/* ========== Design Tokens ========== */
:root {
  --field-green: #1B7A3D;
  --night-blue: #0B1E36;
  --carbon-black: #111111;
  --blood-red: #D32F2F;
  --champion-gold: #FFB300;
  --signal-yellow: #FFD500;
  --data-green: #00E676;
  --paper-white: #F5F5F0;
  --slate-gray: #2A2A2A;
  --fog: #E0E0E0;

  --font-display: 'Noto Sans SC', 'Microsoft YaHei', 'PingFang SC', 'Arial Black', sans-serif;
  --font-editorial: 'Noto Serif SC', 'SimSun', 'Songti SC', serif;
  --font-body: 'Noto Sans SC', 'Microsoft YaHei', 'PingFang SC', sans-serif;
  --font-mono: 'Roboto Mono', 'Consolas', 'Courier New', monospace;

  --container-width: 1240px;
  --header-height: 64px;
  --band-size: 4px;
}

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

html {
  font-size: 16px;
  -webkit-text-size-adjust: 100%;
  scroll-behavior: smooth;
}

body {
  font-family: var(--font-body);
  font-size: 16px;
  line-height: 1.7;
  color: var(--paper-white);
  background: var(--carbon-black);
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
}

h1, h2, h3, h4, h5, h6 {
  font-family: var(--font-display);
  font-style: italic;
  font-weight: 900;
  line-height: 1.2;
  color: inherit;
}

p, li {
  overflow-wrap: break-word;
}

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

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

ul, ol {
  list-style: none;
}

button {
  font: inherit;
  color: inherit;
  background: none;
  border: none;
  cursor: pointer;
}

::selection {
  background: var(--champion-gold);
  color: var(--carbon-black);
}

:focus-visible {
  outline: 2px solid var(--signal-yellow);
  outline-offset: 2px;
}

#main-content {
  scroll-margin-top: calc(var(--header-height) + var(--band-size));
}

/* ========== Accessibility ========== */
.skip-link {
  position: fixed;
  top: 0;
  left: 16px;
  z-index: 2000;
  padding: 10px 18px;
  background: var(--signal-yellow);
  color: var(--carbon-black);
  font-weight: 700;
  font-size: 14px;
  border-radius: 0 0 4px 4px;
  transform: translateY(-120%);
  transition: transform 0.25s ease;
}

.skip-link:focus {
  transform: translateY(0);
}

/* ========== Layout Primitives ========== */
.container {
  max-width: var(--container-width);
  margin: 0 auto;
  padding-left: 24px;
  padding-right: 24px;
}

.container--narrow {
  max-width: 900px;
}

.section {
  padding: 80px 0;
}

.section--pitch {
  background: var(--field-green);
  color: var(--paper-white);
}

.section--dark {
  background: var(--night-blue);
  color: var(--paper-white);
}

.section--light {
  background: var(--paper-white);
  color: var(--slate-gray);
}

.divider {
  height: 16px;
  border-top: 3px solid var(--carbon-black);
  border-bottom: 3px solid var(--carbon-black);
  background: repeating-linear-gradient(
    135deg,
    var(--field-green) 0 12px,
    var(--night-blue) 12px 24px,
    var(--blood-red) 24px 36px
  );
}

/* ========== Buttons ========== */
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  padding: 12px 24px;
  font-family: var(--font-display);
  font-size: 14px;
  font-weight: 900;
  font-style: italic;
  line-height: 1.2;
  border: 2px solid transparent;
  border-radius: 3px;
  transition: background-color 0.2s, color 0.2s, border-color 0.2s;
  cursor: pointer;
  text-align: center;
}

.btn--primary {
  background: var(--blood-red);
  border-color: var(--blood-red);
  color: var(--paper-white);
}

.btn--primary:hover {
  background: var(--champion-gold);
  border-color: var(--champion-gold);
  color: var(--carbon-black);
}

.btn--ghost {
  background: transparent;
  border-color: rgba(255,255,255,0.4);
  color: var(--paper-white);
}

.btn--ghost:hover {
  border-color: var(--signal-yellow);
  color: var(--signal-yellow);
}

.section--light .btn--ghost {
  border-color: var(--slate-gray);
  color: var(--slate-gray);
}

.section--light .btn--ghost:hover {
  border-color: var(--blood-red);
  color: var(--blood-red);
}

.btn--gold {
  background: var(--champion-gold);
  border-color: var(--champion-gold);
  color: var(--carbon-black);
}

.btn--gold:hover {
  background: var(--signal-yellow);
  border-color: var(--signal-yellow);
}

/* ========== Breadcrumb ========== */
.breadcrumb {
  padding: 14px 0;
  font-family: var(--font-mono);
  font-size: 12px;
  color: rgba(255,255,255,0.5);
}

.breadcrumb__list {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 4px 8px;
}

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

.breadcrumb__item + .breadcrumb__item::before {
  content: '/';
  color: var(--data-green);
}

.breadcrumb__link {
  color: var(--champion-gold);
  transition: color 0.2s;
}

.breadcrumb__link:hover {
  color: var(--signal-yellow);
}

.breadcrumb__current {
  color: rgba(255,255,255,0.65);
}

/* ========== Content / Prose ========== */
.content {
  font-size: 16px;
  line-height: 1.85;
}

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

.content h2,
.content h3 {
  margin-top: 1.6em;
  margin-bottom: 0.5em;
}

.content h2 {
  font-size: 24px;
}

.content h3 {
  font-family: var(--font-editorial);
  font-style: normal;
  font-weight: 600;
  font-size: 19px;
}

.content ul {
  list-style: disc;
  padding-left: 1.4em;
  margin-bottom: 1em;
}

.content ol {
  list-style: decimal;
  padding-left: 1.4em;
  margin-bottom: 1em;
}

.content a {
  color: var(--champion-gold);
  text-decoration: underline;
  text-underline-offset: 3px;
  transition: color 0.2s;
}

.content a:hover {
  color: var(--signal-yellow);
}

.section--light .content a {
  color: var(--blood-red);
}

.section--light .content a:hover {
  color: var(--field-green);
}

/* ========== Page Title & Section Header ========== */
.page-title {
  font-family: var(--font-display);
  font-weight: 900;
  font-style: italic;
  font-size: clamp(32px, 5vw, 56px);
  line-height: 1.1;
}

.page-meta {
  margin-top: 8px;
  font-family: var(--font-mono);
  font-size: 13px;
  color: rgba(255,255,255,0.55);
}

.section-header {
  display: flex;
  align-items: flex-end;
  flex-wrap: wrap;
  gap: 14px;
  margin-bottom: 36px;
}

.section-header__index {
  font-family: var(--font-mono);
  font-weight: 700;
  font-size: 13px;
  letter-spacing: 0.06em;
  text-transform: uppercase;
  color: var(--champion-gold);
}

.section-header__title {
  font-size: clamp(28px, 4vw, 44px);
  line-height: 1.15;
}

.section-header__meta {
  margin-left: auto;
  font-family: var(--font-mono);
  font-size: 12px;
  color: rgba(255,255,255,0.5);
}

.section--pitch .section-header__index {
  color: var(--signal-yellow);
}

.section--light .section-header__index {
  color: var(--blood-red);
}

.section--light .section-header__meta {
  color: rgba(0,0,0,0.5);
}

/* ========== Scroll Progress ========== */
.scroll-progress {
  position: fixed;
  top: 0;
  left: 0;
  width: 100%;
  height: var(--band-size);
  background: linear-gradient(90deg, var(--data-green), var(--champion-gold), var(--blood-red));
  transform: scaleX(0);
  transform-origin: left center;
  z-index: 1000;
  pointer-events: none;
}

/* ========== Header ========== */
.site-header {
  position: sticky;
  top: 0;
  z-index: 900;
  background: var(--carbon-black);
  border-bottom: 1px solid rgba(255,255,255,0.08);
}

.site-header__pitchline {
  height: var(--band-size);
  background: linear-gradient(
    90deg,
    var(--field-green) 0%,
    var(--field-green) 85%,
    var(--champion-gold) 85%,
    var(--champion-gold) 100%
  );
}

.site-header__inner {
  display: flex;
  align-items: center;
  gap: 20px;
  min-height: var(--header-height);
}

.site-brand {
  display: inline-flex;
  align-items: center;
  gap: 12px;
  flex-shrink: 0;
  color: var(--paper-white);
}

.site-brand__mark {
  position: relative;
  display: inline-flex;
  align-items: center;
  justify-content: center;
  width: 40px;
  height: 40px;
  background: var(--field-green);
  font-family: var(--font-mono);
  font-weight: 700;
  font-size: 14px;
  letter-spacing: -0.03em;
  border-radius: 2px;
  overflow: hidden;
}

.site-brand__mark::after {
  content: '';
  position: absolute;
  right: -10px;
  bottom: -10px;
  width: 24px;
  height: 24px;
  background: var(--blood-red);
  transform: rotate(45deg);
}

.site-brand__text {
  display: flex;
  flex-direction: column;
  line-height: 1.15;
}

.site-brand__cn {
  font-size: 19px;
  font-weight: 900;
  font-style: italic;
  letter-spacing: 0.02em;
}

.site-brand__cn-strong {
  color: var(--champion-gold);
}

.site-brand__en {
  margin-top: 2px;
  font-family: var(--font-mono);
  font-size: 9px;
  letter-spacing: 0.18em;
  color: rgba(255,255,255,0.45);
  text-transform: uppercase;
}

.site-nav {
  display: flex;
  align-items: center;
  justify-content: center;
  flex: 1;
  gap: 2px;
  counter-reset: nav-index;
}

.site-nav__link {
  position: relative;
  display: inline-flex;
  align-items: baseline;
  padding: 9px 10px;
  font-size: 14px;
  font-weight: 500;
  color: rgba(255,255,255,0.72);
  white-space: nowrap;
  transition: color 0.2s;
  counter-increment: nav-index;
}

.site-nav__link::before {
  content: counter(nav-index, decimal-leading-zero) " /";
  margin-right: 5px;
  font-family: var(--font-mono);
  font-size: 9px;
  font-weight: 400;
  color: var(--data-green);
  opacity: 0.85;
}

.site-nav__link:hover {
  color: var(--paper-white);
}

.site-nav__link[aria-current="page"] {
  color: var(--signal-yellow);
}

.site-nav__link[aria-current="page"]::after {
  content: '';
  position: absolute;
  left: 10px;
  right: 10px;
  bottom: 4px;
  height: 2px;
  background: var(--blood-red);
}

.nav-toggle {
  display: none;
  align-items: center;
  gap: 8px;
  padding: 8px 12px;
  color: var(--paper-white);
  background: rgba(255,255,255,0.04);
  border: 1px solid rgba(255,255,255,0.12);
  border-radius: 3px;
  flex-shrink: 0;
}

.nav-toggle__box {
  display: inline-flex;
  flex-direction: column;
  gap: 4px;
  width: 16px;
}

.nav-toggle__bar {
  display: block;
  height: 2px;
  background: var(--data-green);
  transition: transform 0.25s ease, opacity 0.25s ease;
}

.nav-toggle__label {
  font-size: 13px;
  font-weight: 500;
}

.nav-toggle[aria-expanded="true"] .nav-toggle__bar:nth-child(1) {
  transform: translateY(6px) rotate(45deg);
}

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

.nav-toggle[aria-expanded="true"] .nav-toggle__bar:nth-child(3) {
  transform: translateY(-6px) rotate(-45deg);
}

.header-cta {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 6px;
  padding: 9px 16px;
  background: var(--blood-red);
  color: var(--paper-white);
  font-size: 13px;
  font-weight: 700;
  border-radius: 3px;
  border: 1px solid transparent;
  white-space: nowrap;
  flex-shrink: 0;
  transition: background-color 0.2s, color 0.2s, border-color 0.2s;
}

.header-cta::before {
  content: '↓';
  font-size: 14px;
  line-height: 1;
}

.header-cta:hover {
  background: var(--champion-gold);
  border-color: var(--champion-gold);
  color: var(--carbon-black);
}

/* ========== Footer ========== */
.site-footer {
  position: relative;
  background: var(--night-blue);
  border-top: 1px solid rgba(255,255,255,0.05);
}

.site-footer__band {
  height: var(--band-size);
  background: linear-gradient(
    90deg,
    var(--field-green) 0%,
    var(--field-green) 70%,
    var(--signal-yellow) 70%,
    var(--signal-yellow) 78%,
    var(--blood-red) 78%,
    var(--blood-red) 100%
  );
}

.site-footer__grid {
  display: grid;
  grid-template-columns: 1.4fr 1fr 1fr 1.3fr;
  gap: 48px;
  padding: 56px 0 48px;
}

.site-footer__logo {
  font-family: var(--font-display);
  font-style: italic;
  font-weight: 900;
  font-size: 24px;
  color: var(--paper-white);
}

.site-footer__logo span {
  color: var(--champion-gold);
}

.site-footer__desc {
  margin-top: 14px;
  max-width: 38em;
  font-size: 14px;
  line-height: 1.8;
  color: rgba(245,245,240,0.68);
}

.site-footer__trust {
  margin-top: 16px;
  padding: 12px 14px;
  background: rgba(255,255,255,0.04);
  border-left: 3px solid var(--signal-yellow);
  font-size: 13px;
  line-height: 1.7;
  color: rgba(245,245,240,0.75);
}

.site-footer__heading {
  margin-bottom: 14px;
  font-family: var(--font-display);
  font-style: italic;
  font-weight: 900;
  font-size: 12px;
  letter-spacing: 0.14em;
  text-transform: uppercase;
  color: var(--champion-gold);
}

.site-footer__link {
  display: block;
  padding: 5px 0;
  font-size: 14px;
  color: rgba(245,245,240,0.72);
  transition: color 0.2s, padding-left 0.2s;
}

.site-footer__link:hover {
  color: var(--signal-yellow);
  padding-left: 5px;
}

.site-footer__contact-item {
  padding: 5px 0;
  font-size: 14px;
  line-height: 1.6;
  color: rgba(245,245,240,0.72);
}

.site-footer__bottom {
  border-top: 1px solid rgba(255,255,255,0.08);
  padding: 18px 0;
}

.site-footer__bottom-inner {
  display: flex;
  align-items: center;
  justify-content: space-between;
  flex-wrap: wrap;
  gap: 12px;
}

.site-footer__copy,
.site-footer__icp {
  font-family: var(--font-mono);
  font-size: 12px;
  color: rgba(245,245,240,0.5);
}

/* ========== Scroll Top ========== */
.scroll-top {
  position: fixed;
  right: 20px;
  bottom: 24px;
  z-index: 950;
  width: 46px;
  height: 46px;
  background: var(--blood-red);
  color: var(--paper-white);
  font-family: var(--font-mono);
  font-size: 10px;
  font-weight: 700;
  letter-spacing: 0.04em;
  border: 1px solid rgba(255,255,255,0.15);
  border-radius: 3px;
  opacity: 0;
  visibility: hidden;
  transform: translateY(14px);
  transition: opacity 0.3s, transform 0.3s, visibility 0.3s, background-color 0.2s;
}

.scroll-top[data-visible] {
  opacity: 1;
  visibility: visible;
  transform: translateY(0);
}

.scroll-top:hover {
  background: var(--champion-gold);
  color: var(--carbon-black);
}

/* ========== Grid ========== */
.grid {
  display: grid;
  gap: 24px;
}

.grid--2 {
  grid-template-columns: repeat(2, minmax(0, 1fr));
}

.grid--3 {
  grid-template-columns: repeat(3, minmax(0, 1fr));
}

.grid--4 {
  grid-template-columns: repeat(4, minmax(0, 1fr));
}

.grid--gap-lg {
  gap: 32px;
}

.grid--gap-sm {
  gap: 16px;
}

/* ========== Cards ========== */
.card {
  position: relative;
  display: flex;
  flex-direction: column;
  border-radius: 4px;
  overflow: hidden;
  transition: transform 0.25s ease, box-shadow 0.25s ease;
}

.card--glass {
  background: rgba(255,255,255,0.05);
  border: 1px solid rgba(255,255,255,0.1);
  color: var(--paper-white);
}

.card--glass:hover {
  transform: translateY(-3px);
  box-shadow: 0 8px 24px rgba(0,0,0,0.35);
}

.card--solid {
  background: #fff;
  border: 1px solid var(--fog);
  color: var(--slate-gray);
  box-shadow: 0 2px 8px rgba(0,0,0,0.04);
}

.card--solid:hover {
  transform: translateY(-3px);
  box-shadow: 0 10px 30px rgba(0,0,0,0.08);
}

.card__media {
  position: relative;
  overflow: hidden;
}

.card__body {
  display: flex;
  flex-direction: column;
  gap: 10px;
  flex: 1;
  padding: 20px;
}

.card__title {
  font-size: 18px;
  font-weight: 900;
  font-style: italic;
}

.card__text {
  font-size: 14px;
  line-height: 1.7;
  opacity: 0.75;
}

.card__tag {
  position: absolute;
  top: 12px;
  left: 12px;
  z-index: 2;
}

/* ========== Image Frame ========== */
.image-frame {
  position: relative;
  display: block;
  overflow: hidden;
  background: var(--slate-gray);
}

.image-frame--16-9 {
  aspect-ratio: 16 / 9;
}

.image-frame--4-3 {
  aspect-ratio: 4 / 3;
}

.image-frame--2-1 {
  aspect-ratio: 2 / 1;
}

.image-frame--square {
  aspect-ratio: 1 / 1;
}

.image-frame img {
  width: 100%;
  height: 100%;
  object-fit: cover;
  transition: transform 0.4s ease;
}

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

.image-frame__placeholder {
  position: absolute;
  inset: 0;
  display: flex;
  align-items: center;
  justify-content: center;
  background:
    repeating-linear-gradient(
      -45deg,
      rgba(255,255,255,0.08) 0 10px,
      transparent 10px 20px
    ),
    var(--field-green);
  color: rgba(255,255,255,0.4);
  font-family: var(--font-mono);
  font-size: 11px;
  font-weight: 700;
  letter-spacing: 0.2em;
  text-transform: uppercase;
}

/* ========== Tags ========== */
.tag {
  display: inline-flex;
  align-items: center;
  padding: 4px 10px;
  font-family: var(--font-mono);
  font-size: 11px;
  font-weight: 700;
  letter-spacing: 0.08em;
  border-radius: 2px;
}

.tag--red {
  background: var(--blood-red);
  color: var(--paper-white);
}

.tag--gold {
  background: var(--champion-gold);
  color: var(--carbon-black);
}

.tag--green {
  background: var(--data-green);
  color: var(--carbon-black);
}

.tag--yellow {
  background: var(--signal-yellow);
  color: var(--carbon-black);
}

/* ========== Stats ========== */
.stat {
  position: relative;
  padding: 22px 20px;
  background: rgba(255,255,255,0.04);
  border: 1px solid rgba(255,255,255,0.08);
  border-left: 3px solid var(--champion-gold);
  border-radius: 3px;
}

.stat__num {
  display: block;
  font-family: var(--font-mono);
  font-size: 32px;
  font-weight: 700;
  line-height: 1.2;
  color: var(--champion-gold);
}

.stat__num small {
  font-size: 14px;
  font-weight: 400;
  color: rgba(255,255,255,0.5);
}

.stat__label {
  display: block;
  margin-top: 6px;
  font-size: 13px;
  color: rgba(255,255,255,0.72);
}

/* ========== Reveal Motion ========== */
.js [data-reveal] {
  opacity: 0;
  transform: translateY(24px);
  transition: opacity 0.6s ease, transform 0.6s ease;
}

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

/* ========== Responsive ========== */
@media (max-width: 980px) {
  .section {
    padding: 56px 0;
  }

  .site-nav {
    flex-wrap: wrap;
    row-gap: 2px;
  }

  .js .site-nav {
    display: none;
    position: absolute;
    top: 100%;
    left: 0;
    right: 0;
    flex-direction: column;
    flex-wrap: nowrap;
    align-items: stretch;
    background: var(--carbon-black);
    border-top: 1px solid rgba(255,255,255,0.08);
    padding: 10px 24px 18px;
    max-height: calc(100vh - var(--header-height));
    overflow-y: auto;
    box-shadow: 0 20px 40px rgba(0,0,0,0.5);
  }

  .js .site-nav[data-open] {
    display: flex;
  }

  .js .site-nav__link {
    width: 100%;
    padding: 14px 10px;
    font-size: 15px;
    border-bottom: 1px solid rgba(255,255,255,0.06);
  }

  .js .site-nav__link:last-child {
    border-bottom: none;
  }

  .js .site-nav__link[aria-current="page"]::after {
    bottom: 8px;
  }

  .js .nav-toggle {
    display: inline-flex;
    margin-left: auto;
  }

  .grid--4 {
    grid-template-columns: repeat(2, minmax(0, 1fr));
  }

  .site-footer__grid {
    grid-template-columns: 1fr 1fr;
    gap: 36px;
    padding: 44px 0 36px;
  }
}

@media (max-width: 620px) {
  .grid--2,
  .grid--3 {
    grid-template-columns: 1fr;
  }

  .grid--4 {
    grid-template-columns: 1fr;
  }

  .site-footer__grid {
    grid-template-columns: 1fr;
    gap: 28px;
    padding: 36px 0 28px;
  }
}

@media (max-width: 560px) {
  .header-cta {
    width: 38px;
    height: 38px;
    padding: 0;
    font-size: 0;
  }

  .header-cta::before {
    font-size: 16px;
  }

  .js .nav-toggle {
    margin-left: 0;
  }

  .header-cta {
    margin-left: auto;
  }
}

@media (max-width: 380px) {
  .site-brand__en {
    display: none;
  }

  .site-brand__mark {
    width: 34px;
    height: 34px;
    font-size: 12px;
  }

  .site-brand__cn {
    font-size: 16px;
  }

  .nav-toggle {
    padding: 6px 8px;
  }
}

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

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

  .js [data-reveal] {
    opacity: 1;
    transform: none;
    transition: none;
  }
}