/* c-tools landing — warm charcoal + icon orange (#f87820) */

:root {
  --bg: #16110d;
  --bg-elev: #221a14;
  --ink: #f7f1ea;
  --muted: #b7a99d;
  --line: rgba(247, 241, 234, 0.12);
  --brand: #f87820;
  --brand-deep: #e85a10;
  --brand-dim: rgba(248, 120, 32, 0.16);
  --font-display: 'Syne', 'Avenir Next', system-ui, sans-serif;
  --font-body: 'IBM Plex Sans', 'PingFang SC', 'Microsoft YaHei', sans-serif;
  --font-mono: 'IBM Plex Mono', ui-monospace, monospace;
  --max: 1120px;
  --radius: 18px;
}

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

html {
  scroll-behavior: smooth;
}

body {
  margin: 0;
  min-height: 100vh;
  color: var(--ink);
  background: var(--bg);
  font-family: var(--font-body);
  font-size: 16px;
  line-height: 1.55;
  overflow-x: hidden;
}

a {
  color: inherit;
  text-decoration: none;
}

img {
  display: block;
  max-width: 100%;
  height: auto;
}

/* atmosphere */
.noise {
  pointer-events: none;
  position: fixed;
  inset: 0;
  z-index: 0;
  opacity: 0.04;
  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='0.85' numOctaves='3' stitchTiles='stitch'/%3E%3C/filter%3E%3Crect width='100%25' height='100%25' filter='url(%23n)'/%3E%3C/svg%3E");
}

.orb {
  pointer-events: none;
  position: fixed;
  z-index: 0;
  border-radius: 50%;
  filter: blur(80px);
  opacity: 0.35;
}

.orb-a {
  top: -12%;
  right: -8%;
  width: 42vw;
  height: 42vw;
  background: radial-gradient(circle, rgba(248, 120, 32, 0.42), transparent 70%);
  animation: drift 18s ease-in-out infinite alternate;
}

.orb-b {
  bottom: 10%;
  left: -15%;
  width: 36vw;
  height: 36vw;
  background: radial-gradient(circle, rgba(232, 90, 16, 0.34), transparent 70%);
  animation: drift 22s ease-in-out infinite alternate-reverse;
}

@keyframes drift {
  from {
    transform: translate(0, 0);
  }

  to {
    transform: translate(4%, 6%);
  }
}

.top,
main,
.foot {
  position: relative;
  z-index: 1;
}

/* header */
.top {
  display: flex;
  align-items: center;
  justify-content: space-between;
  max-width: var(--max);
  margin: 0 auto;
  padding: 22px 24px 0;
}

.brand {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  font-family: var(--font-display);
  font-weight: 800;
  font-size: 1.15rem;
  letter-spacing: -0.03em;
}

.brand-icon {
  width: 28px;
  height: 28px;
  border-radius: 7px;
  flex-shrink: 0;
}

.nav {
  display: flex;
  align-items: center;
  gap: 18px;
  font-size: 0.9rem;
  color: var(--muted);
}

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

.nav-cta {
  padding: 8px 14px;
  border-radius: 999px;
  border: 1px solid var(--line);
  color: var(--ink) !important;
  background: color-mix(in srgb, var(--bg-elev) 80%, transparent);
  transition: border-color 0.2s, background 0.2s;
}

.nav-cta:hover {
  border-color: color-mix(in srgb, var(--brand) 45%, transparent);
  background: var(--brand-dim);
}

/* hero */
.hero {
  display: grid;
  grid-template-columns: 1fr;
  gap: 36px;
  max-width: var(--max);
  margin: 0 auto;
  padding: 56px 24px 72px;
}

@media (min-width: 960px) {
  .hero {
    grid-template-columns: minmax(0, 0.95fr) minmax(0, 1.05fr);
    align-items: center;
    gap: 48px;
    padding-top: 72px;
  }
}

.eyebrow {
  margin: 0 0 14px;
  font-family: var(--font-mono);
  font-size: 0.75rem;
  letter-spacing: 0.04em;
  color: var(--brand);
}

.hero h1 {
  margin: 0;
  font-family: var(--font-display);
  font-weight: 800;
  font-size: clamp(2.4rem, 5.2vw, 3.75rem);
  line-height: 1.05;
  letter-spacing: -0.04em;
}

.glow {
  background: linear-gradient(120deg, #ffc48a, var(--brand) 48%, var(--brand-deep));
  -webkit-background-clip: text;
  background-clip: text;
  color: transparent;
}

.lede {
  margin: 18px 0 0;
  max-width: 36em;
  color: var(--muted);
  font-size: 1.05rem;
}

.hero-actions {
  display: flex;
  flex-wrap: wrap;
  gap: 12px;
  margin-top: 28px;
}

.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  min-height: 44px;
  padding: 0 18px;
  border-radius: 12px;
  font-weight: 600;
  font-size: 0.95rem;
  cursor: pointer;
  transition: transform 0.15s ease, background 0.2s, border-color 0.2s, color 0.2s;
}

.btn:hover {
  transform: translateY(-1px);
}

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

.btn-primary {
  color: #2a1204;
  background: var(--brand);
  box-shadow: 0 0 0 1px color-mix(in srgb, var(--brand) 40%, transparent),
    0 12px 40px rgba(248, 120, 32, 0.28);
}

.btn-primary:hover {
  background: #ffa04a;
}

.btn-ghost {
  color: var(--ink);
  border: 1px solid var(--line);
  background: transparent;
}

.btn-ghost:hover {
  border-color: color-mix(in srgb, var(--brand) 40%, transparent);
  background: var(--brand-dim);
}

/* image placeholders */
.ph {
  margin: 0;
  position: relative;
}

.ph-frame {
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  gap: 8px;
  width: 100%;
  height: 100%;
  min-height: inherit;
  border-radius: inherit;
  border: 1.5px dashed color-mix(in srgb, var(--brand) 35%, var(--line));
  background:
    linear-gradient(135deg, rgba(248, 120, 32, 0.08), transparent 42%),
    repeating-linear-gradient(-12deg,
      transparent,
      transparent 10px,
      rgba(232, 237, 245, 0.025) 10px,
      rgba(232, 237, 245, 0.025) 11px),
    var(--bg-elev);
  color: var(--muted);
  text-align: center;
  padding: 24px;
}

.ph-file {
  font-family: var(--font-mono);
  font-size: 0.85rem;
  color: var(--brand);
}

.ph-hint {
  font-size: 0.8rem;
  max-width: 22em;
  line-height: 1.4;
}

/* 已放入真实图片时：隐藏占位框（给 figure 加 class="has-img"） */
.ph.has-img .ph-frame {
  display: none;
}

.ph.has-img img {
  width: 100%;
  height: 100%;
  object-fit: cover;
  border-radius: inherit;
}

.ph-hero {
  aspect-ratio: 16 / 10;
  border-radius: calc(var(--radius) + 4px);
  overflow: hidden;
  box-shadow:
    0 0 0 1px var(--line),
    0 30px 80px rgba(0, 0, 0, 0.45);
}

.ph-hero .ph-frame {
  min-height: 280px;
}

.ph-feature {
  aspect-ratio: 3 / 2;
  border-radius: var(--radius);
  overflow: hidden;
  box-shadow: 0 0 0 1px var(--line);
}

.ph-feature img {
  width: 100%;
  height: 100%;
}

.ph-tile {
  aspect-ratio: 4 / 3;
  border-radius: 14px;
  overflow: hidden;
  box-shadow: 0 0 0 1px var(--line);
}

/* sections */
.section-head {
  max-width: var(--max);
  margin: 0 auto 40px;
  padding: 0 24px;
}

.section-head h2 {
  margin: 0;
  font-family: var(--font-display);
  font-weight: 700;
  font-size: clamp(1.6rem, 3vw, 2.15rem);
  letter-spacing: -0.03em;
}

.section-head p {
  margin: 10px 0 0;
  color: var(--muted);
  max-width: 40em;
}

.features {
  padding: 24px 0 48px;
}

.feature {
  display: grid;
  grid-template-columns: 1fr;
  gap: 28px;
  max-width: var(--max);
  margin: 0 auto 64px;
  padding: 0 24px;
}

@media (min-width: 900px) {
  .feature {
    grid-template-columns: 1fr 1.15fr;
    align-items: center;
    gap: 48px;
  }

  .feature-flip .feature-text {
    order: 2;
  }

  .feature-flip .ph {
    order: 1;
  }
}

.idx {
  display: inline-block;
  font-family: var(--font-mono);
  font-size: 0.78rem;
  color: var(--brand);
  margin-bottom: 8px;
}

.feature h3 {
  margin: 0;
  font-family: var(--font-display);
  font-weight: 700;
  font-size: 1.65rem;
  letter-spacing: -0.03em;
}

.feature-text>p {
  margin: 12px 0 0;
  color: var(--muted);
}

.feature ul {
  margin: 18px 0 0;
  padding: 0;
  list-style: none;
  display: flex;
  flex-direction: column;
  gap: 8px;
}

.feature li {
  position: relative;
  padding-left: 16px;
  font-size: 0.92rem;
  color: color-mix(in srgb, var(--ink) 88%, var(--muted));
}

.feature li::before {
  content: '';
  position: absolute;
  left: 0;
  top: 0.55em;
  width: 7px;
  height: 7px;
  border-radius: 2px;
  background: var(--brand);
  box-shadow: 0 0 10px rgba(248, 120, 32, 0.45);
}

/* stack tiles */
.stack {
  padding: 24px 0 80px;
}

.stack-grid {
  display: grid;
  grid-template-columns: 1fr;
  gap: 16px;
  max-width: var(--max);
  margin: 0 auto;
  padding: 0 24px;
}

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

/* cta */
.cta {
  max-width: var(--max);
  margin: 0 auto 72px;
  padding: 48px 28px;
  text-align: center;
  border-radius: calc(var(--radius) + 6px);
  border: 1px solid var(--line);
  background:
    radial-gradient(ellipse at 50% 0%, var(--brand-dim), transparent 60%),
    var(--bg-elev);
}

.cta h2 {
  margin: 0;
  font-family: var(--font-display);
  font-weight: 700;
  font-size: 1.8rem;
  letter-spacing: -0.03em;
}

.cta p {
  margin: 10px 0 24px;
  color: var(--muted);
}

.foot {
  display: flex;
  align-items: center;
  justify-content: center;
  gap: 10px;
  padding: 0 24px 40px;
  color: var(--muted);
  font-size: 0.85rem;
}

.dot {
  width: 4px;
  height: 4px;
  border-radius: 50%;
  background: var(--muted);
  opacity: 0.5;
}

/* entrance */
.reveal {
  opacity: 0;
  transform: translateY(16px);
  transition: opacity 0.55s ease, transform 0.55s ease;
}

.reveal.is-in {
  opacity: 1;
  transform: none;
}

@media (prefers-reduced-motion: reduce) {
  html {
    scroll-behavior: auto;
  }

  .orb-a,
  .orb-b {
    animation: none;
  }

  .reveal {
    opacity: 1;
    transform: none;
    transition: none;
  }

  .btn:hover {
    transform: none;
  }
}