/* ========== CSS Variables ========== */
:root {
  --bg-deep: #0B0F14;
  --bg-card: #121A24;
  --bg-float: #1A2634;
  --accent-green: #C6FF00;
  --accent-blue: #00E5FF;
  --accent-silver: #CBD2D9;
  --accent-orange: #FF8A3D;
  --text-main: #E6EDF3;
  --text-weak: #8B9AAB;
  --line: #243447;

  --font-head: "Noto Sans SC", "PingFang SC", "Microsoft YaHei", "Helvetica Neue", Arial, sans-serif;
  --font-body: "Noto Sans SC", "PingFang SC", "Microsoft YaHei", "Helvetica Neue", Arial, sans-serif;
  --font-data: "JetBrains Mono", "SF Mono", "Fira Code", "Consolas", monospace;

  --container: 1320px;
  --radius-xs: 6px;
  --radius-sm: 10px;
  --radius-md: 16px;
  --radius-lg: 24px;
  --radius-pill: 999px;
  --ease: cubic-bezier(0.4, 0, 0.2, 1);
  --speed: 0.3s;
}

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

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

body {
  font-family: var(--font-body);
  font-size: 16px;
  line-height: 1.7;
  letter-spacing: 0.02em;
  background-color: var(--bg-deep);
  background-image:
    linear-gradient(135deg, rgba(0, 229, 255, 0.02) 0%, transparent 45%),
    radial-gradient(rgba(198, 255, 0, 0.035) 1px, transparent 1px);
  background-size: 100% 100%, 24px 24px;
  color: var(--text-main);
  min-height: 100vh;
  overflow-x: hidden;
}

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

a {
  color: var(--accent-blue);
  text-decoration: none;
  transition: color var(--speed) var(--ease);
}

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

ul, ol {
  list-style: none;
}

button, input, select, textarea {
  font-family: inherit;
  font-size: inherit;
  line-height: inherit;
  color: inherit;
  background: none;
  border: none;
}

button {
  cursor: pointer;
}

:focus-visible {
  outline: 2px solid var(--accent-green);
  outline-offset: 3px;
  border-radius: 4px;
}

/* ========== Typography ========== */
h1, h2, h3, h4, h5, h6 {
  font-family: var(--font-head);
  color: var(--text-main);
  line-height: 1.3;
  font-weight: 700;
}

h1 {
  font-size: clamp(30px, 4.5vw, 48px);
  font-weight: 900;
  letter-spacing: 0.02em;
  line-height: 1.2;
}

h2 {
  font-size: clamp(22px, 3vw, 32px);
  font-weight: 800;
  letter-spacing: 0.03em;
}

h3 {
  font-size: 18px;
  font-weight: 700;
}

p {
  margin-bottom: 14px;
}

.font-data {
  font-family: var(--font-data);
  font-feature-settings: "tnum" 1;
  letter-spacing: 0;
}

.vertical-meta {
  writing-mode: vertical-rl;
  text-orientation: mixed;
  font-size: 11px;
  letter-spacing: 0.3em;
  color: var(--text-weak);
  font-family: var(--font-data);
  text-transform: uppercase;
}

/* ========== Container ========== */
.container {
  width: 100%;
  max-width: var(--container);
  margin: 0 auto;
  padding: 0 24px;
}

/* ========== Skip Link ========== */
.skip-link {
  position: fixed;
  top: -120px;
  left: 16px;
  z-index: 2000;
  padding: 12px 28px;
  background: var(--accent-green);
  color: #0B0F14;
  font-weight: 600;
  font-size: 14px;
  border-radius: var(--radius-sm);
  box-shadow: 0 8px 24px rgba(0, 0, 0, 0.4);
  transition: top var(--speed) var(--ease);
}

.skip-link:focus {
  top: 16px;
  color: #0B0F14;
}

/* ========== Scroll Progress ========== */
.scroll-progress {
  position: fixed;
  top: 0;
  left: 0;
  width: 0;
  height: 3px;
  background: linear-gradient(90deg, var(--accent-green), var(--accent-blue));
  z-index: 2001;
  pointer-events: none;
  border-radius: 0 2px 2px 0;
  box-shadow: 0 0 12px rgba(0, 229, 255, 0.4);
}

/* ========== Header ========== */
.site-header {
  position: sticky;
  top: 12px;
  z-index: 100;
  padding: 0 16px;
}

.header-inner {
  position: relative;
  max-width: 1360px;
  margin: 0 auto;
  display: flex;
  align-items: center;
  gap: 16px;
  padding: 10px 20px;
  background: rgba(11, 15, 20, 0.82);
  backdrop-filter: blur(20px) saturate(140%);
  -webkit-backdrop-filter: blur(20px) saturate(140%);
  border: 1px solid rgba(36, 52, 71, 0.85);
  border-radius: var(--radius-lg);
  box-shadow: 0 12px 40px rgba(0, 0, 0, 0.35);
  transition:
    padding var(--speed) var(--ease),
    background var(--speed) var(--ease),
    box-shadow var(--speed) var(--ease),
    border-radius var(--speed) var(--ease);
}

.header-inner::after {
  content: "";
  position: absolute;
  bottom: -1px;
  left: 32px;
  right: 32px;
  height: 1px;
  background: linear-gradient(
    90deg,
    transparent,
    rgba(0, 229, 255, 0.35),
    rgba(198, 255, 0, 0.35),
    transparent
  );
  pointer-events: none;
}

.site-header.is-scrolled .header-inner {
  padding-top: 7px;
  padding-bottom: 7px;
  background: rgba(11, 15, 20, 0.92);
  box-shadow: 0 6px 24px rgba(0, 0, 0, 0.45);
}

.site-header.is-scrolled .brand-mark {
  transform: scale(0.92);
}

/* Brand */
.brand {
  display: flex;
  align-items: center;
  gap: 14px;
  flex-shrink: 0;
  flex: 1;
}

.brand-mark {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  width: 46px;
  height: 46px;
  background: var(--accent-green);
  color: #0B0F14;
  font-family: var(--font-data);
  font-weight: 600;
  font-size: 18px;
  letter-spacing: 0;
  clip-path: polygon(0 0, calc(100% - 12px) 0, 100% 12px, 100% 100%, 12px 100%, 0 calc(100% - 12px));
  transition: transform var(--speed) var(--ease);
  box-shadow: 0 0 20px rgba(198, 255, 0, 0.15);
}

.brand-text {
  display: flex;
  flex-direction: column;
  line-height: 1.25;
}

.brand-name {
  font-weight: 900;
  font-size: 20px;
  letter-spacing: 0.08em;
  color: var(--text-main);
  white-space: nowrap;
}

.brand-wordmark {
  font-size: 11px;
  color: var(--text-weak);
  letter-spacing: 0.05em;
  white-space: nowrap;
}

/* Nav Capsule */
.nav-capsule {
  margin: 0 auto;
}

.nav-list {
  display: flex;
  align-items: center;
  gap: 2px;
  padding: 5px;
  background: rgba(26, 38, 52, 0.75);
  border: 1px solid rgba(36, 52, 71, 0.7);
  border-radius: var(--radius-pill);
  backdrop-filter: blur(10px);
  -webkit-backdrop-filter: blur(10px);
}

.nav-link {
  display: inline-block;
  padding: 8px 16px;
  border-radius: var(--radius-pill);
  color: var(--text-weak);
  font-size: 14px;
  font-weight: 500;
  white-space: nowrap;
  transition:
    color var(--speed) var(--ease),
    background var(--speed) var(--ease),
    box-shadow var(--speed) var(--ease);
}

.nav-link:hover {
  color: var(--text-main);
  background: rgba(198, 255, 0, 0.08);
}

.nav-link[aria-current="page"] {
  color: var(--accent-green);
  background: rgba(198, 255, 0, 0.12);
  box-shadow: inset 0 0 0 1px rgba(198, 255, 0, 0.18);
  font-weight: 600;
}

/* Header Status */
.header-status {
  display: flex;
  align-items: center;
  gap: 8px;
  padding: 8px 16px;
  border-radius: var(--radius-pill);
  background: rgba(11, 15, 20, 0.6);
  border: 1px solid var(--line);
  white-space: nowrap;
  flex-shrink: 0;
}

.header-status::before {
  content: "";
  width: 1px;
  height: 18px;
  background: var(--line);
  margin-right: 2px;
}

.status-dot {
  width: 8px;
  height: 8px;
  border-radius: 50%;
  background: var(--accent-green);
  box-shadow: 0 0 10px rgba(198, 255, 0, 0.6);
  animation: status-pulse 2s ease-in-out infinite;
}

.status-text {
  font-size: 12px;
  color: var(--text-weak);
}

@keyframes status-pulse {
  0%, 100% { opacity: 1; transform: scale(1); }
  50% { opacity: 0.45; transform: scale(0.8); }
}

/* Nav Toggle */
.nav-toggle {
  display: none;
  flex-direction: column;
  justify-content: center;
  gap: 5px;
  width: 44px;
  height: 44px;
  padding: 11px;
  border-radius: 12px;
  background: var(--bg-float);
  border: 1px solid var(--line);
  transition: background var(--speed) var(--ease), border-color var(--speed) var(--ease);
  flex-shrink: 0;
}

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

.toggle-line {
  display: block;
  width: 100%;
  height: 2px;
  border-radius: 2px;
  background: var(--text-main);
  transition: transform var(--speed) var(--ease), opacity var(--speed) var(--ease);
}

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

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

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

/* ========== Footer ========== */
.site-footer {
  position: relative;
  background: #090D12;
  border-top: 1px solid var(--line);
  margin-top: 100px;
  padding: 64px 24px 0;
}

.site-footer::before {
  content: "";
  position: absolute;
  top: -1px;
  left: 0;
  width: 180px;
  height: 2px;
  background: linear-gradient(90deg, var(--accent-green), transparent);
}

.site-footer::after {
  content: "";
  position: absolute;
  top: -1px;
  right: 0;
  width: 140px;
  height: 2px;
  background: linear-gradient(90deg, transparent, var(--accent-blue));
}

.footer-top {
  max-width: var(--container);
  margin: 0 auto;
  display: grid;
  grid-template-columns: 1.4fr 1fr 1fr 1.2fr;
  gap: 40px;
  padding-bottom: 48px;
}

/* Footer Brand */
.footer-brand-mark {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  width: 52px;
  height: 52px;
  background: var(--accent-green);
  color: #0B0F14;
  font-family: var(--font-data);
  font-weight: 600;
  font-size: 20px;
  letter-spacing: 0;
  clip-path: polygon(0 0, calc(100% - 14px) 0, 100% 14px, 100% 100%, 14px 100%, 0 calc(100% - 14px));
  margin-bottom: 18px;
  box-shadow: 0 0 24px rgba(198, 255, 0, 0.12);
}

.footer-brand-text {
  display: flex;
  flex-direction: column;
  margin-bottom: 12px;
}

.footer-brand-name {
  font-size: 24px;
  font-weight: 900;
  letter-spacing: 0.08em;
  color: var(--text-main);
  line-height: 1.3;
}

.footer-brand-wordmark {
  font-size: 12px;
  color: var(--text-weak);
  letter-spacing: 0.05em;
}

.footer-tagline {
  font-size: 13px;
  color: var(--text-weak);
  letter-spacing: 0.08em;
  border-left: 3px solid var(--accent-green);
  padding-left: 12px;
  margin-bottom: 0;
  line-height: 1.7;
}

/* Footer Columns */
.footer-col {
  min-width: 0;
}

.footer-heading {
  display: flex;
  align-items: baseline;
  gap: 10px;
  font-size: 15px;
  font-weight: 700;
  color: var(--text-main);
  letter-spacing: 0.06em;
  margin-bottom: 20px;
  padding-bottom: 10px;
  border-bottom: 1px solid rgba(36, 52, 71, 0.7);
  text-transform: uppercase;
}

.footer-heading-index {
  font-family: var(--font-data);
  font-size: 13px;
  font-weight: 600;
  color: var(--accent-green);
}

.footer-links li {
  margin-bottom: 10px;
}

.footer-links a {
  color: var(--text-weak);
  font-size: 14px;
  transition: color var(--speed) var(--ease), padding-left var(--speed) var(--ease);
  position: relative;
  padding-left: 0;
}

.footer-links a:hover {
  color: var(--accent-blue);
  padding-left: 8px;
}

.footer-contact-item {
  font-size: 13px;
  color: var(--text-weak);
  line-height: 1.8;
  margin-bottom: 8px;
  word-break: break-all;
}

.footer-contact-item:last-child {
  margin-bottom: 0;
}

/* Footer Bottom */
.footer-bottom {
  border-top: 1px solid rgba(36, 52, 71, 0.6);
  padding: 24px 0;
}

.footer-bottom-inner {
  max-width: var(--container);
  margin: 0 auto;
  display: flex;
  align-items: center;
  justify-content: space-between;
  flex-wrap: wrap;
  gap: 12px;
  font-size: 12px;
  color: var(--text-weak);
}

.footer-copyright {
  margin: 0;
}

.footer-icp {
  margin: 0;
  font-family: var(--font-data);
}

.footer-trust {
  margin: 0;
  flex-basis: 100%;
  text-align: center;
  font-size: 12px;
  color: var(--text-weak);
  padding-top: 8px;
  border-top: 1px dashed rgba(36, 52, 71, 0.5);
}

/* ========== Buttons ========== */
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 8px;
  padding: 12px 28px;
  font-size: 14px;
  font-weight: 600;
  font-family: var(--font-body);
  color: #0B0F14;
  background: var(--accent-green);
  border-radius: 4px;
  clip-path: polygon(0 0, calc(100% - 14px) 0, 100% 14px, 100% 100%, 14px 100%, 0 calc(100% - 14px));
  transition: transform var(--speed) var(--ease), box-shadow var(--speed) var(--ease), filter var(--speed) var(--ease);
}

.btn:hover {
  transform: translateY(-2px);
  box-shadow: 0 10px 28px rgba(198, 255, 0, 0.25);
  filter: brightness(1.08);
  color: #0B0F14;
}

.btn-secondary {
  background: transparent;
  border: 1px solid var(--accent-blue);
  color: var(--accent-blue);
  clip-path: polygon(0 0, calc(100% - 14px) 0, 100% 14px, 100% 100%, 14px 100%, 0 calc(100% - 14px));
}

.btn-secondary:hover {
  background: rgba(0, 229, 255, 0.08);
  box-shadow: 0 8px 24px rgba(0, 229, 255, 0.15);
  color: var(--accent-blue);
}

/* ========== Panels & Cut Corners ========== */
.clip-corner {
  clip-path: polygon(0 0, calc(100% - 24px) 0, 100% 24px, 100% 100%, 24px 100%, 0 calc(100% - 24px));
}

.panel {
  background: var(--bg-card);
  border: 1px solid var(--line);
  padding: 28px;
}

/* ========== Breadcrumbs ========== */
.breadcrumbs {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 10px;
  padding: 18px 0;
  font-size: 13px;
  color: var(--text-weak);
}

.breadcrumbs a {
  color: var(--accent-blue);
  transition: color var(--speed) var(--ease);
}

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

.breadcrumbs .breadcrumb-sep {
  font-family: var(--font-data);
  color: var(--line);
  font-size: 12px;
}

.breadcrumbs .breadcrumb-current {
  color: var(--accent-silver);
  font-weight: 500;
}

/* ========== Chapter Header ========== */
.chapter-header {
  display: flex;
  align-items: baseline;
  gap: 18px;
  margin-bottom: 36px;
  position: relative;
}

.chapter-index {
  font-family: var(--font-data);
  font-size: 14px;
  font-weight: 600;
  color: var(--accent-green);
  letter-spacing: 0.1em;
}

.chapter-title {
  font-size: clamp(24px, 3vw, 36px);
  font-weight: 900;
  letter-spacing: 0.04em;
  color: var(--text-main);
  line-height: 1.2;
}

.chapter-meta {
  writing-mode: vertical-rl;
  text-orientation: mixed;
  font-size: 11px;
  font-family: var(--font-data);
  color: var(--text-weak);
  letter-spacing: 0.3em;
  align-self: stretch;
  margin-left: auto;
}

/* ========== Legend ========== */
.legend {
  display: flex;
  align-items: center;
  flex-wrap: wrap;
  gap: 20px;
  padding: 14px 20px;
  background: var(--bg-card);
  border: 1px solid var(--line);
  border-radius: var(--radius-sm);
  font-size: 12px;
  color: var(--text-weak);
  font-family: var(--font-data);
}

.legend-item {
  display: flex;
  align-items: center;
  gap: 8px;
}

.legend-dot {
  width: 10px;
  height: 10px;
  border-radius: 2px;
  flex-shrink: 0;
}

.legend-dot-green { background: var(--accent-green); }
.legend-dot-blue { background: var(--accent-blue); }
.legend-dot-orange { background: var(--accent-orange); }
.legend-dot-silver { background: var(--accent-silver); }

/* ========== Bento Grid ========== */
.bento-grid {
  display: grid;
  grid-template-columns: repeat(12, 1fr);
  gap: 20px;
}

.bento-main { grid-column: span 8; }
.bento-side { grid-column: span 4; }
.bento-wide { grid-column: span 12; }
.bento-half { grid-column: span 6; }
.bento-third { grid-column: span 4; }
.bento-quarter { grid-column: span 3; }

/* ========== Image Placeholder Base ========== */
.img-frame {
  position: relative;
  overflow: hidden;
  background: linear-gradient(135deg, var(--bg-card), var(--bg-float));
  border: 1px solid var(--line);
}

.img-frame img {
  width: 100%;
  height: 100%;
  object-fit: cover;
  transition: transform 0.6s var(--ease);
}

.img-frame:hover img {
  transform: scale(1.03);
}

.img-frame::after {
  content: "";
  position: absolute;
  inset: 0;
  background: linear-gradient(180deg, transparent 60%, rgba(11, 15, 20, 0.55));
  pointer-events: none;
}

/* ========== Responsive ========== */
@media (max-width: 1200px) {
  .header-status {
    display: none;
  }

  .brand {
    flex: 0 0 auto;
  }

  .nav-capsule {
    margin-left: auto;
  }
}

@media (max-width: 960px) {
  .site-header {
    top: 8px;
  }

  .header-inner {
    border-radius: var(--radius-md);
    padding: 8px 14px;
    gap: 12px;
  }

  .brand {
    flex: 1;
    gap: 10px;
  }

  .brand-mark {
    width: 40px;
    height: 40px;
    font-size: 16px;
  }

  .brand-name {
    font-size: 17px;
  }

  .brand-wordmark {
    font-size: 10px;
  }

  .nav-capsule {
    position: absolute;
    top: calc(100% + 8px);
    left: 0;
    right: 0;
    background: rgba(18, 26, 36, 0.97);
    border: 1px solid var(--line);
    border-radius: var(--radius-md);
    padding: 14px;
    opacity: 0;
    transform: translateY(-10px) scale(0.98);
    pointer-events: none;
    transition: opacity var(--speed) var(--ease), transform var(--speed) var(--ease);
    backdrop-filter: blur(20px);
    -webkit-backdrop-filter: blur(20px);
    box-shadow: 0 20px 48px rgba(0, 0, 0, 0.5);
  }

  .nav-capsule[data-open] {
    opacity: 1;
    transform: translateY(0) scale(1);
    pointer-events: auto;
  }

  .nav-list {
    flex-direction: column;
    align-items: stretch;
    gap: 4px;
    background: transparent;
    border: none;
    padding: 0;
    border-radius: 0;
  }

  .nav-link {
    display: block;
    padding: 12px 16px;
    border-radius: var(--radius-sm);
    font-size: 15px;
  }

  .nav-link[aria-current="page"] {
    background: rgba(198, 255, 0, 0.12);
  }

  .nav-toggle {
    display: flex;
  }

  .footer-top {
    grid-template-columns: 1fr 1fr;
    gap: 32px;
    padding-bottom: 36px;
  }
}

@media (max-width: 640px) {
  .container {
    padding: 0 16px;
  }

  .site-header {
    padding: 0 10px;
  }

  .brand-wordmark {
    display: none;
  }

  .footer-top {
    grid-template-columns: 1fr;
    gap: 28px;
  }

  .footer-bottom-inner {
    flex-direction: column;
    text-align: center;
    gap: 8px;
  }

  .footer-trust {
    text-align: center;
  }

  .bento-main,
  .bento-side,
  .bento-half,
  .bento-third,
  .bento-quarter {
    grid-column: span 12;
  }
}

/* ========== Reveal Animation ========== */
html.js [data-reveal] {
  opacity: 0;
  transform: translateY(24px);
  transition:
    opacity 0.7s var(--ease),
    transform 0.7s var(--ease);
  will-change: opacity, transform;
}

html.js [data-reveal].reveal-in {
  opacity: 1;
  transform: translateY(0);
}

/* ========== 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;
    transition-delay: 0ms !important;
  }

  [data-reveal] {
    opacity: 1 !important;
    transform: none !important;
    transition: none !important;
  }

  .status-dot {
    animation: none;
  }

  .scroll-progress {
    box-shadow: none;
  }
}