/* ============================================================
   IMCA 战队招新宣传站  ·  样式表
   风格：浅色为主 + 深色首屏，克制留白，橙红取自 logo 作点缀
   ============================================================ */

:root {
  --ink: #16181d;          /* 主文字 / 近黑 */
  --ink-soft: #4a4f59;     /* 次级文字 */
  --ink-dim: #8b909b;      /* 弱化文字 */
  --paper: #ffffff;        /* 纯白底 */
  --paper-warm: #f6f5f2;   /* 暖白分区底 */
  --paper-warm2: #efeee9;  /* 更深一档暖白 */
  --line: #e3e2dd;         /* 分隔线 */
  --line-soft: #eceae5;
  --brand: #e4531c;        /* 取自 logo 的橙红 */
  --brand-dark: #c4410f;
  --brand-tint: #fbeee7;   /* 橙红极浅底 */
  --dark: #16181d;         /* 深色首屏底 */
  --dark-2: #1e2128;
  --radius: 4px;
  --maxw: 1160px;
  --pad: 32px;
}

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

body {
  font-family: "Noto Sans SC", "Microsoft YaHei", -apple-system, BlinkMacSystemFont, sans-serif;
  color: var(--ink);
  background: var(--paper);
  line-height: 1.85;
  -webkit-font-smoothing: antialiased;
  overflow-x: hidden;
}

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

.en { font-family: "Barlow", "Noto Sans SC", sans-serif; }

/* ===== 通用容器 ===== */
.wrap { max-width: var(--maxw); margin: 0 auto; padding: 0 var(--pad); }

section { padding: 104px 0; }
section.tight { padding: 80px 0; }

/* ===== 章节标题 ===== */
.sec-head { margin-bottom: 56px; max-width: 760px; }
.sec-head .kicker {
  font-family: "Barlow", sans-serif;
  font-size: .82rem; font-weight: 600; letter-spacing: 3px;
  text-transform: uppercase; color: var(--brand);
  display: inline-flex; align-items: center; gap: 12px; margin-bottom: 16px;
}
.sec-head .kicker::before {
  content: ""; width: 26px; height: 2px; background: var(--brand);
}
.sec-head h2 {
  font-size: clamp(1.7rem, 3.6vw, 2.4rem); font-weight: 900;
  letter-spacing: 1px; line-height: 1.25; color: var(--ink);
}
.sec-head p {
  margin-top: 16px; color: var(--ink-soft); font-size: 1rem; max-width: 680px;
}
.center { text-align: center; margin-left: auto; margin-right: auto; }
.center .kicker { justify-content: center; }

/* ===== 导航栏 ===== */
.nav {
  position: sticky; top: 0; z-index: 100;
  background: rgba(255, 255, 255, .88);
  backdrop-filter: blur(12px) saturate(1.2);
  border-bottom: 1px solid var(--line);
}
.nav .inner {
  max-width: var(--maxw); margin: 0 auto; padding: 0 var(--pad);
  height: 66px; display: flex; align-items: center; justify-content: space-between;
}
.nav .brand { display: flex; align-items: center; gap: 12px; }
.nav .brand img { width: 34px; height: 34px; object-fit: contain; }
.nav .brand b {
  font-weight: 800; font-size: 1.05rem; letter-spacing: 1px; color: var(--ink);
}
.nav .brand span {
  font-family: "Barlow", sans-serif; font-weight: 600;
  color: var(--brand); letter-spacing: 2px; font-size: .95rem;
}
.nav ul { list-style: none; display: flex; gap: 30px; align-items: center; }
.nav ul a {
  font-size: .92rem; color: var(--ink-soft); letter-spacing: 1px;
  position: relative; padding: 4px 0; transition: color .2s;
}
.nav ul a::after {
  content: ""; position: absolute; left: 0; bottom: -2px; width: 0; height: 2px;
  background: var(--brand); transition: width .25s;
}
.nav ul a:hover { color: var(--ink); }
.nav ul a:hover::after { width: 100%; }
.nav .nav-cta {
  padding: 8px 20px; background: var(--brand); color: #fff !important;
  border-radius: var(--radius); font-weight: 600; font-size: .9rem;
}
.nav .nav-cta::after { display: none; }
.nav .nav-cta:hover { background: var(--brand-dark); }
.nav .burger { display: none; background: none; border: 0; cursor: pointer; padding: 6px; }
.nav .burger span { display: block; width: 22px; height: 2px; background: var(--ink); margin: 4px 0; transition: .25s; }

/* ===== 首屏 Hero（深色） ===== */
.hero {
  position: relative; background: var(--dark); color: #fff;
  min-height: 88vh; display: flex; align-items: center;
  overflow: hidden;
}
.hero .hero-bg {
  position: absolute; inset: 0; z-index: 1;
  width: 100%; height: 100%; object-fit: cover; opacity: .38;
}
.hero .hero-bg-ph {
  position: absolute; inset: 0; z-index: 0;
  background:
    radial-gradient(circle at 78% 30%, rgba(228, 83, 28, .18), transparent 45%),
    linear-gradient(160deg, #1a1d24 0%, #16181d 60%, #101216 100%);
}
.hero .overlay {
  position: absolute; inset: 0; z-index: 2;
  background: linear-gradient(90deg, rgba(16,18,21,.92) 0%, rgba(16,18,21,.68) 55%, rgba(16,18,21,.35) 100%);
}
.hero .inner {
  position: relative; z-index: 3;
  max-width: var(--maxw); margin: 0 auto; padding: 120px var(--pad);
  width: 100%;
}
.hero .badge {
  display: inline-flex; align-items: center; gap: 10px;
  border: 1px solid rgba(255, 255, 255, .22); border-radius: 999px;
  padding: 6px 16px; font-family: "Barlow", sans-serif;
  font-size: .78rem; letter-spacing: 2px; color: #d9dbe0; margin-bottom: 28px;
}
.hero .badge i {
  width: 7px; height: 7px; border-radius: 50%; background: var(--brand);
  box-shadow: 0 0 0 4px rgba(228, 83, 28, .2);
}
.hero h1 {
  font-size: clamp(2.6rem, 6.5vw, 4.6rem); font-weight: 900;
  line-height: 1.1; letter-spacing: 2px;
}
.hero h1 .en-name {
  display: block; font-family: "Barlow", sans-serif; color: var(--brand);
  font-size: clamp(3rem, 8vw, 5.6rem); letter-spacing: 4px; margin-bottom: 4px;
}
.hero .slogan {
  margin-top: 26px; font-size: clamp(1.05rem, 2.4vw, 1.5rem);
  font-weight: 300; letter-spacing: 8px; color: #d9dbe0;
}
.hero .slogan b { color: #fff; font-weight: 500; }
.hero .lead {
  margin-top: 22px; max-width: 540px; color: #a9adb6; font-size: 1.02rem;
}
.hero .btns { margin-top: 44px; display: flex; gap: 16px; flex-wrap: wrap; }

.btn {
  display: inline-flex; align-items: center; gap: 8px;
  padding: 14px 34px; border-radius: var(--radius);
  font-weight: 600; font-size: .98rem; letter-spacing: 1px;
  transition: transform .18s, background .2s, border-color .2s, color .2s;
  cursor: pointer; border: 1px solid transparent;
}
.btn:hover { transform: translateY(-2px); }
.btn-primary { background: var(--brand); color: #fff; }
.btn-primary:hover { background: var(--brand-dark); }
.btn-ghost { border-color: rgba(255, 255, 255, .32); color: #fff; }
.btn-ghost:hover { border-color: #fff; background: rgba(255, 255, 255, .08); }
.btn-dark { background: var(--ink); color: #fff; }
.btn-dark:hover { background: #000; }
.btn-outline { border-color: var(--line); color: var(--ink); background: #fff; }
.btn-outline:hover { border-color: var(--brand); color: var(--brand); }

/* ===== 数据条 ===== */
.stats {
  background: var(--paper-warm); border-top: 1px solid var(--line); border-bottom: 1px solid var(--line);
}
.stats .grid {
  max-width: var(--maxw); margin: 0 auto; padding: 48px var(--pad);
  display: grid; grid-template-columns: repeat(4, 1fr);
}
.stat { text-align: center; padding: 8px 16px; position: relative; }
.stat + .stat::before {
  content: ""; position: absolute; left: 0; top: 22%; height: 56%; width: 1px; background: var(--line);
}
.stat .num {
  font-family: "Barlow", sans-serif; font-size: clamp(2.2rem, 5vw, 3rem);
  font-weight: 700; color: var(--ink); line-height: 1;
}
.stat .num .u { color: var(--brand); }
.stat .num small { font-size: 1.2rem; color: var(--ink-dim); }
.stat p { margin-top: 10px; color: var(--ink-soft); font-size: .9rem; letter-spacing: .5px; }

/* ===== 概况 About ===== */
.about-grid {
  display: grid; grid-template-columns: 1fr 1fr; gap: 56px; align-items: center;
}
.about-copy h3 {
  font-size: 1.35rem; font-weight: 800; margin: 4px 0 16px; letter-spacing: .5px;
}
.about-copy p { color: var(--ink-soft); margin-bottom: 16px; }
.about-copy .glory {
  margin-top: 24px; padding: 22px 24px; background: var(--brand-tint);
  border-left: 3px solid var(--brand); border-radius: 0 var(--radius) var(--radius) 0;
}
.about-copy .glory b { color: var(--brand-dark); }
.about-copy .glory .t {
  font-family: "Barlow", sans-serif; font-size: .74rem; font-weight: 600;
  letter-spacing: 2px; text-transform: uppercase; color: var(--brand); display: block; margin-bottom: 6px;
}

/* ===== 图片占位 / 图片 ===== */
.ph {
  position: relative; width: 100%; background: var(--paper-warm2);
  border: 1px dashed #cfcdc6; border-radius: var(--radius);
  display: flex; flex-direction: column; align-items: center; justify-content: center;
  color: var(--ink-dim); text-align: center; padding: 24px; min-height: 240px; gap: 8px;
}
.ph svg { width: 34px; height: 34px; opacity: .5; }
.ph .fn {
  font-family: "Barlow", monospace; font-size: .82rem; color: var(--ink-soft);
  background: #fff; border: 1px solid var(--line); border-radius: 3px; padding: 2px 8px;
}
.ph .hint { font-size: .82rem; }
.frame { border-radius: var(--radius); overflow: hidden; border: 1px solid #c9cbcf; }
.frame img { width: 100%; height: 100%; object-fit: cover; }
.about-media .ph, .about-media .frame { min-height: 360px; height: 100%; }

/* ===== 组别 Groups ===== */
.groups { background: var(--paper-warm); }
.group-grid { display: flex; flex-wrap: wrap; justify-content: center; gap: 20px; }
.group-grid > .gcard { flex: 0 1 calc((100% - 20px) / 2); }
.gcard {
  background: #fff; border: 1px solid var(--line); border-radius: 6px;
  padding: 30px 30px 32px; transition: transform .22s, box-shadow .22s, border-color .22s;
  position: relative; overflow: hidden;
}
.gcard::before {
  content: ""; position: absolute; left: 0; top: 0; width: 3px; height: 0;
  background: var(--brand); transition: height .3s;
}
.gcard:hover {
  transform: translateY(-4px); border-color: #d7d5cf;
  box-shadow: 0 14px 40px rgba(22, 24, 29, .08);
}
.gcard:hover::before { height: 100%; }
.gcard .top { display: flex; align-items: flex-start; gap: 16px; }
.gcard .ic {
  flex: 0 0 auto; width: 46px; height: 46px; border-radius: 10px;
  background: var(--brand-tint); color: var(--brand);
  display: flex; align-items: center; justify-content: center;
}
.gcard .ic svg { width: 24px; height: 24px; }
.gcard .no {
  margin-left: auto; font-family: "Barlow", sans-serif; font-weight: 700;
  font-size: 1.6rem; color: var(--line); line-height: 1;
}
.gcard h3 { font-size: 1.25rem; font-weight: 800; letter-spacing: .5px; margin-top: 2px; }
.gcard .role {
  font-family: "Barlow", sans-serif; font-size: .76rem; font-weight: 600;
  letter-spacing: 1.5px; text-transform: uppercase; color: var(--brand); margin-top: 2px;
}
.gcard .desc { color: var(--ink-soft); font-size: .95rem; margin: 16px 0 0; }
.gcard ul { list-style: none; margin-top: 14px; }
.gcard ul li {
  position: relative; padding-left: 20px; color: var(--ink-soft);
  font-size: .9rem; margin-bottom: 6px; line-height: 1.6;
}
.gcard ul li::before {
  content: ""; position: absolute; left: 2px; top: 12px;
  width: 6px; height: 6px; background: var(--brand); border-radius: 1px; transform: rotate(45deg);
}
.chips { margin-top: 18px; display: flex; flex-wrap: wrap; gap: 8px; }
.chip {
  font-family: "Barlow", "Noto Sans SC", sans-serif; font-size: .76rem;
  padding: 4px 12px; border-radius: 999px; color: var(--ink-soft);
  background: var(--paper-warm); border: 1px solid var(--line);
}

/* ===== 兵种 Robots（深色卡片风） ===== */
#robots { background: var(--dark); }
#robots .sec-head h2 { color: #fff; }
#robots .sec-head p { color: #a9adb6; }
.robot-grid { display: flex; flex-wrap: wrap; justify-content: center; gap: 24px; }
.robot-grid > .rcard { flex: 0 1 calc((100% - 72px) / 4); }
.rcard {
  background: var(--dark-2); border: 1px solid rgba(255, 255, 255, .06); border-radius: 14px;
  overflow: hidden; display: flex; flex-direction: column;
  transition: transform .22s, box-shadow .22s, border-color .22s;
}
.rcard:hover {
  transform: translateY(-5px); border-color: rgba(255, 255, 255, .16);
  box-shadow: 0 20px 50px rgba(0, 0, 0, .45);
}
.rcard .pic {
  position: relative; aspect-ratio: 1 / 1; overflow: hidden;
}
.rcard .pic img {
  position: absolute; inset: 0; width: 100%; height: 100%;
  object-fit: contain; object-position: center;
}
.rcard .pic .ph {
  position: absolute; inset: 0; width: 100%; height: 100%; min-height: 0; border: 0;
  background: transparent; color: #5b6270;
}
.rcard .pic .ph .fn { background: rgba(255,255,255,.06); border-color: rgba(255,255,255,.12); color: #a9adb6; }
.rcard .body {
  padding: 4px 24px 32px; flex: 1;
  display: flex; flex-direction: column; align-items: center; text-align: center;
}
.rcard h3 { font-size: 1.5rem; font-weight: 800; letter-spacing: 2px; color: #fff; }
.rcard .label {
  margin-top: 14px; display: flex; align-items: center; gap: 12px;
  font-size: .84rem; letter-spacing: 3px; color: #c9cdd4;
}
.rcard .label::before, .rcard .label::after {
  content: ""; width: 24px; height: 2px; background: var(--brand);
}

/* ===== 招新流程 Process ===== */
.process { background: var(--dark); color: #fff; }
.process .sec-head h2 { color: #fff; }
.process .sec-head p { color: #a9adb6; }
.steps { display: grid; grid-template-columns: repeat(4, 1fr); gap: 22px; }
.step {
  position: relative; padding: 30px 26px; border-radius: 6px;
  background: var(--dark-2); border: 1px solid rgba(255, 255, 255, .08);
}
.step:not(:last-child)::after {
  content: ""; position: absolute; right: -13px; top: 44px; width: 22px; height: 2px;
  background: rgba(255, 255, 255, .16); z-index: 1;
}
.step .no {
  font-family: "Barlow", sans-serif; font-size: 2.4rem; font-weight: 700;
  color: var(--brand); line-height: 1;
}
.step h4 { margin: 14px 0 8px; font-size: 1.08rem; font-weight: 700; letter-spacing: .5px; }
.step p { color: #a9adb6; font-size: .9rem; }

/* ===== FAQ ===== */
.faq-wrap { max-width: 840px; margin: 0 auto; }
.faq {
  background: #fff; border: 1px solid var(--line); border-radius: 6px;
  margin-bottom: 12px; overflow: hidden; transition: border-color .2s;
}
.faq[open] { border-color: #d3d1ca; }
.faq summary {
  cursor: pointer; list-style: none; padding: 20px 56px 20px 24px;
  font-weight: 600; font-size: 1rem; position: relative; color: var(--ink);
}
.faq summary::-webkit-details-marker { display: none; }
.faq summary::after {
  content: ""; position: absolute; right: 26px; top: 50%; width: 12px; height: 12px;
  border-right: 2px solid var(--brand); border-bottom: 2px solid var(--brand);
  transform: translateY(-70%) rotate(45deg); transition: transform .25s;
}
.faq[open] summary::after { transform: translateY(-30%) rotate(-135deg); }
.faq .ans { padding: 0 24px 22px; color: var(--ink-soft); font-size: .95rem; }

/* ===== 加入我们 / 二维码 ===== */
.join { background: var(--paper-warm); }
.join-grid {
  display: grid; grid-template-columns: 1.2fr .8fr; gap: 56px; align-items: center;
}
.join-copy h2 {
  font-size: clamp(1.8rem, 4vw, 2.6rem); font-weight: 900; letter-spacing: 1px; line-height: 1.2;
}
.join-copy p { color: var(--ink-soft); margin-top: 18px; font-size: 1.05rem; max-width: 480px; }
.join-copy .btns { margin-top: 30px; display: flex; gap: 14px; flex-wrap: wrap; }
.qr-card {
  background: #fff; border: 1px solid var(--line); border-radius: 10px;
  padding: 26px; text-align: center; box-shadow: 0 14px 40px rgba(22, 24, 29, .06);
}
.qr-card .qr-img { width: 100%; aspect-ratio: 1; }
.qr-card .qr-img img { width: 100%; height: 100%; object-fit: contain; }
.qr-card .qr-img .ph { min-height: 0; height: 100%; }
.qr-card .cap { margin-top: 16px; font-weight: 600; color: var(--ink); }
.qr-card .sub { font-size: .85rem; color: var(--ink-dim); margin-top: 2px; }

/* ===== 了解更多 / 社交媒体 ===== */
.follow { background: var(--paper); }
.follow-grid {
  display: flex; flex-wrap: wrap; justify-content: center; gap: 24px;
}
.follow-grid > .fcard { flex: 0 1 calc((100% - 48px) / 3); }
.fcard {
  background: #fff; border: 1px solid var(--line); border-radius: 10px;
  padding: 34px 30px 30px; text-align: center;
  display: flex; flex-direction: column; align-items: center;
  transition: transform .22s, box-shadow .22s, border-color .22s;
}
.fcard:hover {
  transform: translateY(-4px); border-color: #d7d5cf;
  box-shadow: 0 14px 40px rgba(22, 24, 29, .08);
}
.fcard .fic {
  width: 54px; height: 54px; border-radius: 14px;
  display: flex; align-items: center; justify-content: center;
  background: var(--brand-tint); color: var(--brand);
}
.fcard .fic svg { width: 30px; height: 30px; }
.fcard .fic.bili { background: #e9f6fb; color: #00a1d6; }
.fcard .fic.douyin { background: #f1f1f4; color: #16181d; }
.fcard h3 { font-size: 1.2rem; font-weight: 800; letter-spacing: .5px; margin-top: 16px; }
.fcard .fname { font-size: .88rem; color: var(--ink-dim); margin-top: 4px; }
.fcard .fqr {
  width: 168px; height: 168px; margin: 20px auto 0;
  border: 1px solid var(--line); border-radius: 8px; overflow: hidden;
  background: var(--paper-warm);
}
.fcard .fqr img { width: 100%; height: 100%; object-fit: contain; }
.fcard .fqr .ph { min-height: 0; height: 100%; border: 0; padding: 14px; }
.fcard .ftip {
  margin-top: 14px; font-size: .85rem; color: var(--ink-soft); letter-spacing: 1px;
  display: inline-flex; align-items: center; gap: 8px;
}
.fcard .ftip::before {
  content: ""; width: 18px; height: 2px; background: var(--brand);
}

/* ===== 页脚 ===== */
.footer {
  background: var(--dark); color: #a9adb6; padding: 56px 0 40px; text-align: center;
}
.footer .brand { display: inline-flex; align-items: center; gap: 12px; margin-bottom: 18px; }
.footer .brand img { width: 40px; height: 40px; object-fit: contain; }
.footer .brand b { color: #fff; font-size: 1.1rem; font-weight: 800; letter-spacing: 1px; }
.footer .fs {
  font-size: 1.15rem; letter-spacing: 8px; color: #fff; font-weight: 600; margin-bottom: 12px;
}
.footer .fs b { color: var(--brand); }
.footer .meta { font-size: .88rem; }
.footer .en-foot {
  margin-top: 10px; font-family: "Barlow", sans-serif; font-size: .76rem;
  letter-spacing: 2px; color: #6b6f78;
}

/* ===== 滚动淡入 ===== */
.reveal { opacity: 0; transform: translateY(26px); transition: opacity .7s ease, transform .7s ease; }
.reveal.visible { opacity: 1; transform: none; }
@media (prefers-reduced-motion: reduce) {
  .reveal { opacity: 1; transform: none; transition: none; }
  html { scroll-behavior: auto; }
}

/* ===== 响应式 ===== */
@media (max-width: 960px) {
  section { padding: 80px 0; }
  .group-grid > .gcard { flex-basis: 100%; }
  .robot-grid > .rcard { flex-basis: calc((100% - 24px) / 2); }
  .steps { grid-template-columns: repeat(2, 1fr); }
  .step:nth-child(2)::after { display: none; }
  .about-grid { grid-template-columns: 1fr; gap: 36px; }
  .about-media { order: -1; }
  .about-media .ph, .about-media .frame { min-height: 260px; }
  .join-grid { grid-template-columns: 1fr; gap: 36px; }
  .qr-card { max-width: 320px; margin: 0 auto; }
  .follow-grid > .fcard { flex-basis: 100%; max-width: 340px; }
}
@media (max-width: 640px) {
  :root { --pad: 20px; }
  .nav ul {
    position: fixed; top: 66px; left: 0; right: 0; flex-direction: column;
    gap: 0; background: #fff; border-bottom: 1px solid var(--line);
    padding: 8px 0; transform: translateY(-140%); transition: transform .3s;
    box-shadow: 0 14px 30px rgba(0,0,0,.08);
  }
  .nav ul.open { transform: translateY(0); }
  .nav ul li { width: 100%; }
  .nav ul a { display: block; padding: 12px 24px; }
  .nav ul a::after { display: none; }
  .nav .nav-cta { margin: 8px 24px; text-align: center; }
  .nav .burger { display: block; }
  .stats .grid { grid-template-columns: repeat(2, 1fr); gap: 28px 0; }
  .stat:nth-child(3)::before { display: none; }
  .robot-grid > .rcard { flex-basis: 100%; }
  .steps { grid-template-columns: 1fr; }
  .step::after { display: none !important; }
  .hero .slogan { letter-spacing: 4px; }
}