font-weight: 800; letter-spacing: .04em; color: #fff; transition: color .3s; }
.logo__en { font-size: 10px; letter-spacing: .22em; color: rgba(255,255,255,.6); text-transform: uppercase; transition: color .3s; }
.nav.scrolled .logo__cn { color: var(--navy); }
.nav.scrolled .logo__en { color: var(--gray-light); }

.nav__menu { display: flex; gap: 34px; align-items: center; }
.nav__menu a {
  font-size: 15px;
  font-weight: 500;
  color: rgba(255,255,255,.88);
  position: relative;
  padding: 6px 0;
  transition: color .25s;
}
.nav__menu a::after {
  content: "";
  position: absolute; left: 0; bottom: 0;
  width: 0; height: 2px;
  background: var(--teal-light);
  transition: width .28s ease;
}
.nav__menu a:hover::after { width: 100%; }
.nav.scrolled .nav__menu a { color: var(--ink); }
.nav.scrolled .nav__menu a:hover { color: var(--teal); }

.nav__cta {
  padding: 9px 22px;
  border-radius: 999px;
  background: var(--gold);
  color: #22303c !important;
  font-weight: 700;
  font-size: 14px;
  transition: transform .25s, box-shadow .25s;
}
.nav__cta:hover { transform: translateY(-2px); box-shadow: 0 8px 20px rgba(245,166,35,.4); }

.burger { display: none; flex-direction: column; gap: 5px; cursor: pointer; background: none; border: 0; padding: 8px; }
.burger span { width: 24px; height: 2px; background: #fff; border-radius: 2px; transition: all .3s; }
.nav.scrolled .burger span { background: var(--navy); }

/* ---------- 首屏 ---------- */
.hero {
  position: relative;
  min-height: 100vh;
  display: flex;
  align-items: center;
  background: linear-gradient(135deg, #072033 0%, #0b2b45 45%, #14456e 100%);
  overflow: hidden;
  padding-top: var(--nav-h);
}
.hero__bg { position: absolute; inset: 0; opacity: .5; }
.hero__bg::before {
  content: "";
  position: absolute; inset: 0;
  background-image:
    linear-gradient(rgba(255,255,255,.045) 1px, transparent 1px),
    linear-gradient(90deg, rgba(255,255,255,.045) 1px, transparent 1px);
  background-size: 56px 56px;
  mask-image: radial-gradient(ellipse 90% 70% at 50% 40%, #000 20%, transparent 78%);
  -webkit-mask-image: radial-gradient(ellipse 90% 70% at 50% 40%, #000 20%, transparent 78%);
}
.hero__glow {
  position: absolute;
  border-radius: 50%;
  filter: blur(90px);
  opacity: .5;
}
.hero__glow--1 { width: 520px; height: 520px; background: #12a594; top: -140px; right: -80px; }
.hero__glow--2 { width: 420px; height: 420px; background: #1a5a92; bottom: -160px; left: -60px; }

.hero__inner { position: relative; z-index: 2; display: grid; grid-template-columns: 1.15fr .85fr; gap: 60px; align-items: center; width: 100%; }
.hero__badge {
  display: inline-flex; align-items: center; gap: 9px;
  padding: 7px 16px 7px 8px;
  border-radius: 999px;
  background: rgba(255,255,255,.09);
  border: 1px solid rgba(255,255,255,.16);
  color: #cfe8e4;
  font-size: 13px;
  margin-bottom: 26px;
}
.hero__badge i {
  width: 7px; height: 7px; border-radius: 50%;
  background: var(--teal-light);
  box-shadow: 0 0 0 4px rgba(79,209,197,.22);
  animation: pulse 2.2s infinite;
}
@keyframes pulse {
  0%,100% { box-shadow: 0 0 0 4px rgba(79,209,197,.22); }
  50% { box-shadow: 0 0 0 9px rgba(79,209,197,0); }
}
.hero h1 {
  font-size: 54px;
  line-height: 1.24;
  font-weight: 800;
  color: #fff;
  letter-spacing: -.015em;
}
.hero h1 em {
  font-style: normal;
  background: linear-gradient(100deg, var(--teal-light), var(--gold));
  -webkit-background-clip: text;
  background-clip: text;
  color: transparent;
}
.hero__lead {
  margin-top: 22px;
  font-size: 17px;
  color: rgba(255,255,255,.74);
  max-width: 520px;
  line-height: 1.9;
}
.hero__actions { margin-top: 38px; display: flex; gap: 14px; flex-wrap: wrap; }

.hero__stats {
  margin-top: 56px;
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 20px;
  max-width: 560px;
  padding-top: 30px;
  border-top: 1px solid rgba(255,255,255,.13);
}
.stat__num {
  font-size: 34px;
  font-weight: 800;
  color: #fff;
  line-height: 1.1;
  font-variant-numeric: tabular-nums;
}
.stat__num small { font-size: 15px; font-weight: 600; margin-left: 3px; color: var(--teal-light); }
.stat__label { font-size: 13px; color: rgba(255,255,255,.6); margin-top: 4px; }

/* 首屏右侧：工艺卡片 */
.hero__card {
  background: rgba(255,255,255,.07);
  border: 1px solid rgba(255,255,255,.15);
  border-radius: 20px;
  padding: 28px;
  backdrop-filter: blur(14px);
  box-shadow: var(--shadow-lg);
}
.hero__card h3 { color: #fff; font-size: 16px; font-weight: 700; margin-bottom: 20px; display: flex; align-items: center; gap: 9px; }
.hero__card h3::before { content: ""; width: 3px; height: 16px; background: var(--teal-light); border-radius: 2px; }
.flow { display: flex; flex-direction: column; gap: 11px; }
.flow__item {
  display: flex; align-items: center; gap: 13px;
  padding: 13px 15px;
  border-radius: 11px;
  background: rgba(255,255,255,.055);
  border: 1px solid rgba(255,255,255,.09);
  transition: all .3s ease;
}
.flow__item:hover { background: rgba(79,209,197,.14); border-color: rgba(79,209,197,.4); transform: translateX(4px); }
.flow__ico {
  width: 34px; height: 34px; border-radius: 9px;
  background: rgba(79,209,197,.16);
  display: grid; place-items: center; flex-shrink: 0;
}
.flow__ico svg { width: 17px; height: 17px; stroke: var(--teal-light); fill: none; stroke-width: 1.9; }
.flow__txt { color: rgba(255,255,255,.9); font-size: 14px; font-weight: 500; }
.flow__txt span { display: block; font-size: 11.5px; color: rgba(255,255,255,.48); font-weight: 400; margin-top: 1px; }
.flow__arrow { text-align: center; color: rgba(255,255,255,.28); font-size: 13px; line-height: 1; }

/* ---------- 业务板块 ---------- */
.grid-3 { display: grid; grid-template-columns: repeat(3, 1fr); gap: 26px; }

.svc {
  background: #fff;
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 34px 30px;
  position: relative;
  overflow: hidden;
  transition: all .35s cubic-bezier(.4,0,.2,1);
}
.svc::before {
  content: "";
  position: absolute;
  top: 0; left: 0; right: 0;
  height: 3px;
  background: linear-gradient(90deg, var(--teal), var(--navy-3));
  transform: scaleX(0);
  transform-origin: left;
  transition: transform .4s ease;
}
.svc:hover { transform: translateY(-8px); box-shadow: var(--shadow); border-color: transparent; }
.svc:hover::before { transform: scaleX(1); }
.svc__ico {
  width: 54px; height: 54px;
  border-radius: 13px;
  display: grid; place-items: center;
  background: linear-gradient(135deg, rgba(18,165,148,.13), rgba(26,90,146,.13));
  margin-bottom: 20px;
}
.svc__ico svg { width: 26px; height: 26px; stroke: var(--navy-2); fill: none; stroke-width: 1.7; stroke-linecap: round; stroke-linejoin: round; }
.svc h3 { font-size: 19px; font-weight: 700; color: var(--navy); margin-bottom: 10px; }
.svc p { color: var(--gray); font-size: 14.5px; line-height: 1.85; }
.svc__tags { margin-top: 18px; display: flex; flex-wrap: wrap; gap: 7px; }
.svc__tags span {
  font-size: 12px;
  padding: 4px 11px;
  border-radius: 999px;
  background: var(--bg-soft);
  color: var(--gray);
  border: 1px solid var(--border);
}

/* ---------- 技术优势 ---------- */
.tech { display: grid; grid-template-columns: 1fr 1fr; gap: 56px; align-items: center; }
.tech__list { display: flex; flex-direction: column; gap: 22px; }
.tech__item { display: flex; gap: 16px; }
.tech__no {
  font-size: 13px; font-weight: 800;
  color: var(--teal);
  background: rgba(18,165,148,.1);
  width: 34px; height: 34px;
  border-radius: 9px;
  display: grid; place-items: center;
  flex-shrink: 0;
}
.tech__item h4 { font-size: 17px; font-weight: 700; color: var(--navy); margin-bottom: 5px; }
.tech__item p { font-size: 14.5px; color: var(--gray); line-height: 1.8; }

.tech__visual {
  position: relative;
  border-radius: 20px;
  overflow: hidden;
  background: linear-gradient(145deg, var(--navy-2), var(--navy));
  padding: 38px;
  min-height: 380px;
  display: flex;
  flex-direction: column;
  justify-content: space-between;
  box-shadow: var(--shadow-lg);
}
.tech__visual::after {
  content: "";
  position: absolute;
  width: 280px; height: 280px;
  border-radius: 50%;
  background: radial-gradient(circle, rgba(79,209,197,.3), transparent 70%);
  right: -90px; bottom: -90px;
}
.kpi-grid { display: grid; grid-template-columns: 1fr 1fr; gap: 18px; position: relative; z-index: 2; }
.kpi {
  background: rgba(255,255,255,.08);
  border: 1px solid rgba(255,255,255,.14);
  border-radius: 13px;
  padding: 20px;
}
.kpi b { display: block; font-size: 27px; color: #fff; font-weight: 800; line-height: 1.2; }
.kpi b small { font-size: 13px; font-weight: 600; color: var(--teal-light); margin-left: 2px; }
.kpi span { font-size: 12.5px; color: rgba(255,255,255,.62); }
.tech__visual > p { position: relative; z-index: 2; color: rgba(255,255,255,.55); font-size: 13px; margin-top: 22px; }

/* ---------- 项目案例 ---------- */
.cases { display: grid; grid-template-columns: repeat(3, 1fr); gap: 26px; }
.case {
  border-radius: var(--radius);
  overflow: hidden;
  background: #fff;
  border: 1px solid var(--border);
  transition: all .35s ease;
}
.case:hover { transform: translateY(-6px); box-shadow: var(--shadow); border-color: transparent; }
.case__thumb { height: 178px; position: relative; display: grid; place-items: center; overflow: hidden; }
.case__thumb::after {
  content: "";
  position: absolute; inset: 0;
  background-image:
    linear-gradient(rgba(255,255,255,.09) 1px, transparent 1px),
    linear-gradient(90deg, rgba(255,255,255,.09) 1px, transparent 1px);
  background-size: 26px 26px;
}
.case__thumb svg { width: 54px; height: 54px; stroke: rgba(255,255,255,.85); fill: none; stroke-width: 1.5; position: relative; z-index: 2; }
.case__scale {
  position: absolute; top: 14px; right: 14px; z-index: 3;
  background: rgba(255,255,255,.94);
  color: var(--navy);
  font-size: 12px; font-weight: 700;
  padding: 5px 12px; border-radius: 999px;
}
.case__body { padding: 24px 24px 26px; }
.case__body h3 { font-size: 17.5px; font-weight: 700; color: var(--navy); margin-bottom: 8px; }
.case__body p { font-size: 14px; color: var(--gray); line-height: 1.8; }
.case__meta { margin-top: 16px; padding-top: 14px; border-top: 1px dashed var(--border); display: flex; justify-content: space-between; font-size: 12.5px; color: var(--gray-light); }
.case__meta b { color: var(--teal); font-weight: 700; }

/* ---------- 关于 ---------- */
.about { display: grid; grid-template-columns: 1fr 1fr; gap: 60px; align-items: center; }
.about__text h2 { font-size: 32px; font-weight: 800; color: var(--navy); line-height: 1.4; margin-bottom: 20px; }
.about__text p { color: var(--gray); font-size: 15.5px; line-height: 2; margin-bottom: 16px; }
.about__points { margin-top: 26px; display: flex; flex-direction: column; gap: 13px; }
.about__points li { display: flex; align-items: flex-start; gap: 11px; font-size: 15px; color: var(--ink); }
.about__points svg { width: 19px; height: 19px; flex-shrink: 0; margin-top: 4px; stroke: var(--teal); fill: none; stroke-width: 2.2; }

.about__visual { position: relative; }
.about__img {
  border-radius: 20px;
  background: linear-gradient(150deg, #0b2b45, #1a5a92 55%, #12a594);
  min-height: 400px;
  position: relative;
  overflow: hidden;
  box-shadow: var(--shadow-lg);
}
.about__img::after {
  content: "";
  position: absolute; inset: 0;
  background-image: radial-gradient(circle at 30% 25%, rgba(255,255,255,.16), transparent 45%);
}
.about__badge {
  position: absolute;
  bottom: -22px; left: -22px;
  background: #fff;
  border-radius: 14px;
  padding: 20px 26px;
  box-shadow: var(--shadow);
  z-index: 3;
}
.about__badge b { display: block; font-size: 30px; color: var(--navy); font-weight: 800; line-height: 1.15; }
.about__badge span { font-size: 13px; color: var(--gray); }

/* ---------- 联系 ---------- */
.contact { background: linear-gradient(160deg, #072033, #0b2b45 60%, #103c60); position: relative; }
.contact .sec-title { color: #fff; }
.contact .sec-desc { color: rgba(255,255,255,.68); }
.contact__grid { display: grid; grid-template-columns: 1fr 1fr; gap: 40px; }
.contact__info { display: flex; flex-direction: column; gap: 20px; }
.cinfo { display: flex; gap: 16px; align-items: flex-start; }
.cinfo__ico {
  width: 46px; height: 46px; border-radius: 12px;
  background: rgba(79,209,197,.14);
  border: 1px solid rgba(79,209,197,.25);
  display: grid; place-items: center; flex-shrink: 0;
}
.cinfo__ico svg { width: 21px; height: 21px; stroke: var(--teal-light); fill: none; stroke-width: 1.8; }
.cinfo__t { font-size: 12.5px; color: rgba(255,255,255,.5); letter-spacing: .06em; }
.cinfo__v { font-size: 16px; color: #fff; font-weight: 600; margin-top: 2px; }

.form {
  background: rgba(255,255,255,.06);
  border: 1px solid rgba(255,255,255,.14);
  border-radius: 18px;
  padding: 30px;
  backdrop-filter: blur(10px);
}
.form__row { display: grid; grid-template-columns: 1fr 1fr; gap: 14px; }
.form input, .form textarea {
  width: 100%;
  background: rgba(255,255,255,.07);
  border: 1px solid rgba(255,255,255,.16);
  border-radius: 10px;
  padding: 12px 14px;
  color: #fff;
  font-size: 14.5px;
  font-family: inherit;
  margin-bottom: 14px;
  transition: border-color .25s, background .25s;
}
.form input::placeholder, .form textarea::placeholder { color: rgba(255,255,255,.4); }
.form input:focus, .form textarea:focus {
  outline: none;
  border-color: var(--teal-light);
  background: rgba(255,255,255,.1);
}
.form textarea { resize: vertical; min-height: 96px; }
.form button { width: 100%; justify-content: center; border: 0; font-size: 15px; }
.form__note { font-size: 12px; color: rgba(255,255,255,.45); margin-top: 10px; text-align: center; }

/* ---------- 页脚 ---------- */
.footer { background: #061a2b; color: rgba(255,255,255,.55); padding: 56px 0 26px; font-size: 14px; }
.footer__grid { display: grid; grid-template-columns: 1.4fr 1fr 1fr 1.2fr; gap: 40px; padding-bottom: 36px; border-bottom: 1px solid rgba(255,255,255,.09); }
.footer h4 { color: #fff; font-size: 15px; font-weight: 700; margin-bottom: 16px; }
.footer p { line-height: 1.9; }
.footer ul li { margin-bottom: 9px; }
.footer ul a { transition: color .25s; }
.footer ul a:hover { color: var(--teal-light); }
.footer .logo__cn { color: #fff; }
.footer .logo__en { color: rgba(255,255,255,.45); }
.footer__bottom { padding-top: 22px; display: flex; justify-content: space-between; flex-wrap: wrap; gap: 10px; font-size: 13px; color: rgba(255,255,255,.4); }

/* ---------- 回到顶部 ---------- */
.totop {
  position: fixed; right: 26px; bottom: 26px;
  width: 46px; height: 46px; border-radius: 50%;
  background: var(--teal); color: #fff;
  display: grid; place-items: center;
  box-shadow: 0 8px 22px rgba(18,165,148,.34);
  cursor: pointer; border: 0;
  opacity: 0; pointer-events: none;
  transform: translateY(12px);
  transition: all .3s ease;
  z-index: 90;
}
.totop.show { opacity: 1; pointer-events: auto; transform: translateY(0); }
.totop:hover { background: #0e8d80; transform: translateY(-3px); }
.totop svg { width: 20px; height: 20px; stroke: #fff; fill: none; stroke-width: 2.2; }

/* ---------- 滚动入场动画 ---------- */
.reveal { opacity: 0; transform: translateY(26px); transition: opacity .7s ease, transform .7s ease; }
.reveal.in { opacity: 1; transform: none; }

/* ---------- 响应式 ---------- */
@media (max-width: 1000px) {
  .hero__inner { grid-template-columns: 1fr; gap: 44px; }
  .hero__card { max-width: 520px; }
  .grid-3, .cases { grid-template-columns: 1fr 1fr; }
  .tech, .about, .contact__grid { grid-template-columns: 1fr; gap: 40px; }
  .footer__grid { grid-template-columns: 1fr 1fr; gap: 32px; }
}
@media (max-width: 720px) {
  .nav__menu {
    position: fixed;
    top: var(--nav-h); left: 0; right: 0;
    background: #fff;
    flex-direction: column;
    gap: 0;
    padding: 12px 24px 20px;
    box-shadow: var(--shadow);
    transform: translateY(-12px);
    opacity: 0;
    pointer-events: none;
    transition: all .3s ease;
  }
  .nav__menu.open { transform: translateY(0); opacity: 1; pointer-events: auto; }
  .nav__menu a { color: var(--ink) !important; padding: 13px 0; width: 100%; border-bottom: 1px solid var(--border); }
  .nav__menu .nav__cta { color: #22303c !important; text-align: center; border: 0; margin-top: 10px; }
  .burger { display: flex; }
  .section { padding: 64px 0; }
  .sec-title { font-size: 26px; }
  .hero h1 { font-size: 34px; }
  .hero__lead { font-size: 15px; }
  .hero__stats { grid-template-columns: repeat(3, 1fr); gap: 10px; }
  .stat__num { font-size: 24px; }
  .grid-3, .cases, .kpi-grid, .form__row { grid-template-columns: 1fr; }
  .footer__grid { grid-template-columns: 1fr; }
  .about__badge { left: 0; right: 0; bottom: -18px; text-align: center; }
}