/* ============================================================
   R-Power 复兴动力 — Corporate Website
   Design ref: Boston Dynamics (industrial restraint) x Linear (dark technical)
   Zero external dependencies. System font stacks only.
   ============================================================ */

:root {
  --bg: #0a0e14;
  --bg-2: #0e1420;
  --panel: #121a28;
  --panel-2: #16203300;
  --line: #1f2c42;
  --line-strong: #2c3d5c;
  --text: #e8ecf3;
  --muted: #93a1b8;
  --dim: #5d6b82;
  --accent: #46b1ff;
  --accent-soft: rgba(70, 177, 255, 0.12);
  --amber: #ffb347;
  --mono: "SFMono-Regular", ui-monospace, "Cascadia Mono", Menlo, Consolas, "Liberation Mono", monospace;
  --sans: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, "Helvetica Neue", Arial, "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei", "Noto Sans CJK SC", sans-serif;
  --maxw: 1180px;
  --radius: 10px;
}

* { margin: 0; padding: 0; box-sizing: border-box; }
html { scroll-behavior: smooth; }
body {
  background: var(--bg);
  color: var(--text);
  font-family: var(--sans);
  font-size: 16px;
  line-height: 1.7;
  -webkit-font-smoothing: antialiased;
  text-rendering: optimizeLegibility;
  overflow-x: hidden;
}

/* Blueprint grid backdrop */
body::before {
  content: "";
  position: fixed;
  inset: 0;
  background-image:
    linear-gradient(rgba(70,177,255,0.035) 1px, transparent 1px),
    linear-gradient(90deg, rgba(70,177,255,0.035) 1px, transparent 1px);
  background-size: 48px 48px;
  pointer-events: none;
  z-index: 0;
}
body::after {
  content: "";
  position: fixed;
  inset: 0;
  background: radial-gradient(1100px 500px at 75% -8%, rgba(70,177,255,0.10), transparent 60%);
  pointer-events: none;
  z-index: 0;
}

a { color: var(--accent); text-decoration: none; }
a:hover { text-decoration: underline; }
img, svg { max-width: 100%; display: block; }
.wrap { position: relative; z-index: 1; max-width: var(--maxw); margin: 0 auto; padding: 0 28px; }

/* ---------------- Header / Nav ---------------- */
header.site {
  position: sticky; top: 0; z-index: 50;
  background: rgba(10,14,20,0.82);
  backdrop-filter: blur(12px);
  -webkit-backdrop-filter: blur(12px);
  border-bottom: 1px solid var(--line);
}
.nav {
  display: flex; align-items: center; gap: 32px;
  max-width: var(--maxw); margin: 0 auto; padding: 0 28px;
  height: 64px;
}
.brand { display: flex; align-items: center; gap: 11px; color: var(--text); font-weight: 700; letter-spacing: 0.2px; }
.brand:hover { text-decoration: none; }
.brand .mark { width: 30px; height: 30px; flex: none; }
.brand .name { font-size: 17px; }
.brand .name small { display: block; font-family: var(--mono); font-size: 10px; color: var(--dim); letter-spacing: 2.5px; font-weight: 400; }
nav.links { display: flex; gap: 4px; margin-left: auto; align-items: center; }
nav.links a {
  color: var(--muted); font-size: 14.5px; padding: 8px 13px; border-radius: 7px;
  transition: color .15s, background .15s; white-space: nowrap;
}
nav.links a:hover { color: var(--text); background: rgba(255,255,255,0.05); text-decoration: none; }
nav.links a.active { color: var(--accent); background: var(--accent-soft); }
.lang-switch {
  font-family: var(--mono); font-size: 12.5px; letter-spacing: 1px;
  border: 1px solid var(--line-strong); border-radius: 7px;
  padding: 6px 11px; color: var(--muted); margin-left: 8px;
}
.lang-switch:hover { color: var(--text); border-color: var(--accent); text-decoration: none; }
.nav-toggle { display: none; background: none; border: 1px solid var(--line-strong); border-radius: 7px; color: var(--text); font-size: 18px; width: 40px; height: 36px; cursor: pointer; margin-left: auto; }

/* ---------------- Hero ---------------- */
.hero { padding: 108px 0 84px; position: relative; }
.hero .tag {
  display: inline-flex; align-items: center; gap: 8px;
  font-family: var(--mono); font-size: 12px; letter-spacing: 2.5px; color: var(--accent);
  border: 1px solid rgba(70,177,255,0.35); border-radius: 999px; padding: 6px 15px;
  margin-bottom: 30px; background: var(--accent-soft);
}
.hero .tag::before { content: ""; width: 6px; height: 6px; border-radius: 50%; background: var(--accent); box-shadow: 0 0 8px var(--accent); }
.hero h1 {
  font-size: clamp(34px, 5.2vw, 58px); line-height: 1.18; font-weight: 800;
  letter-spacing: -0.5px; max-width: 900px;
}
.hero h1 .hl { color: var(--accent); }
.hero p.sub { margin-top: 24px; font-size: clamp(16px, 1.8vw, 19px); color: var(--muted); max-width: 760px; }
.hero .cta-row { margin-top: 40px; display: flex; gap: 14px; flex-wrap: wrap; }
.btn {
  display: inline-flex; align-items: center; gap: 9px;
  padding: 13px 26px; border-radius: 9px; font-size: 15px; font-weight: 600;
  border: 1px solid transparent; cursor: pointer; transition: all .16s;
}
.btn:hover { text-decoration: none; transform: translateY(-1px); }
.btn-primary { background: var(--accent); color: #06121f; }
.btn-primary:hover { background: #6cc2ff; }
.btn-ghost { border-color: var(--line-strong); color: var(--text); background: rgba(255,255,255,0.02); }
.btn-ghost:hover { border-color: var(--accent); }

.hero-stats { margin-top: 64px; display: grid; grid-template-columns: repeat(auto-fit, minmax(200px, 1fr)); gap: 1px; background: var(--line); border: 1px solid var(--line); border-radius: var(--radius); overflow: hidden; }
.hero-stats .stat { background: var(--bg-2); padding: 22px 24px; }
.hero-stats .stat b { display: block; font-family: var(--mono); font-size: 21px; color: var(--text); font-weight: 600; }
.hero-stats .stat span { font-size: 13px; color: var(--dim); }

/* ---------------- Sections ---------------- */
section.block { padding: 84px 0; border-top: 1px solid var(--line); position: relative; z-index: 1; }
.kicker { font-family: var(--mono); font-size: 12px; letter-spacing: 3px; color: var(--accent); text-transform: uppercase; margin-bottom: 14px; }
h2.title { font-size: clamp(26px, 3.4vw, 38px); font-weight: 750; letter-spacing: -0.4px; line-height: 1.25; max-width: 820px; }
p.lead { margin-top: 18px; color: var(--muted); font-size: 17px; max-width: 780px; }

.grid-3 { display: grid; grid-template-columns: repeat(auto-fit, minmax(300px, 1fr)); gap: 20px; margin-top: 48px; }
.grid-2 { display: grid; grid-template-columns: repeat(auto-fit, minmax(340px, 1fr)); gap: 20px; margin-top: 48px; }

.card {
  background: linear-gradient(180deg, var(--panel), rgba(14,20,32,0.6));
  border: 1px solid var(--line); border-radius: var(--radius);
  padding: 30px 28px; position: relative; overflow: hidden;
  transition: border-color .2s, transform .2s;
}
.card:hover { border-color: var(--line-strong); transform: translateY(-2px); }
.card .corner { position: absolute; top: 10px; right: 12px; color: var(--dim); font-family: var(--mono); font-size: 15px; opacity: .6; }
.card .icon { width: 44px; height: 44px; margin-bottom: 20px; color: var(--accent); }
.card h3 { font-size: 19.5px; font-weight: 700; margin-bottom: 10px; }
.card p { color: var(--muted); font-size: 14.5px; }
.card .foot { margin-top: 18px; padding-top: 16px; border-top: 1px dashed var(--line); font-family: var(--mono); font-size: 12px; color: var(--dim); letter-spacing: 0.5px; }

/* Spec table */
table.spec { width: 100%; border-collapse: collapse; margin-top: 26px; font-size: 14.5px; }
table.spec th, table.spec td { text-align: left; padding: 12px 14px; border-bottom: 1px solid var(--line); }
table.spec th { font-family: var(--mono); font-size: 11.5px; letter-spacing: 1.5px; color: var(--dim); text-transform: uppercase; font-weight: 500; }
table.spec td { color: var(--muted); }
table.spec td:first-child { color: var(--text); font-weight: 600; white-space: nowrap; }
table.spec .target { font-family: var(--mono); color: var(--amber); font-size: 13px; }

/* Flow / flywheel diagram */
.flow { margin-top: 52px; display: flex; flex-direction: column; gap: 0; }
.flow .node {
  border: 1px solid var(--line-strong); background: var(--bg-2);
  border-radius: var(--radius); padding: 18px 24px;
  display: flex; align-items: baseline; gap: 18px; flex-wrap: wrap;
}
.flow .node b { font-size: 16px; }
.flow .node .m { font-family: var(--mono); font-size: 11.5px; color: var(--accent); letter-spacing: 1.5px; }
.flow .node p { color: var(--muted); font-size: 13.5px; width: 100%; }
.flow .arrow { text-align: center; color: var(--dim); font-family: var(--mono); padding: 6px 0; font-size: 15px; }

/* Tech stack strip */
.stack-strip {
  margin-top: 48px; border: 1px solid rgba(70,177,255,0.28); border-radius: var(--radius);
  background: linear-gradient(120deg, rgba(70,177,255,0.07), rgba(70,177,255,0.015));
  padding: 32px 30px;
}
.stack-strip .nv { font-family: var(--mono); font-size: 12px; letter-spacing: 2px; color: var(--accent); margin-bottom: 12px; }
.stack-strip p { color: var(--text); font-size: 16.5px; max-width: 900px; }
.stack-strip .disclaimer { margin-top: 16px; font-size: 12.5px; color: var(--dim); }

/* Team */
.team-grid { display: grid; grid-template-columns: repeat(auto-fill, minmax(260px, 1fr)); gap: 18px; margin-top: 48px; }
.member { border: 1px solid var(--line); border-radius: var(--radius); padding: 26px 24px; background: var(--bg-2); transition: border-color .2s; }
.member:hover { border-color: var(--line-strong); }
.member .avatar {
  width: 54px; height: 54px; border-radius: 12px; margin-bottom: 18px;
  background: linear-gradient(135deg, var(--accent-soft), rgba(70,177,255,0.25));
  border: 1px solid rgba(70,177,255,0.4);
  display: flex; align-items: center; justify-content: center;
  font-family: var(--mono); font-weight: 700; color: var(--accent); font-size: 18px;
}
.member h3 { font-size: 17px; }
.member .role { font-family: var(--mono); font-size: 11.5px; letter-spacing: 1.5px; color: var(--accent); margin: 5px 0 12px; text-transform: uppercase; }
.member p { font-size: 13.5px; color: var(--muted); }

/* Timeline */
.timeline { margin-top: 52px; position: relative; padding-left: 26px; }
.timeline::before { content: ""; position: absolute; left: 6px; top: 6px; bottom: 6px; width: 1px; background: var(--line-strong); }
.tl-item { position: relative; padding: 0 0 30px 22px; }
.tl-item::before { content: ""; position: absolute; left: -24px; top: 7px; width: 11px; height: 11px; border-radius: 50%; background: var(--bg); border: 2px solid var(--accent); }
.tl-item .when { font-family: var(--mono); font-size: 12px; color: var(--accent); letter-spacing: 2px; }
.tl-item b { display: block; margin: 4px 0; font-size: 16px; }
.tl-item p { color: var(--muted); font-size: 14px; max-width: 680px; }

/* Notice / disclosure */
.notice {
  margin-top: 44px; border: 1px dashed var(--line-strong); border-radius: var(--radius);
  padding: 24px 26px; background: rgba(255,255,255,0.015);
}
.notice h4 { font-family: var(--mono); font-size: 12px; letter-spacing: 2px; color: var(--amber); margin-bottom: 12px; text-transform: uppercase; }
.notice p, .notice li { font-size: 13.5px; color: var(--muted); }
.notice ul { padding-left: 20px; }

/* Contact */
.contact-grid { display: grid; grid-template-columns: 1fr 1.15fr; gap: 40px; margin-top: 48px; }
@media (max-width: 860px) { .contact-grid { grid-template-columns: 1fr; } }
.contact-item { padding: 20px 0; border-bottom: 1px solid var(--line); }
.contact-item .k { font-family: var(--mono); font-size: 11.5px; letter-spacing: 2px; color: var(--dim); text-transform: uppercase; margin-bottom: 6px; }
.contact-item .v { font-size: 16.5px; color: var(--text); }
.contact-item .v a { word-break: break-all; }
form.contact-form { display: grid; gap: 14px; }
form.contact-form label { font-family: var(--mono); font-size: 11.5px; letter-spacing: 1.5px; color: var(--dim); text-transform: uppercase; display: block; margin-bottom: 6px; }
form.contact-form input, form.contact-form textarea {
  width: 100%; background: var(--bg-2); border: 1px solid var(--line-strong);
  border-radius: 8px; color: var(--text); padding: 12px 14px; font-size: 15px;
  font-family: var(--sans); outline: none; transition: border-color .15s;
}
form.contact-form input:focus, form.contact-form textarea:focus { border-color: var(--accent); }
form.contact-form textarea { min-height: 130px; resize: vertical; }

/* CTA band */
.cta-band { border-top: 1px solid var(--line); padding: 72px 0; text-align: center; position: relative; z-index: 1; }
.cta-band h2 { font-size: clamp(24px, 3vw, 34px); font-weight: 750; }
.cta-band p { color: var(--muted); margin: 14px auto 30px; max-width: 560px; }

/* Footer */
footer.site { border-top: 1px solid var(--line); background: var(--bg-2); position: relative; z-index: 1; }
footer.site .cols { display: grid; grid-template-columns: 2fr 1fr 1fr 1.4fr; gap: 36px; padding: 56px 0 40px; }
@media (max-width: 860px) { footer.site .cols { grid-template-columns: 1fr 1fr; } }
@media (max-width: 560px) { footer.site .cols { grid-template-columns: 1fr; } }
footer.site h5 { font-family: var(--mono); font-size: 11.5px; letter-spacing: 2px; color: var(--dim); text-transform: uppercase; margin-bottom: 14px; font-weight: 500; }
footer.site a { color: var(--muted); font-size: 14px; display: block; padding: 4px 0; }
footer.site a:hover { color: var(--text); }
footer.site .about-brand { color: var(--muted); font-size: 13.5px; max-width: 320px; margin-top: 14px; }
footer .legal { border-top: 1px solid var(--line); padding: 22px 0 30px; }
footer .legal p { font-size: 12px; color: var(--dim); max-width: 900px; margin-bottom: 6px; }

/* Page hero (interior pages) */
.page-hero { padding: 84px 0 56px; }
.page-hero h1 { font-size: clamp(30px, 4.2vw, 46px); font-weight: 800; letter-spacing: -0.4px; }
.page-hero p { margin-top: 16px; color: var(--muted); font-size: 17px; max-width: 780px; }

/* Utility */
.mono { font-family: var(--mono); }
.mt-40 { margin-top: 40px; }
.pill-row { display: flex; flex-wrap: wrap; gap: 10px; margin-top: 26px; }
.pill {
  font-family: var(--mono); font-size: 12.5px; letter-spacing: 0.5px;
  border: 1px solid var(--line-strong); color: var(--muted);
  padding: 7px 14px; border-radius: 999px; background: rgba(255,255,255,0.02);
}
.pill.hot { border-color: rgba(70,177,255,0.5); color: var(--accent); background: var(--accent-soft); }

/* ===== media / proof / split ===== */
.media-grid { display:grid; grid-template-columns:1fr 1fr; gap:18px; margin:26px 0 8px; }
.media-grid figure { margin:0; border:1px solid var(--line); border-radius:10px; overflow:hidden; background:var(--panel); }
.media-grid img { display:block; width:100%; height:auto; aspect-ratio:16/10; object-fit:cover; }
.media-grid figcaption { padding:10px 14px; font-size:12.5px; color:var(--dim); border-top:1px solid var(--line); letter-spacing:.04em; }
.split { display:grid; grid-template-columns:1.05fr .95fr; gap:34px; align-items:start; }
.proof-grid { display:grid; grid-template-columns:repeat(3,1fr); gap:18px; margin-top:26px; }
.proof-col { border:1px solid var(--line); border-radius:10px; background:var(--panel); padding:20px 22px; }
.proof-col h4 { font-size:12.5px; letter-spacing:.14em; color:var(--accent); margin:0 0 4px; }
.proof-col .sub { font-size:12px; color:var(--dim); margin:0 0 14px; }
.proof-col ul { list-style:none; padding:0; margin:0; }
.proof-col li { font-size:13.5px; color:var(--muted); padding:7px 0 7px 18px; border-bottom:1px dashed var(--line); position:relative; }
.proof-col li:last-child { border-bottom:none; }
.proof-col li::before { content:""; position:absolute; left:0; top:14px; width:7px; height:7px; border:1.5px solid var(--accent); border-radius:2px; }
.proof-col.done li::before { background:var(--accent); }
@media (max-width: 900px) { .split { grid-template-columns:1fr; } .proof-grid { grid-template-columns:1fr; } .media-grid { grid-template-columns:1fr; } }

/* Responsive nav */
@media (max-width: 860px) {
  .nav { flex-wrap: wrap; height: auto; padding-top: 10px; padding-bottom: 10px; }
  .nav-toggle { display: block; }
  nav.links { display: none; width: 100%; flex-direction: column; align-items: stretch; padding: 10px 0 6px; gap: 2px; }
  nav.links.open { display: flex; }
  nav.links a { padding: 11px 12px; }
  .lang-switch { margin: 0 0 0 auto; }
  .hero { padding: 72px 0 60px; }
}

/* ===== brand film ===== */
.video-wrap { margin-top: 26px; border: 1px solid var(--line); border-radius: var(--radius); overflow: hidden; background: #000; }
.video-wrap video { display: block; width: 100%; height: auto; }
.film-note { margin-top: 12px; font-size: 13px; color: var(--muted); }