/* ============================================================
   北京新绎科技 · 官网（设计师重构版）
   设计语言：现代东方 / 空气感 / 高对比排版

   配色系统（v3 · 黛蓝）：
   ─ 黛蓝主色     #3A6270   Hue ≈ 194° 青蓝
   ─ 暖金点缀     #C99957   低饱和金 · 深底与强调
   ─ 宣纸白       #FBF7F1   暖调纸感底
   ─ 夜幕蓝底     #18333E   (深色区块 / 页脚)
   ============================================================ */

:root {
  /* —— 黛蓝色阶 —— */
  --blue-50:  #eef4f6;                 /* 极浅 tint：徽章/浅底 */
  --blue-100: #d7e3e7;                 /* 浅青蓝：图形底色 */
  --blue-600: #3a6270;                 /* 主色 */
  --blue-700: #2d505c;                 /* 深一阶：hover/描边 */
  --blue-800: #213e49;                 /* 更深 */
  --blue-900: #18333e;                 /* 夜幕蓝：深块/页脚 */

  /* —— 语义别名 —— */
  --primary:     var(--blue-600);
  --primary-deep:var(--blue-700);
  --accent:      #c99957;               /* 暖金 */
  --night:       var(--blue-900);       /* 夜幕蓝 */
  --night-deep:  #122733;               /* 页脚更深一阶 */
  --ink-bg:      var(--night);          /* 旧名保持可用 */

  /* —— 中性 & 纸张 —— */
  --ink:   #16231f;
  --muted: #4f6059;                     /* 加深 → 小字对比 ≥ 5:1，保证清晰 */
  --line:  #dfe7e3;
  --paper:   #fbf7f1;                   /* 暖纸感 */
  --paper-2: #f2f5f2;                   /* 浅青灰分区底 */
  --on-dark: #f4f8f6;                   /* 深底上的正文（高亮 → 保证可读） */
  --on-dark-dim: #c6d5d0;               /* 深底上的次级文字 */

  --radius: 14px;
  --shadow: 0 16px 44px rgba(28, 42, 38, 0.07);
  --font-x: "Noto Serif SC", serif;
}

* { margin: 0; padding: 0; box-sizing: border-box; }
html { scroll-behavior: smooth; }

body {
  font-family: "Noto Sans SC", "PingFang SC", "Microsoft YaHei", sans-serif;
  color: var(--ink);
  background: var(--paper);
  line-height: 1.7;
  overflow-x: hidden;
  -webkit-font-smoothing: antialiased;
}
img, svg { max-width: 100%; display: block; }
a { text-decoration: none; color: inherit; }
ul { list-style: none; }
b, strong { font-weight: 600; }

.container { width: min(1120px, 92%); margin: 0 auto; }

/* ---------- 通用元素 ---------- */
.eyebrow {
  display: inline-block; color: var(--primary);
  font-size: 12.5px; font-weight: 600; letter-spacing: 4px;
}
.btn {
  display: inline-flex; align-items: center; justify-content: center; gap: 8px;
  padding: 12px 26px; border-radius: 999px;
  font-weight: 600; font-size: 15px; font-family: inherit;
  border: 1.5px solid transparent; cursor: pointer;
  transition: transform .2s, box-shadow .2s, background .2s, border-color .2s;
}
.btn:hover { transform: translateY(-2px); }
.btn--primary { background: var(--primary); color: #fff; box-shadow: 0 10px 22px rgba(47,107,94,.28); }
.btn--primary:hover { background: var(--primary-deep); }
.btn--ghost { background: transparent; border-color: var(--line); color: var(--ink); }
.btn--ghost:hover { border-color: var(--primary); color: var(--primary); }
.btn--sm { padding: 10px 20px; font-size: 14px; }
.btn--block { width: 100%; justify-content: center; }
.arrow { display: inline-block; transition: transform .2s; }
.btn:hover .arrow { transform: translateX(3px); }

/* ---------- 导航 ---------- */
.nav { position: sticky; top: 0; z-index: 60; background: rgba(251,247,241,.9); backdrop-filter: blur(14px); border-bottom: 1px solid transparent; }
.nav.scrolled { border-bottom-color: var(--line); }
.nav__inner { display: flex; align-items: center; justify-content: space-between; height: 66px; }
.brand { display: flex; align-items: center; gap: 11px; font-weight: 700; font-size: 17px; }
.brand__logo { width: 38px; height: 38px; flex-shrink: 0; }
.nav__links { display: flex; gap: 30px; }
.nav__links a { color: var(--muted); font-size: 15px; font-weight: 500; transition: color .2s; }
.nav__links a:hover { color: var(--primary); }
.nav__toggle { display: none; background: none; border: 0; flex-direction: column; gap: 5px; cursor: pointer; }
.nav__toggle span { width: 22px; height: 2px; background: var(--ink); border-radius: 2px; transition: .3s; }

/* ---------- Hero ---------- */
.hero { padding: 92px 0 72px; }
.hero__inner { display: grid; grid-template-columns: 1.06fr 0.94fr; gap: 48px; align-items: center; }
.hero__title {
  font-family: var(--font-x);
  font-size: clamp(38px, 5.2vw, 60px);
  line-height: 1.22; font-weight: 900; letter-spacing: 1px; margin: 22px 0 22px;
}
.hero__title .accent { color: var(--accent); }
.hero__sub { color: var(--muted); font-size: 16.5px; max-width: 30em; margin-bottom: 30px; }
.hero__actions { display: flex; gap: 14px; flex-wrap: wrap; }
.hero__trust { display: flex; gap: 24px; flex-wrap: wrap; margin-top: 34px; padding-top: 24px; border-top: 1px solid var(--line); }
.hero__trust li { color: var(--muted); font-size: 14px; }
.hero__trust b { color: var(--primary); font-size: 16px; }

/* Hero 图形：音波 */
.hero__visual { display: flex; justify-content: center; }
.wave_card {
  width: 360px; height: 360px; border-radius: 50%;
  background: radial-gradient(circle at 50% 38%,
    #fff, var(--blue-100));
  border: 1px solid var(--line);
  box-shadow: var(--shadow);
  display: flex; flex-direction: column; align-items: center; justify-content: center;
  position: relative; overflow: hidden;
}
.wave {
  position: relative; width: 260px; height: 160px;
}
.wave span {
  position: absolute; left: 50%;
  width: 3px; height: 40%;
  background: var(--primary); border-radius: 3px;
  transform: translate(-50%, -50%); top: 50%;
  opacity: .85;
  animation: wave .9s ease-in-out infinite;
}
@keyframes wave {
  0%,100% { height: 18%; }
  50% { height: 100%; }
}
.wave_card__cap {
  margin-top: 8px; font-size: 13px; letter-spacing: 3px; color: var(--muted);
}

/* ---------- Marquee 语言带 ---------- */
.marquee { overflow: hidden; background: var(--paper-2); border-block: 1px solid var(--line); padding: 16px 0; }
.marquee__track { display: flex; gap: 40px; white-space: nowrap; width: max-content; animation: scroll 26s linear infinite; }
.marquee__track span { font-family: var(--font-x); font-size: 18px; font-weight: 900; color: var(--ink); letter-spacing: 2px; }
.marquee__track i { color: var(--accent); font-style: normal; }
@keyframes scroll { from { transform: translateX(0); } to { transform: translateX(-50%); } }

/* ---------- Section 通用 ---------- */
.section { padding: 96px 0; }
.section--tint { background: var(--paper-2); }
.section--ink { background: var(--ink-bg); color: var(--on-dark); }
.section--ink .eyebrow { color: var(--accent); }
.section--ink .section__title { color: #fff; }
.section__head { max-width: 600px; margin: 0 auto 56px; text-align: center; }
.section__title { font-family: var(--font-x); font-size: clamp(28px, 3.4vw, 38px); font-weight: 900; margin: 16px 0 0; line-height: 1.3; }
.section__desc { color: var(--muted); font-size: 15.5px; margin-top: 14px; }

/* ---------- 产品 ---------- */
.products__grid { display: grid; grid-template-columns: 1.35fr 0.65fr; gap: 22px; align-items: stretch; }
.product {
  background: #fff; border: 1px solid var(--line); border-radius: var(--radius);
  overflow: hidden; display: flex; flex-direction: column;
  transition: box-shadow .25s, transform .25s;
}
.product:hover { box-shadow: var(--shadow); transform: translateY(-4px); }
.product--main .product__media { height: 300px; position: relative; }
.product__media--zither {
  display: flex; align-items: center; justify-content: center;
  background: radial-gradient(circle at 50% 15%, rgba(58,98,112,.3), transparent 60%), linear-gradient(160deg, #213e49, #122733);
}
.zither { text-align: center; }
.zither__label {
  display: block; font-family: var(--font-x); font-size: 26px; font-weight: 900;
  color: var(--on-dark); letter-spacing: 8px; margin-bottom: 24px;
}
.zither__strings { display: flex; justify-content: center; gap: 9px; }
.zither__strings i {
  width: 3px; height: 92px; border-radius: 2px; background: var(--blue-100);
  box-shadow: 0 0 8px rgba(219,232,227,.28);
}
.product__live {
  position: absolute; top: 16px; left: 16px;
  background: rgba(255,255,255,.12); color: var(--on-dark);
  font-size: 12px; letter-spacing: 1px; padding: 5px 13px; border-radius: 999px;
  backdrop-filter: blur(4px);
}
.product__body { padding: 28px 30px 30px; display: flex; flex-direction: column; flex-grow: 1; }
.product__body h3 { font-family: var(--font-x); font-size: 26px; font-weight: 900; }
.product__desc { color: var(--muted); font-size: 15px; margin: 10px 0 22px; }
.product__spec { margin-bottom: 26px; }
.product__spec li {
  display: flex; gap: 12px; align-items: baseline; padding: 8px 0;
  border-bottom: 1px dashed var(--line); font-size: 15px;
}
.product__spec i { font-style: normal; color: var(--accent); font-weight: 700; font-size: 13px; }
.product__body .btn { align-self: flex-start; margin-top: auto; }

/* 右侧小卡（规划） */
.product--stack { display: flex; flex-direction: column; gap: 22px; }
.product__mini {
  flex: 1; background: #fff; border: 1px solid var(--line); border-radius: var(--radius);
  padding: 26px; display: flex; gap: 18px;
}
.product__mini-icon { font-size: 34px; }
.product__tag { display: inline-block; font-size: 11px; font-weight: 600; letter-spacing: 1px; color: var(--muted); background: var(--paper-2); padding: 2px 10px; border-radius: 999px; margin-bottom: 6px; }
.product__mini h4 { font-family: var(--font-x); font-size: 18px; font-weight: 900; margin-bottom: 4px; }
.product__mini p { color: var(--muted); font-size: 13.5px; }

/* ---------- 数据条 ---------- */
.statsband { background: var(--primary); }
.statsband__inner { display: grid; grid-template-columns: repeat(4,1fr); gap: 20px; padding: 40px 0; }
.stat { text-align: center; color: var(--on-dark); }
.stat strong { display: block; font-family: var(--font-x); font-size: 40px; font-weight: 900; color: #fff; }
.stat span { font-size: 13px; opacity: .85; letter-spacing: 1px; }

/* ---------- 关于 ---------- */
.about__grid { display: grid; grid-template-columns: 1.1fr 0.9fr; gap: 60px; align-items: center; }
.about__p { color: var(--muted); font-size: 16px; margin: 16px 0; line-height: 2; }
.link-more { display: inline-block; margin-top: 12px; color: var(--primary); font-weight: 600; font-size: 15px; }
.link-more:hover { color: var(--accent); }
.about__quote {
  background: var(--primary); color: #fff; border-radius: var(--radius);
  padding: 44px 38px; position: relative; overflow: hidden;
}
.about__quote-mark { font-family: var(--font-x); font-size: 96px; line-height: 0; color: rgba(255,255,255,.3); display: block; margin: 10px 0 26px; }
.about__quote p { font-family: var(--font-x); font-size: 26px; font-weight: 900; line-height: 1.6; }
.about__quote-en { margin-top: 22px !important; font-family: inherit !important; font-size: 14px !important; font-weight: 400 !important; opacity: .8; }

/* ---------- 愿景 ---------- */
.vision__inner { text-align: center; }
.vision__title { font-family: var(--font-x); font-size: clamp(26px, 3.4vw, 40px); font-weight: 900; line-height: 1.5; margin-top: 20px; }
.vision__pillars { display: flex; justify-content: center; gap: 70px; margin-top: 52px; flex-wrap: wrap; }
.pillar strong {
  display: inline-flex; width: 66px; height: 66px; align-items: center; justify-content: center;
  border-radius: 50%; border: 1px solid rgba(255,255,255,.35); color: var(--accent);
  font-family: var(--font-x); font-size: 30px; margin-bottom: 14px;
}
.pillar span { color: var(--on-dark-dim); font-size: 15px; display: block; }

/* ---------- 合作 ---------- */
.coop__row { display: grid; grid-template-columns: repeat(3,1fr); gap: 18px; }
.coop__item {
  background: #fff; border: 1px solid var(--line); border-radius: var(--radius);
  padding: 30px 26px; text-align: center; transition: box-shadow .25s, transform .25s;
}
.coop__item:hover { box-shadow: var(--shadow); transform: translateY(-4px); }
.coop__item span { font-size: 32px; }
.coop__item h4 { font-family: var(--font-x); font-size: 18px; font-weight: 900; margin: 12px 0 4px; }
.coop__item p { color: var(--muted); font-size: 14px; }
.coop__cta { margin-top: 40px; }
.section #cooperate .section-head, #cooperate { text-align: center; }

/* ---------- 联系 ---------- */
.contact__grid { display: grid; grid-template-columns: 1fr 1fr; gap: 56px; align-items: start; }
.contact__info .section__title { margin-top: 14px; }
.contact__list { margin-top: 30px; }
.contact__list li { padding: 16px 0; border-bottom: 1px solid rgba(255,255,255,.12); font-size: 15px; display: flex; align-items: baseline; gap: 20px; }
.contact__list b { width: 48px; color: var(--accent); font-weight: 600; font-size: 13px; letter-spacing: 1px; flex-shrink: 0; }
.contact__list a { color: #fff; }
.contact__list a:hover { color: var(--accent); }
.contact__form {
  background: rgba(255,255,255,.05); border: 1px solid rgba(255,255,255,.12);
  border-radius: var(--radius); padding: 30px; display: grid; gap: 14px;
}
.contact__form input, .contact__form textarea {
  width: 100%; padding: 13px 16px;
  background: rgba(255,255,255,.07); border: 1px solid rgba(255,255,255,.14);
  border-radius: 10px; font-family: inherit; font-size: 15px; color: #fff;
  transition: border-color .2s;
}
.contact__form input::placeholder, .contact__form textarea::placeholder { color: rgba(232,239,236,.45); }
.contact__form input:focus, .contact__form textarea:focus { outline: none; border-color: var(--accent); }
.contact__ok { color: #8fe0a8; font-size: 14px; font-weight: 600; }

/* ---------- 页脚 ---------- */
.footer { background: var(--night-deep); color: var(--on-dark-dim); padding-top: 56px; }
.footer__inner { display: grid; grid-template-columns: 1.5fr 1fr 1fr 1fr; gap: 40px; padding-bottom: 40px; }
.footer .brand { color: #fff; margin-bottom: 14px; }
.footer__brand p { font-size: 14px; }
.footer__col h4 { color: #fff; font-size: 14px; font-weight: 600; margin-bottom: 14px; }
.footer__col a { display: block; padding: 6px 0; font-size: 14px; color: var(--on-dark-dim); transition: color .2s; }
.footer__col a:hover { color: #fff; }
.footer__bottom { border-top: 1px solid rgba(255,255,255,.1); padding: 18px 0; font-size: 13px; color: var(--on-dark-dim); }
.footer__bottom a { color: inherit; }
.footer__bottom a:hover { color: #fff; }

/* ---------- 响应式 ---------- */
@media (max-width: 900px) {
  .hero__inner { grid-template-columns: 1fr; text-align: center; }
  .hero__text { display: flex; flex-direction: column; align-items: center; }
  .hero__trust { justify-content: center; }
  .hero__visual { margin-top: 12px; }
  .products__grid { grid-template-columns: 1fr; }
  .about__grid { grid-template-columns: 1fr; gap: 40px; }
  .contact__grid { grid-template-columns: 1fr; }
  .statsband__inner { grid-template-columns: repeat(2,1fr); gap: 28px; }
  .footer__inner { grid-template-columns: repeat(2,1fr); }
  .coop__row { grid-template-columns: 1fr; }
}
@media (max-width: 640px) {
  .nav__links, .nav__cta { display: none; }
  .nav__toggle { display: flex; position: relative; z-index: 70; }
  .nav__links.open {
    display: flex; flex-direction: column; gap: 22px;
    position: fixed; inset: 0; background: var(--paper);
    padding: 100px 8% 0; font-size: 20px; z-index: 65;
  }
  .food { /* nop */ }
}