/* ============================================================
   LED 打call · ledparty.cn
   Cyberpunk HUD aesthetic — neon dark, scanlines, noise grain
   ============================================================ */

:root {
  /* Backgrounds */
  --bg-void: #05060B;
  --bg-deep: #0B0F1A;
  --bg-panel: #11172A;
  --bg-panel-alpha: rgba(17, 23, 42, 0.72);

  /* Ink */
  --ink-hi: #E6F1FF;
  --ink-lo: #8A94B8;
  --ink-dim: #5A6488;

  /* Neon */
  --pink: #FF2E88;
  --cyan: #22E8FF;
  --lime: #B8FF4F;
  --violet: #8A5CFF;
  --amber: #FFB020;

  /* Lines & shadows */
  --line: rgba(230, 241, 255, 0.12);
  --line-strong: rgba(230, 241, 255, 0.22);

  /* Type */
  --f-display: 'Orbitron', system-ui, -apple-system, sans-serif;
  --f-alt: 'Rajdhani', system-ui, sans-serif;
  --f-zh: 'ZCOOL KuaiLe', 'PingFang SC', system-ui, sans-serif;
  --f-body: 'Inter', system-ui, -apple-system, 'PingFang SC', sans-serif;

  /* Layout */
  --max-w: 1200px;
  --gutter: 32px;
}

* { box-sizing: border-box; }

html, body {
  margin: 0;
  padding: 0;
  background: var(--bg-void);
  color: var(--ink-hi);
  font-family: var(--f-body);
  font-size: 15px;
  line-height: 1.6;
  -webkit-font-smoothing: antialiased;
  text-rendering: optimizeLegibility;
}

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

/* ---------- Background layers ---------- */

.bg-grid {
  position: fixed;
  inset: 0;
  z-index: -3;
  background:
    radial-gradient(ellipse at 20% 0%, rgba(138, 92, 255, 0.18), transparent 50%),
    radial-gradient(ellipse at 80% 100%, rgba(34, 232, 255, 0.12), transparent 55%),
    radial-gradient(ellipse at 50% 50%, rgba(255, 46, 136, 0.06), transparent 70%),
    var(--bg-void);
}

.bg-grid::before {
  content: '';
  position: absolute;
  inset: 0;
  background-image:
    linear-gradient(to right, rgba(230, 241, 255, 0.04) 1px, transparent 1px),
    linear-gradient(to bottom, rgba(230, 241, 255, 0.04) 1px, transparent 1px);
  background-size: 80px 80px;
  mask-image: radial-gradient(ellipse at center, black 30%, transparent 80%);
}

.bg-scan {
  position: fixed;
  inset: 0;
  z-index: -2;
  pointer-events: none;
  background: repeating-linear-gradient(
    to bottom,
    transparent 0,
    transparent 3px,
    rgba(0, 0, 0, 0.18) 3px,
    rgba(0, 0, 0, 0.18) 4px
  );
  mix-blend-mode: multiply;
  opacity: 0.55;
}

.bg-noise {
  position: fixed;
  inset: 0;
  z-index: -1;
  pointer-events: none;
  opacity: 0.06;
  background-image: url("data:image/svg+xml,%3Csvg viewBox='0 0 200 200' xmlns='http://www.w3.org/2000/svg'%3E%3Cfilter id='n'%3E%3CfeTurbulence type='fractalNoise' baseFrequency='1.2' numOctaves='2' stitchTiles='stitch'/%3E%3CfeColorMatrix values='0 0 0 0 1, 0 0 0 0 1, 0 0 0 0 1, 0 0 0 0.7 0'/%3E%3C/filter%3E%3Crect width='100%25' height='100%25' filter='url(%23n)'/%3E%3C/svg%3E");
}

/* ---------- Nav ---------- */

.nav {
  position: sticky;
  top: 0;
  z-index: 50;
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 18px var(--gutter);
  backdrop-filter: blur(14px) saturate(140%);
  -webkit-backdrop-filter: blur(14px) saturate(140%);
  background: linear-gradient(to bottom, rgba(5, 6, 11, 0.85), rgba(5, 6, 11, 0.55));
  border-bottom: 1px solid var(--line);
}

.brand {
  display: flex;
  align-items: center;
  gap: 10px;
  font-family: var(--f-display);
  font-weight: 700;
  font-size: 15px;
  letter-spacing: 0.18em;
  color: var(--ink-hi);
}

.brand-mark {
  color: var(--pink);
  text-shadow: 0 0 12px rgba(255, 46, 136, 0.7);
  font-size: 18px;
  line-height: 1;
}

.brand-name { font-family: var(--f-zh); letter-spacing: 0.08em; }

.nav nav {
  display: flex;
  gap: 28px;
  font-family: var(--f-alt);
  font-size: 14px;
  letter-spacing: 0.12em;
  text-transform: uppercase;
}

.nav nav a {
  color: var(--ink-lo);
  position: relative;
  padding: 4px 0;
  transition: color .15s;
}

.nav nav a:hover { color: var(--cyan); }
.nav nav a:hover::after {
  content: '';
  position: absolute;
  left: 0; right: 0; bottom: -2px;
  height: 1px;
  background: var(--cyan);
  box-shadow: 0 0 8px var(--cyan);
}

/* ---------- Layout & sections ---------- */

main { padding: 0 var(--gutter); }

.wrap { max-width: var(--max-w); margin: 0 auto; }

.section {
  padding: 80px 0;
  border-bottom: 1px solid var(--line);
}

.section:last-of-type { border-bottom: none; }

.section-tag {
  font-family: var(--f-alt);
  font-size: 12px;
  letter-spacing: 0.4em;
  text-transform: uppercase;
  color: var(--cyan);
  margin: 0 0 16px;
  display: inline-flex;
  align-items: center;
  gap: 10px;
}

.section-tag::before {
  content: '';
  display: inline-block;
  width: 6px; height: 6px;
  background: var(--cyan);
  box-shadow: 0 0 10px var(--cyan);
}

.section-title {
  font-family: var(--f-zh);
  font-size: 38px;
  margin: 0 0 16px;
  letter-spacing: 0.04em;
  color: var(--ink-hi);
}

.section-lead {
  font-size: 16px;
  color: var(--ink-lo);
  max-width: 60ch;
}

/* ---------- HERO ---------- */

.hero {
  position: relative;
  padding: 120px 0 100px;
  overflow: hidden;
}

.hero-meta {
  font-family: var(--f-display);
  font-size: 11px;
  letter-spacing: 0.5em;
  color: var(--lime);
  text-shadow: 0 0 8px rgba(184, 255, 79, 0.45);
  margin-bottom: 24px;
}

.hero-title {
  font-family: var(--f-display);
  font-weight: 700;
  font-size: clamp(54px, 12vw, 156px);
  line-height: 0.92;
  margin: 0 0 24px;
  letter-spacing: -0.02em;
}

.hero-title .a {
  display: block;
  background: linear-gradient(120deg, var(--cyan), var(--violet) 60%, var(--pink));
  -webkit-background-clip: text;
  background-clip: text;
  color: transparent;
  filter: drop-shadow(0 0 24px rgba(138, 92, 255, 0.4));
}

.hero-title .b {
  display: block;
  font-family: var(--f-zh);
  font-size: 0.62em;
  color: var(--ink-hi);
  text-shadow: 0 0 30px rgba(34, 232, 255, 0.4);
}

.hero-title .b em {
  font-style: normal;
  font-family: var(--f-display);
  color: var(--pink);
  letter-spacing: 0.05em;
  margin-left: 0.1em;
}

.hero-sub {
  font-family: var(--f-zh);
  font-size: 22px;
  color: var(--ink-lo);
  letter-spacing: 0.05em;
  max-width: 640px;
  margin: 0 0 40px;
}

.hero-cta { display: flex; gap: 14px; flex-wrap: wrap; }

/* ---------- Buttons ---------- */

.btn {
  position: relative;
  display: inline-flex;
  align-items: center;
  gap: 12px;
  padding: 14px 28px;
  font-family: var(--f-alt);
  font-size: 14px;
  letter-spacing: 0.18em;
  text-transform: uppercase;
  border: 1px solid currentColor;
  background: transparent;
  cursor: pointer;
  transition: all .18s ease;
}

.btn::before, .btn::after {
  content: '';
  position: absolute;
  width: 8px; height: 8px;
  border-color: currentColor;
  border-style: solid;
  border-width: 0;
}

.btn::before { top: -1px; left: -1px; border-top-width: 1px; border-left-width: 1px; }
.btn::after  { bottom: -1px; right: -1px; border-bottom-width: 1px; border-right-width: 1px; }

.btn-primary {
  color: var(--bg-void);
  background: var(--cyan);
  border-color: var(--cyan);
  box-shadow: 0 0 0 0 rgba(34, 232, 255, 0.5), 0 0 32px rgba(34, 232, 255, 0.3);
}

.btn-primary:hover {
  box-shadow: 0 0 0 2px rgba(34, 232, 255, 0.4), 0 0 48px rgba(34, 232, 255, 0.5);
  transform: translateY(-1px);
}

.btn-ghost {
  color: var(--ink-hi);
  border-color: var(--line-strong);
}

.btn-ghost:hover {
  color: var(--pink);
  border-color: var(--pink);
  box-shadow: 0 0 24px rgba(255, 46, 136, 0.3);
}

/* ---------- Features grid ---------- */

.features-grid {
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: 18px;
  margin-top: 48px;
}

@media (min-width: 900px) {
  .features-grid { grid-template-columns: repeat(4, 1fr); }
}

.feature {
  position: relative;
  padding: 32px 24px;
  background: var(--bg-panel-alpha);
  border: 1px solid var(--line);
  transition: border-color .2s, transform .2s;
}

.feature::before, .feature::after {
  content: '';
  position: absolute;
  width: 14px; height: 14px;
  border-color: var(--accent, var(--cyan));
  border-style: solid;
  border-width: 0;
  transition: border-color .2s;
}

.feature::before {
  top: -1px; left: -1px;
  border-top-width: 2px; border-left-width: 2px;
}

.feature::after {
  bottom: -1px; right: -1px;
  border-bottom-width: 2px; border-right-width: 2px;
}

.feature:hover {
  transform: translateY(-2px);
  border-color: var(--accent, var(--cyan));
}

.feature-icon {
  font-family: var(--f-display);
  font-size: 11px;
  letter-spacing: 0.4em;
  color: var(--accent, var(--cyan));
  margin-bottom: 20px;
}

.feature-title {
  font-family: var(--f-zh);
  font-size: 22px;
  margin: 0 0 10px;
  color: var(--ink-hi);
}

.feature-desc {
  font-size: 14px;
  color: var(--ink-lo);
  line-height: 1.7;
  margin: 0;
}

.feature[data-accent="pink"]   { --accent: var(--pink); }
.feature[data-accent="cyan"]   { --accent: var(--cyan); }
.feature[data-accent="lime"]   { --accent: var(--lime); }
.feature[data-accent="violet"] { --accent: var(--violet); }

/* ---------- Use cases / showcase ---------- */

.use-cases {
  display: grid;
  grid-template-columns: 1fr;
  gap: 20px;
  margin-top: 36px;
}

@media (min-width: 720px) {
  .use-cases { grid-template-columns: repeat(3, 1fr); }
}

.use {
  padding: 24px;
  border-left: 2px solid var(--violet);
  background: linear-gradient(90deg, rgba(138, 92, 255, 0.08), transparent 80%);
}

.use-num {
  font-family: var(--f-display);
  font-size: 12px;
  letter-spacing: 0.35em;
  color: var(--violet);
  margin-bottom: 10px;
}

.use-title {
  font-family: var(--f-zh);
  font-size: 20px;
  margin: 0 0 6px;
  color: var(--ink-hi);
}

.use-desc {
  font-size: 14px;
  color: var(--ink-lo);
  margin: 0;
}

/* ---------- Download CTA ---------- */

.download {
  text-align: center;
  padding: 100px 0;
}

.download-stores {
  display: flex;
  justify-content: center;
  gap: 16px;
  flex-wrap: wrap;
  margin-top: 32px;
}

.store {
  display: inline-flex;
  align-items: center;
  gap: 14px;
  padding: 16px 28px;
  background: var(--bg-panel);
  border: 1px solid var(--line);
  font-family: var(--f-alt);
  letter-spacing: 0.1em;
  font-size: 13px;
  text-transform: uppercase;
  color: var(--ink-lo);
}

.store strong {
  font-family: var(--f-zh);
  font-size: 15px;
  color: var(--ink-hi);
  font-weight: normal;
  letter-spacing: 0.04em;
}

.store-mark {
  font-family: var(--f-display);
  color: var(--lime);
  font-size: 14px;
}

.store-status {
  margin-left: 6px;
  padding: 2px 8px;
  font-size: 10px;
  border: 1px solid var(--amber);
  color: var(--amber);
  letter-spacing: 0.2em;
}

/* ---------- Long-form (privacy/terms) ---------- */

.doc {
  max-width: 820px;
  margin: 0 auto;
  padding: 80px 0 60px;
}

.doc-meta {
  font-family: var(--f-alt);
  font-size: 12px;
  letter-spacing: 0.35em;
  text-transform: uppercase;
  color: var(--lime);
  margin-bottom: 16px;
}

.doc h1 {
  font-family: var(--f-zh);
  font-size: 44px;
  margin: 0 0 12px;
  letter-spacing: 0.03em;
}

.doc-sub {
  color: var(--ink-lo);
  font-size: 14px;
  margin: 0 0 8px;
}

.doc-update {
  color: var(--ink-dim);
  font-size: 12px;
  font-family: var(--f-alt);
  letter-spacing: 0.2em;
  margin-bottom: 60px;
  padding-bottom: 20px;
  border-bottom: 1px solid var(--line);
}

.doc h2 {
  font-family: var(--f-zh);
  font-size: 24px;
  margin: 56px 0 14px;
  color: var(--ink-hi);
  position: relative;
  padding-left: 18px;
}

.doc h2::before {
  content: '';
  position: absolute;
  left: 0;
  top: 8px;
  width: 4px;
  height: 22px;
  background: var(--cyan);
  box-shadow: 0 0 12px var(--cyan);
}

.doc h2 .num {
  font-family: var(--f-display);
  font-size: 13px;
  color: var(--cyan);
  letter-spacing: 0.3em;
  margin-right: 12px;
  vertical-align: middle;
  font-weight: 500;
}

.doc h3 {
  font-family: var(--f-zh);
  font-size: 17px;
  margin: 28px 0 10px;
  color: var(--ink-hi);
}

.doc p {
  color: var(--ink-lo);
  line-height: 1.8;
  margin: 0 0 16px;
}

.doc ul, .doc ol {
  color: var(--ink-lo);
  line-height: 1.8;
  padding-left: 22px;
  margin: 0 0 16px;
}

.doc li { margin-bottom: 8px; }

.doc strong { color: var(--ink-hi); font-weight: 600; }

.doc table {
  width: 100%;
  border-collapse: collapse;
  margin: 18px 0 24px;
  font-size: 14px;
}

.doc th, .doc td {
  padding: 12px 14px;
  text-align: left;
  border-bottom: 1px solid var(--line);
}

.doc th {
  font-family: var(--f-alt);
  font-size: 12px;
  letter-spacing: 0.18em;
  text-transform: uppercase;
  color: var(--cyan);
  border-bottom-color: var(--line-strong);
}

.doc td:first-child {
  color: var(--ink-hi);
  font-weight: 500;
  width: 30%;
}

.callout {
  margin: 24px 0;
  padding: 18px 22px;
  border-left: 2px solid var(--lime);
  background: linear-gradient(90deg, rgba(184, 255, 79, 0.06), transparent 80%);
  font-size: 14px;
  color: var(--ink-hi);
}

.callout-tag {
  font-family: var(--f-display);
  font-size: 11px;
  letter-spacing: 0.3em;
  color: var(--lime);
  display: block;
  margin-bottom: 6px;
}

/* ---------- Contact ---------- */

.contact-card {
  max-width: 560px;
  margin: 60px auto;
  padding: 40px;
  background: var(--bg-panel-alpha);
  border: 1px solid var(--line);
  position: relative;
}

.contact-card::before {
  content: '';
  position: absolute;
  inset: 0;
  border: 1px solid transparent;
  background: linear-gradient(135deg, var(--pink), transparent 30%, transparent 70%, var(--cyan)) border-box;
  -webkit-mask: linear-gradient(#000 0 0) padding-box, linear-gradient(#000 0 0);
  -webkit-mask-composite: xor;
          mask-composite: exclude;
  pointer-events: none;
}

.contact-row {
  display: flex;
  justify-content: space-between;
  align-items: baseline;
  padding: 16px 0;
  border-bottom: 1px solid var(--line);
}

.contact-row:last-child { border-bottom: none; }

.contact-label {
  font-family: var(--f-alt);
  font-size: 12px;
  letter-spacing: 0.3em;
  text-transform: uppercase;
  color: var(--ink-lo);
}

.contact-val {
  font-family: var(--f-display);
  color: var(--cyan);
  font-size: 16px;
  letter-spacing: 0.05em;
}

.contact-val.pink { color: var(--pink); }

/* ---------- Footer ---------- */

.footer {
  padding: 50px var(--gutter) 36px;
  text-align: center;
  border-top: 1px solid var(--line);
  background: var(--bg-deep);
}

.footer-grid {
  display: flex;
  justify-content: center;
  gap: 28px;
  flex-wrap: wrap;
  font-family: var(--f-alt);
  font-size: 12px;
  letter-spacing: 0.18em;
  color: var(--ink-dim);
  text-transform: uppercase;
}

.footer-grid a:hover { color: var(--cyan); }

.footer-icp {
  margin-top: 18px;
  font-family: var(--f-alt);
  font-size: 11px;
  letter-spacing: 0.25em;
  color: var(--ink-dim);
}

.footer-icp a { color: var(--ink-lo); }
.footer-icp a:hover { color: var(--lime); }

.footer-icp .placeholder {
  color: var(--amber);
  font-family: var(--f-display);
  letter-spacing: 0.18em;
}

/* ---------- Animations ---------- */

@keyframes pulse-glow {
  0%, 100% { opacity: 0.85; }
  50% { opacity: 1; }
}

.brand-mark { animation: pulse-glow 2.4s ease-in-out infinite; }

@keyframes title-rise {
  from { transform: translateY(20px); opacity: 0; }
  to   { transform: translateY(0); opacity: 1; }
}

.hero-meta, .hero-title, .hero-sub, .hero-cta {
  animation: title-rise .8s cubic-bezier(.2, .8, .2, 1) backwards;
}
.hero-title { animation-delay: .08s; }
.hero-sub   { animation-delay: .18s; }
.hero-cta   { animation-delay: .28s; }

@media (prefers-reduced-motion: reduce) {
  *, *::before, *::after {
    animation-duration: .01ms !important;
    transition-duration: .01ms !important;
  }
}

/* ---------- Responsive tweaks ---------- */

@media (max-width: 680px) {
  :root { --gutter: 18px; }
  .nav { padding: 14px var(--gutter); }
  .nav nav { gap: 16px; font-size: 12px; }
  .brand-name { display: none; }
  .section { padding: 60px 0; }
  .section-title { font-size: 28px; }
  .hero { padding: 60px 0 70px; }
  .hero-sub { font-size: 18px; }
  .doc h1 { font-size: 32px; }
  .doc h2 { font-size: 20px; }
}

/* ---------- Hero grid (text + art) ---------- */

.hero-grid {
  display: grid;
  grid-template-columns: 1fr;
  gap: 48px;
  align-items: center;
}

@media (min-width: 960px) {
  .hero-grid {
    grid-template-columns: 1.05fr 1fr;
    gap: 64px;
  }
}

.hero-art {
  position: relative;
  aspect-ratio: 1280 / 660;
  border: 1px solid var(--line-strong);
  background: var(--bg-panel);
  overflow: hidden;
  box-shadow:
    0 0 80px rgba(255, 46, 136, 0.25),
    0 0 0 1px rgba(255, 46, 136, 0.18) inset;
}

.hero-art img {
  display: block;
  width: 100%;
  height: 100%;
  object-fit: cover;
  filter: saturate(1.08);
}

.hero-art-tag {
  position: absolute;
  left: 14px; bottom: 12px;
  font-family: var(--f-display);
  font-size: 11px;
  letter-spacing: 0.5em;
  color: var(--pink);
  text-shadow: 0 0 8px rgba(255, 46, 136, 0.55);
  background: rgba(5, 6, 11, 0.55);
  padding: 4px 10px;
  border: 1px solid rgba(255, 46, 136, 0.4);
}

/* ---------- Modes grid (玩法预览) ---------- */

.modes-grid {
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: 18px;
  margin-top: 48px;
}

@media (min-width: 900px) {
  .modes-grid { grid-template-columns: repeat(4, 1fr); }
}

.mode {
  margin: 0;
  background: var(--bg-panel-alpha);
  border: 1px solid var(--line);
  overflow: hidden;
  transition: border-color .2s, transform .2s;
}

.mode:hover {
  border-color: var(--cyan);
  transform: translateY(-2px);
}

.mode img {
  display: block;
  width: 100%;
  aspect-ratio: 1 / 1;
  object-fit: cover;
}

.mode figcaption {
  padding: 14px 16px 18px;
  display: flex;
  flex-direction: column;
  gap: 4px;
}

.mode figcaption strong {
  font-family: var(--f-zh);
  font-size: 18px;
  color: var(--ink-hi);
  letter-spacing: 0.04em;
}

.mode figcaption span {
  font-size: 13px;
  color: var(--ink-lo);
}

/* ---------- Templates grid (模板墙) ---------- */

.templates-grid {
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: 14px;
  margin-top: 48px;
}

@media (min-width: 700px) {
  .templates-grid { grid-template-columns: repeat(3, 1fr); }
}

@media (min-width: 1000px) {
  .templates-grid { grid-template-columns: repeat(4, 1fr); }
}

.tpl {
  position: relative;
  display: block;
  border: 1px solid var(--line);
  overflow: hidden;
  background: var(--bg-panel);
  text-decoration: none;
  transition: border-color .2s, transform .2s;
}

.tpl:hover {
  border-color: var(--pink);
  transform: translateY(-2px);
}

.tpl img {
  display: block;
  width: 100%;
  aspect-ratio: 4 / 3;
  object-fit: contain;
  background: #05060B;
}

.tpl span {
  position: absolute;
  left: 0; right: 0; bottom: 0;
  padding: 10px 14px;
  font-family: var(--f-zh);
  font-size: 14px;
  letter-spacing: 0.05em;
  color: var(--ink-hi);
  background: linear-gradient(to top, rgba(5, 6, 11, 0.88), rgba(5, 6, 11, 0));
}