@import url('https://fonts.googleapis.com/css2?family=Inter:wght@400;600;700;800&display=swap');

/* ─── Reset & Base ─── */
*, *::before, *::after { box-sizing: border-box; margin: 0; padding: 0; }

:root {
  --green: #69ff69;
  --cyan: #00ffff;
  --dark: #172617;
  --dark2: #0e1a0e;
  --dark3: #1e341e;
  --mid: #2a4a2a;
  --text: #d4ffd4;
  --text-dim: #8db88d;
  --white: #ffffff;
  --card-radius: 18px;
  --nav-h: 64px;
  --font: 'Inter', system-ui, -apple-system, sans-serif;
  --glow-green: 0 0 24px #69ff6988, 0 0 48px #69ff6944;
  --glow-cyan: 0 0 24px #00ffff88, 0 0 48px #00ffff44;
  scroll-behavior: smooth;
}

html { font-size: 16px; line-height: 1.6; }

body.y2k-body {
  font-family: var(--font);
  background-color: var(--dark2);
  color: var(--text);
  min-height: 100vh;
  overflow-x: hidden;
  padding-bottom: calc(var(--nav-h) + 16px);
}

a { color: var(--green); text-decoration: none; transition: color 0.2s; }
a:hover { color: var(--cyan); }

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

ul { list-style: none; }

/* ─── Topbar ─── */
.topbar {
  position: sticky;
  top: 0;
  z-index: 80;
  display: flex;
  align-items: center;
  gap: 16px;
  padding: 0 24px;
  height: 52px;
  background: linear-gradient(90deg, var(--dark2) 0%, #0e2a1a 100%);
  border-bottom: 1.5px solid var(--mid);
  backdrop-filter: blur(12px);
}

.topbar__brand {
  display: flex;
  align-items: center;
  flex-shrink: 0;
}

.brand-logo { height: 32px; width: auto; }

.brand-text {
  font-size: 1.3rem;
  font-weight: 800;
  background: linear-gradient(135deg, var(--green), var(--cyan));
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
  letter-spacing: -0.03em;
}

.topbar__tagline {
  font-size: 0.78rem;
  color: var(--text-dim);
  white-space: nowrap;
  overflow: hidden;
  text-overflow: ellipsis;
}

/* ─── Hero ─── */
.hero {
  position: relative;
  min-height: 100vh;
  display: flex;
  align-items: center;
  justify-content: center;
  overflow: hidden;
  background: linear-gradient(160deg, var(--dark2) 0%, #0a2a0a 40%, #0a1a2a 100%);
}

.hero__backdrop {
  position: absolute;
  inset: 0;
  pointer-events: none;
  z-index: 0;
}

.hero__glow {
  position: absolute;
  border-radius: 50%;
  filter: blur(80px);
  opacity: 0.35;
  animation: glowPulse 4s ease-in-out infinite alternate;
}

.hero__glow--green {
  width: 480px; height: 480px;
  background: var(--green);
  top: -80px; left: -120px;
}

.hero__glow--cyan {
  width: 400px; height: 400px;
  background: var(--cyan);
  bottom: -60px; right: -100px;
  animation-delay: 2s;
}

@keyframes glowPulse {
  from { opacity: 0.25; transform: scale(1); }
  to   { opacity: 0.45; transform: scale(1.1); }
}

/* Bubbles */
.hero__bubbles { position: absolute; inset: 0; }
.bubble {
  position: absolute;
  border-radius: 50%;
  background: linear-gradient(135deg, rgba(105,255,105,0.18), rgba(0,255,255,0.12));
  border: 1.5px solid rgba(105,255,105,0.25);
  animation: bubbleFloat linear infinite;
}
.bubble--1 { width: 80px; height: 80px; left: 8%; top: 20%; animation-duration: 8s; animation-delay: 0s; }
.bubble--2 { width: 120px; height: 120px; left: 75%; top: 10%; animation-duration: 11s; animation-delay: 1.5s; }
.bubble--3 { width: 50px; height: 50px; left: 55%; top: 65%; animation-duration: 7s; animation-delay: 3s; }
.bubble--4 { width: 90px; height: 90px; left: 20%; top: 70%; animation-duration: 13s; animation-delay: 0.8s; }
.bubble--5 { width: 60px; height: 60px; left: 88%; top: 50%; animation-duration: 9s; animation-delay: 2s; }

@keyframes bubbleFloat {
  0% { transform: translateY(0) scale(1); opacity: 0.6; }
  50% { transform: translateY(-40px) scale(1.05); opacity: 1; }
  100% { transform: translateY(0) scale(1); opacity: 0.6; }
}

.hero__media {
  position: absolute;
  inset: 0;
  z-index: 1;
}
.hero__media .hero__img {
  width: 100%; height: 100%;
  object-fit: cover;
  opacity: 0.22;
}

.hero__content {
  position: relative;
  z-index: 2;
  text-align: center;
  padding: 0 24px;
  max-width: 720px;
}

.hero__title {
  font-size: clamp(2.2rem, 7vw, 5rem);
  font-weight: 800;
  line-height: 1.1;
  letter-spacing: -0.04em;
  background: linear-gradient(135deg, var(--green) 0%, var(--cyan) 60%, #fff 100%);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
  text-shadow: none;
  margin-bottom: 20px;
  filter: drop-shadow(0 0 24px rgba(105,255,105,0.5));
}

.hero__sub {
  font-size: clamp(1rem, 2.5vw, 1.25rem);
  color: var(--text-dim);
  margin-bottom: 36px;
  line-height: 1.7;
}

.btn-cta {
  display: inline-block;
  padding: 14px 40px;
  font-size: 1.05rem;
  font-weight: 700;
  border-radius: 50px;
  background: linear-gradient(135deg, var(--green), var(--cyan));
  color: var(--dark);
  cursor: pointer;
  border: none;
  box-shadow: var(--glow-green);
  transition: transform 0.2s, box-shadow 0.2s;
  letter-spacing: 0.02em;
}
.btn-cta:hover {
  transform: translateY(-3px) scale(1.04);
  box-shadow: var(--glow-cyan);
  color: var(--dark);
}

/* Hero arc bottom */
.hero__arc {
  position: absolute;
  bottom: -2px;
  left: 0;
  right: 0;
  height: 80px;
  background: var(--dark2);
  clip-path: ellipse(55% 100% at 50% 100%);
  z-index: 3;
}

/* ─── Content Layout ─── */
.content-layout {
  display: flex;
  gap: 32px;
  max-width: 1200px;
  margin: 0 auto;
  padding: 48px 24px 64px;
  align-items: flex-start;
}

/* ─── Sidebar (aside 在内容左侧) ─── */
.sidebar {
  flex: 0 0 220px;
  position: sticky;
  top: 64px;
  display: flex;
  flex-direction: column;
  gap: 24px;
}

.sidebar__nav { }
.sidebar__nav-head {
  font-size: 0.72rem;
  font-weight: 700;
  letter-spacing: 0.12em;
  color: var(--text-dim);
  text-transform: uppercase;
  margin-bottom: 12px;
  padding-bottom: 8px;
  border-bottom: 1px solid var(--mid);
}

.sidebar__nav ul {
  display: flex;
  flex-direction: column;
  gap: 2px;
}

.nav-link {
  display: block;
  padding: 9px 14px;
  border-radius: 10px;
  font-size: 0.88rem;
  font-weight: 600;
  color: var(--text-dim);
  transition: background 0.2s, color 0.2s, box-shadow 0.2s;
  border-left: 2px solid transparent;
}
.nav-link:hover,
.nav-link--active {
  background: var(--dark3);
  color: var(--green);
  border-left-color: var(--green);
  box-shadow: inset 0 0 12px rgba(105,255,105,0.08);
}

.sidebar__deco {
  display: flex;
  flex-direction: column;
  gap: 8px;
}

.sidebar__badge {
  display: inline-block;
  padding: 6px 14px;
  border-radius: 50px;
  font-size: 0.78rem;
  font-weight: 800;
  letter-spacing: 0.06em;
  background: linear-gradient(135deg, var(--green), #3aff3a);
  color: var(--dark);
  text-align: center;
}
.sidebar__badge--cyan {
  background: linear-gradient(135deg, var(--cyan), #0099cc);
  color: var(--dark);
}
.sidebar__badge--outline {
  background: transparent;
  border: 1.5px solid var(--mid);
  color: var(--text-dim);
}

/* ─── Main Area ─── */
.main-area {
  flex: 1;
  min-width: 0;
}

.wrap { width: 100%; }

.content-section { }

.content-article {
  font-size: 1.05rem;
  line-height: 1.75;
  color: var(--text);
}

/* Inject content styles */
.content-article h2 {
  font-size: clamp(1.4rem, 3vw, 2rem);
  font-weight: 800;
  margin: 2.5em 0 0.8em;
  background: linear-gradient(90deg, var(--green), var(--cyan));
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
  scroll-margin-top: calc(var(--nav-h) + 64px + 16px);
}

.content-article h2 span {
  display: inline;
}

.content-article h3 {
  font-size: 1.2rem;
  font-weight: 700;
  color: var(--cyan);
  margin: 1.8em 0 0.6em;
  scroll-margin-top: calc(var(--nav-h) + 64px + 16px);
}

.content-article h3 span { display: inline; }

.content-article p {
  margin-bottom: 1.2em;
}

.content-article ul,
.content-article ol {
  margin: 0.8em 0 1.2em 1.4em;
}

.content-article li { margin-bottom: 0.5em; }

.content-article a {
  color: var(--green);
  border-bottom: 1px solid rgba(105,255,105,0.3);
  transition: color 0.2s, border-color 0.2s;
}
.content-article a:hover {
  color: var(--cyan);
  border-bottom-color: var(--cyan);
}

.content-article strong { color: var(--green); font-weight: 700; }
.content-article em { color: var(--cyan); font-style: italic; }

.content-article blockquote {
  border-left: 3px solid var(--green);
  padding: 12px 20px;
  margin: 1.5em 0;
  background: var(--dark3);
  border-radius: 0 12px 12px 0;
  color: var(--text-dim);
}

.content-article section {
  margin-bottom: 3em;
  padding: 32px;
  background: linear-gradient(135deg, var(--dark3) 0%, #1a2a1a 100%);
  border-radius: var(--card-radius);
  border-bottom: 3px solid var(--green);
  box-shadow: 0 4px 32px rgba(0,0,0,0.3);
  scroll-margin-top: calc(var(--nav-h) + 64px + 16px);
  transition: transform 0.3s, box-shadow 0.3s;
}

.content-article section:hover {
  transform: translateY(-4px);
  box-shadow: 0 8px 48px rgba(105,255,105,0.12);
}

.content-article section:nth-child(even) {
  border-bottom-color: var(--cyan);
}

/* ─── Footer ─── */
.site-footer {
  background: linear-gradient(160deg, var(--dark) 0%, var(--dark2) 100%);
  border-top: 1.5px solid var(--mid);
  padding: 56px 24px 32px;
}

.footer__brand-block {
  text-align: center;
  margin-bottom: 40px;
}

.footer__brand-name {
  font-size: clamp(3rem, 8vw, 6rem);
  font-weight: 800;
  letter-spacing: -0.06em;
  background: linear-gradient(135deg, var(--green), var(--cyan));
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
  filter: drop-shadow(0 0 24px rgba(105,255,105,0.4));
  line-height: 1;
  margin-bottom: 12px;
}

.footer__brand-desc {
  font-size: 0.95rem;
  color: var(--text-dim);
  max-width: 520px;
  margin: 0 auto;
  line-height: 1.6;
}

.footer__cols {
  display: flex;
  gap: 32px;
  justify-content: center;
  flex-wrap: wrap;
  max-width: 900px;
  margin: 0 auto 40px;
}

.footer__dl {
  flex: 1;
  min-width: 160px;
}

.footer__dl dt {
  font-size: 0.72rem;
  font-weight: 700;
  letter-spacing: 0.12em;
  color: var(--green);
  text-transform: uppercase;
  margin-bottom: 12px;
  padding-bottom: 6px;
  border-bottom: 1px solid var(--mid);
}

.footer__dl dd {
  margin-bottom: 8px;
}

.footer__dl dd a,
.footer__dl dd span {
  font-size: 0.88rem;
  color: var(--text-dim);
  transition: color 0.2s;
}

.footer__dl dd a:hover { color: var(--cyan); }

.footer__bottom {
  text-align: center;
  font-size: 0.8rem;
  color: var(--text-dim);
  padding-top: 24px;
  border-top: 1px solid var(--mid);
  display: flex;
  align-items: center;
  justify-content: center;
  gap: 12px;
  flex-wrap: wrap;
}

.footer__bottom-sep { opacity: 0.4; }

/* ─── Bottom Fixed Nav ─── */
.bottom-nav-wrap {
  position: fixed;
  bottom: 0;
  left: 0;
  right: 0;
  z-index: 100;
}

.bottom-nav {
  background: linear-gradient(90deg, rgba(23,38,23,0.97), rgba(14,26,14,0.97));
  border-top: 1.5px solid var(--mid);
  backdrop-filter: blur(16px);
  height: var(--nav-h);
  padding: 0 16px;
}

.bottom-nav > ul {
  display: flex;
  align-items: center;
  height: 100%;
  gap: 8px;
}

.bottom-nav__brand {
  display: flex;
  align-items: center;
  padding: 12px 12px;
  min-height: 44px;
  border-radius: 10px;
  flex-shrink: 0;
}

.bottom-nav__brand-text {
  font-size: 1rem;
  font-weight: 800;
  background: linear-gradient(135deg, var(--green), var(--cyan));
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
}

.bottom-nav__group {
  position: relative;
  flex: 1;
}

.bottom-nav__toggle {
  display: flex;
  align-items: center;
  gap: 6px;
  padding: 12px 16px;
  min-height: 44px;
  width: 100%;
  background: var(--dark3);
  border: 1.5px solid var(--mid);
  border-radius: 10px;
  color: var(--text);
  font-size: 0.9rem;
  font-weight: 600;
  font-family: var(--font);
  cursor: pointer;
  transition: background 0.2s, border-color 0.2s;
}

.bottom-nav__toggle:hover {
  background: var(--mid);
  border-color: var(--green);
  color: var(--green);
}

.bottom-nav__arrow {
  transition: transform 0.25s;
  font-size: 0.7rem;
  opacity: 0.6;
}

.bottom-nav__toggle[aria-expanded="true"] .bottom-nav__arrow {
  transform: rotate(180deg);
}

.bottom-nav__dropdown {
  position: absolute;
  bottom: calc(100% + 8px);
  left: 0;
  right: 0;
  background: linear-gradient(160deg, var(--dark) 0%, var(--dark2) 100%);
  border: 1.5px solid var(--mid);
  border-radius: 14px;
  padding: 8px;
  display: none;
  box-shadow: 0 -8px 40px rgba(0,0,0,0.5), var(--glow-green);
}

.bottom-nav__dropdown.is-open {
  display: block;
}

.bottom-nav__dropdown li a {
  display: flex;
  align-items: center;
  padding: 12px 14px;
  min-height: 44px;
  border-radius: 8px;
  font-size: 0.9rem;
  font-weight: 600;
  color: var(--text-dim);
  transition: background 0.15s, color 0.15s;
}

.bottom-nav__dropdown li a:hover {
  background: var(--dark3);
  color: var(--green);
}

.bottom-nav__cta-wrap {
  flex-shrink: 0;
}

.bottom-nav__cta {
  display: flex;
  align-items: center;
  padding: 12px 20px;
  min-height: 44px;
  border-radius: 50px;
  background: linear-gradient(135deg, var(--green), var(--cyan));
  color: var(--dark);
  font-size: 0.9rem;
  font-weight: 700;
  white-space: nowrap;
  box-shadow: var(--glow-green);
  transition: transform 0.2s, box-shadow 0.2s;
}

.bottom-nav__cta:hover {
  transform: scale(1.05);
  box-shadow: var(--glow-cyan);
  color: var(--dark);
}

/* ─── Page Wrapper ─── */
.page-wrapper {
  min-height: 100vh;
}

/* ─── Scroll margin for sections ─── */
section[id] {
  scroll-margin-top: calc(var(--nav-h) + 52px + 16px);
}

/* ─── Parallax / Stagger animations ─── */
@media (prefers-reduced-motion: no-preference) {
  .content-article section {
    opacity: 0;
    transform: translateY(32px);
    animation: fadeSlideUp 0.6s ease forwards;
  }
  .content-article section:nth-child(1) { animation-delay: 0.05s; }
  .content-article section:nth-child(2) { animation-delay: 0.15s; }
  .content-article section:nth-child(3) { animation-delay: 0.25s; }
  .content-article section:nth-child(4) { animation-delay: 0.35s; }
  .content-article section:nth-child(5) { animation-delay: 0.45s; }
  .content-article section:nth-child(6) { animation-delay: 0.55s; }
  .content-article section:nth-child(7) { animation-delay: 0.65s; }

  @keyframes fadeSlideUp {
    to { opacity: 1; transform: translateY(0); }
  }
}

@media (prefers-reduced-motion: reduce) {
  *, *::before, *::after {
    animation-duration: 0.01ms !important;
    transition-duration: 0.01ms !important;
  }
}

/* ─── Responsive ─── */
@media (max-width: 768px) {
  .content-layout {
    flex-direction: column;
    padding: 32px 16px 48px;
    gap: 24px;
  }

  .sidebar {
    position: static;
    flex: none;
    width: 100%;
  }

  .sidebar__nav ul {
    display: flex;
    flex-direction: row;
    flex-wrap: wrap;
    gap: 6px;
  }

  .nav-link {
    padding: 10px 14px;
    min-height: 44px;
    display: flex;
    align-items: center;
    font-size: 0.82rem;
    border-left: none;
    border-bottom: 2px solid transparent;
  }
  .nav-link:hover,
  .nav-link--active {
    border-left: none;
    border-bottom-color: var(--green);
  }

  .sidebar__deco {
    flex-direction: row;
    flex-wrap: wrap;
  }

  .topbar__tagline { display: none; }

  .footer__cols {
    flex-direction: column;
    gap: 24px;
    align-items: flex-start;
    padding: 0 8px;
  }

  .footer__dl { min-width: 0; width: 100%; }

  .bottom-nav__brand-text { font-size: 0.85rem; }

  .content-article section {
    padding: 20px 16px;
  }

  .hero__arc { height: 48px; }
}

@media (max-width: 480px) {
  .bottom-nav { padding: 0 8px; }
  .bottom-nav__toggle { padding: 12px 10px; font-size: 0.82rem; min-height: 44px; }
  .bottom-nav__cta { padding: 12px 14px; font-size: 0.82rem; min-height: 44px; }
  .btn-cta { padding: 12px 28px; font-size: 0.95rem; }
}

/* ─── Iridescent chrome accent ─── */
.iridescent {
  background: linear-gradient(135deg, #69ff69 0%, #00ffff 33%, #ff69b4 66%, #69ff69 100%);
  background-size: 300% 300%;
  animation: iridShift 6s ease infinite;
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
}

@keyframes iridShift {
  0% { background-position: 0% 50%; }
  50% { background-position: 100% 50%; }
  100% { background-position: 0% 50%; }
}

/* ─── Metallic divider ─── */
.metal-divider {
  height: 2px;
  background: linear-gradient(90deg, transparent, var(--green), var(--cyan), var(--green), transparent);
  margin: 40px 0;
  border-radius: 2px;
}

button[aria-expanded]{min-width:44px;min-height:44px}