/* ============================================================
   欧科新能源官网 - 样式表
   视觉方向：深海军蓝 + 青绿能量 + 工业坐标网格
   ============================================================ */

:root {
  /* 色彩 token */
  --bg-0: #060d16;
  --bg-1: #0a1626;
  --bg-2: #0e1f33;
  --bg-3: #12283f;
  --line: rgba(148, 191, 224, 0.16);
  --line-soft: rgba(148, 191, 224, 0.09);
  --ink-hi: #eaf2f8;
  --ink-mid: #a7bacb;
  --ink-low: #5f7489;
  --acc: #2ce4b3;
  --acc-dim: rgba(44, 228, 179, 0.14);
  --blue: #4fa3ff;
  --grid: rgba(130, 178, 222, 0.05);

  /* 字体 */
  --f-body: "Noto Sans SC", "PingFang SC", "Microsoft YaHei", sans-serif;
  --f-num: "Space Grotesk", "Noto Sans SC", sans-serif;

  --nav-h: 72px;
  --radius: 10px;
  --maxw: 1200px;
}

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

html { scroll-behavior: smooth; }

body {
  background: var(--bg-0);
  color: var(--ink-hi);
  font-family: var(--f-body);
  font-size: 16px;
  line-height: 1.75;
  -webkit-font-smoothing: antialiased;
  overflow-x: hidden;
}

/* 全局坐标网格背景（签名元素之一） */
body::before {
  content: "";
  position: fixed;
  inset: 0;
  background-image:
    linear-gradient(var(--grid) 1px, transparent 1px),
    linear-gradient(90deg, var(--grid) 1px, transparent 1px);
  background-size: 44px 44px;
  pointer-events: none;
  z-index: 0;
}

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

::selection { background: var(--acc); color: #04121c; }

/* ===== 通用布局 ===== */
.wrap { max-width: var(--maxw); margin: 0 auto; padding: 0 28px; position: relative; z-index: 1; }

.section { padding: 92px 0; }
.section-alt { background: var(--bg-1); border-block: 1px solid var(--line-soft); }

.sec-head { max-width: 640px; margin-bottom: 44px; }
.sec-head-more { float: right; margin-top: -52px; }

.sec-label {
  font-family: var(--f-num);
  font-size: 13px;
  letter-spacing: 0.28em;
  color: var(--acc);
  margin-bottom: 14px;
}

h1, h2, h3 { font-weight: 900; line-height: 1.25; letter-spacing: 0.01em; }
h2 { font-size: clamp(28px, 4vw, 40px); }
h3 { font-size: 19px; }

.sec-desc { color: var(--ink-mid); margin-top: 14px; font-size: 16px; }
.note { color: var(--ink-low); font-size: 14px; }
.note-inline { color: var(--ink-low); font-size: 13px; }
.link-more { display: inline-block; margin-top: 20px; font-weight: 700; color: var(--acc); font-size: 15px; }
.link-more span { transition: transform 0.25s ease; display: inline-block; }
.link-more:hover span { transform: translateX(5px); }

/* ===== 按钮 ===== */
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 8px;
  padding: 14px 30px;
  border-radius: 6px;
  font-weight: 700;
  font-size: 15px;
  border: 1px solid transparent;
  cursor: pointer;
  transition: transform 0.2s ease, box-shadow 0.2s ease, background 0.2s ease, border-color 0.2s ease;
  font-family: var(--f-body);
}
.btn-accent { background: var(--acc); color: #04121c; }
.btn-accent:hover { transform: translateY(-2px); box-shadow: 0 10px 28px rgba(44, 228, 179, 0.22); }
.btn-ghost { border-color: var(--line); color: var(--ink-hi); background: rgba(10, 22, 38, 0.4); }
.btn-ghost:hover { border-color: var(--acc); color: var(--acc); }
.btn-sm { padding: 10px 20px; font-size: 14px; }

/* ===== 顶部导航 ===== */
.site-header {
  position: fixed;
  top: 0; left: 0; right: 0;
  height: var(--nav-h);
  z-index: 100;
  background: rgba(6, 13, 22, 0.82);
  backdrop-filter: blur(10px);
  border-bottom: 1px solid var(--line-soft);
  transition: background 0.3s ease;
}
.nav-inner {
  max-width: var(--maxw);
  margin: 0 auto;
  padding: 0 28px;
  height: 100%;
  display: flex;
  align-items: center;
  gap: 32px;
}
.brand { display: flex; align-items: center; gap: 12px; color: var(--acc); }
.brand-mark { display: inline-flex; }
.brand-text { display: flex; flex-direction: column; line-height: 1.15; }
.brand-text strong { font-size: 17px; font-weight: 900; color: var(--ink-hi); letter-spacing: 0.04em; }
.brand-text em { font-style: normal; font-family: var(--f-num); font-size: 10px; letter-spacing: 0.34em; color: var(--ink-low); }

.site-nav { display: flex; gap: 6px; margin-left: auto; }
.nav-link {
  position: relative;
  padding: 8px 16px;
  font-size: 15px;
  color: var(--ink-mid);
  transition: color 0.2s ease;
}
.nav-link::after {
  content: "";
  position: absolute;
  left: 16px; right: 16px; bottom: 2px;
  height: 2px;
  background: var(--acc);
  transform: scaleX(0);
  transform-origin: left;
  transition: transform 0.25s ease;
}
.nav-link:hover { color: var(--ink-hi); }
.nav-link.is-active { color: var(--ink-hi); }
.nav-link.is-active::after { transform: scaleX(1); }

.nav-actions { display: flex; align-items: center; gap: 14px; }

.nav-toggle {
  display: none;
  flex-direction: column;
  gap: 5px;
  background: none;
  border: 0;
  cursor: pointer;
  padding: 6px;
}
.nav-toggle span {
  width: 22px; height: 2px;
  background: var(--ink-hi);
  transition: transform 0.25s ease, opacity 0.25s ease;
}
.nav-toggle[aria-expanded="true"] span:nth-child(1) { transform: translateY(7px) rotate(45deg); }
.nav-toggle[aria-expanded="true"] span:nth-child(2) { opacity: 0; }
.nav-toggle[aria-expanded="true"] span:nth-child(3) { transform: translateY(-7px) rotate(-45deg); }

/* ===== Hero ===== */
.hero {
  position: relative;
  min-height: 100vh;
  display: flex;
  align-items: center;
  padding: calc(var(--nav-h) + 48px) 28px 96px;
  overflow: hidden;
}
.hero-media { position: absolute; inset: 0; }
.hero-media img { width: 100%; height: 100%; object-fit: cover; }
.hero-shade {
  position: absolute; inset: 0;
  background:
    linear-gradient(180deg, rgba(6, 13, 22, 0.92) 0%, rgba(6, 13, 22, 0.62) 45%, rgba(6, 13, 22, 0.88) 100%),
    linear-gradient(90deg, rgba(6, 13, 22, 0.85) 0%, rgba(6, 13, 22, 0.15) 70%);
}
.hero-grid {
  position: absolute; inset: 0;
  background-image:
    linear-gradient(rgba(130, 178, 222, 0.07) 1px, transparent 1px),
    linear-gradient(90deg, rgba(130, 178, 222, 0.07) 1px, transparent 1px);
  background-size: 64px 64px;
  mask-image: radial-gradient(ellipse at 60% 40%, #000 30%, transparent 75%);
}

/* 能量流线（签名元素） */
.energy-line {
  position: absolute;
  left: 0; right: 0; bottom: 0;
  width: 100%;
  height: 120px;
  z-index: 2;
  pointer-events: none;
}
.energy-path {
  stroke-dasharray: 90 220;
  animation: energyFlow 5.5s linear infinite;
  filter: drop-shadow(0 0 8px rgba(44, 228, 179, 0.55));
}
@keyframes energyFlow {
  from { stroke-dashoffset: 620; }
  to { stroke-dashoffset: 0; }
}

.hero-content {
  position: relative;
  z-index: 3;
  max-width: 760px;
}
.eyebrow {
  display: flex;
  align-items: center;
  gap: 10px;
  font-family: var(--f-num);
  font-size: 13px;
  letter-spacing: 0.24em;
  color: var(--acc);
  margin-bottom: 22px;
}
.eyebrow-dot {
  width: 7px; height: 7px;
  border-radius: 50%;
  background: var(--acc);
  box-shadow: 0 0 0 5px var(--acc-dim);
}
.hero h1 {
  font-size: clamp(38px, 6.4vw, 72px);
  letter-spacing: 0.01em;
  margin-bottom: 22px;
}
.grad-word {
  background: linear-gradient(100deg, var(--acc) 10%, var(--blue) 90%);
  -webkit-background-clip: text;
  background-clip: text;
  color: transparent;
}
.hero-sub {
  max-width: 560px;
  color: var(--ink-mid);
  font-size: 17px;
  margin-bottom: 34px;
}
.hero-cta { display: flex; gap: 16px; flex-wrap: wrap; margin-bottom: 44px; }
.hero-tags {
  display: flex;
  align-items: center;
  gap: 14px;
  flex-wrap: wrap;
  color: var(--ink-mid);
  font-size: 14px;
}
.hero-tags i { width: 4px; height: 4px; border-radius: 50%; background: var(--acc); opacity: 0.7; }

.hero-scroll {
  position: absolute;
  bottom: 34px; left: 50%;
  transform: translateX(-50%);
  width: 22px; height: 36px;
  border: 1.5px solid rgba(234, 242, 248, 0.35);
  border-radius: 12px;
  z-index: 3;
}
.hero-scroll span {
  position: absolute;
  left: 50%; top: 7px;
  width: 4px; height: 8px;
  margin-left: -2px;
  border-radius: 3px;
  background: var(--acc);
  animation: scrollHint 1.8s ease-in-out infinite;
}
@keyframes scrollHint {
  0% { transform: translateY(0); opacity: 1; }
  70% { transform: translateY(12px); opacity: 0; }
  100% { transform: translateY(0); opacity: 0; }
}

/* ===== 网格 / 卡片 ===== */
.grid { display: grid; gap: 22px; }
.grid-2 { grid-template-columns: repeat(2, 1fr); }
.grid-4 { grid-template-columns: repeat(4, 1fr); }

.card {
  position: relative;
  background: var(--bg-2);
  border: 1px solid var(--line-soft);
  border-radius: var(--radius);
  padding: 30px 26px;
  overflow: hidden;
  transition: border-color 0.25s ease, transform 0.25s ease, background 0.25s ease;
}
.card::before {
  content: "";
  position: absolute;
  top: 0; left: 0; right: 0;
  height: 2px;
  background: linear-gradient(90deg, var(--acc), transparent 70%);
  opacity: 0;
  transition: opacity 0.25s ease;
}
.card:hover { border-color: var(--line); background: var(--bg-3); transform: translateY(-4px); }
.card:hover::before { opacity: 1; }

.card-idx {
  position: absolute;
  top: 18px; right: 22px;
  font-family: var(--f-num);
  font-size: 13px;
  letter-spacing: 0.14em;
  color: var(--ink-low);
}
.card-ico { width: 46px; height: 46px; color: var(--acc); margin-bottom: 18px; }
.biz-card h3 { margin-bottom: 10px; }
.biz-card p { color: var(--ink-mid); font-size: 14.5px; }
.tag {
  display: inline-block;
  margin-top: 16px;
  padding: 3px 10px;
  border-radius: 999px;
  font-size: 12px;
  letter-spacing: 0.06em;
}
.tag-tbd { color: var(--ink-low); background: rgba(95, 116, 137, 0.14); border: 1px solid var(--line-soft); }

/* ===== 公司优势 ===== */
.adv { padding: 26px 6px; border-top: 1px solid var(--line); }
.adv-num {
  font-family: var(--f-num);
  font-size: 15px;
  letter-spacing: 0.2em;
  color: var(--acc);
  display: block;
  margin-bottom: 16px;
}
.adv h3 { margin-bottom: 10px; }
.adv p { color: var(--ink-mid); font-size: 14.5px; }

/* ===== 关于我们预览 ===== */
.about-preview {
  display: grid;
  grid-template-columns: 1.05fr 1fr;
  gap: 60px;
  align-items: center;
}
.about-media { border-radius: var(--radius); overflow: hidden; border: 1px solid var(--line-soft); }
.about-media img { width: 100%; height: 100%; object-fit: cover; aspect-ratio: 4 / 3; }
.about-copy h2 { margin-bottom: 18px; }
.about-copy p { color: var(--ink-mid); margin-bottom: 14px; }
.about-copy .note { margin-top: 4px; }
.about-copy .link-more { margin-top: 8px; }

/* ===== 新闻 ===== */
.news-list { display: grid; gap: 14px; }
.news-item {
  display: grid;
  grid-template-columns: 120px 1fr;
  gap: 26px;
  align-items: center;
  padding: 22px 10px;
  border-bottom: 1px solid var(--line-soft);
  transition: background 0.2s ease, padding 0.2s ease;
}
.news-item:hover { background: rgba(14, 31, 51, 0.6); padding-inline: 16px; }
.news-date { display: flex; flex-direction: column; align-items: flex-start; }
.n-d {
  font-family: var(--f-num);
  font-size: 34px;
  font-weight: 600;
  color: var(--acc);
  line-height: 1;
}
.n-m { font-size: 12px; letter-spacing: 0.16em; color: var(--ink-low); margin-top: 4px; }
.news-body h3 { font-size: 17px; margin-bottom: 4px; }
.news-body p { color: var(--ink-mid); font-size: 14px; }
.news-list-full { margin-top: 34px; }

/* ===== 子页面头 ===== */
.page-hero {
  position: relative;
  padding: calc(var(--nav-h) + 76px) 0 58px;
  border-bottom: 1px solid var(--line-soft);
  background: linear-gradient(180deg, #0a1626 0%, var(--bg-0) 100%);
  overflow: hidden;
}
.page-hero-grid {
  position: absolute; inset: 0;
  background-image:
    linear-gradient(rgba(130, 178, 222, 0.06) 1px, transparent 1px),
    linear-gradient(90deg, rgba(130, 178, 222, 0.06) 1px, transparent 1px);
  background-size: 56px 56px;
}
.page-hero h1 { font-size: clamp(34px, 5vw, 54px); margin-bottom: 12px; position: relative; }
.page-sub { color: var(--ink-mid); font-size: 16px; position: relative; }
.page-hero .eyebrow { position: relative; }

/* ===== 提示框 ===== */
.notice-box {
  display: flex;
  gap: 14px;
  align-items: flex-start;
  padding: 18px 22px;
  border: 1px dashed var(--line);
  border-radius: var(--radius);
  color: var(--ink-mid);
  font-size: 14.5px;
  background: rgba(14, 31, 51, 0.5);
  margin-bottom: 40px;
}
.notice-box svg { color: var(--acc); flex: none; margin-top: 2px; }

/* ===== 产品卡片 ===== */
.product-card { padding: 0 0 28px; }
.product-ph {
  position: relative;
  height: 210px;
  background:
    linear-gradient(var(--line-soft) 1px, transparent 1px),
    linear-gradient(90deg, var(--line-soft) 1px, transparent 1px);
  background-size: 26px 26px;
  display: flex;
  align-items: center;
  justify-content: center;
  border-bottom: 1px solid var(--line-soft);
}
.ph-line {
  position: absolute;
  left: 26px; right: 26px; top: 50%;
  height: 2px;
  background: linear-gradient(90deg, transparent, var(--acc) 30%, var(--acc) 70%, transparent);
  opacity: 0.5;
}
.ph-label {
  font-size: 13px;
  letter-spacing: 0.12em;
  color: var(--ink-low);
  border: 1px solid var(--line);
  padding: 6px 16px;
  border-radius: 999px;
  background: rgba(6, 13, 22, 0.7);
}
.product-card h3 { padding: 24px 26px 8px; }
.product-card p { padding: 0 26px; color: var(--ink-mid); font-size: 14.5px; }

/* ===== 关于我们全文 ===== */
.about-full {
  display: grid;
  grid-template-columns: 1.05fr 1fr;
  gap: 60px;
  align-items: start;
}
.about-full h2 { margin-bottom: 18px; }
.about-full h3 { font-size: 17px; margin: 20px 0 8px; color: var(--ink-hi); }
.about-full p { color: var(--ink-mid); }
.about-list { margin-top: 6px; }
.about-list li {
  display: flex;
  align-items: center;
  gap: 12px;
  padding: 8px 0;
  color: var(--ink-mid);
  font-size: 15px;
}
.about-list li span {
  width: 6px; height: 6px;
  background: var(--acc);
  border-radius: 1px;
  transform: rotate(45deg);
  flex: none;
}

/* ===== 联系页 ===== */
.contact-grid {
  display: grid;
  grid-template-columns: 1fr 1.15fr;
  gap: 60px;
  align-items: start;
}
.contact-list { margin: 20px 0 24px; display: grid; gap: 18px; }
.contact-list li { display: flex; gap: 16px; align-items: flex-start; }
.contact-list svg { color: var(--acc); flex: none; margin-top: 3px; }
.contact-list em { display: block; font-style: normal; font-size: 13px; letter-spacing: 0.1em; color: var(--ink-low); margin-bottom: 2px; }
.contact-list span { color: var(--ink-hi); font-size: 16px; }

.contact-form {
  background: var(--bg-2);
  border: 1px solid var(--line-soft);
  border-radius: var(--radius);
  padding: 34px 32px;
}
.contact-form h2 { font-size: 24px; margin-bottom: 22px; }
.form-row { display: grid; grid-template-columns: 1fr 1fr; gap: 16px; }
.contact-form label { display: block; margin-bottom: 16px; }
.contact-form label > span { display: block; font-size: 13.5px; color: var(--ink-mid); margin-bottom: 7px; }
.contact-form input,
.contact-form textarea {
  width: 100%;
  background: var(--bg-0);
  border: 1px solid var(--line);
  border-radius: 6px;
  color: var(--ink-hi);
  font-family: var(--f-body);
  font-size: 15px;
  padding: 12px 14px;
  transition: border-color 0.2s ease;
}
.contact-form input:focus,
.contact-form textarea:focus {
  outline: none;
  border-color: var(--acc);
}
.contact-form input::placeholder,
.contact-form textarea::placeholder { color: var(--ink-low); }
.contact-form textarea { resize: vertical; min-height: 130px; }
.form-tip { margin-top: 14px; font-size: 14px; min-height: 22px; }
.form-tip.ok { color: var(--acc); }
.form-tip.err { color: #ff7a7a; }

/* ===== 页脚 ===== */
.site-footer {
  border-top: 1px solid var(--line-soft);
  background: var(--bg-1);
  padding: 52px 0 26px;
}
.footer-grid {
  display: flex;
  justify-content: space-between;
  align-items: flex-start;
  gap: 30px;
  flex-wrap: wrap;
  padding-bottom: 34px;
}
.footer-brand { display: flex; gap: 12px; align-items: flex-start; }
.footer-brand .brand-mark { color: var(--acc); }
.footer-brand p { font-weight: 700; }
.footer-en { font-family: var(--f-num); font-size: 12px; letter-spacing: 0.22em; color: var(--ink-low); font-weight: 400; }
.footer-nav { display: flex; gap: 26px; flex-wrap: wrap; }
.footer-nav a { color: var(--ink-mid); font-size: 14.5px; transition: color 0.2s ease; }
.footer-nav a:hover { color: var(--acc); }
.footer-bottom {
  display: flex;
  justify-content: space-between;
  gap: 14px;
  flex-wrap: wrap;
  padding-top: 20px;
  border-top: 1px solid var(--line-soft);
  color: var(--ink-low);
  font-size: 13px;
}

/* ===== 滚动显现动画 ===== */
.reveal { opacity: 0; transform: translateY(26px); transition: opacity 0.65s ease, transform 0.65s ease; }
.reveal.is-visible { opacity: 1; transform: none; }

/* ===== 响应式 ===== */
@media (max-width: 1024px) {
  .grid-4 { grid-template-columns: repeat(2, 1fr); }
  .about-preview, .about-full, .contact-grid { grid-template-columns: 1fr; gap: 40px; }
  .section { padding: 76px 0; }
}

@media (max-width: 720px) {
  :root { --nav-h: 62px; }
  .wrap { padding: 0 20px; }

  .site-nav {
    position: fixed;
    top: var(--nav-h); left: 0; right: 0;
    flex-direction: column;
    background: rgba(6, 13, 22, 0.97);
    border-bottom: 1px solid var(--line-soft);
    padding: 14px 20px 22px;
    gap: 4px;
    transform: translateY(-12px);
    opacity: 0;
    visibility: hidden;
    transition: opacity 0.25s ease, transform 0.25s ease, visibility 0.25s ease;
    margin-left: 0;
  }
  .site-nav.is-open { transform: none; opacity: 1; visibility: visible; }
  .nav-link { padding: 12px 8px; font-size: 16px; }
  .nav-toggle { display: flex; }

  .hero { padding-inline: 20px; padding-bottom: 80px; }
  .grid-2, .grid-4 { grid-template-columns: 1fr; }
  .form-row { grid-template-columns: 1fr; }
  .news-item { grid-template-columns: 84px 1fr; gap: 18px; }
  .n-d { font-size: 28px; }
  .sec-head-more { float: none; display: inline-block; margin-top: 10px; }
  .hero-tags { gap: 10px; }
}

/* ===== 减弱动效 ===== */
@media (prefers-reduced-motion: reduce) {
  html { scroll-behavior: auto; }
  .energy-path { animation: none; }
  .hero-scroll span { animation: none; opacity: 0.6; }
  .reveal { opacity: 1; transform: none; transition: none; }
  .btn, .card, .nav-link::after, .link-more span { transition: none; }
}