:root {
  --ink: #0F172A;
  --muted: #64748B;
  --line: #E5E7EB;
  --accent: #2563EB;
  --accent2: #06B6D4;
  --warn: #D97706;
  --danger: #DC2626;
  --bg: #F4F6FB;
}
* { box-sizing: border-box; }
html { scroll-behavior: smooth; }
body {
  margin: 0;
  font-family: -apple-system, "PingFang SC", "Microsoft YaHei", "Noto Sans CJK SC", sans-serif;
  color: var(--ink);
  background: var(--bg);
  line-height: 1.7;
}
.wrap { max-width: 1100px; margin: 0 auto; padding: 0 20px; }

/* ---------- Hero ---------- */
.hero { position: relative; color: #fff; overflow: hidden; }
.hero-bg {
  position: absolute; inset: 0;
  background: linear-gradient(120deg, #0B1E4B, #123B8F, #1D4ED8, #06B6D4, #123B8F, #0B1E4B);
  background-size: 400% 400%;
  animation: heroShift 18s ease infinite;
}
.hero-bg::after {
  content: ""; position: absolute; inset: 0;
  background-image: radial-gradient(rgba(255,255,255,.14) 1px, transparent 1px);
  background-size: 26px 26px;
  mask-image: linear-gradient(to bottom, rgba(0,0,0,.7), transparent);
}
@keyframes heroShift { 0% { background-position: 0% 50%; } 50% { background-position: 100% 50%; } 100% { background-position: 0% 50%; } }
.hero-inner { position: relative; padding: 54px 20px 30px; }
.kicker { font-size: 13px; letter-spacing: 2px; opacity: .85; margin-bottom: 10px; }
.hero h1 { font-size: 34px; margin: 0 0 8px; font-weight: 800; letter-spacing: 1px; }
.hero h1 .grad {
  margin-left: 12px;
  background: linear-gradient(90deg, #7DD3FC, #F0ABFC, #FDE68A, #7DD3FC);
  background-size: 300% 100%;
  -webkit-background-clip: text; background-clip: text; color: transparent;
  animation: gradText 6s linear infinite;
}
@keyframes gradText { to { background-position: 300% 0; } }
.hero .sub { font-size: 14.5px; opacity: .92; margin: 0 0 26px; }
.counters { display: grid; grid-template-columns: repeat(4, 1fr); gap: 14px; max-width: 860px; }
.counter {
  background: rgba(255, 255, 255, .10);
  border: 1px solid rgba(255, 255, 255, .22);
  border-radius: 12px; padding: 14px 16px;
  backdrop-filter: blur(6px);
  transition: transform .25s ease, background .25s ease;
}
.counter:hover { transform: translateY(-3px); background: rgba(255, 255, 255, .18); }
.counter .num { font-size: 30px; font-weight: 800; line-height: 1.1; font-variant-numeric: tabular-nums; }
.counter .lab { font-size: 12.5px; opacity: .85; margin-top: 4px; }
@media (max-width: 860px) { .counters { grid-template-columns: repeat(2, 1fr); } .hero h1 { font-size: 26px; } }

.topnav { position: relative; background: rgba(8, 20, 50, .55); backdrop-filter: blur(8px); }
.topnav .wrap { display: flex; gap: 4px; overflow-x: auto; }
.topnav a {
  color: rgba(255, 255, 255, .82); text-decoration: none; font-size: 14px;
  padding: 12px 16px; white-space: nowrap; border-bottom: 2px solid transparent;
  transition: color .2s, border-color .2s;
}
.topnav a:hover { color: #fff; }
.topnav a.active { color: #fff; border-bottom-color: #7DD3FC; }

/* ---------- 卡片与动效 ---------- */
main { padding: 26px 0 8px; }
.card {
  background: #fff; border: 1px solid var(--line); border-radius: 14px;
  padding: 26px 28px; margin-bottom: 22px;
  box-shadow: 0 1px 3px rgba(16, 24, 40, .05);
  transition: box-shadow .3s ease, transform .3s ease;
}
.card:hover { box-shadow: 0 10px 30px rgba(37, 99, 235, .10); transform: translateY(-2px); }
.card h2 { font-size: 18px; margin: 0 0 10px; display: flex; align-items: center; gap: 9px; }
.card h3 { font-size: 15px; margin: 18px 0 8px; }
.card p { font-size: 14px; margin: 8px 0; }
.dot { width: 9px; height: 9px; border-radius: 50%; background: linear-gradient(135deg, var(--accent), var(--accent2)); box-shadow: 0 0 0 4px rgba(37, 99, 235, .12); }
.small { font-size: 12.5px; color: var(--muted); }
code { background: #F1F5F9; padding: 1px 6px; border-radius: 4px; font-size: 12.5px; font-family: "SF Mono", Consolas, monospace; }

.reveal { opacity: 0; transform: translateY(26px); transition: opacity .7s ease, transform .7s ease; }
.reveal.shown { opacity: 1; transform: none; }

.grid4 { display: grid; grid-template-columns: repeat(4, 1fr); gap: 12px; margin-top: 10px; }
.mcard {
  border: 1px solid var(--line); border-radius: 10px; padding: 13px 15px;
  background: linear-gradient(180deg, #fff, #F8FAFF);
  transition: transform .25s ease, border-color .25s ease;
}
.mcard:hover { transform: translateY(-3px); border-color: var(--accent); }
.mcard .t { font-size: 13px; color: var(--muted); margin-bottom: 6px; }
.mcard .v { font-size: 15px; font-weight: 700; font-variant-numeric: tabular-nums; }
.mcard .v span { font-weight: 400; color: var(--muted); font-size: 12px; }

.controls { display: flex; flex-wrap: wrap; gap: 10px; margin: 10px 0 14px; }
.btnrow { display: flex; flex-wrap: wrap; gap: 8px; }
.btnrow button {
  border: 1px solid var(--line); background: #fff; border-radius: 999px;
  padding: 6px 16px; font-size: 13px; cursor: pointer; color: var(--ink);
  transition: all .2s ease;
}
.btnrow button.active {
  background: linear-gradient(135deg, var(--accent), #1D4ED8);
  border-color: transparent; color: #fff;
  box-shadow: 0 4px 12px rgba(37, 99, 235, .35);
}
.btnrow button:hover { border-color: var(--accent); transform: translateY(-1px); }

.chartbox { position: relative; border: 1px solid #EEF2F7; border-radius: 10px; padding: 6px; background: #FDFEFF; }
canvas { width: 100%; display: block; border-radius: 6px; }
.two { display: grid; grid-template-columns: 1fr 1fr; gap: 20px; }
@media (max-width: 860px) { .two, .grid4 { grid-template-columns: 1fr; } }

.note {
  background: #FFFBEB; border: 1px solid #FDE68A; border-radius: 8px;
  padding: 10px 14px; font-size: 13px; margin-top: 12px; color: #92400E;
}
.metricline { font-size: 13px; color: var(--muted); margin-top: 8px; }
.metricline b { color: var(--ink); }

.imgrow { display: grid; grid-template-columns: 1fr 1fr; gap: 16px; margin: 14px 0; }
.imgrow figure { margin: 0; text-align: center; }
.imgrow img { max-width: 100%; border: 1px solid var(--line); border-radius: 8px; transition: transform .3s ease; }
.imgrow img:hover { transform: scale(1.015); }
.imgrow figcaption { font-size: 12.5px; color: var(--muted); margin-top: 6px; }
@media (max-width: 860px) { .imgrow { grid-template-columns: 1fr; } }

/* ---------- 工程应用流程 ---------- */
.flow { display: flex; align-items: stretch; gap: 6px; margin: 16px 0; flex-wrap: wrap; }
.fbox {
  flex: 1; min-width: 130px;
  border: 1.5px solid var(--accent); color: var(--accent);
  border-radius: 12px; padding: 12px 10px; text-align: center; font-size: 14px; font-weight: 700;
  background: linear-gradient(180deg, #EFF6FF, #fff);
  transition: transform .25s ease, box-shadow .25s ease;
}
.fbox:hover { transform: translateY(-3px); box-shadow: 0 8px 18px rgba(37, 99, 235, .18); }
.fbox span { display: block; font-size: 12px; font-weight: 400; color: var(--muted); margin-top: 4px; }
.farrow {
  align-self: center; color: var(--accent); font-size: 20px; font-weight: 700;
  animation: arrowPulse 1.6s ease-in-out infinite;
}
@keyframes arrowPulse { 0%, 100% { transform: translateX(0); opacity: .55; } 50% { transform: translateX(4px); opacity: 1; } }

/* ---------- 预警滑块与大数字 ---------- */
.warnpanel { border: 1px solid #EEF2F7; border-radius: 12px; padding: 14px 16px; background: linear-gradient(180deg, #fff, #FBFCFF); }
.sliderow { display: flex; align-items: center; gap: 12px; margin-top: 10px; font-size: 13px; color: var(--muted); }
.sliderow b { color: var(--ink); min-width: 42px; text-align: right; font-variant-numeric: tabular-nums; }
input[type="range"] { flex: 1; appearance: none; height: 6px; border-radius: 999px; background: linear-gradient(90deg, var(--accent), var(--accent2)); outline: none; }
input[type="range"]::-webkit-slider-thumb {
  appearance: none; width: 20px; height: 20px; border-radius: 50%;
  background: #fff; border: 3px solid var(--accent);
  box-shadow: 0 2px 8px rgba(37, 99, 235, .4); cursor: pointer;
  transition: transform .15s ease;
}
input[type="range"]::-webkit-slider-thumb:hover { transform: scale(1.15); }
.leadnum {
  display: flex; align-items: baseline; gap: 10px; margin-top: 12px;
  font-size: 14px; color: var(--muted);
}
.leadnum b {
  font-size: 38px; font-weight: 800; line-height: 1;
  background: linear-gradient(135deg, var(--accent), var(--accent2));
  -webkit-background-clip: text; background-clip: text; color: transparent;
  font-variant-numeric: tabular-nums; transition: opacity .2s ease;
}
.leadnum .unit { font-size: 13px; }

/* ---------- 悬浮读数 ---------- */
.tooltip {
  position: fixed; z-index: 50; pointer-events: none; display: none;
  background: rgba(15, 23, 42, .92); color: #fff; font-size: 12px;
  border-radius: 8px; padding: 8px 11px; line-height: 1.6;
  box-shadow: 0 8px 22px rgba(15, 23, 42, .3); max-width: 260px;
}
.tooltip .tt-x { color: #93C5FD; font-weight: 700; margin-bottom: 2px; }
.tooltip .tt-row { display: flex; align-items: center; gap: 6px; }
.tooltip .tt-dot { width: 8px; height: 8px; border-radius: 50%; }

table.mini { border-collapse: collapse; width: 100%; margin-top: 12px; font-size: 12.5px; }
table.mini th, table.mini td { border: 1px solid var(--line); padding: 6px 10px; text-align: left; }
table.mini th { background: #F8FAFC; }
table.mini tr:hover td { background: #F8FAFF; }
footer { color: var(--muted); font-size: 12.5px; text-align: center; padding: 18px 0 30px; }
ul { font-size: 14px; padding-left: 20px; }
li { margin: 6px 0; }