:root {
  --navy: #1F2D75;
  --navy-2: #17235e;
  --navy-3: #2a397f;
  --blue: #1677ff;
  --blue-soft: #eaf3ff;
  --gold: #d7a84a;
  --gold-light: #f3d58d;
  --ink: #102033;
  --muted: #607184;
  --line: #dfe7ef;
  --paper: #f5f8fb;
  --white: #ffffff;
  --shell: min(75rem, calc(100% - 3rem));
}

* { box-sizing: border-box; }
html { scroll-behavior: smooth; }
body { margin: 0; color: var(--ink); background: var(--white); font-family: "Microsoft YaHei", "PingFang SC", "Noto Sans CJK SC", Arial, sans-serif; line-height: 1.7; -webkit-font-smoothing: antialiased; overflow-x: clip; }
a { color: inherit; }
img { display: block; max-width: 100%; }
.shell { width: var(--shell); margin-inline: auto; }

.prototype-bar { padding: 0.55rem 1rem; color: var(--gold-light); background: var(--navy); font-size: 0.75rem; letter-spacing: 0.03em; text-align: center; }
.site-header { position: sticky; top: 0; z-index: 20; border-bottom: 1px solid var(--line); background: rgba(255, 255, 255, 0.96); backdrop-filter: blur(14px); }
.header-inner { display: flex; min-height: 4.75rem; align-items: center; justify-content: space-between; gap: 2rem; }
.brand { display: inline-flex; min-width: 0; align-items: center; gap: 1rem; text-decoration: none; }
.brand-logo { width: 8.4rem; height: auto; }
.brand-divider { width: 1px; height: 1.7rem; background: var(--line); }
.brand-context { color: var(--navy); font-size: 0.86rem; font-weight: 800; letter-spacing: 0.04em; }
.site-nav { display: flex; align-items: center; gap: 1.55rem; color: var(--muted); font-size: 0.86rem; }
.site-nav a { text-decoration: none; }
.site-nav a:hover { color: var(--blue); }
.site-nav .nav-cta { padding: 0.65rem 1rem; border-radius: 0.45rem; color: var(--navy); background: var(--gold-light); font-weight: 800; }
.nav-toggle { display: none; }

.hero { position: relative; overflow: hidden; padding: clamp(5.5rem, 10vw, 8.5rem) 0 clamp(4.5rem, 8vw, 7rem); color: var(--white); background: radial-gradient(circle at 78% 36%, rgba(22, 119, 255, 0.28), transparent 28%), linear-gradient(135deg, #06111f 0%, var(--navy-2) 58%, var(--navy) 100%); }
.hero::before { position: absolute; inset: 0; content: ""; opacity: 0.18; background-image: linear-gradient(rgba(255, 255, 255, 0.09) 1px, transparent 1px), linear-gradient(90deg, rgba(255, 255, 255, 0.09) 1px, transparent 1px); background-size: 48px 48px; -webkit-mask-image: linear-gradient(90deg, transparent, #000 55%, transparent); mask-image: linear-gradient(90deg, transparent, #000 55%, transparent); }
.hero-grid { position: relative; display: grid; grid-template-columns: minmax(0, 1.06fr) minmax(25rem, 0.94fr); gap: clamp(3rem, 7vw, 7rem); align-items: center; }
.hero-copy { position: relative; z-index: 1; }
.eyebrow, .section-number { margin: 0 0 1rem; color: var(--blue); font-size: 0.76rem; font-weight: 800; letter-spacing: 0.1em; }
.hero .eyebrow { color: var(--gold-light); }
.eyebrow { display: flex; align-items: center; gap: 0.55rem; }
.eyebrow-dot { width: 0.52rem; height: 0.52rem; border-radius: 50%; background: currentColor; }
h1, h2, h3 { margin-top: 0; line-height: 1.2; letter-spacing: -0.035em; }
h1, h2 { font-weight: 800; }
h1 { max-width: 15ch; margin-bottom: 1.55rem; font-size: clamp(2rem, 4vw, 3.65rem); }
h2 { max-width: 15ch; font-size: clamp(2rem, 4vw, 3.65rem); }
h3 { margin-bottom: 0.45rem; font-size: 1.1rem; }
.hero-summary { max-width: 39rem; margin: 0 0 2rem; color: rgba(255, 255, 255, 0.74); font-size: clamp(1rem, 1.4vw, 1.16rem); line-height: 1.8; }
.hero-actions { display: flex; align-items: center; flex-wrap: wrap; gap: 0.8rem; }
.button { display: inline-flex; min-height: 3.1rem; align-items: center; justify-content: center; gap: 0.65rem; padding: 0.85rem 1.2rem; border: 1px solid transparent; border-radius: 0.5rem; font-size: 0.88rem; font-weight: 800; text-decoration: none; transition: transform 180ms ease, background-color 180ms ease, box-shadow 180ms ease; }
.button:hover { transform: translateY(-2px); }
.button-primary { color: var(--navy); background: var(--gold-light); box-shadow: 0 14px 32px rgba(215, 168, 74, 0.16); }
.button-primary:hover { background: #ffe6a8; }
.button-dark { color: var(--white); background: var(--navy); }
.text-link { padding: 0.8rem; color: var(--white); font-size: 0.88rem; font-weight: 800; text-decoration: none; border: 1px solid rgba(255, 255, 255, 0.28); border-radius: 0.5rem; }
.text-link:hover { border-color: var(--gold-light); color: var(--gold-light); }
.hero-proof { display: flex; flex-wrap: wrap; gap: 0; margin-top: 3.5rem; }
.hero-proof div { display: grid; grid-template-columns: auto 1fr; gap: 0.55rem; align-items: baseline; padding: 0 1.35rem; border-left: 1px solid rgba(255, 255, 255, 0.18); }
.hero-proof div:first-child { padding-left: 0; border-left: 0; }
.hero-proof strong { color: var(--gold-light); font: 800 0.72rem/1 Arial, sans-serif; }
.hero-proof span { color: rgba(255, 255, 255, 0.65); font-size: 0.78rem; }

.hero-visual { position: relative; margin: 0; }
.visual-kicker { margin: 0 0 0.75rem; color: rgba(255, 255, 255, 0.62); font-size: 0.72rem; letter-spacing: 0.08em; }
.board-wrap { position: relative; padding: 0.9rem; border: 1px solid rgba(255, 255, 255, 0.28); border-radius: 1.1rem; background: rgba(255, 255, 255, 0.09); box-shadow: 0 30px 70px rgba(0, 0, 0, 0.34); }
.board-wrap .hero-photo { width: 100%; aspect-ratio: 16 / 9; object-fit: cover; object-position: center; border-radius: 0.6rem; }
.hero-visual figcaption { max-width: 32rem; margin-top: 1rem; color: rgba(255, 255, 255, 0.62); font-size: 0.74rem; }

.path-section { background: var(--white); }
.section { padding: clamp(5rem, 9vw, 8rem) 0; }
.section-intro { display: grid; grid-template-columns: 0.85fr 1.15fr; gap: 3rem; align-items: end; margin-bottom: 3.5rem; }
.section-intro h2 { max-width: 14ch; margin-bottom: 0; }
.section-intro > p:last-child { max-width: 32rem; margin: 0 0 0.25rem; color: var(--muted); }
.field-photo { margin: 0 0 3.5rem; }
.field-photo img { width: 100%; max-height: 32rem; border-radius: 1rem; object-fit: cover; object-position: center 52%; box-shadow: 0 18px 50px rgba(7, 20, 38, 0.14); }
.field-photo figcaption { margin-top: 0.75rem; color: var(--muted); font-size: 0.74rem; }
.path-line { display: grid; grid-template-columns: repeat(3, 1fr); gap: 0; border-top: 2px solid var(--line); }
.path-step, .path-step-offset { position: relative; min-height: 12rem; padding: 2rem 1.5rem 1rem 0; border-right: 1px solid var(--line); }
.path-step + .path-step { padding-left: 1.5rem; }
.path-step:last-child { border-right: 0; padding-right: 0; }
.path-step-offset { padding-top: 4rem; }
.step-no { display: inline-flex; width: 2rem; height: 2rem; align-items: center; justify-content: center; margin-bottom: 1.75rem; border-radius: 50%; color: var(--blue); background: var(--blue-soft); font: 800 0.72rem/1 Arial, sans-serif; }
.path-step:nth-child(2) .step-no { color: var(--navy); background: var(--gold-light); }
.path-step:nth-child(3) .step-no { color: var(--white); background: var(--blue); }
.path-step p, .output-item p, .fit-copy > p { max-width: 22rem; margin: 0; color: var(--muted); font-size: 0.9rem; }

.outputs-section { color: var(--white); background: var(--navy); }
.outputs-grid { display: grid; grid-template-columns: 0.82fr 1.18fr; gap: clamp(3rem, 8vw, 9rem); }
.outputs-section .section-number { color: var(--gold-light); }
.outputs-section h2 { max-width: 12ch; }
.output-list { border-top: 1px solid rgba(255, 255, 255, 0.24); }
.output-item { display: grid; grid-template-columns: 2.2rem 1fr auto; gap: 1rem; align-items: start; padding: 1.45rem 0; border-bottom: 1px solid rgba(255, 255, 255, 0.18); }
.output-index { color: var(--gold-light); font: 800 0.78rem/1 Arial, sans-serif; }
.output-item p { color: rgba(255, 255, 255, 0.68); }
.output-arrow { color: var(--gold-light); font-size: 1.25rem; }
.featured-output { padding: 1.45rem 1rem; border-radius: 0.6rem; background: var(--blue); }
.featured-output .output-index, .featured-output .output-arrow { color: var(--white); }
.featured-output p { color: rgba(255, 255, 255, 0.8); }

.case-section { color: var(--white); background: var(--navy-2); }
.case-grid { display: grid; grid-template-columns: 0.85fr 1.15fr; gap: clamp(3rem, 8vw, 8rem); align-items: start; }
.case-section .section-number { color: var(--gold-light); }
.case-section h2 { max-width: 12ch; }
.case-copy > p:not(.section-number) { max-width: 31rem; color: rgba(255, 255, 255, 0.72); font-size: 1rem; }
.case-facts { margin-top: 2.5rem; border-top: 1px solid rgba(255, 255, 255, 0.24); }
.case-facts div { display: grid; grid-template-columns: 5rem 1fr; gap: 1rem; padding: 0.85rem 0; border-bottom: 1px solid rgba(255, 255, 255, 0.15); font-size: 0.86rem; }
.case-facts strong { color: var(--gold-light); }
.case-facts span { color: rgba(255, 255, 255, 0.72); }
.case-media { display: block; }
.case-media figure { margin: 0; }
.case-media img { width: 100%; border: 1px solid rgba(255, 255, 255, 0.25); border-radius: 0.7rem; background: var(--white); }
.hummingbird-pair { display: grid; grid-template-columns: repeat(2, minmax(0, 1fr)); gap: 1rem; }
.hummingbird-pair img { aspect-ratio: 4 / 3; object-fit: cover; }
.case-media figcaption { margin-top: 0.65rem; color: rgba(255, 255, 255, 0.58); font-size: 0.7rem; line-height: 1.5; }

.fit-section { background: var(--paper); }
.fit-grid { display: grid; grid-template-columns: 0.95fr 1.05fr; gap: clamp(3rem, 9vw, 10rem); align-items: start; }
.fit-copy { padding-top: 0.5rem; }
.fit-copy > p { max-width: 31rem; font-size: 1.05rem; }
.fit-tags { display: flex; flex-wrap: wrap; gap: 0.65rem; margin-top: 2rem; }
.fit-tags span { padding: 0.55rem 0.8rem; border: 1px solid #c8d7e8; border-radius: 0.45rem; color: var(--navy-2); background: var(--white); font-size: 0.8rem; font-weight: 700; }

.contact-section { padding: 0 0 5rem; background: var(--paper); }
.contact-panel { display: flex; align-items: end; justify-content: space-between; gap: 2rem; padding: clamp(2rem, 5vw, 4.5rem); border-radius: 1rem; color: var(--white); background: var(--blue); box-shadow: 0 20px 55px rgba(22, 119, 255, 0.18); }
.contact-panel .section-number { color: var(--gold-light); }
.contact-panel h2 { max-width: 10ch; margin-bottom: 1rem; }
.contact-panel p:not(.section-number) { max-width: 33rem; margin: 0; color: rgba(255, 255, 255, 0.78); }
.site-footer { padding: 1.3rem 0 3.3rem; color: rgba(255, 255, 255, 0.62); background: #040c16; font-size: 0.74rem; }
.footer-inner { display: flex; justify-content: space-between; gap: 1rem; }

:focus-visible { outline: 3px solid #7db7ff; outline-offset: 3px; }

@media (max-width: 820px) {
  :root { --shell: min(100% - 2rem, 75rem); }
  .hero-grid, .outputs-grid, .fit-grid, .case-grid { grid-template-columns: 1fr; }
  .hero-grid { gap: 3.5rem; }
  .hero-visual { max-width: 42rem; margin-inline: auto; }
  .section-intro { grid-template-columns: 1fr; gap: 1rem; }
  .section-intro h2, .outputs-section h2, .case-section h2 { max-width: 14ch; }
  .outputs-grid, .case-grid { gap: 3.5rem; }
  .case-media { max-width: 44rem; }
}

@media (max-width: 640px) {
  .prototype-bar { font-size: 0.67rem; }
  .header-inner { min-height: 4.2rem; }
  .brand { gap: 0.65rem; }
  .brand-logo { width: 7.3rem; }
  .brand-divider { height: 1.35rem; }
  .brand-context { max-width: 7.2rem; font-size: 0.68rem; line-height: 1.35; }
  .nav-toggle { display: grid; width: 2.7rem; height: 2.7rem; place-content: center; gap: 0.32rem; border: 1px solid var(--navy); border-radius: 50%; background: var(--white); }
  .nav-toggle span { display: block; width: 1rem; height: 2px; background: var(--navy); }
  .site-nav { position: absolute; inset: 4.2rem 0 auto; display: none; flex-direction: column; align-items: stretch; gap: 0; padding: 0.8rem 1rem 1rem; border-bottom: 1px solid var(--line); background: var(--white); }
  .site-nav[data-open="true"] { display: flex; }
  .site-nav a { padding: 0.78rem 0; border-bottom: 1px solid var(--line); }
  .site-nav .nav-cta { margin-top: 0.75rem; border-bottom: 0; text-align: center; }
  .hero { padding-top: 4.6rem; }
  h1 { max-width: 14ch; font-size: clamp(2rem, 10.5vw, 3.2rem); }
  h2 { font-size: clamp(2rem, 10.5vw, 3.2rem); }
  .hero-proof { gap: 0.75rem 0; margin-top: 2.8rem; }
  .hero-proof div { padding: 0 0.8rem; }
  .hero-proof div:first-child { padding-left: 0; }
  .hero-proof div:last-child { padding-right: 0; }
  .path-line { grid-template-columns: 1fr; gap: 0; }
  .path-step, .path-step-offset, .path-step + .path-step { min-height: 0; padding: 1.5rem 0; border-right: 0; border-bottom: 1px solid var(--line); }
  .path-step:last-child { border-bottom: 0; }
  .step-no { margin-bottom: 1rem; }
  .hummingbird-pair { grid-template-columns: 1fr 1fr; }
  .output-item { grid-template-columns: 1.7rem 1fr auto; }
  .featured-output { margin-inline: -0.5rem; padding-inline: 0.5rem; }
  .contact-panel { align-items: start; flex-direction: column; }
  .footer-inner { align-items: start; flex-direction: column; }
}

@media (prefers-reduced-motion: reduce) {
  html { scroll-behavior: auto; }
  *, *::before { transition: none !important; animation: none !important; }
}