/* ── 美动力官方网站 · Design Tokens ── */
:root {
  --color-bg: #0a0b0f;
  --color-bg-elevated: #12141c;
  --color-bg-card: rgba(255, 255, 255, 0.04);
  --color-surface: #f8f6f3;
  --color-text: #1a1a1c;
  --color-text-muted: rgba(255, 255, 255, 0.62);
  --color-text-soft: #808080;
  --color-brand: #1e3463;
  --color-accent: #efa978;
  --color-accent-light: #fff6f1;
  --color-gold: #c9a87c;
  --color-border: rgba(255, 255, 255, 0.08);
  --font-serif: "Noto Serif SC", "Songti SC", serif;
  --font-sans: "Noto Sans SC", "PingFang SC", "Microsoft YaHei", sans-serif;
  --header-h: 72px;
  --container: min(1200px, calc(100% - 48px));
  --ease: cubic-bezier(0.22, 1, 0.36, 1);
}

*, *::before, *::after {
  box-sizing: border-box;
  margin: 0;
  padding: 0;
}

html {
  scroll-behavior: smooth;
  font-size: 16px;
}

body {
  font-family: var(--font-sans);
  background: var(--color-bg);
  color: #fff;
  line-height: 1.7;
  overflow-x: hidden;
  -webkit-font-smoothing: antialiased;
}

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

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

.container {
  width: var(--container);
  margin-inline: auto;
}

.eyebrow {
  font-family: var(--font-sans);
  font-size: 0.75rem;
  font-weight: 500;
  letter-spacing: 0.28em;
  color: var(--color-accent);
  margin-bottom: 1rem;
}

/* ── Header ── */
.site-header {
  position: fixed;
  inset: 0 0 auto;
  z-index: 100;
  height: var(--header-h);
  transition: background 0.4s var(--ease), backdrop-filter 0.4s;
}

.site-header.scrolled {
  background: rgba(10, 11, 15, 0.82);
  backdrop-filter: blur(16px);
  border-bottom: 1px solid var(--color-border);
}

.nav {
  display: flex;
  align-items: center;
  justify-content: space-between;
  height: 100%;
}

.nav-brand {
  display: flex;
  align-items: center;
  gap: 10px;
  font-family: var(--font-serif);
  font-size: 1.125rem;
  font-weight: 600;
  letter-spacing: 0.06em;
}

.nav-brand img {
  border-radius: 8px;
}

.nav-links {
  display: flex;
  gap: 2rem;
  list-style: none;
}

.nav-links a {
  font-size: 0.875rem;
  font-weight: 400;
  color: rgba(255, 255, 255, 0.75);
  transition: color 0.25s;
  position: relative;
}

.nav-links a::after {
  content: "";
  position: absolute;
  left: 0;
  bottom: -4px;
  width: 0;
  height: 1px;
  background: var(--color-accent);
  transition: width 0.3s var(--ease);
}

.nav-links a:hover {
  color: #fff;
}

.nav-links a:hover::after {
  width: 100%;
}

.nav-toggle {
  display: none;
  flex-direction: column;
  gap: 5px;
  background: none;
  border: none;
  cursor: pointer;
  padding: 4px;
}

.nav-toggle span {
  display: block;
  width: 22px;
  height: 1.5px;
  background: #fff;
  transition: transform 0.3s, opacity 0.3s;
}

/* ── Buttons ── */
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  padding: 0.875rem 2rem;
  font-size: 0.9375rem;
  font-weight: 500;
  border-radius: 999px;
  transition: transform 0.25s var(--ease), box-shadow 0.25s, background 0.25s;
}

.btn:hover {
  transform: translateY(-2px);
}

.btn-primary {
  background: linear-gradient(135deg, var(--color-accent) 0%, #d4895a 100%);
  color: var(--color-text);
  box-shadow: 0 8px 32px rgba(239, 169, 120, 0.28);
}

.btn-primary:hover {
  box-shadow: 0 12px 40px rgba(239, 169, 120, 0.38);
}

.btn-outline {
  border: 1px solid rgba(255, 255, 255, 0.28);
  color: #fff;
  backdrop-filter: blur(8px);
}

.btn-outline:hover {
  border-color: rgba(255, 255, 255, 0.5);
  background: rgba(255, 255, 255, 0.06);
}

/* ── Hero ── */
.hero {
  position: relative;
  min-height: 100vh;
  display: flex;
  align-items: center;
  padding-top: var(--header-h);
  overflow: hidden;
}

.hero-bg {
  position: absolute;
  inset: 0;
  background:
    radial-gradient(ellipse 80% 60% at 70% 40%, rgba(30, 52, 99, 0.35) 0%, transparent 60%),
    radial-gradient(ellipse 50% 40% at 20% 80%, rgba(239, 169, 120, 0.12) 0%, transparent 50%),
    linear-gradient(180deg, #0a0b0f 0%, #0f1118 50%, #0a0b0f 100%);
}

.hero-glow {
  position: absolute;
  border-radius: 50%;
  filter: blur(80px);
  pointer-events: none;
}

.hero-glow--1 {
  width: 400px;
  height: 400px;
  top: 10%;
  right: 5%;
  background: rgba(201, 168, 124, 0.15);
}

.hero-glow--2 {
  width: 300px;
  height: 300px;
  bottom: 20%;
  left: -5%;
  background: rgba(30, 52, 99, 0.25);
}

.hero-inner {
  position: relative;
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 4rem;
  align-items: center;
  padding-block: 4rem 6rem;
}

.hero-copy h1 {
  font-family: var(--font-serif);
  font-size: clamp(2.5rem, 5vw, 3.75rem);
  font-weight: 600;
  line-height: 1.25;
  letter-spacing: 0.02em;
  margin-bottom: 1.5rem;
}

.hero-desc {
  font-size: 1.0625rem;
  color: var(--color-text-muted);
  max-width: 480px;
  margin-bottom: 2.5rem;
  font-weight: 300;
}

.hero-actions {
  display: flex;
  flex-wrap: wrap;
  gap: 1rem;
  margin-bottom: 3.5rem;
}

.hero-stats {
  display: flex;
  gap: 3rem;
  padding-top: 2rem;
  border-top: 1px solid var(--color-border);
}

.hero-stats dt {
  font-family: var(--font-serif);
  font-size: 1.5rem;
  font-weight: 600;
  color: var(--color-gold);
  margin-bottom: 0.25rem;
}

.hero-stats dd {
  font-size: 0.8125rem;
  color: var(--color-text-muted);
}

.hero-visual {
  display: flex;
  justify-content: center;
  align-items: center;
}

.hero-device-frame {
  position: relative;
  padding: 2rem;
}

.hero-device-frame::before {
  content: "";
  position: absolute;
  inset: 0;
  border-radius: 50%;
  background: radial-gradient(circle, rgba(201, 168, 124, 0.2) 0%, transparent 70%);
  animation: pulse 4s ease-in-out infinite;
}

@keyframes pulse {
  0%, 100% { opacity: 0.6; transform: scale(1); }
  50% { opacity: 1; transform: scale(1.05); }
}

.hero-device {
  position: relative;
  width: min(420px, 100%);
  filter: drop-shadow(0 24px 64px rgba(0, 0, 0, 0.5));
  animation: float 6s ease-in-out infinite;
}

@keyframes float {
  0%, 100% { transform: translateY(0); }
  50% { transform: translateY(-16px); }
}

.scroll-hint {
  position: absolute;
  bottom: 2rem;
  left: 50%;
  transform: translateX(-50%);
  width: 24px;
  height: 40px;
  border: 1px solid rgba(255, 255, 255, 0.2);
  border-radius: 12px;
  display: flex;
  justify-content: center;
  padding-top: 8px;
}

.scroll-hint span {
  width: 3px;
  height: 8px;
  background: var(--color-accent);
  border-radius: 2px;
  animation: scroll-bounce 2s infinite;
}

@keyframes scroll-bounce {
  0%, 100% { transform: translateY(0); opacity: 1; }
  50% { transform: translateY(8px); opacity: 0.3; }
}

/* ── Sections ── */
.section {
  padding: 7rem 0;
}

.section-head {
  text-align: center;
  max-width: 640px;
  margin-inline: auto;
  margin-bottom: 4rem;
}

.section-head h2 {
  font-family: var(--font-serif);
  font-size: clamp(2rem, 4vw, 2.75rem);
  font-weight: 600;
  margin-bottom: 1rem;
}

.section-desc {
  color: var(--color-text-muted);
  font-size: 1rem;
  font-weight: 300;
}

/* ── Product ── */
.product {
  background: linear-gradient(180deg, var(--color-bg) 0%, var(--color-bg-elevated) 100%);
}

.product-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 1.5rem;
  margin-bottom: 4rem;
}

.product-card {
  padding: 2rem;
  background: var(--color-bg-card);
  border: 1px solid var(--color-border);
  border-radius: 16px;
  transition: border-color 0.3s, transform 0.3s var(--ease);
}

.product-card:hover {
  border-color: rgba(239, 169, 120, 0.3);
  transform: translateY(-4px);
}

.product-index {
  font-family: var(--font-serif);
  font-size: 2rem;
  font-weight: 600;
  color: rgba(201, 168, 124, 0.35);
  display: block;
  margin-bottom: 1rem;
}

.product-card h3 {
  font-size: 1.125rem;
  font-weight: 500;
  margin-bottom: 0.75rem;
}

.product-card p {
  font-size: 0.875rem;
  color: var(--color-text-muted);
  font-weight: 300;
}

.product-showcase {
  position: relative;
  display: flex;
  justify-content: center;
  align-items: center;
  min-height: 360px;
  border-radius: 24px;
  background: linear-gradient(135deg, rgba(30, 52, 99, 0.2) 0%, rgba(239, 169, 120, 0.08) 100%);
  border: 1px solid var(--color-border);
  overflow: hidden;
}

.product-showcase-bg {
  position: absolute;
  width: 280px;
  opacity: 0.06;
  filter: blur(2px);
}

.product-showcase-img {
  position: relative;
  width: min(320px, 70%);
  filter: drop-shadow(0 20px 48px rgba(0, 0, 0, 0.4));
}

/* ── Features ── */
.features {
  background: var(--color-surface);
  color: var(--color-text);
}

.features .eyebrow {
  color: var(--color-brand);
}

.features .section-desc {
  color: var(--color-text-soft);
}

.features-grid {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 1.5rem;
}

.feature-item {
  padding: 2rem 1.5rem;
  background: #fff;
  border-radius: 16px;
  box-shadow: 0 4px 24px rgba(26, 26, 28, 0.06);
  transition: transform 0.3s var(--ease), box-shadow 0.3s;
}

.feature-item:hover {
  transform: translateY(-6px);
  box-shadow: 0 12px 40px rgba(26, 26, 28, 0.1);
}

.feature-icon {
  width: 48px;
  height: 48px;
  display: flex;
  align-items: center;
  justify-content: center;
  background: var(--color-accent-light);
  border-radius: 12px;
  color: var(--color-accent);
  margin-bottom: 1.25rem;
}

.feature-icon svg {
  width: 24px;
  height: 24px;
}

.feature-item h3 {
  font-size: 1.0625rem;
  font-weight: 600;
  margin-bottom: 0.625rem;
  color: var(--color-brand);
}

.feature-item p {
  font-size: 0.875rem;
  color: var(--color-text-soft);
  line-height: 1.65;
}

/* ── Technology ── */
.technology {
  background: var(--color-bg);
}

.technology-inner {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 4rem;
  align-items: center;
}

.technology-copy h2 {
  font-family: var(--font-serif);
  font-size: clamp(2rem, 4vw, 2.75rem);
  font-weight: 600;
  line-height: 1.3;
  margin-bottom: 2.5rem;
}

.tech-list {
  list-style: none;
  display: flex;
  flex-direction: column;
  gap: 1.75rem;
}

.tech-list li {
  padding-left: 1.25rem;
  border-left: 2px solid var(--color-accent);
}

.tech-list strong {
  display: block;
  font-size: 1rem;
  font-weight: 500;
  margin-bottom: 0.25rem;
}

.tech-list span {
  font-size: 0.875rem;
  color: var(--color-text-muted);
  font-weight: 300;
}

.technology-visual {
  position: relative;
  display: flex;
  align-items: center;
  justify-content: center;
  min-height: 400px;
}

.tech-ring {
  position: absolute;
  border-radius: 50%;
  border: 1px solid rgba(201, 168, 124, 0.2);
}

.tech-ring--outer {
  width: 360px;
  height: 360px;
  animation: spin 20s linear infinite;
}

.tech-ring--inner {
  width: 260px;
  height: 260px;
  border-color: rgba(30, 52, 99, 0.4);
  animation: spin 15s linear infinite reverse;
}

@keyframes spin {
  to { transform: rotate(360deg); }
}

.tech-center {
  position: relative;
  z-index: 1;
  text-align: center;
  padding: 3rem;
  background: radial-gradient(circle, rgba(30, 52, 99, 0.4) 0%, transparent 70%);
  border-radius: 50%;
}

.tech-label {
  display: block;
  font-size: 0.75rem;
  letter-spacing: 0.3em;
  color: var(--color-accent);
  margin-bottom: 0.5rem;
}

.tech-value {
  font-family: var(--font-serif);
  font-size: 2.5rem;
  font-weight: 600;
}

/* ── App ── */
.app-section {
  background: linear-gradient(180deg, var(--color-bg-elevated) 0%, var(--color-bg) 100%);
}

.app-inner {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 4rem;
  align-items: center;
}

.app-copy h2 {
  font-family: var(--font-serif);
  font-size: clamp(2rem, 4vw, 2.75rem);
  font-weight: 600;
  margin-bottom: 1rem;
}

.app-copy .section-desc {
  margin-bottom: 2rem;
}

.store-buttons {
  display: flex;
  flex-wrap: wrap;
  gap: 1rem;
  margin-bottom: 1rem;
}

.store-btn {
  display: flex;
  flex-direction: column;
  padding: 0.75rem 1.5rem;
  min-width: 160px;
  background: rgba(255, 255, 255, 0.06);
  border: 1px solid var(--color-border);
  border-radius: 12px;
  transition: background 0.25s, border-color 0.25s;
}

.store-btn:hover {
  background: rgba(255, 255, 255, 0.1);
  border-color: rgba(255, 255, 255, 0.2);
}

.store-btn-label {
  font-size: 0.6875rem;
  color: var(--color-text-muted);
}

.store-btn-name {
  font-size: 1.125rem;
  font-weight: 500;
}

.app-note {
  font-size: 0.75rem;
  color: rgba(255, 255, 255, 0.35);
}

.phone-frame {
  width: 260px;
  margin-inline: auto;
  padding: 12px;
  background: linear-gradient(145deg, #2a2a2e 0%, #1a1a1c 100%);
  border-radius: 36px;
  box-shadow:
    0 0 0 1px rgba(255, 255, 255, 0.1),
    0 32px 64px rgba(0, 0, 0, 0.5);
}

.phone-screen {
  background: var(--color-surface);
  border-radius: 28px;
  padding: 2rem 1.25rem 1.5rem;
  min-height: 420px;
}

.phone-header {
  font-family: var(--font-serif);
  font-size: 1rem;
  font-weight: 600;
  color: var(--color-brand);
  text-align: center;
  margin-bottom: 1.5rem;
}

.phone-card {
  height: 100px;
  background: var(--color-brand);
  border-radius: 12px;
  margin-bottom: 0.75rem;
  opacity: 0.9;
}

.phone-card--short {
  height: 48px;
  background: #fff;
  border: 1px solid #eee;
  opacity: 1;
}

.phone-grid {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 0.75rem;
  margin-top: 1rem;
}

.phone-grid div {
  height: 80px;
  background: #fff;
  border-radius: 12px;
  border: 1px solid #eee;
}

/* ── Contact ── */
.contact {
  background: var(--color-surface);
  color: var(--color-text);
}

.contact .eyebrow {
  color: var(--color-brand);
}

.contact-inner {
  text-align: center;
}

.contact-copy {
  max-width: 560px;
  margin-inline: auto;
  margin-bottom: 3rem;
}

.contact-copy h2 {
  font-family: var(--font-serif);
  font-size: clamp(2rem, 4vw, 2.75rem);
  font-weight: 600;
  margin-bottom: 1rem;
}

.contact-copy p {
  color: var(--color-text-soft);
  font-weight: 300;
}

.contact-cards {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 1.5rem;
  max-width: 900px;
  margin-inline: auto;
}

.contact-card {
  padding: 2rem 1.5rem;
  background: #fff;
  border-radius: 16px;
  box-shadow: 0 4px 24px rgba(26, 26, 28, 0.06);
}

.contact-label {
  display: block;
  font-size: 0.75rem;
  letter-spacing: 0.1em;
  color: var(--color-text-soft);
  margin-bottom: 0.5rem;
}

.contact-card a,
.contact-card span {
  font-size: 0.9375rem;
  font-weight: 500;
  color: var(--color-brand);
}

.contact-card a:hover {
  color: var(--color-accent);
}

/* ── Footer ── */
.site-footer {
  padding: 3rem 0;
  background: var(--color-bg);
  border-top: 1px solid var(--color-border);
  text-align: center;
}

.footer-brand {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  font-family: var(--font-serif);
  font-size: 1rem;
  font-weight: 600;
  margin-bottom: 0.5rem;
}

.footer-brand img {
  border-radius: 6px;
}

.footer-tagline {
  font-size: 0.8125rem;
  color: var(--color-text-muted);
  margin-bottom: 1rem;
}

.footer-links {
  display: flex;
  align-items: center;
  justify-content: center;
  flex-wrap: wrap;
  gap: 0.35rem 0.5rem;
  margin-bottom: 0.75rem;
  font-size: 0.8125rem;
}

.footer-links a {
  color: rgba(255, 255, 255, 0.72);
  text-decoration: none;
  transition: color 0.2s var(--ease);
}

.footer-links a:hover {
  color: var(--color-accent);
}

.footer-sep {
  color: rgba(255, 255, 255, 0.28);
}

.footer-company {
  margin: 0 0 0.5rem;
  font-size: 0.75rem;
  color: rgba(255, 255, 255, 0.45);
}

.footer-copy {
  font-size: 0.75rem;
  color: rgba(255, 255, 255, 0.35);
}

/* ── Reveal animations ── */
.reveal {
  opacity: 0;
  transform: translateY(32px);
  transition: opacity 0.8s var(--ease), transform 0.8s var(--ease);
}

.reveal.visible {
  opacity: 1;
  transform: translateY(0);
}

.reveal-delay { transition-delay: 0.15s; }
.reveal-delay-2 { transition-delay: 0.3s; }
.reveal-delay-3 { transition-delay: 0.45s; }

/* ── Responsive ── */
@media (max-width: 1024px) {
  .hero-inner,
  .technology-inner,
  .app-inner {
    grid-template-columns: 1fr;
    text-align: center;
  }

  .hero-desc,
  .hero-stats {
    margin-inline: auto;
  }

  .hero-stats {
    justify-content: center;
  }

  .hero-actions {
    justify-content: center;
  }

  .hero-visual {
    order: -1;
  }

  .hero-device {
    width: min(300px, 80%);
  }

  .product-grid,
  .features-grid,
  .contact-cards {
    grid-template-columns: 1fr;
  }

  .technology-visual {
    min-height: 300px;
  }

  .tech-ring--outer { width: 280px; height: 280px; }
  .tech-ring--inner { width: 200px; height: 200px; }
}

@media (max-width: 768px) {
  .nav-toggle {
    display: flex;
  }

  .nav-links {
    position: fixed;
    inset: var(--header-h) 0 auto;
    flex-direction: column;
    gap: 0;
    background: rgba(10, 11, 15, 0.96);
    backdrop-filter: blur(16px);
    padding: 1rem 0;
    border-bottom: 1px solid var(--color-border);
    transform: translateY(-120%);
    opacity: 0;
    pointer-events: none;
    transition: transform 0.35s var(--ease), opacity 0.35s;
  }

  .nav-links.open {
    transform: translateY(0);
    opacity: 1;
    pointer-events: auto;
  }

  .nav-links li {
    border-bottom: 1px solid var(--color-border);
  }

  .nav-links a {
    display: block;
    padding: 1rem 1.5rem;
    font-size: 1rem;
  }

  .nav-toggle.open span:nth-child(1) {
    transform: translateY(6.5px) rotate(45deg);
  }

  .nav-toggle.open span:nth-child(2) {
    opacity: 0;
  }

  .nav-toggle.open span:nth-child(3) {
    transform: translateY(-6.5px) rotate(-45deg);
  }

  .section {
    padding: 5rem 0;
  }

  .hero-stats {
    flex-direction: column;
    gap: 1.5rem;
    align-items: center;
  }
}