/* ===== CSS Variables ===== */
:root {
  --color-bg: #0a1128;
  --color-panel: #112240;
  --color-panel-deep: #0d1b33;
  --color-accent-green: #39ff14;
  --color-accent-orange: #ff6b35;
  --color-accent-cyan: #00d4ff;
  --color-accent-yellow: #ffd400;
  --color-text: #e6f1ff;
  --color-text-dim: #a8b2d1;
  --font-sans: 'Noto Sans SC', 'PingFang SC', 'Microsoft YaHei', -apple-system, BlinkMacSystemFont, sans-serif;
  --font-mono: 'JetBrains Mono', 'SFMono-Regular', Consolas, Menlo, monospace;
  --container-width: 1280px;
  --space-1: 8px;
  --space-2: 16px;
  --space-3: 24px;
  --space-4: 32px;
  --space-5: 48px;
  --space-6: 64px;
  --radius: 6px;
  --transition: 300ms ease-out;
  --z-header: 1000;
  --z-skip: 2000;
  --z-progress: 1500;
}

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

html {
  scroll-behavior: smooth;
  -webkit-text-size-adjust: 100%;
  text-size-adjust: 100%;
}

body {
  font-family: var(--font-sans);
  font-size: 16px;
  line-height: 1.7;
  color: var(--color-text);
  background: var(--color-bg);
  min-height: 100vh;
  overflow-x: hidden;
  -webkit-font-smoothing: antialiased;
}

h1,
h2,
h3,
h4,
h5,
h6 {
  font-weight: 900;
  line-height: 1.25;
  color: var(--color-text);
}

h1 { font-size: clamp(40px, 6vw, 64px); letter-spacing: -0.5px; }
h2 { font-size: clamp(28px, 4vw, 40px); letter-spacing: -0.3px; }
h3 { font-size: 20px; letter-spacing: 0; }

p {
  color: var(--color-text-dim);
}

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

a {
  color: var(--color-accent-cyan);
  text-decoration: none;
  transition: color var(--transition);
}

ul,
ol {
  padding-left: 1.2em;
}

::selection {
  background: var(--color-accent-green);
  color: var(--color-bg);
}

/* ===== Scrollbar ===== */
::-webkit-scrollbar {
  width: 10px;
}

::-webkit-scrollbar-track {
  background: var(--color-bg);
}

::-webkit-scrollbar-thumb {
  background: #233554;
  border-radius: 5px;
}

::-webkit-scrollbar-thumb:hover {
  background: var(--color-accent-cyan);
}

/* ===== Layout ===== */
.container {
  width: 100%;
  max-width: var(--container-width);
  margin-inline: auto;
  padding-inline: 24px;
}

/* ===== Utilities ===== */
.sr-only {
  position: absolute;
  width: 1px;
  height: 1px;
  padding: 0;
  margin: -1px;
  overflow: hidden;
  clip: rect(0, 0, 0, 0);
  white-space: nowrap;
  border: 0;
}

.data-num {
  font-family: var(--font-mono);
  font-weight: 500;
  font-size: 0.9em;
  letter-spacing: 0.5px;
}

.text-gradient {
  background: linear-gradient(90deg, var(--color-accent-green), var(--color-accent-cyan));
  -webkit-background-clip: text;
  background-clip: text;
  color: transparent;
}

/* ===== Skip link ===== */
.skip-link {
  position: fixed;
  top: -100px;
  left: 16px;
  z-index: var(--z-skip);
  background: var(--color-accent-green);
  color: var(--color-bg);
  font-weight: 700;
  font-size: 14px;
  padding: 12px 24px;
  border-radius: 0 0 6px 6px;
  text-decoration: none;
  transition: top var(--transition);
}

.skip-link:focus {
  top: 0;
}

/* ===== Buttons ===== */
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 10px;
  font-family: var(--font-sans);
  font-size: 15px;
  font-weight: 700;
  line-height: 1;
  padding: 13px 22px;
  border-radius: var(--radius);
  border: 1px solid transparent;
  text-decoration: none;
  cursor: pointer;
  white-space: nowrap;
  transition: transform var(--transition), box-shadow var(--transition), background var(--transition), border-color var(--transition);
}

.btn--primary {
  background: var(--color-accent-orange);
  color: var(--color-bg);
  box-shadow: 0 4px 20px rgba(255, 107, 53, 0.35);
}

.btn--primary:hover,
.btn--primary:focus-visible {
  background: #ff8557;
  color: var(--color-bg);
  transform: translateY(-2px);
  box-shadow: 0 6px 28px rgba(255, 107, 53, 0.5);
}

.btn__arrow {
  font-family: var(--font-mono);
  font-size: 18px;
  line-height: 1;
}

/* ===== Header ===== */
.site-header {
  position: sticky;
  top: 0;
  z-index: var(--z-header);
  background: rgba(10, 17, 40, 0.92);
  backdrop-filter: blur(14px);
  -webkit-backdrop-filter: blur(14px);
  border-bottom: 1px solid rgba(0, 212, 255, 0.15);
}

.site-header__top {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 16px;
  padding-top: 18px;
  padding-bottom: 14px;
}

.site-header__brand {
  display: inline-flex;
  align-items: center;
  gap: 14px;
  text-decoration: none;
}

.site-header__brand-logo {
  position: relative;
  display: inline-block;
  width: 38px;
  height: 42px;
  flex-shrink: 0;
  background: var(--color-panel);
  border: 2px solid var(--color-accent-green);
  clip-path: polygon(0 0, 100% 0, 100% 78%, 50% 100%, 0 78%);
  box-shadow: 0 0 16px rgba(57, 255, 20, 0.2);
}

.site-header__brand-shield {
  position: absolute;
  inset: 3px;
  border: 1px solid rgba(0, 212, 255, 0.2);
  clip-path: polygon(0 0, 100% 0, 100% 78%, 50% 100%, 0 78%);
}

.site-header__brand-bolt {
  position: absolute;
  left: 50%;
  top: 50%;
  width: 14px;
  height: 20px;
  background: var(--color-accent-green);
  clip-path: polygon(34% 0, 0 58%, 34% 58%, 26% 100%, 100% 36%, 52% 36%);
  transform: translate(-50%, -52%);
}

.site-header__brand-name {
  font-family: var(--font-sans);
  font-size: 28px;
  font-weight: 900;
  letter-spacing: 2px;
  line-height: 1.1;
  color: var(--color-text);
  position: relative;
}

.site-header__brand-name::after {
  content: 'APP';
  display: block;
  font-family: var(--font-mono);
  font-size: 9px;
  letter-spacing: 4px;
  color: var(--color-accent-cyan);
  margin-top: 3px;
  font-weight: 500;
}

.site-header__actions {
  display: flex;
  align-items: center;
  gap: 14px;
}

.site-header__cta {
  padding: 11px 18px;
  font-size: 14px;
}

.site-header__divider {
  height: 2px;
  background: linear-gradient(90deg, var(--color-accent-green), var(--color-accent-cyan) 40%, var(--color-accent-orange) 100%);
  opacity: 0.8;
}

/* ===== Navigation (desktop) ===== */
.site-header__nav {
  display: block;
}

.site-header__nav-list {
  list-style: none;
  display: flex;
  justify-content: center;
  align-items: center;
  gap: 6px;
  padding: 0;
}

.site-header__nav-item {
  margin: 0;
}

.site-header__nav-link {
  position: relative;
  display: block;
  padding: 16px 14px;
  font-size: 15px;
  font-weight: 500;
  letter-spacing: 2px;
  color: var(--color-text-dim);
  text-decoration: none;
  transition: color var(--transition);
}

.site-header__nav-link::after {
  content: '';
  position: absolute;
  left: 50%;
  bottom: 8px;
  width: 0;
  height: 2px;
  background: var(--color-accent-green);
  transform: translateX(-50%);
  transition: width var(--transition);
}

.site-header__nav-link:hover,
.site-header__nav-link:focus-visible {
  color: var(--color-text);
  outline: none;
}

.site-header__nav-link:hover::after,
.site-header__nav-link:focus-visible::after {
  width: 60%;
}

.site-header__nav-link[aria-current="page"] {
  color: var(--color-accent-green);
  font-weight: 700;
}

.site-header__nav-link[aria-current="page"]::after {
  width: 60%;
}

/* ===== Navigation toggle (mobile) ===== */
.site-header__nav-toggle {
  display: none;
  flex-direction: column;
  justify-content: center;
  align-items: center;
  gap: 5px;
  width: 44px;
  height: 44px;
  background: transparent;
  border: 1px solid rgba(0, 212, 255, 0.3);
  border-radius: 6px;
  cursor: pointer;
  padding: 0;
  transition: border-color var(--transition), background var(--transition);
}

.site-header__nav-toggle:hover {
  border-color: var(--color-accent-green);
}

.site-header__nav-toggle:focus-visible {
  outline: 2px solid var(--color-accent-green);
  outline-offset: 2px;
}

.site-header__nav-toggle-bar {
  display: block;
  width: 20px;
  height: 2px;
  background: var(--color-accent-green);
  transition: transform var(--transition), opacity var(--transition), background var(--transition);
}

.site-header__nav-toggle[aria-expanded="true"] .site-header__nav-toggle-bar:nth-child(1) {
  transform: translateY(7px) rotate(45deg);
}

.site-header__nav-toggle[aria-expanded="true"] .site-header__nav-toggle-bar:nth-child(2) {
  opacity: 0;
}

.site-header__nav-toggle[aria-expanded="true"] .site-header__nav-toggle-bar:nth-child(3) {
  transform: translateY(-7px) rotate(-45deg);
}

/* ===== Footer ===== */
.site-footer {
  position: relative;
  background: linear-gradient(180deg, var(--color-bg) 0%, #060b18 100%);
  border-top: 1px solid rgba(0, 212, 255, 0.14);
  overflow: hidden;
}

.site-footer::before {
  content: '';
  position: absolute;
  inset: 0;
  background-image:
    linear-gradient(rgba(0, 212, 255, 0.04) 1px, transparent 1px),
    linear-gradient(90deg, rgba(0, 212, 255, 0.04) 1px, transparent 1px);
  background-size: 40px 40px;
  pointer-events: none;
}

.site-footer__beam {
  position: relative;
  height: 4px;
  background: linear-gradient(100deg, var(--color-accent-green) 0%, transparent 45%, var(--color-accent-orange) 100%);
  opacity: 0.6;
  z-index: 1;
}

.site-footer__inner {
  position: relative;
  z-index: 1;
  display: grid;
  grid-template-columns: 1.1fr 2.3fr;
  gap: 48px;
  padding-top: 56px;
  padding-bottom: 48px;
}

.site-footer__info {
  max-width: 380px;
}

.site-footer__brand {
  display: inline-flex;
  align-items: center;
  text-decoration: none;
}

.site-footer__brand-name {
  font-size: 24px;
  font-weight: 900;
  letter-spacing: 2px;
  color: var(--color-text);
  line-height: 1.2;
}

.site-footer__brand-name::before {
  content: '';
  display: inline-block;
  width: 10px;
  height: 10px;
  background: var(--color-accent-green);
  margin-right: 10px;
  clip-path: polygon(50% 0, 100% 50%, 50% 100%, 0 50%);
  transform: translateY(-2px);
}

.site-footer__about {
  margin-top: 18px;
  font-size: 14px;
  line-height: 1.8;
  color: var(--color-text-dim);
}

.site-footer__trust {
  margin-top: 14px;
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: 0.5px;
  color: var(--color-accent-cyan);
}

.site-footer__panel {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 32px;
}

.site-footer__heading {
  font-size: 14px;
  font-weight: 700;
  letter-spacing: 3px;
  color: var(--color-text);
  text-transform: uppercase;
  position: relative;
  padding-bottom: 10px;
  margin-bottom: 20px;
}

.site-footer__heading::after {
  content: '';
  position: absolute;
  left: 0;
  bottom: 0;
  width: 28px;
  height: 2px;
  background: var(--color-accent-green);
}

.site-footer__list {
  list-style: none;
  display: flex;
  flex-direction: column;
  gap: 10px;
  padding: 0;
}

.site-footer__link {
  display: inline-block;
  color: var(--color-text-dim);
  font-size: 14px;
  text-decoration: none;
  transition: color var(--transition), padding-left var(--transition);
}

.site-footer__link:hover,
.site-footer__link:focus-visible {
  color: var(--color-accent-green);
  padding-left: 6px;
  outline: none;
}

.site-footer__contact {
  list-style: none;
  display: flex;
  flex-direction: column;
  gap: 14px;
  padding: 0;
}

.site-footer__contact-item {
  display: flex;
  flex-direction: column;
  gap: 2px;
}

.site-footer__contact-label {
  font-family: var(--font-mono);
  font-size: 11px;
  letter-spacing: 2px;
  color: var(--color-accent-cyan);
}

.site-footer__contact-value {
  font-size: 14px;
  color: var(--color-text-dim);
  word-break: break-all;
}

.site-footer__bottom {
  position: relative;
  z-index: 1;
  border-top: 1px solid rgba(0, 212, 255, 0.12);
  padding: 18px 0;
}

.site-footer__bottom-inner {
  display: flex;
  justify-content: space-between;
  align-items: center;
  gap: 16px;
  flex-wrap: wrap;
}

.site-footer__copyright {
  font-size: 13px;
  color: var(--color-text-dim);
}

.site-footer__icp {
  font-size: 13px;
  color: var(--color-text-dim);
  text-decoration: none;
  transition: color var(--transition);
}

.site-footer__icp:hover,
.site-footer__icp:focus-visible {
  color: var(--color-accent-green);
  outline: none;
}

/* ===== Breadcrumb ===== */
.breadcrumb {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 8px;
  list-style: none;
  font-size: 14px;
  color: var(--color-text-dim);
  padding: 0;
}

.breadcrumb li + li::before {
  content: '/';
  margin-right: 8px;
  color: var(--color-accent-cyan);
}

.breadcrumb a {
  color: var(--color-text-dim);
  text-decoration: none;
}

.breadcrumb a:hover,
.breadcrumb a:focus-visible {
  color: var(--color-accent-green);
  outline: none;
}

.breadcrumb [aria-current="page"] {
  color: var(--color-accent-green);
}

/* ===== Prose ===== */
.prose {
  font-size: 16px;
  line-height: 1.8;
  color: var(--color-text-dim);
}

.prose h1,
.prose h2,
.prose h3,
.prose h4 {
  color: var(--color-text);
  margin: 1.4em 0 0.6em;
}

.prose h1:first-child,
.prose h2:first-child,
.prose h3:first-child {
  margin-top: 0;
}

.prose p {
  margin-bottom: 1em;
}

.prose ul,
.prose ol {
  margin-bottom: 1em;
}

.prose a {
  color: var(--color-accent-cyan);
  text-decoration: underline;
  text-underline-offset: 4px;
}

.prose a:hover {
  color: var(--color-accent-green);
}

.prose code {
  font-family: var(--font-mono);
  background: var(--color-panel);
  padding: 2px 8px;
  border-radius: 4px;
  font-size: 0.9em;
}

/* ===== Grid ===== */
.grid {
  display: grid;
  grid-template-columns: repeat(12, 1fr);
  gap: 24px;
}

.grid__span-3 { grid-column: span 3; }
.grid__span-4 { grid-column: span 4; }
.grid__span-6 { grid-column: span 6; }
.grid__span-8 { grid-column: span 8; }
.grid__span-12 { grid-column: span 12; }

/* ===== Panel ===== */
.panel {
  background: var(--color-panel);
  border: 1px solid rgba(0, 212, 255, 0.18);
  border-radius: var(--radius);
}

/* ===== Image frame ===== */
.image-frame {
  position: relative;
  display: block;
  overflow: hidden;
  aspect-ratio: 3 / 2;
  background: var(--color-panel);
  border: 1px solid rgba(0, 212, 255, 0.18);
  border-radius: var(--radius);
}

.image-frame::before {
  content: '';
  position: absolute;
  inset: 0;
  z-index: 1;
  background-image:
    linear-gradient(rgba(0, 212, 255, 0.08) 1px, transparent 1px),
    linear-gradient(90deg, rgba(0, 212, 255, 0.08) 1px, transparent 1px);
  background-size: 32px 32px;
  pointer-events: none;
}

.image-frame::after {
  content: '';
  position: absolute;
  inset: 0;
  z-index: 2;
  background: linear-gradient(135deg, transparent 40%, rgba(57, 255, 20, 0.08) 80%, rgba(255, 107, 53, 0.12));
  pointer-events: none;
}

.image-frame img,
.image-frame picture {
  position: absolute;
  inset: 0;
  width: 100%;
  height: 100%;
  object-fit: cover;
  z-index: 3;
}

/* ===== Reveal animation ===== */
[data-reveal].anim-init {
  opacity: 0;
  transform: translateY(24px);
}

[data-reveal].is-visible {
  opacity: 1;
  transform: none;
  transition: opacity 600ms ease-out, transform 600ms ease-out;
}

/* ===== Scroll progress ===== */
.scroll-progress {
  position: fixed;
  top: 0;
  left: 0;
  height: 3px;
  width: 0%;
  background: linear-gradient(90deg, var(--color-accent-green), var(--color-accent-cyan));
  z-index: var(--z-progress);
  pointer-events: none;
}

/* ===== Back to top ===== */
.back-top {
  position: fixed;
  right: 24px;
  bottom: 24px;
  width: 48px;
  height: 48px;
  display: flex;
  align-items: center;
  justify-content: center;
  border-radius: 50%;
  border: 1px solid var(--color-accent-cyan);
  background: rgba(10, 17, 40, 0.88);
  color: var(--color-accent-green);
  font-size: 22px;
  font-family: var(--font-mono);
  line-height: 1;
  cursor: pointer;
  backdrop-filter: blur(6px);
  -webkit-backdrop-filter: blur(6px);
  z-index: 900;
  opacity: 0;
  visibility: hidden;
  transform: translateY(8px);
  transition: opacity var(--transition), visibility var(--transition), transform var(--transition), border-color var(--transition), color var(--transition);
}

.back-top.is-visible {
  opacity: 1;
  visibility: visible;
  transform: translateY(0);
}

.back-top:hover,
.back-top:focus-visible {
  border-color: var(--color-accent-green);
  color: var(--color-accent-cyan);
  transform: translateY(-4px);
  outline: none;
}

/* ===== Responsive ===== */
@media (max-width: 1023px) {
  .site-footer__inner {
    grid-template-columns: 1fr;
    gap: 40px;
  }

  .site-footer__panel {
    gap: 28px;
  }

  .grid__span-3,
  .grid__span-4,
  .grid__span-6,
  .grid__span-8 {
    grid-column: span 6;
  }
}

@media (max-width: 767px) {
  .site-header__top {
    padding-top: 14px;
    padding-bottom: 12px;
  }

  .site-header__brand-logo {
    width: 34px;
    height: 38px;
  }

  .site-header__brand-name {
    font-size: 22px;
  }

  .site-header__brand-name::after {
    font-size: 8px;
    letter-spacing: 3px;
  }

  .site-header__cta {
    display: none;
  }

  .site-header__nav-toggle {
    display: flex;
  }

  .site-header__nav {
    display: none;
    position: absolute;
    top: 100%;
    left: 0;
    right: 0;
    background: rgba(7, 13, 32, 0.98);
    border-top: 1px solid rgba(0, 212, 255, 0.2);
    border-bottom: 1px solid rgba(0, 212, 255, 0.3);
    box-shadow: 0 16px 32px rgba(0, 0, 0, 0.45);
    z-index: calc(var(--z-header) - 1);
    backdrop-filter: blur(14px);
    -webkit-backdrop-filter: blur(14px);
  }

  .site-header__nav[data-open] {
    display: block;
  }

  .site-header__nav-list {
    flex-direction: column;
    align-items: stretch;
    gap: 0;
    padding: 8px 0;
  }

  .site-header__nav-item {
    width: 100%;
  }

  .site-header__nav-link {
    display: block;
    padding: 14px 24px;
    font-size: 15px;
    border-left: 3px solid transparent;
  }

  .site-header__nav-link[aria-current="page"] {
    border-left-color: var(--color-accent-green);
  }

  .site-footer__inner {
    padding-top: 40px;
    padding-bottom: 32px;
    gap: 36px;
  }

  .site-footer__panel {
    grid-template-columns: 1fr;
    gap: 32px;
  }

  .site-footer__bottom-inner {
    flex-direction: column;
    justify-content: center;
    text-align: center;
  }

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

  .grid > * {
    grid-column: span 1 !important;
  }

  .back-top {
    right: 16px;
    bottom: 16px;
    width: 42px;
    height: 42px;
  }
}

/* ===== Focus ===== */
:focus-visible {
  outline: 2px solid var(--color-accent-green);
  outline-offset: 2px;
}

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

  *,
  *::before,
  *::after {
    animation-duration: 0.01ms !important;
    animation-iteration-count: 1 !important;
    transition-duration: 0.01ms !important;
    scroll-behavior: auto !important;
  }

  [data-reveal].anim-init {
    opacity: 1;
    transform: none;
  }

  .btn--primary:hover,
  .btn--primary:focus-visible,
  .back-top:hover,
  .back-top:focus-visible {
    transform: none;
  }
}