/* =========================================================
   淮安迈达斯新材料科技有限公司 · 官网首页
   base.css —— 变量、基础排版、头部、首屏、通用按钮
   ========================================================= */

/* ---------- tokens ---------- */
:root{
  --blue:#0B66C3;
  --blue-600:#0557AC;
  --blue-300:#7FB4E6;
  --blue-100:#E8F2FC;
  --navy:#04243F;
  --navy-700:#063258;
  --ink:#0A2C50;
  --body:#43566B;
  --muted:#7A8DA3;
  --line:#E3ECF5;
  --paper:#F5F8FC;
  --yellow:#F4B72B;
  --yellow-soft:#FFD87A;

  --ff:"PingFang SC","Hiragino Sans GB","Microsoft YaHei","Source Han Sans SC",system-ui,-apple-system,"Segoe UI",sans-serif;

  --container:1600px;
  --pad:20px;
  --header-h:72px;
  --ease:cubic-bezier(.22,.61,.36,1);
}

@media (min-width:768px){ :root{ --pad:32px; --header-h:84px; } }
@media (min-width:1200px){ :root{ --pad:48px; --header-h:96px; } }

/* ---------- reset ---------- */
*,*::before,*::after{box-sizing:border-box;}
html{-webkit-text-size-adjust:100%;scroll-behavior:smooth;}
body{
  margin:0;
  font-family:var(--ff);
  font-size:16px;
  line-height:1.75;
  color:var(--body);
  background:#fff;
  overflow-x:hidden;
  -webkit-font-smoothing:antialiased;
}
img{max-width:100%;height:auto;display:block;border:0;}
a{color:inherit;text-decoration:none;}
button{font:inherit;color:inherit;background:none;border:0;cursor:pointer;}
h1,h2,h3,h4,p,ul,ol,figure{margin:0;}
ul,ol{padding:0;list-style:none;}
svg{display:block;}
::selection{background:var(--blue);color:#fff;}
:focus-visible{outline:2px solid var(--yellow);outline-offset:3px;}

/* ---------- layout ---------- */
section[id],footer[id]{scroll-margin-top:calc(var(--header-h) - 4px);}

.container{
  width:100%;
  max-width:var(--container);
  margin:0 auto;
  padding-inline:var(--pad);
}

/* 滚动进度条 */
.scroll-bar{
  position:fixed;top:0;left:0;right:0;height:2px;z-index:130;
  background:rgba(255,255,255,0);
  pointer-events:none;
}
.scroll-bar span{
  display:block;height:100%;width:100%;
  background:linear-gradient(90deg,var(--blue),var(--yellow));
  transform:scaleX(0);transform-origin:0 50%;
  transition:transform .12s linear;
}

/* ---------- header ---------- */
.header{
  position:fixed;top:0;left:0;right:0;z-index:120;
  height:var(--header-h);
  display:flex;align-items:center;
  background:transparent;
  transition:background .35s var(--ease),box-shadow .35s var(--ease);
}
.header.is-solid{
  background:rgba(255,255,255,.93);
  -webkit-backdrop-filter:saturate(160%) blur(14px);
  backdrop-filter:saturate(160%) blur(14px);
  box-shadow:0 10px 34px rgba(6,39,71,.10);
}
/* 移动端菜单展开时，避免 backdrop-filter 让导航的定位基准变成头部容器 */
.header.nav-open,
body.nav-open .header{
  -webkit-backdrop-filter:none;
  backdrop-filter:none;
  background:transparent;
  box-shadow:none;
}

.header__inner{
  display:flex;align-items:center;justify-content:space-between;gap:18px;
  width:100%;
}
.logo{display:block;flex:0 0 auto;position:relative;z-index:2;}
.logo img{height:30px;width:auto;}
@media (min-width:768px){ .logo img{height:36px;} }
@media (min-width:1200px){ .logo img{height:40px;} }

/* 导航 */
.nav{
  position:fixed;inset:0;
  z-index:1;
  padding:calc(var(--header-h) + 8px) var(--pad) 32px;
  background:#fff;
  opacity:0;visibility:hidden;transform:translateY(-10px);
  transition:opacity .3s var(--ease),transform .3s var(--ease),visibility .3s;
  overflow-y:auto;
}
.nav.is-open{opacity:1;visibility:visible;transform:none;}
.nav__list{display:flex;flex-direction:column;gap:2px;}
.nav__item{border-bottom:1px solid var(--line);}
.nav__link{
  display:block;padding:14px 2px;
  font-size:17px;font-weight:500;color:var(--ink);
  transition:color .25s;
}
.nav__link:hover{color:var(--blue);}
.nav__link.is-active{color:var(--blue);}
.drop{
  display:flex;flex-direction:column;gap:2px;
  padding:0 0 12px 2px;
}
.drop a{
  font-size:14px;color:var(--muted);padding:6px 0;
  transition:color .2s;
}
.drop a:hover{color:var(--blue);}

@media (min-width:1100px){
  .nav{
    position:static;
    padding:0;
    background:none;
    opacity:1;visibility:visible;transform:none;
    overflow:visible;
    flex:1 1 auto;
  }
  .nav__list{flex-direction:row;justify-content:center;gap:clamp(4px,1.6vw,26px);}
  .nav__item{border-bottom:0;position:relative;}
  .nav__link{
    position:relative;
    display:inline-block;padding:8px 2px;
    font-size:15px;letter-spacing:.02em;
  }
  .nav__link::after{
    content:"";position:absolute;left:0;right:0;bottom:0;
    height:2px;background:var(--yellow);
    transform:scaleX(0);transform-origin:center;
    transition:transform .35s var(--ease);
  }
  .nav__link:hover::after,
  .nav__link.is-active::after{transform:scaleX(1);}
  .drop{
    position:absolute;top:calc(100% + 6px);left:50%;
    transform:translate(-50%,10px);
    min-width:176px;
    padding:10px;
    background:#fff;
    border-radius:2px;
    box-shadow:0 18px 44px rgba(6,39,71,.14);
    opacity:0;visibility:hidden;pointer-events:none;
    transition:opacity .3s var(--ease),transform .3s var(--ease),visibility .3s;
    z-index:10;
  }
  .nav__item.has-drop:hover .drop,
  .nav__item.has-drop:focus-within .drop{
    opacity:1;visibility:visible;pointer-events:auto;
    transform:translate(-50%,0);
  }
  .drop a{padding:9px 12px;font-size:14px;border-radius:2px;}
  .drop a:hover{background:var(--blue-100);color:var(--blue);}
}

/* 头部右侧 */
.header__actions{display:flex;align-items:center;gap:2px;flex:0 0 auto;position:relative;z-index:2;}
.action{
  position:relative;
  display:flex;align-items:center;gap:8px;
  padding:8px 10px;
  color:var(--ink);
  cursor:pointer;
}
.action__icon{
  display:grid;place-items:center;
  width:34px;height:34px;
  border:1px solid rgba(10,44,80,.16);
  border-radius:50%;
  font-size:16px;
  transition:background .3s,color .3s,border-color .3s;
}
.action:hover .action__icon,
.action:focus-visible .action__icon{
  background:var(--blue);color:#fff;border-color:var(--blue);
}
.action__text{
  display:none;
  font-size:14px;color:var(--ink);white-space:nowrap;
}
@media (min-width:1400px){ .action__text{display:inline;} }
.pop{
  position:absolute;top:calc(100% + 4px);right:0;z-index:20;
  min-width:214px;
  padding:16px 18px;
  background:#fff;
  border-radius:2px;
  box-shadow:0 20px 46px rgba(6,39,71,.16);
  opacity:0;visibility:hidden;transform:translateY(8px);
  transition:opacity .3s var(--ease),transform .3s var(--ease),visibility .3s;
  text-align:left;
}
.pop--qr{min-width:0;width:176px;text-align:center;padding:14px;}
.pop img{width:100%;height:auto;margin:0 auto 8px;}
.action:hover .pop,
.action:focus-within .pop,
.action.is-open .pop{opacity:1;visibility:visible;transform:none;}
.pop__label{font-size:12px;color:var(--muted);letter-spacing:.04em;}
.pop__tel{
  display:block;
  font-size:22px;font-weight:700;color:var(--blue);
  letter-spacing:.01em;margin:4px 0 2px;
  font-variant-numeric:tabular-nums;
}
.pop__note{font-size:12px;color:var(--muted);}

.burger{
  display:grid;place-items:center;
  width:40px;height:40px;margin-left:2px;
  font-size:20px;color:var(--ink);
}
@media (min-width:1100px){ .burger{display:none;} }

/* ---------- 首屏 ---------- */
.hero{
  position:relative;
  height:100vh;
  height:100svh;
  min-height:600px;
  background:var(--navy);
  overflow:hidden;
}
.heroSwiper{height:100%;}
.hero__slide{position:relative;overflow:hidden;}
.hero__bg{position:absolute;inset:0;}
.hero__bg img{
  width:100%;height:100%;object-fit:cover;object-position:center;
  transform:scale(1.04);
  will-change:transform;
}
.hero__slide::after{
  content:"";position:absolute;inset:0;
  background:
    linear-gradient(180deg,rgba(255,255,255,.82) 0%,rgba(255,255,255,.35) 26%,rgba(255,255,255,0) 46%),
    linear-gradient(90deg,rgba(255,255,255,.96) 0%,rgba(255,255,255,.86) 34%,rgba(255,255,255,.42) 58%,rgba(255,255,255,0) 84%);
}
.hero__inner{
  position:relative;z-index:2;
  height:100%;
  display:flex;align-items:center;
  padding-top:var(--header-h);
}
.hero__copy{max-width:640px;padding-bottom:48px;}
.hero__eyebrow{
  display:inline-flex;align-items:center;gap:10px;
  font-size:13px;letter-spacing:.08em;color:var(--blue);
  margin-bottom:18px;
}
.hero__eyebrow::before{
  content:"";width:26px;height:2px;background:var(--yellow);
}
.hero__title{
  font-size:clamp(30px,7.4vw,62px);
  line-height:1.16;
  font-weight:700;
  letter-spacing:-.02em;
  color:var(--ink);
  margin-bottom:18px;
}
.hero__sub{
  font-size:clamp(14px,2.6vw,17px);
  line-height:1.8;
  color:#41576E;
  max-width:520px;
  margin-bottom:28px;
}
.hero__cta{display:flex;flex-wrap:wrap;gap:12px;}

.hero__bar{
  position:absolute;left:0;right:0;bottom:0;z-index:3;
  padding:16px 0 22px;
}
.hero__bar-inner{
  display:flex;align-items:center;justify-content:space-between;gap:20px;
}
.hero__count{
  display:flex;align-items:center;gap:12px;
  font-size:14px;color:var(--ink);
  font-variant-numeric:tabular-nums;
  letter-spacing:.06em;
}
.hero__count i{display:block;width:46px;height:1px;background:rgba(10,44,80,.3);}
.hero__pager{display:none;flex:1 1 auto;}
.hero__scroll{
  display:flex;align-items:center;gap:10px;
  font-size:13px;color:#41576E;letter-spacing:.04em;
}
.hero__scroll i{animation:bob 2s ease-in-out infinite;font-size:14px;}
@keyframes bob{
  0%,100%{transform:translateY(0);}
  50%{transform:translateY(5px);}
}

@media (min-width:768px){
  .hero{min-height:640px;}
  .hero__pager{display:flex;}
  .hero__copy{padding-bottom:30px;}
}
@media (min-width:1200px){
  .hero__copy{max-width:720px;}
  .hero__title{margin-bottom:22px;}
  .hero__sub{margin-bottom:36px;}
}
@media (min-width:1600px){
  .hero__title{font-size:66px;}
}

/* ---------- 按钮 ---------- */
.btn{
  display:inline-flex;align-items:center;justify-content:center;gap:10px;
  height:50px;padding:0 26px;
  font-size:15px;letter-spacing:.02em;
  border:1px solid transparent;
  border-radius:2px;
  transition:background .3s var(--ease),color .3s var(--ease),
             border-color .3s var(--ease),transform .3s var(--ease),
             box-shadow .3s var(--ease);
}
.btn i{font-size:15px;transition:transform .3s var(--ease);}
.btn:hover i{transform:translateX(4px);}

.btn--blue{background:var(--blue);color:#fff;}
.btn--blue:hover{background:var(--blue-600);transform:translateY(-2px);box-shadow:0 14px 26px rgba(11,102,195,.26);}

.btn--ghost{
  background:rgba(255,255,255,.55);
  border-color:rgba(10,44,80,.22);
  color:var(--ink);
}
.btn--ghost:hover{
  background:#fff;border-color:var(--blue);color:var(--blue);
  transform:translateY(-2px);
}

.btn--outline{
  background:#fff;border-color:#CFDCEB;color:var(--ink);
  padding:0 30px;
}
.btn--outline:hover{
  background:var(--blue);border-color:var(--blue);color:#fff;
  transform:translateY(-2px);box-shadow:0 14px 26px rgba(11,102,195,.22);
}

/* ---------- 区块标题 ---------- */
.section{padding:64px 0;}
@media (min-width:768px){ .section{padding:88px 0;} }
@media (min-width:1200px){ .section{padding:112px 0;} }

.sec-head{max-width:720px;margin:0 auto 34px;text-align:center;}
.sec-head--row{
  max-width:none;
  display:flex;align-items:flex-end;justify-content:space-between;
  gap:20px;text-align:left;
  margin-bottom:38px;
}
.sec-title{
  position:relative;
  display:inline-block;
  font-size:clamp(24px,3.4vw,36px);
  line-height:1.3;
  font-weight:700;
  letter-spacing:-.01em;
  color:var(--ink);
  padding-bottom:14px;
}
.sec-title::after{
  content:"";position:absolute;left:50%;bottom:0;
  width:48px;height:3px;background:var(--yellow);
  transform:translateX(-50%);
}
.sec-head--row .sec-title::after{left:0;transform:none;}
.sec-title--light{color:#fff;}
.sec-sub{
  margin-top:14px;
  font-size:14.5px;line-height:1.8;
  color:var(--muted);
}
.sec-sub--light{color:rgba(255,255,255,.62);}

.link-more{
  display:inline-flex;align-items:center;gap:8px;
  font-size:14px;color:var(--body);
  padding-bottom:4px;border-bottom:1px solid var(--line);
  transition:color .25s,border-color .25s;
  white-space:nowrap;
}
.link-more:hover{color:var(--blue);border-color:var(--blue);}
.link-more i{font-size:13px;}

/* ---------- 滚动出现动效 ---------- */
.rv,.rv-left,.rv-right{
  /*opacity:0;*/
  transition:opacity .75s var(--ease),transform .75s var(--ease);
  will-change:opacity,transform;
}
.rv{transform:translateY(28px);}
.rv-left{transform:translateX(-34px);}
.rv-right{transform:translateX(34px);}
.rv.is-in,.rv-left.is-in,.rv-right.is-in{
  opacity:1;transform:none;
}
.rv.is-in,.rv-left.is-in,.rv-right.is-in{will-change:auto;}

@media (prefers-reduced-motion:reduce){
  html{scroll-behavior:auto;}
  .rv,.rv-left,.rv-right{opacity:1;transform:none;transition:none;}
  .hero__scroll i{animation:none;}
  .hero__bg img{transform:none !important;}
  *{transition-duration:.01ms !important;animation-duration:.01ms !important;}
}