/* 科宝落地页 — 黑金品牌
   取自 App 图标：深黑面板 + 金色文字/轨道
*/

:root {
  --bg: #0b0b0c;
  --bg-2: #121214;
  --bg-3: #1a1a1d;
  --ink: #f3efe6;
  --muted: #a39e93;
  --line: rgba(212, 168, 87, 0.16);
  --line-strong: rgba(212, 168, 87, 0.38);
  --gold: #d4a857;
  --gold-hi: #f0d48a;
  --gold-lo: #a67c2e;
  --panel: rgba(255, 255, 255, 0.025);
  --radius: 16px;
  --max: 980px;
  --font-display: "Songti SC", "Noto Serif SC", "Source Han Serif SC", Georgia, serif;
  --font-body: "PingFang SC", "Microsoft YaHei", "Segoe UI", system-ui, sans-serif;
  --font-mono: "SF Mono", "Cascadia Code", Consolas, monospace;
}

*,
*::before,
*::after { box-sizing: border-box; }

html { scroll-behavior: smooth; }

body {
  margin: 0;
  color: var(--ink);
  background:
    radial-gradient(1200px 600px at 50% -10%, rgba(212, 168, 87, 0.09), transparent 55%),
    radial-gradient(800px 400px at 90% 40%, rgba(212, 168, 87, 0.04), transparent 50%),
    var(--bg);
  font-family: var(--font-body);
  font-size: 16px;
  line-height: 1.7;
  -webkit-font-smoothing: antialiased;
}

code {
  font-family: var(--font-mono);
  font-size: 0.88em;
  color: var(--gold-hi);
  background: rgba(212, 168, 87, 0.1);
  padding: 0.1em 0.4em;
  border-radius: 4px;
}

a { color: inherit; }

:focus-visible {
  outline: 2px solid var(--gold);
  outline-offset: 3px;
}

/* top */
.top {
  position: sticky;
  top: 0;
  z-index: 30;
  display: flex;
  align-items: center;
  justify-content: space-between;
  max-width: var(--max);
  margin: 0 auto;
  padding: 0.85rem 1.25rem;
  background: rgba(11, 11, 12, 0.72);
  backdrop-filter: blur(14px);
  border-bottom: 1px solid transparent;
}

.brand {
  display: inline-flex;
  align-items: center;
  gap: 0.65rem;
  text-decoration: none;
}

.brand-logo,
.hero-badge img,
.download-logo,
.foot-row img {
  border-radius: 8px;
  box-shadow: 0 0 0 1px rgba(212, 168, 87, 0.25);
}

.brand-name {
  font-family: var(--font-display);
  font-size: 1.15rem;
  font-weight: 700;
  letter-spacing: 0.08em;
  background: linear-gradient(135deg, var(--gold-hi), var(--gold), var(--gold-lo));
  -webkit-background-clip: text;
  background-clip: text;
  color: transparent;
}

.nav {
  display: flex;
  gap: 1.35rem;
  font-size: 0.92rem;
  color: var(--muted);
}

.nav a {
  text-decoration: none;
  transition: color 0.15s ease;
}

.nav a:hover { color: var(--gold-hi); }

/* hero */
.hero {
  max-width: var(--max);
  margin: 0 auto;
  padding: 5.5rem 1.25rem 4rem;
  text-align: center;
}

.hero-badge {
  display: inline-flex;
  align-items: center;
  gap: 0.55rem;
  margin-bottom: 1.5rem;
  padding: 0.35rem 0.85rem 0.35rem 0.4rem;
  border: 1px solid var(--line);
  border-radius: 999px;
  font-size: 0.82rem;
  color: var(--muted);
  background: var(--panel);
}

.hero-title {
  margin: 0 auto 1.35rem;
  max-width: 12em;
  font-family: var(--font-display);
  font-weight: 700;
  font-size: clamp(2.3rem, 6vw, 3.75rem);
  line-height: 1.18;
  letter-spacing: -0.02em;
}

.hero-title-gold {
  background: linear-gradient(120deg, var(--gold-hi), var(--gold) 50%, var(--gold-lo));
  -webkit-background-clip: text;
  background-clip: text;
  color: transparent;
}

.hero-lead {
  margin: 0 auto 2.25rem;
  max-width: 34em;
  color: var(--muted);
  font-size: 1.08rem;
}

.br-desk { display: none; }
@media (min-width: 640px) { .br-desk { display: inline; } }

.hero-actions {
  display: flex;
  flex-wrap: wrap;
  gap: 0.85rem;
  justify-content: center;
  margin-bottom: 1.25rem;
}

.hero-meta {
  margin: 0;
  font-size: 0.82rem;
  color: rgba(163, 158, 147, 0.75);
  font-family: var(--font-mono);
  letter-spacing: 0.02em;
}

/* buttons */
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  min-height: 46px;
  padding: 0.7rem 1.5rem;
  border-radius: 999px;
  border: 1px solid transparent;
  font: inherit;
  font-size: 0.95rem;
  font-weight: 600;
  text-decoration: none;
  cursor: pointer;
  transition: transform 0.15s ease, box-shadow 0.15s ease, background 0.15s ease, color 0.15s ease, border-color 0.15s ease;
}

.btn-gold {
  background: linear-gradient(135deg, #f0d48a, #d4a857 45%, #b8862d);
  color: #1a1205;
  box-shadow: 0 8px 28px rgba(212, 168, 87, 0.22);
}

.btn-gold:hover {
  transform: translateY(-1px);
  box-shadow: 0 12px 32px rgba(212, 168, 87, 0.32);
}

.btn-line {
  background: transparent;
  border-color: var(--line-strong);
  color: var(--ink);
}

.btn-line:hover {
  border-color: var(--gold);
  color: var(--gold-hi);
}

.btn-lg {
  min-height: 54px;
  padding: 0.9rem 2rem;
  font-size: 1.02rem;
  width: 100%;
}

.btn[aria-disabled="true"] {
  opacity: 0.4;
  pointer-events: none;
  box-shadow: none;
}

/* sections */
.section {
  max-width: var(--max);
  margin: 0 auto;
  padding: 4.25rem 1.25rem;
}

.section-head {
  max-width: 36em;
  margin-bottom: 2.5rem;
}

.eyebrow {
  margin: 0 0 0.55rem;
  font-family: var(--font-mono);
  font-size: 0.75rem;
  letter-spacing: 0.16em;
  text-transform: uppercase;
  color: var(--gold);
}

.section-head h2 {
  margin: 0 0 0.75rem;
  font-family: var(--font-display);
  font-size: clamp(1.75rem, 3.4vw, 2.35rem);
  font-weight: 700;
  letter-spacing: -0.015em;
}

.section-desc {
  margin: 0;
  color: var(--muted);
}

/* dual panels */
.dual {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 1.15rem;
  margin-bottom: 2.75rem;
}

.panel {
  position: relative;
  padding: 1.65rem 1.5rem 1.5rem;
  border-radius: calc(var(--radius) + 4px);
  border: 1px solid var(--line);
  background:
    linear-gradient(160deg, rgba(212, 168, 87, 0.06), transparent 42%),
    var(--bg-2);
  overflow: hidden;
}

.panel::before {
  content: "";
  position: absolute;
  inset: 0 0 auto 0;
  height: 1px;
  background: linear-gradient(90deg, transparent, rgba(240, 212, 138, 0.55), transparent);
}

.panel-kicker {
  display: inline-block;
  margin-bottom: 0.55rem;
  font-family: var(--font-mono);
  font-size: 0.72rem;
  letter-spacing: 0.14em;
  text-transform: uppercase;
  color: var(--gold);
}

.panel h3 {
  margin: 0 0 0.25rem;
  font-family: var(--font-display);
  font-size: 1.55rem;
  font-weight: 700;
}

.panel-sub {
  margin: 0 0 1rem;
  color: var(--muted);
  font-size: 0.92rem;
}

.panel-body {
  margin: 0 0 1.25rem;
  color: rgba(243, 239, 230, 0.82);
  font-size: 0.95rem;
}

.panel-list {
  list-style: none;
  margin: 0;
  padding: 0;
  display: grid;
  gap: 0.7rem;
}

.panel-list li {
  display: grid;
  grid-template-columns: 4.2rem 1fr;
  gap: 0.65rem;
  align-items: baseline;
  font-size: 0.92rem;
  color: var(--muted);
  padding-top: 0.7rem;
  border-top: 1px solid rgba(212, 168, 87, 0.1);
}

.li-label {
  font-family: var(--font-mono);
  font-size: 0.75rem;
  letter-spacing: 0.04em;
  color: var(--gold-hi);
}

/* spectrum */
.spectrum {
  margin: 0;
  padding: 1.25rem 1rem 1rem;
  border: 1px solid var(--line);
  border-radius: var(--radius);
  background: var(--panel);
}

.spectrum svg {
  display: block;
  width: 100%;
  height: auto;
}

.spectrum figcaption {
  margin-top: 0.85rem;
  font-size: 0.84rem;
  color: var(--muted);
}

/* craft */
.craft-grid {
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: 1.15rem;
}

.craft-item {
  padding: 1.25rem 1.35rem;
  border-radius: var(--radius);
  border: 1px solid var(--line);
  background: var(--panel);
}

.craft-item h3 {
  margin: 0 0 0.45rem;
  font-size: 1.05rem;
  font-weight: 600;
}

.craft-item p {
  margin: 0;
  color: var(--muted);
  font-size: 0.93rem;
}

/* download */
.download {
  padding-top: 2rem;
  padding-bottom: 5rem;
}

.download-card {
  max-width: 560px;
  margin: 0 auto;
  padding: 2rem 1.75rem 1.75rem;
  border-radius: calc(var(--radius) + 8px);
  border: 1px solid var(--line-strong);
  background:
    radial-gradient(500px 220px at 50% 0%, rgba(212, 168, 87, 0.12), transparent 70%),
    var(--bg-2);
  text-align: center;
  box-shadow: 0 24px 60px rgba(0, 0, 0, 0.35);
}

.download-brand {
  display: flex;
  align-items: center;
  justify-content: center;
  gap: 1rem;
  text-align: left;
  margin-bottom: 1.5rem;
}

.download-brand h2 {
  margin: 0;
  font-family: var(--font-display);
  font-size: 1.65rem;
  font-weight: 700;
}

.download-brand p {
  margin: 0.2rem 0 0;
  color: var(--muted);
  font-size: 0.9rem;
}

.meta-grid {
  margin: 0 0 1.5rem;
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 0.85rem 1rem;
  text-align: left;
}

.meta-grid dt {
  font-family: var(--font-mono);
  font-size: 0.7rem;
  letter-spacing: 0.1em;
  text-transform: uppercase;
  color: var(--muted);
}

.meta-grid dd {
  margin: 0.2rem 0 0;
  font-size: 0.95rem;
  font-weight: 500;
}

.download-hint {
  margin: 0.85rem 0 0;
  font-size: 0.8rem;
  color: var(--muted);
}

.steps {
  list-style: none;
  margin: 1.75rem 0 0;
  padding: 1.25rem 0 0;
  border-top: 1px solid var(--line);
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 0.75rem;
  text-align: left;
}

.steps li {
  display: flex;
  flex-direction: column;
  gap: 0.25rem;
  font-size: 0.88rem;
  color: var(--muted);
}

.steps span {
  font-family: var(--font-mono);
  font-size: 0.72rem;
  letter-spacing: 0.08em;
  color: var(--gold);
}

/* footer */
.foot {
  max-width: var(--max);
  margin: 0 auto;
  padding: 2.25rem 1.25rem 3rem;
  border-top: 1px solid var(--line);
  color: var(--muted);
  font-size: 0.88rem;
}

.foot-row {
  display: inline-flex;
  align-items: center;
  gap: 0.55rem;
  margin-bottom: 0.65rem;
  font-family: var(--font-display);
  font-size: 1.05rem;
  color: var(--gold-hi);
}

.foot p { margin: 0 0 0.75rem; max-width: 42em; }

.foot-copy {
  margin: 0 !important;
  font-family: var(--font-mono);
  font-size: 0.75rem;
}

/* motion */
@media (prefers-reduced-motion: no-preference) {
  .hero-title,
  .hero-lead,
  .hero-actions,
  .hero-badge {
    animation: rise 0.7s ease both;
  }
  .hero-lead { animation-delay: 0.08s; }
  .hero-actions { animation-delay: 0.16s; }

  .panel {
    animation: rise 0.65s ease both;
  }
  .panel-research { animation-delay: 0.08s; }

  @keyframes rise {
    from { opacity: 0; transform: translateY(12px); }
    to { opacity: 1; transform: none; }
  }
}

/* responsive */
@media (max-width: 800px) {
  .dual,
  .craft-grid,
  .meta-grid,
  .steps {
    grid-template-columns: 1fr;
  }

  .hero { padding-top: 3.25rem; }

  .download-brand { flex-direction: column; text-align: center; }
  .download-brand > div { text-align: center; }
}

@media (max-width: 420px) {
  .hero-actions { flex-direction: column; }
  .btn { width: 100%; }
  .nav { gap: 0.85rem; font-size: 0.86rem; }
}