/* 深北电力 · 现代科技风格 */
:root {
  --bg: #0b1220;
  --bg-alt: #0f182b;
  --card: rgba(255, 255, 255, 0.06);
  --glass: rgba(255, 255, 255, 0.08);
  --text: #e6f0ff;
  --muted: #a1b4d6;
  --primary: #00e1ff;
  --primary-2: #7a5cff;
  --accent: #18e299;
  --danger: #ff4d6d;
  --shadow: 0 10px 30px rgba(0, 225, 255, 0.08);
  --radius: 14px;
  --radius-lg: 22px;
  --container: 1240px;
}

* { box-sizing: border-box }
html, body { height: 100% }
body {
  margin: 0;
  font-family: ui-sans-serif, -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto,
    PingFangSC, "Hiragino Sans GB", "Microsoft YaHei", "Noto Sans CJK SC",
    "Helvetica Neue", Arial, sans-serif;
  color: var(--text);
  background: radial-gradient(1200px 800px at 70% -10%, rgba(0,225,255,.07), transparent 60%),
              radial-gradient(900px 600px at 10% -10%, rgba(122,92,255,.08), transparent 60%),
              var(--bg);
  overflow-x: hidden;
}

.container {
  width: min(100% - 32px, var(--container));
  margin-inline: auto;
}

/* 背景特效画布 */
#fx-bg {
  position: fixed; inset: 0; z-index: -1;
  background: transparent;
}

/* Header / Nav */
.site-header {
  position: sticky; top: 0; z-index: 20;
  backdrop-filter: saturate(160%) blur(10px);
  background: linear-gradient(180deg, rgba(11,18,32,.75), rgba(11,18,32,.3));
  border-bottom: 1px solid rgba(255,255,255,.08);
}
.nav { display: flex; align-items: center; justify-content: space-between; height: 64px; }
.brand { display: inline-flex; align-items: center; gap: 10px; color: var(--text); text-decoration: none; font-weight: 700; letter-spacing: .4px; }
.brand__logo { display: grid; place-items: center; width: 28px; height: 28px; border-radius: 8px; background: linear-gradient(135deg, var(--primary), var(--primary-2)); box-shadow: var(--shadow); }
.brand__img { display: block; height: 28px; width: auto; filter: drop-shadow(0 2px 6px rgba(0,0,0,.2)); }
.brand__text { font-size: 18px }
.nav__links { display: flex; align-items: center; gap: 22px; }
.nav__links a { color: var(--muted); text-decoration: none; font-weight: 500; }
.nav__links a:hover { color: var(--text) }
.nav__toggle { display: none; background: transparent; border: 0; color: var(--text); font-size: 22px; }

/* Buttons */
.btn { display:inline-flex; align-items:center; gap:10px; padding: 10px 16px; border-radius: 12px; border: 1px solid rgba(255,255,255,.12); text-decoration: none; color: var(--text); font-weight: 600; transition: .25s ease; }
.btn--primary { background: linear-gradient(135deg, var(--primary), var(--primary-2)); color: #001018; border: 0; box-shadow: var(--shadow); }
.btn--primary:hover { transform: translateY(-1px); filter: brightness(1.06); }
.btn--ghost:hover { background: var(--glass); }
.btn--sm { padding: 6px 10px; font-size: 13px; border-radius: 10px; }

/* Hero */
.hero { position: relative; padding: 96px 0 56px; }
.hero__inner { display: grid; grid-template-columns: 1.1fr .9fr; align-items: center; gap: 40px; }
.eyebrow { text-transform: uppercase; letter-spacing: .28em; color: var(--accent); font-weight: 700; font-size: 12px; margin: 0 0 12px; }
.hero h1 { font-size: clamp(28px, 4vw, 52px); line-height: 1.08; margin: 8px 0 16px; }
.subtitle { color: var(--muted); font-size: 16px; line-height: 1.7; }
.cta { margin: 24px 0 12px; display: flex; gap: 12px; flex-wrap: wrap; }
.trust { list-style: none; padding: 0; margin: 18px 0 0; display: flex; gap: 18px; color: var(--muted); }
.trust li { padding-left: 22px; position: relative; }
.trust li::before { content: ""; position: absolute; left: 0; top: .45em; width: 10px; height: 10px; border-radius: 3px; background: linear-gradient(135deg, var(--accent), var(--primary)); box-shadow: 0 0 0 2px rgba(24,226,153,.15); }

.hero__viz { position: relative; min-height: 360px; }
.orb { position: absolute; filter: blur(18px); border-radius: 50%; opacity: .75; mix-blend-mode: screen; }
.orb--a { width: 200px; height: 200px; right: 18%; top: 6%; background: radial-gradient(circle at 30% 30%, #00e1ff, transparent 60%), radial-gradient(circle at 70% 70%, #7a5cff, transparent 60%); animation: floatA 9s ease-in-out infinite; }
.orb--b { width: 320px; height: 320px; right: -30px; bottom: -20px; background: radial-gradient(circle at 20% 20%, #18e299, transparent 60%), radial-gradient(circle at 70% 60%, #00e1ff, transparent 60%); animation: floatB 12s ease-in-out infinite; }
@keyframes floatA { 0%,100%{ transform: translateY(0) } 50% { transform: translateY(-12px) } }
@keyframes floatB { 0%,100%{ transform: translate(-10px, 0) } 50% { transform: translate(6px, -10px) } }
.grid-3d { position: absolute; inset: 10% 0 0 0; margin: auto; width: 78%; height: 70%; border-radius: var(--radius-lg); background: linear-gradient(rgba(255,255,255,.06), rgba(255,255,255,.02)); box-shadow: inset 0 0 0 1px rgba(255,255,255,.06); overflow: hidden; }
.grid-3d::before { content:""; position: absolute; inset: 0; background-image: linear-gradient(rgba(255,255,255,.08) 1px, transparent 1px), linear-gradient(90deg, rgba(255,255,255,.08) 1px, transparent 1px); background-size: 42px 42px; transform: perspective(700px) rotateX(55deg) translateY(30%); transform-origin: top center; opacity: .55; }

/* Sections */
.section { padding: 84px 0; }
.section--alt { background: linear-gradient(180deg, rgba(255,255,255,.03), rgba(255,255,255,0)); }
.section--accent { background: radial-gradient(700px 400px at 10% 0%, rgba(0,225,255,.12), transparent 60%), radial-gradient(600px 360px at 90% 0%, rgba(122,92,255,.10), transparent 60%); border-top: 1px solid rgba(255,255,255,.06); border-bottom: 1px solid rgba(255,255,255,.06); }
.section__head { text-align: center; margin-bottom: 28px; }
.section__head h2 { margin: 0 0 10px; font-size: clamp(22px, 2.6vw, 34px); }
.section__head p { margin: 0; color: var(--muted); }

/* Cards */
.cards { display: grid; grid-template-columns: repeat(3, 1fr); gap: 18px; }
.cards--4 { grid-template-columns: repeat(4, 1fr); }
.card { background: var(--card); border: 1px solid rgba(255,255,255,.08); border-radius: var(--radius-lg); padding: 18px; box-shadow: var(--shadow); transition: transform .25s ease, border-color .25s ease; }
.card:hover { transform: translateY(-4px); border-color: rgba(0,225,255,.45); }
.card__icon { width: 52px; height: 52px; display: grid; place-items: center; border-radius: 12px; color: var(--primary); background: linear-gradient(135deg, rgba(0,225,255,.2), rgba(122,92,255,.2)); box-shadow: inset 0 0 0 1px rgba(255,255,255,.1); margin-bottom: 10px; }
.card h3 { margin: 8px 0 8px; font-size: 18px; }
.card p { margin: 0 0 12px; color: var(--muted); line-height: 1.7; }
.meta { margin: 0; padding: 0; list-style: none; color: var(--muted); font-size: 14px; display: grid; gap: 6px; }

/* Solutions */
.solutions { display: grid; grid-template-columns: repeat(4, 1fr); gap: 18px; }
.solution { padding: 18px; border-radius: var(--radius); background: var(--glass); border: 1px solid rgba(255,255,255,.08); min-height: 132px; box-shadow: var(--shadow); }
.solution h3 { margin: 2px 0 6px; }
.solution p { margin: 0; color: var(--muted); }

/* Certs */
.certs { display: grid; grid-template-columns: repeat(4, 1fr); gap: 18px; }
.cert { background: var(--glass); border: 1px solid rgba(255,255,255,.1); border-radius: var(--radius-lg); padding: 16px; box-shadow: var(--shadow); position: relative; }
.cert .badge { position: absolute; top: 12px; right: 12px; font-size: 12px; background: linear-gradient(135deg, var(--primary), var(--accent)); color: #001018; padding: 2px 8px; border-radius: 999px; font-weight: 800; letter-spacing: .4px; }

/* About */
.about__grid { display: grid; grid-template-columns: 1.2fr .8fr; gap: 28px; align-items: center; }
.about__text { background: var(--glass); border: 1px solid rgba(255,255,255,.08); border-radius: var(--radius-lg); padding: 20px; }
.ticks { margin: 12px 0 0; padding-left: 20px; color: var(--muted); }
.stats { display: grid; grid-template-columns: repeat(3, 1fr); gap: 14px; }
.stat { background: linear-gradient(135deg, rgba(0,225,255,.10), rgba(122,92,255,.10)); border: 1px solid rgba(255,255,255,.12); border-radius: var(--radius-lg); display: grid; place-items: center; min-height: 120px; }
.stat__num { font-size: 28px; font-weight: 800; letter-spacing: .5px; }
.stat__txt { color: var(--muted); }

/* News */
.news { display: grid; grid-template-columns: repeat(3, 1fr); gap: 18px; }
.news__item { background: var(--card); border: 1px solid rgba(255,255,255,.08); border-radius: var(--radius); padding: 18px; box-shadow: var(--shadow); }
.news__item h3 { margin: 4px 0 8px; }
.news__item p { margin: 0 0 10px; color: var(--muted); }
.news__item time { color: #8aa2c8; font-size: 13px; }

/* Contact */
.contact { max-width: 900px; }
.form { background: var(--glass); border: 1px solid rgba(255,255,255,.08); border-radius: var(--radius-lg); padding: 18px; box-shadow: var(--shadow); }
.form__row { display: grid; grid-template-columns: 1fr 1fr; gap: 14px; }
label { display: grid; gap: 8px; color: var(--text); font-weight: 600; }
input, textarea { width: 100%; padding: 12px 12px; border-radius: 12px; border: 1px solid rgba(255,255,255,.12); color: var(--text); background: rgba(5,10,20,.5); outline: none; }
input::placeholder, textarea::placeholder { color: #7f93b9; }
.form__actions { display: flex; align-items: center; gap: 12px; margin-top: 14px; }
.form__hint { color: var(--muted); font-size: 13px; }

/* Footer */
.site-footer { padding: 24px 0; border-top: 1px solid rgba(255,255,255,.08); background: rgba(0,0,0,.15); }
.footer { display: flex; align-items: center; justify-content: space-between; gap: 18px; flex-wrap: wrap; }
.footer__brand { display: grid; gap: 6px; }
.footer__links { display: flex; gap: 14px; list-style: none; margin: 0; padding: 0; }
.footer__links a { color: var(--muted); text-decoration: none; }
.footer__links a:hover { color: var(--text); }

/* Reveal on scroll */
.reveal { opacity: 0; transform: translateY(12px); transition: .5s ease; }
.reveal.is-visible { opacity: 1; transform: translateY(0); }

/* Logos */
.logos { display: grid; grid-template-columns: repeat(8, 1fr); gap: 14px; list-style: none; padding: 0; margin: 0; }
.logo { display: grid; place-items: center; aspect-ratio: 3/1.2; border-radius: 10px; background: rgba(255,255,255,.05); color: var(--muted); font-weight: 800; border: 1px solid rgba(255,255,255,.06); }

/* Steps */
.steps { list-style: none; padding: 0; margin: 0; display: grid; grid-template-columns: repeat(5, 1fr); gap: 14px; }
.steps li { background: var(--card); border: 1px solid rgba(255,255,255,.08); border-radius: var(--radius-lg); padding: 16px; box-shadow: var(--shadow); }
.steps li span { display: inline-grid; place-items: center; width: 28px; height: 28px; border-radius: 8px; background: linear-gradient(135deg, var(--primary), var(--primary-2)); color: #001018; font-weight: 800; margin-bottom: 8px; }
.steps h3 { margin: 4px 0 6px; font-size: 16px; }
.steps p { margin: 0; color: var(--muted); }

/* CTA band */
.cta-band { padding: 42px 0; background: radial-gradient(800px 400px at 85% 0%, rgba(0,225,255,.12), transparent 60%), radial-gradient(600px 360px at 15% 0%, rgba(122,92,255,.12), transparent 60%); border-top: 1px solid rgba(255,255,255,.06); border-bottom: 1px solid rgba(255,255,255,.06); }
.cta-band__inner { display: flex; align-items: center; justify-content: space-between; gap: 12px; flex-wrap: wrap; }
.cta-band__inner h2 { margin: 0; font-size: clamp(18px, 2.4vw, 26px) }

/* Accessibility */
.skip-link { position: absolute; left: -999px; top: auto; width: 1px; height: 1px; overflow: hidden; }
.skip-link:focus { position: static; width: auto; height: auto; padding: 8px 12px; background: #000; border-radius: 8px; }

/* Cases */
.cases__toolbar { display: flex; gap: 10px; align-items: center; margin-bottom: 10px; flex-wrap: wrap; }
#case-q { flex: 1; min-width: 220px; padding: 10px 12px; border-radius: 12px; border: 1px solid rgba(255,255,255,.12); background: rgba(5,10,20,.5); color: var(--text); }
#case-type, #case-region, #case-sort, #case-size {
  appearance: none; -webkit-appearance: none; -moz-appearance: none;
  padding: 10px 38px 10px 12px;
  border-radius: 12px;
  border: 0;
  color: #001018;
  font-weight: 700;
  cursor: pointer;
  box-shadow: var(--shadow);
  background-image:
    url("data:image/svg+xml,%3Csvg xmlns='http://www.w3.org/2000/svg' width='16' height='16' viewBox='0 0 24 24'%3E%3Cpath fill='%23001018' d='M7 10l5 5 5-5z'/%3E%3C/svg%3E"),
    linear-gradient(135deg, var(--primary), var(--primary-2));
  background-repeat: no-repeat, no-repeat;
  background-position: right 10px center, 0 0;
}
#case-type:hover, #case-region:hover { filter: brightness(1.06); transform: translateY(-1px); }
.toggle { display: inline-flex; align-items: center; gap: 6px; color: var(--muted); font-size: 13px; user-select: none; }
.toggle input { transform: translateY(1px); }
.cases__actions { display: flex; gap: 8px; margin-left: auto; }
.cases__stats { margin: 6px 0 14px; color: var(--muted); font-size: 13px; }
.cases__pager { display: flex; align-items: center; justify-content: space-between; margin: 6px 0 12px; }
.pager__left { display: flex; align-items: center; gap: 8px; }
.pager__right { color: var(--muted); font-size: 13px; }
.cases { display: grid; grid-template-columns: repeat(3, 1fr); gap: 12px; }
.case { background: var(--card); border: 1px solid rgba(255,255,255,.08); border-radius: var(--radius); padding: 12px; box-shadow: var(--shadow); }
.case h4 { margin: 0 0 6px; font-size: 15px; }
.case .muted { color: var(--muted); font-size: 13px; }
.case .chips { display: flex; flex-wrap: wrap; gap: 6px; margin-top: 6px; }
.chip { display: inline-block; padding: 2px 8px; border-radius: 999px; background: rgba(255,255,255,.08); border: 1px solid rgba(255,255,255,.1); color: var(--muted); font-size: 12px; }
.case-group { grid-column: 1 / -1; margin: 8px 0 -4px; padding: 6px 8px; color: var(--muted); border-left: 3px solid var(--primary); font-weight: 700; background: rgba(255,255,255,.04); border-radius: 8px; }

/* Region filter chips */
.filters { display: flex; gap: 8px; flex-wrap: wrap; align-items: center; }
.filter-chip { display: inline-flex; align-items: center; gap: 6px; padding: 6px 10px; border-radius: 999px; border: 1px solid rgba(255,255,255,.16); background: rgba(255,255,255,.06); color: var(--muted); cursor: pointer; font-size: 13px; user-select: none; }
.filter-chip:hover { border-color: rgba(255,255,255,.28); color: var(--text); }
.filter-chip.is-active { background: linear-gradient(135deg, var(--primary), var(--primary-2)); color: #001018; border-color: transparent; box-shadow: var(--shadow); }
.filter-chip .count { display: inline-grid; place-items: center; min-width: 18px; height: 18px; padding: 0 4px; border-radius: 999px; background: rgba(0,0,0,.3); color: currentColor; font-size: 11px; font-weight: 700; }

/* Certs / PDF Thumbs + Modal */
.pdf-thumb { width: 100%; height: auto; border-radius: 10px; border: 1px solid rgba(255,255,255,.08); cursor: zoom-in; box-shadow: var(--shadow); }
.modal { position: fixed; inset: 0; display: none; }
.modal[aria-hidden="false"] { display: block; }
.modal__backdrop { position: absolute; inset: 0; background: rgba(0,0,0,.6); backdrop-filter: blur(2px); }
.modal__dialog { position: relative; width: min(96vw, 1080px); height: min(90vh, 880px); margin: 5vh auto; background: var(--bg-alt); border: 1px solid rgba(255,255,255,.12); border-radius: var(--radius-lg); overflow: hidden; box-shadow: 0 20px 60px rgba(0,0,0,.6); }
.modal__close { position: absolute; right: 8px; top: 6px; z-index: 2; border: 0; background: rgba(255,255,255,.12); color: var(--text); width: 28px; height: 28px; border-radius: 8px; cursor: pointer; }
.modal__body { position: absolute; inset: 0; padding: 36px 10px 10px; }

/* Responsive */
@media (max-width: 1080px) {
  .cards, .cards--4 { grid-template-columns: repeat(2, 1fr); }
  .solutions { grid-template-columns: repeat(2, 1fr); }
  .certs { grid-template-columns: repeat(2, 1fr); }
  .about__grid { grid-template-columns: 1fr; }
  .logos { grid-template-columns: repeat(4, 1fr); }
  .steps { grid-template-columns: repeat(3, 1fr); }
  .cases { grid-template-columns: repeat(2, 1fr); }
}
@media (max-width: 760px) {
  .nav__links { display: none; }
  .nav__toggle { display: inline-block; }
  .hero__inner { grid-template-columns: 1fr; }
  .news { grid-template-columns: 1fr; }
  .form__row { grid-template-columns: 1fr; }
  .solutions { grid-template-columns: 1fr; }
  .certs { grid-template-columns: 1fr; }
  .logos { grid-template-columns: repeat(2, 1fr); }
  .steps { grid-template-columns: 1fr; }
  .cases { grid-template-columns: 1fr; }
}