/* ========================================
   换乐官网 - 设计系统
   ======================================== */

:root {
  --bg: #f7faf8;
  --bg-elevated: #ffffff;
  --text: #07120e;
  --text-muted: #4e6b5e;
  --primary: #00c853;
  --primary-2: #00e676;
  --primary-soft: rgba(0, 200, 83, 0.12);
  --surface: rgba(255, 255, 255, 0.72);
  --border: rgba(7, 18, 14, 0.08);
  --shadow: 0 28px 90px rgba(0, 0, 0, 0.08);
  --shadow-sm: 0 10px 30px rgba(0, 0, 0, 0.06);
  --radius: 28px;
  --radius-sm: 18px;
  --font: "Geist", system-ui, -apple-system, BlinkMacSystemFont, "Segoe UI", sans-serif;
  --transition: 0.35s cubic-bezier(0.16, 1, 0.3, 1);
}

[data-theme="dark"] {
  --bg: #030806;
  --bg-elevated: #0b1612;
  --text: #e8f5ee;
  --text-muted: #8caaa0;
  --primary: #00e676;
  --primary-2: #00c853;
  --primary-soft: rgba(0, 230, 118, 0.14);
  --surface: rgba(11, 22, 18, 0.72);
  --border: rgba(232, 245, 238, 0.08);
  --shadow: 0 28px 90px rgba(0, 0, 0, 0.45);
  --shadow-sm: 0 10px 30px rgba(0, 0, 0, 0.25);
}

@media (prefers-color-scheme: dark) {
  [data-theme="system"] {
    --bg: #030806;
    --bg-elevated: #0b1612;
    --text: #e8f5ee;
    --text-muted: #8caaa0;
    --primary: #00e676;
    --primary-2: #00c853;
    --primary-soft: rgba(0, 230, 118, 0.14);
    --surface: rgba(11, 22, 18, 0.72);
    --border: rgba(232, 245, 238, 0.08);
    --shadow: 0 28px 90px rgba(0, 0, 0, 0.45);
    --shadow-sm: 0 10px 30px rgba(0, 0, 0, 0.25);
  }
}

* {
  box-sizing: border-box;
}

html {
  scroll-behavior: smooth;
}

body {
  margin: 0;
  font-family: var(--font);
  background: var(--bg);
  color: var(--text);
  line-height: 1.6;
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
  transition: background-color var(--transition), color var(--transition);
}

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

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

button {
  font-family: inherit;
  cursor: pointer;
}

.skip-link {
  position: absolute;
  top: -40px;
  left: 16px;
  background: var(--primary);
  color: #000;
  padding: 8px 14px;
  border-radius: 10px;
  font-weight: 600;
  z-index: 9999;
  transition: top 0.2s;
}

.skip-link:focus {
  top: 16px;
}

.container {
  width: min(1200px, 92%);
  margin-inline: auto;
}

/* 导航 */
.site-header {
  position: fixed;
  inset: 0 0 auto 0;
  z-index: 1000;
  padding-block: 14px;
}

.navbar {
  display: flex;
  align-items: center;
  justify-content: space-between;
  width: min(1200px, 94%);
  margin-inline: auto;
  padding: 10px 18px;
  background: var(--surface);
  backdrop-filter: blur(24px) saturate(180%);
  -webkit-backdrop-filter: blur(24px) saturate(180%);
  border: 1px solid var(--border);
  border-radius: 999px;
  box-shadow: var(--shadow-sm);
  transition: background-color var(--transition), border-color var(--transition);
}

.nav-brand {
  display: flex;
  align-items: center;
  gap: 10px;
  font-weight: 700;
  font-size: 1.25rem;
  letter-spacing: -0.02em;
}

.brand-logo {
  width: 38px;
  height: 38px;
  border-radius: 10px;
  object-fit: cover;
}

.nav-menu {
  display: flex;
  align-items: center;
  gap: 32px;
}

.nav-links {
  display: flex;
  gap: 28px;
  list-style: none;
  margin: 0;
  padding: 0;
  font-size: 0.95rem;
  font-weight: 500;
}

.nav-links a {
  position: relative;
  color: var(--text-muted);
  transition: color var(--transition);
}

.nav-links a:hover,
.nav-links a:focus-visible {
  color: var(--text);
}

.nav-links a::after {
  content: "";
  position: absolute;
  left: 0;
  bottom: -4px;
  width: 0;
  height: 2px;
  background: var(--primary);
  border-radius: 2px;
  transition: width var(--transition);
}

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

.theme-switcher {
  display: flex;
  align-items: center;
  gap: 6px;
  padding: 4px;
  background: var(--bg-elevated);
  border: 1px solid var(--border);
  border-radius: 999px;
}

.theme-btn {
  display: grid;
  place-items: center;
  width: 32px;
  height: 32px;
  padding: 0;
  border: none;
  border-radius: 50%;
  background: transparent;
  color: var(--text-muted);
  transition: background-color var(--transition), color var(--transition);
}

.theme-btn svg {
  width: 16px;
  height: 16px;
}

.theme-btn:hover {
  color: var(--text);
}

.theme-btn.active {
  background: var(--primary);
  color: #000;
}

.nav-toggle {
  display: none;
  width: 40px;
  height: 40px;
  border: none;
  background: transparent;
  border-radius: 10px;
  position: relative;
}

.hamburger,
.hamburger::before,
.hamburger::after {
  display: block;
  width: 22px;
  height: 2px;
  background: var(--text);
  border-radius: 2px;
  transition: transform 0.3s ease, opacity 0.3s ease;
}

.hamburger {
  margin: auto;
  position: relative;
}

.hamburger::before,
.hamburger::after {
  content: "";
  position: absolute;
  left: 0;
}

.hamburger::before {
  top: -7px;
}

.hamburger::after {
  top: 7px;
}

.nav-toggle[aria-expanded="true"] .hamburger {
  background: transparent;
}

.nav-toggle[aria-expanded="true"] .hamburger::before {
  transform: translateY(7px) rotate(45deg);
}

.nav-toggle[aria-expanded="true"] .hamburger::after {
  transform: translateY(-7px) rotate(-45deg);
}

/* 按钮 */
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 8px;
  padding: 14px 28px;
  border-radius: 999px;
  font-weight: 600;
  font-size: 0.95rem;
  border: 1px solid transparent;
  transition: transform 0.2s ease, box-shadow var(--transition), background-color var(--transition), border-color var(--transition);
  will-change: transform;
}

.btn-primary {
  background: var(--primary);
  color: #000;
  box-shadow: 0 12px 32px rgba(0, 200, 83, 0.28);
}

.btn-primary:hover {
  background: var(--primary-2);
  box-shadow: 0 16px 40px rgba(0, 230, 118, 0.34);
}

.btn-ghost {
  background: var(--surface);
  color: var(--text);
  border-color: var(--border);
  backdrop-filter: blur(12px);
}

.btn-ghost:hover {
  background: var(--bg-elevated);
  border-color: var(--primary);
}

.btn:active {
  transform: scale(0.97);
}

/* Hero */
.hero {
  position: relative;
  min-height: 100dvh;
  display: flex;
  align-items: center;
  padding-block: 140px 100px;
  overflow: hidden;
}

.hero-particles {
  position: absolute;
  inset: 0;
  width: 100%;
  height: 100%;
  z-index: 0;
  pointer-events: none;
}

.hero-glow {
  position: absolute;
  top: 50%;
  left: 60%;
  transform: translate(-50%, -50%);
  width: 600px;
  height: 600px;
  background: radial-gradient(circle, var(--primary-soft) 0%, transparent 70%);
  filter: blur(40px);
  z-index: 0;
  pointer-events: none;
}

.hero-grid {
  position: relative;
  z-index: 1;
  display: grid;
  grid-template-columns: 1.05fr 0.95fr;
  gap: 64px;
  align-items: center;
}

.eyebrow {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  padding: 6px 14px;
  background: var(--primary-soft);
  color: var(--primary-2);
  border-radius: 999px;
  font-size: 0.85rem;
  font-weight: 600;
  margin-bottom: 24px;
  width: fit-content;
}

.hero-title {
  font-size: clamp(2.6rem, 5.5vw, 4.8rem);
  line-height: 1.08;
  font-weight: 800;
  letter-spacing: -0.04em;
  margin: 0 0 24px;
}

.hero-lead {
  font-size: clamp(1.05rem, 1.6vw, 1.25rem);
  color: var(--text-muted);
  max-width: 540px;
  margin: 0 0 36px;
}

.hero-actions {
  display: flex;
  flex-wrap: wrap;
  gap: 16px;
  margin-bottom: 48px;
}

.hero-stats {
  display: flex;
  flex-wrap: wrap;
  gap: 32px;
}

.hero-stats div {
  display: flex;
  flex-direction: column;
  gap: 2px;
}

.hero-stats strong {
  font-size: 1.1rem;
  font-weight: 700;
}

.hero-stats span {
  font-size: 0.9rem;
  color: var(--text-muted);
}

/* Hero Visual */
.hero-visual {
  position: relative;
  min-height: 520px;
  display: flex;
  align-items: center;
  justify-content: center;
}

.orbit {
  position: absolute;
  border: 1px dashed var(--border);
  border-radius: 50%;
  pointer-events: none;
}

.orbit-1 {
  width: 340px;
  height: 340px;
  animation: spin 24s linear infinite;
}

.orbit-2 {
  width: 480px;
  height: 480px;
  animation: spin-reverse 34s linear infinite;
}

.hero-icon {
  position: relative;
  z-index: 2;
  width: 200px;
  height: 200px;
  border-radius: 44px;
  overflow: hidden;
  box-shadow: 0 40px 100px rgba(0, 200, 83, 0.25);
  animation: float 6s ease-in-out infinite;
}

.hero-icon img {
  width: 100%;
  height: 100%;
  object-fit: cover;
}

.floating-card {
  position: absolute;
  z-index: 3;
  display: inline-flex;
  align-items: center;
  gap: 10px;
  padding: 12px 18px;
  background: var(--surface);
  backdrop-filter: blur(16px);
  -webkit-backdrop-filter: blur(16px);
  border: 1px solid var(--border);
  border-radius: 999px;
  font-size: 0.9rem;
  font-weight: 600;
  box-shadow: var(--shadow-sm);
  animation: float 7s ease-in-out infinite;
}

.floating-card .dot {
  width: 10px;
  height: 10px;
  border-radius: 50%;
  background: var(--primary);
  box-shadow: 0 0 12px var(--primary);
}

.card-1 { top: 12%; left: 2%; animation-delay: 0s; }
.card-2 { bottom: 18%; left: -4%; animation-delay: 1.5s; }
.card-3 { top: 44%; right: -2%; animation-delay: 3s; }

.scroll-cue {
  position: absolute;
  bottom: 32px;
  left: 50%;
  transform: translateX(-50%);
  width: 32px;
  height: 50px;
  border: 2px solid var(--border);
  border-radius: 16px;
  display: grid;
  place-items: start center;
  padding-top: 8px;
}

.scroll-cue span {
  display: block;
  width: 4px;
  height: 10px;
  background: var(--primary);
  border-radius: 2px;
  animation: scroll-bounce 1.8s infinite;
}

/* Sections */
.section {
  padding-block: 120px;
}

.section-tag {
  display: inline-block;
  padding: 6px 14px;
  background: var(--primary-soft);
  color: var(--primary-2);
  border-radius: 999px;
  font-size: 0.85rem;
  font-weight: 700;
  margin-bottom: 16px;
}

.section-title {
  font-size: clamp(2rem, 4vw, 3.2rem);
  line-height: 1.12;
  font-weight: 700;
  letter-spacing: -0.03em;
  margin: 0 0 16px;
}

.section-subtitle {
  color: var(--text-muted);
  font-size: 1.1rem;
  max-width: 560px;
  margin: 0 auto;
}

.section-head {
  text-align: center;
  margin-bottom: 64px;
}

/* About */
.about {
  background: linear-gradient(180deg, transparent 0%, var(--bg-elevated) 40%, var(--bg-elevated) 60%, transparent 100%);
}

.section-grid {
  display: grid;
  grid-template-columns: 0.9fr 1.1fr;
  gap: 72px;
  align-items: center;
}

.about-card {
  position: relative;
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  gap: 14px;
  width: min(360px, 100%);
  aspect-ratio: 1;
  margin-inline: auto;
  background: var(--bg-elevated);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  box-shadow: var(--shadow);
  overflow: hidden;
}

.about-card::before {
  content: "";
  position: absolute;
  inset: 0;
  background: radial-gradient(circle at 30% 30%, var(--primary-soft), transparent 60%);
}

.about-card img {
  width: 96px;
  height: 96px;
  border-radius: 24px;
  position: relative;
  z-index: 1;
}

.about-card h3 {
  margin: 0;
  font-size: 1.8rem;
  font-weight: 700;
  position: relative;
  z-index: 1;
}

.about-card p {
  margin: 0;
  color: var(--text-muted);
  position: relative;
  z-index: 1;
}

.section-copy p {
  color: var(--text-muted);
  font-size: 1.05rem;
  margin-bottom: 20px;
}

.checklist {
  list-style: none;
  padding: 0;
  margin: 28px 0 0;
  display: flex;
  flex-direction: column;
  gap: 14px;
}

.checklist li {
  position: relative;
  padding-left: 34px;
  color: var(--text);
  font-weight: 500;
}

.checklist li::before {
  content: "";
  position: absolute;
  left: 0;
  top: 4px;
  width: 20px;
  height: 20px;
  background: var(--primary-soft);
  border-radius: 50%;
}

.checklist li::after {
  content: "";
  position: absolute;
  left: 5px;
  top: 8px;
  width: 6px;
  height: 10px;
  border-right: 2px solid var(--primary);
  border-bottom: 2px solid var(--primary);
  transform: rotate(45deg);
}

/* Bento */
.business {
  background: var(--bg-elevated);
}

.bento-grid {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 22px;
}

.bento-card {
  padding: 32px;
  background: var(--bg);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  transition: transform var(--transition), box-shadow var(--transition), border-color var(--transition);
}

.bento-card:hover {
  transform: translateY(-6px);
  box-shadow: var(--shadow);
  border-color: rgba(0, 200, 83, 0.25);
}

.bento-card.wide {
  grid-column: span 2;
}

.card-icon {
  width: 52px;
  height: 52px;
  display: grid;
  place-items: center;
  border-radius: 16px;
  background: var(--primary-soft);
  color: var(--primary-2);
  margin-bottom: 22px;
}

.card-icon svg {
  width: 26px;
  height: 26px;
  stroke-width: 1.8;
}

.bento-card h3 {
  margin: 0 0 12px;
  font-size: 1.25rem;
  font-weight: 700;
}

.bento-card p {
  margin: 0;
  color: var(--text-muted);
  font-size: 0.97rem;
  line-height: 1.65;
}

/* Stats */
.advantages {
  position: relative;
}

.stats-grid {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 22px;
}

.stat-card {
  padding: 36px 28px;
  background: var(--bg-elevated);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  text-align: center;
  transition: transform var(--transition), box-shadow var(--transition);
}

.stat-card:hover {
  transform: translateY(-4px);
  box-shadow: var(--shadow);
}

.stat-number {
  font-size: 3.2rem;
  font-weight: 800;
  line-height: 1;
  color: var(--primary);
  letter-spacing: -0.04em;
}

.stat-suffix {
  font-size: 1.1rem;
  font-weight: 600;
  color: var(--text-muted);
  margin-top: 4px;
}

.stat-label {
  margin: 16px 0 0;
  color: var(--text-muted);
  font-size: 0.95rem;
}

/* Steps */
.steps-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 28px;
  counter-reset: step;
}

.step {
  position: relative;
  padding: 40px 32px;
  background: var(--bg-elevated);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  transition: transform var(--transition), box-shadow var(--transition);
}

.step:hover {
  transform: translateY(-4px);
  box-shadow: var(--shadow);
}

.step-num {
  font-size: 3rem;
  font-weight: 800;
  line-height: 1;
  color: var(--primary-soft);
  -webkit-text-stroke: 1px var(--primary);
  margin-bottom: 18px;
}

.step h3 {
  margin: 0 0 10px;
  font-size: 1.35rem;
}

.step p {
  margin: 0;
  color: var(--text-muted);
}

/* CTA */
.cta-card {
  position: relative;
  padding: 80px 64px;
  background: var(--bg-elevated);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  text-align: center;
  overflow: hidden;
  box-shadow: var(--shadow);
}

.cta-card::before {
  content: "";
  position: absolute;
  inset: 0;
  background: radial-gradient(circle at 50% 0%, var(--primary-soft), transparent 55%);
  pointer-events: none;
}

.cta-title {
  position: relative;
  font-size: clamp(1.8rem, 3.5vw, 2.8rem);
  font-weight: 700;
  margin: 0 0 16px;
}

.cta-text {
  position: relative;
  color: var(--text-muted);
  max-width: 620px;
  margin: 0 auto 36px;
  font-size: 1.1rem;
}

.cta-actions {
  position: relative;
  display: flex;
  justify-content: center;
  flex-wrap: wrap;
  gap: 16px;
  margin-bottom: 48px;
}

.contact-info {
  position: relative;
  display: flex;
  justify-content: center;
  flex-wrap: wrap;
  gap: 48px;
}

.contact-item {
  display: flex;
  flex-direction: column;
  gap: 4px;
  text-align: left;
}

.contact-label {
  font-size: 0.8rem;
  color: var(--text-muted);
  font-weight: 600;
  text-transform: uppercase;
  letter-spacing: 0.06em;
}

.contact-value {
  font-weight: 600;
  color: var(--text);
}

/* Footer */
.site-footer {
  padding-block: 64px 32px;
  border-top: 1px solid var(--border);
  background: var(--bg-elevated);
}

.footer-grid {
  display: grid;
  grid-template-columns: 1.2fr 1fr 1.2fr;
  gap: 40px;
  margin-bottom: 48px;
}

.footer-brand {
  display: flex;
  flex-direction: column;
  gap: 10px;
}

.footer-brand span {
  display: flex;
  align-items: center;
  gap: 10px;
  font-weight: 700;
  font-size: 1.2rem;
}

.footer-brand p {
  margin: 0;
  color: var(--text-muted);
}

.footer-links {
  display: flex;
  flex-direction: column;
  gap: 12px;
}

.footer-links a {
  color: var(--text-muted);
  font-weight: 500;
  transition: color var(--transition);
}

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

.footer-contact {
  color: var(--text-muted);
  line-height: 1.8;
}

.footer-bottom {
  text-align: center;
  padding-top: 24px;
  border-top: 1px solid var(--border);
  color: var(--text-muted);
  font-size: 0.9rem;
}

/* Reveal animation */
.reveal {
  opacity: 0;
  transform: translateY(28px);
  transition: opacity 0.7s cubic-bezier(0.16, 1, 0.3, 1), transform 0.7s cubic-bezier(0.16, 1, 0.3, 1);
}

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

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

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

@keyframes float {
  0%, 100% { transform: translateY(0); }
  50% { transform: translateY(-14px); }
}

@keyframes scroll-bounce {
  0%, 100% { transform: translateY(0); opacity: 1; }
  50% { transform: translateY(8px); opacity: 0.5; }
}

/* Reduced motion */
@media (prefers-reduced-motion: reduce) {
  html {
    scroll-behavior: auto;
  }
  .reveal {
    opacity: 1;
    transform: none;
    transition: none;
  }
  .orbit, .hero-icon, .floating-card, .scroll-cue span {
    animation: none;
  }
}

/* Responsive */
@media (max-width: 1024px) {
  .bento-grid {
    grid-template-columns: repeat(2, 1fr);
  }
  .bento-card.wide {
    grid-column: span 2;
  }
  .stats-grid {
    grid-template-columns: repeat(2, 1fr);
  }
}

@media (max-width: 768px) {
  .nav-toggle {
    display: grid;
    place-items: center;
  }

  .nav-menu {
    position: absolute;
    top: calc(100% + 12px);
    left: 3%;
    right: 3%;
    flex-direction: column;
    align-items: stretch;
    gap: 20px;
    padding: 24px;
    background: var(--surface);
    backdrop-filter: blur(24px);
    border: 1px solid var(--border);
    border-radius: var(--radius);
    box-shadow: var(--shadow);
    transform: translateY(-12px);
    opacity: 0;
    visibility: hidden;
    transition: opacity var(--transition), transform var(--transition), visibility var(--transition);
  }

  .nav-menu.open {
    opacity: 1;
    visibility: visible;
    transform: translateY(0);
  }

  .nav-links {
    flex-direction: column;
    gap: 16px;
  }

  .theme-switcher {
    align-self: flex-start;
  }

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

  .hero-content {
    display: flex;
    flex-direction: column;
    align-items: center;
  }

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

  .hero-visual {
    min-height: 420px;
    order: -1;
  }

  .orbit-1 { width: 260px; height: 260px; }
  .orbit-2 { width: 360px; height: 360px; }
  .hero-icon { width: 150px; height: 150px; border-radius: 36px; }
  .floating-card { font-size: 0.8rem; padding: 9px 13px; }
  .card-1 { top: 6%; left: 0; }
  .card-2 { bottom: 10%; left: -8%; }
  .card-3 { top: 38%; right: -8%; }

  .section-grid {
    grid-template-columns: 1fr;
    gap: 48px;
  }

  .bento-grid {
    grid-template-columns: 1fr;
  }
  .bento-card.wide {
    grid-column: span 1;
  }

  .stats-grid {
    grid-template-columns: 1fr;
  }

  .steps-grid {
    grid-template-columns: 1fr;
  }

  .cta-card {
    padding: 56px 28px;
  }

  .contact-info {
    flex-direction: column;
    gap: 24px;
    align-items: center;
  }

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

  .footer-grid {
    grid-template-columns: 1fr;
    text-align: center;
    gap: 32px;
  }

  .footer-brand span {
    justify-content: center;
  }

  .footer-links {
    align-items: center;
  }
}