*,
*::before,
*::after {
  box-sizing: border-box;
}

:root {
  --c-primary: #0A1B3D;
  --c-primary-soft: #10254D;
  --c-accent: #FF6B2C;
  --c-bg: #F2F4F8;
  --c-white: #FFFFFF;
  --c-ink: #1E1E1E;
  --c-muted: #5A6274;
  --c-line: #D1D6E0;
  --c-green: #1FA86B;
  --c-red: #D64040;
  --font-sans: 'PingFang SC', 'Hiragino Sans GB', 'Microsoft YaHei', 'Helvetica Neue', Arial, sans-serif;
  --font-mono: 'Roboto Mono', 'SF Mono', 'Consolas', 'Liberation Mono', monospace;
  --shadow-sm: 0 2px 10px rgba(10, 27, 61, 0.06);
  --shadow-md: 0 12px 32px rgba(10, 27, 61, 0.14);
  --content-max: 1440px;
  --reading-max: 1080px;
}

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

body {
  margin: 0;
  min-height: 100vh;
  display: flex;
  flex-direction: column;
  background: var(--c-bg);
  color: var(--c-ink);
  font-family: var(--font-sans);
  font-size: 16px;
  line-height: 1.75;
  font-weight: 400;
}

#main-content {
  display: block;
  flex: 1;
  scroll-margin-top: 138px;
}

ul,
ol {
  margin: 0;
  padding: 0;
}

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

button {
  font: inherit;
  cursor: pointer;
}

a {
  color: inherit;
  text-decoration-thickness: 0.08em;
}

:where(a, button, [tabindex]):focus-visible {
  outline: 3px solid var(--c-accent);
  outline-offset: 3px;
  border-radius: 2px;
}

body.no-scroll {
  overflow: hidden;
}

.container {
  width: 100%;
  max-width: var(--content-max);
  margin-inline: auto;
  padding-inline: clamp(16px, 4vw, 56px);
}

.container-narrow {
  width: 100%;
  max-width: var(--reading-max);
  margin-inline: auto;
  padding-inline: clamp(16px, 4vw, 56px);
}

.section {
  padding-block: clamp(64px, 10vw, 128px);
  padding-inline: clamp(16px, 4vw, 56px);
}

.section-dark {
  background: var(--c-primary);
  color: rgba(255, 255, 255, 0.82);
}

.section-dark h1,
.section-dark h2,
.section-dark h3,
.section-dark h4 {
  color: var(--c-white);
}

.section-light {
  background: var(--c-bg);
}

h1,
h2,
h3,
h4 {
  margin: 0;
  font-weight: 900;
  line-height: 1.15;
  color: var(--c-ink);
  letter-spacing: -0.02em;
}

.display-title {
  font-size: clamp(2.8rem, 8vw, 6rem);
  font-weight: 900;
  line-height: 0.96;
  letter-spacing: -0.04em;
}

.section-title {
  font-size: clamp(1.7rem, 3.6vw, 2.9rem);
}

.lead {
  font-size: clamp(1rem, 2vw, 1.22rem);
  color: var(--c-muted);
  max-width: 62ch;
}

.eyebrow {
  display: inline-flex;
  align-items: center;
  gap: 10px;
  margin-bottom: 14px;
  font-family: var(--font-mono);
  font-size: 0.75rem;
  font-weight: 700;
  letter-spacing: 0.22em;
  text-transform: uppercase;
  color: var(--c-accent);
}

.eyebrow::before {
  content: "";
  width: 30px;
  height: 2px;
  background: var(--c-accent);
}

.skip-link {
  position: fixed;
  top: 8px;
  left: 8px;
  z-index: 2000;
  padding: 10px 18px;
  background: var(--c-accent);
  color: var(--c-white);
  text-decoration: none;
  font-weight: 700;
  transform: translateY(-180%);
  transition: transform 0.2s ease;
}

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

.site-header {
  position: fixed;
  top: 0;
  left: 0;
  right: 0;
  z-index: 1000;
  background: linear-gradient(180deg, rgba(10, 27, 61, 0.92), rgba(10, 27, 61, 0.62) 72%, transparent);
  transition: background 0.25s ease, box-shadow 0.25s ease;
}

.site-header.is-scrolled {
  background: var(--c-primary);
  box-shadow: 0 12px 36px rgba(0, 0, 0, 0.22);
}

.site-header.is-scrolled .header-ribbon {
  border-bottom-color: rgba(255, 255, 255, 0.09);
}

.scroll-progress {
  position: absolute;
  top: 0;
  left: 0;
  height: 3px;
  width: calc(var(--progress, 0) * 100%);
  background: var(--c-accent);
  z-index: 1;
  pointer-events: none;
}

.header-ribbon {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 24px;
  padding: 10px clamp(16px, 4vw, 56px);
  border-bottom: 1px solid rgba(255, 255, 255, 0.16);
  transition: border-color 0.25s ease;
}

.brand {
  display: inline-flex;
  align-items: baseline;
  gap: 8px;
  color: var(--c-white);
  text-decoration: none;
  line-height: 1.1;
}

.brand-mark {
  font-size: 1.22rem;
  font-weight: 900;
  letter-spacing: 0.04em;
}

.brand-divider {
  color: var(--c-accent);
  font-weight: 900;
}

.brand-sub {
  font-size: 0.82rem;
  font-weight: 500;
  letter-spacing: 0.18em;
  opacity: 0.78;
}

.quick-nav {
  display: flex;
  align-items: center;
  gap: clamp(12px, 1.6vw, 26px);
}

.quick-link {
  position: relative;
  display: inline-flex;
  align-items: baseline;
  gap: 6px;
  padding: 6px 0;
  color: rgba(255, 255, 255, 0.82);
  font-size: 0.78rem;
  font-weight: 700;
  letter-spacing: 0.08em;
  text-decoration: none;
  white-space: nowrap;
  transition: color 0.2s ease, opacity 0.2s ease;
}

.quick-link::after {
  content: "";
  position: absolute;
  left: 0;
  bottom: 2px;
  width: 100%;
  height: 1px;
  background: var(--c-accent);
  transform: scaleX(0);
  transform-origin: left;
  transition: transform 0.22s ease;
}

.quick-link:hover {
  color: var(--c-accent);
  opacity: 1;
}

.quick-link:hover::after {
  transform: scaleX(1);
}

.quick-index {
  font-family: var(--font-mono);
  font-size: 0.64rem;
  color: var(--c-accent);
}

.header-navbar {
  display: flex;
  align-items: center;
  justify-content: flex-end;
  min-height: 52px;
  padding: 0 clamp(16px, 4vw, 56px);
}

.nav-toggle {
  display: none;
  align-items: center;
  gap: 8px;
  padding: 8px 14px;
  background: transparent;
  border: 1px solid rgba(255, 255, 255, 0.3);
  color: var(--c-white);
  line-height: 1;
  font-weight: 700;
  letter-spacing: 0.06em;
  text-transform: uppercase;
  transition: border-color 0.2s ease, background 0.2s ease;
}

.nav-toggle:hover {
  border-color: var(--c-accent);
  background: rgba(255, 107, 44, 0.12);
}

.nav-toggle-box {
  display: block;
  position: relative;
  width: 18px;
  height: 12px;
}

.nav-toggle-line {
  position: absolute;
  left: 0;
  width: 18px;
  height: 2px;
  background: currentColor;
  transition: transform 0.2s ease, top 0.2s ease, bottom 0.2s ease;
}

.nav-toggle-line:first-child {
  top: 0;
}

.nav-toggle-line:last-child {
  bottom: 0;
}

.nav-toggle[aria-expanded="true"] .nav-toggle-line:first-child {
  top: 5px;
  transform: rotate(45deg);
}

.nav-toggle[aria-expanded="true"] .nav-toggle-line:last-child {
  bottom: 5px;
  transform: rotate(-45deg);
}

.nav-toggle-text {
  font-size: 0.8rem;
}

.site-nav {
  display: flex;
  align-items: center;
}

.nav-links {
  display: flex;
  align-items: center;
  gap: clamp(10px, 2vw, 30px);
}

.nav-link {
  position: relative;
  display: block;
  padding: 12px 2px;
  color: rgba(255, 255, 255, 0.88);
  font-size: 0.95rem;
  font-weight: 700;
  letter-spacing: 0.03em;
  text-decoration: none;
  transition: color 0.2s ease;
}

.nav-link::after {
  content: "";
  position: absolute;
  left: 0;
  right: 100%;
  bottom: 0;
  height: 3px;
  background: var(--c-accent);
  transition: right 0.25s ease;
}

.nav-link:hover {
  color: var(--c-white);
}

.nav-link:hover::after,
.nav-link[aria-current="page"]::after {
  right: 0;
}

.nav-link[aria-current="page"] {
  color: var(--c-white);
}

.nav-close {
  display: none;
  align-items: center;
  gap: 8px;
  padding: 0;
  background: transparent;
  border: 0;
  color: var(--c-white);
  font-size: 0.8rem;
  font-weight: 700;
  letter-spacing: 0.1em;
  text-transform: uppercase;
}

.nav-close-icon {
  position: relative;
  display: block;
  width: 18px;
  height: 2px;
  background: var(--c-accent);
  transform: rotate(45deg);
}

.nav-close-icon::before {
  content: "";
  position: absolute;
  left: 0;
  top: 0;
  width: 18px;
  height: 2px;
  background: var(--c-accent);
  transform: rotate(90deg);
}

.to-top {
  position: fixed;
  right: 28px;
  bottom: 28px;
  z-index: 950;
  display: inline-flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  gap: 2px;
  width: 56px;
  height: 56px;
  background: var(--c-accent);
  border: 0;
  color: var(--c-white);
  box-shadow: 0 12px 30px rgba(255, 107, 44, 0.35);
  opacity: 0;
  visibility: hidden;
  transform: translateY(14px);
  transition: background 0.2s ease, transform 0.2s ease, opacity 0.2s ease, visibility 0.2s ease;
}

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

.to-top:hover {
  background: #ff5724;
}

.to-top-icon {
  font-size: 1.2rem;
  line-height: 1;
}

.to-top-text {
  font-size: 0.58rem;
  font-weight: 700;
  letter-spacing: 0.1em;
}

.site-footer {
  flex-shrink: 0;
  background: var(--c-primary);
  color: rgba(255, 255, 255, 0.74);
  position: relative;
}

.footer-accent {
  height: 4px;
  background: linear-gradient(90deg, var(--c-accent) 0, var(--c-accent) 32%, transparent 32%);
}

.footer-inner {
  display: grid;
  grid-template-columns: 2fr 1.2fr 1fr 1.4fr;
  gap: 48px;
  max-width: var(--content-max);
  margin: 0 auto;
  padding: 64px clamp(16px, 4vw, 56px) 48px;
}

.footer-brand {
  display: flex;
  flex-direction: column;
  align-items: flex-start;
  gap: 18px;
}

.footer-logo {
  color: var(--c-white);
  text-decoration: none;
  font-size: 1.32rem;
  font-weight: 900;
  letter-spacing: 0.04em;
  line-height: 1.2;
}

.footer-logo span {
  color: var(--c-accent);
  margin: 0 4px;
}

.footer-note {
  margin: 0;
  max-width: 34em;
  font-size: 0.92rem;
  color: rgba(255, 255, 255, 0.62);
}

.footer-trust {
  display: flex;
  flex-wrap: wrap;
  gap: 12px 24px;
}

.trust-status {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  color: rgba(255, 255, 255, 0.8);
  font-size: 0.82rem;
  font-family: var(--font-mono);
}

.status-dot {
  width: 8px;
  height: 8px;
  border-radius: 50%;
  background: var(--c-green);
  box-shadow: 0 0 0 4px rgba(31, 168, 107, 0.16);
}

.status-dot-accent {
  background: var(--c-accent);
  box-shadow: 0 0 0 4px rgba(255, 107, 44, 0.18);
}

.footer-column {
  display: flex;
  flex-direction: column;
  align-items: flex-start;
  gap: 12px;
}

.footer-heading {
  margin: 0 0 6px;
  padding-left: 12px;
  border-left: 3px solid var(--c-accent);
  color: var(--c-white);
  font-size: 0.82rem;
  font-weight: 900;
  letter-spacing: 0.16em;
  text-transform: uppercase;
}

.footer-column a {
  color: rgba(255, 255, 255, 0.78);
  text-decoration: none;
  font-size: 0.92rem;
  transition: color 0.2s ease, transform 0.2s ease;
}

.footer-column a:hover {
  color: var(--c-accent);
  transform: translateX(3px);
}

.footer-address {
  display: flex;
  flex-direction: column;
  gap: 10px;
  font-style: normal;
  font-size: 0.9rem;
  color: rgba(255, 255, 255, 0.7);
}

.footer-bottom {
  border-top: 1px solid rgba(255, 255, 255, 0.12);
  padding: 18px 0;
}

.footer-bottom-inner {
  display: flex;
  flex-wrap: wrap;
  gap: 12px 30px;
  max-width: var(--content-max);
  margin: 0 auto;
  padding: 0 clamp(16px, 4vw, 56px);
  font-size: 0.75rem;
  color: rgba(255, 255, 255, 0.5);
}

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

.grid-2 > * {
  grid-column: span 6;
}

.grid-3 > * {
  grid-column: span 4;
}

.g-col-4 {
  grid-column: span 4;
}

.g-col-5 {
  grid-column: span 5;
}

.g-col-6 {
  grid-column: span 6;
}

.g-col-7 {
  grid-column: span 7;
}

.g-col-8 {
  grid-column: span 8;
}

.panel {
  position: relative;
  background: var(--c-white);
  border: 1px solid var(--c-line);
  box-shadow: var(--shadow-sm);
  padding: clamp(24px, 4vw, 42px);
}

.panel::before {
  content: "";
  position: absolute;
  top: -1px;
  left: -1px;
  width: 42px;
  height: 42px;
  border-top: 4px solid var(--c-accent);
  border-left: 4px solid var(--c-accent);
  pointer-events: none;
}

.panel.is-dark {
  background: var(--c-primary-soft);
  border-color: rgba(255, 255, 255, 0.14);
  color: rgba(255, 255, 255, 0.82);
}

.panel.is-dark h1,
.panel.is-dark h2,
.panel.is-dark h3,
.panel.is-dark h4 {
  color: var(--c-white);
}

.diagonal-panel {
  position: relative;
  background: var(--c-primary-soft);
  color: rgba(255, 255, 255, 0.86);
  padding: clamp(28px, 5vw, 56px);
}

.diagonal-panel::before {
  content: "";
  position: absolute;
  inset: 0;
  background: linear-gradient(135deg, rgba(255, 107, 44, 0.95) 0, rgba(255, 107, 44, 0.95) 10px, transparent 10px);
  pointer-events: none;
}

.diagonal-panel > * {
  position: relative;
  z-index: 1;
}

.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 10px;
  padding: 13px 24px;
  border: 1px solid transparent;
  font-weight: 700;
  font-size: 0.92rem;
  line-height: 1.2;
  text-decoration: none;
  background: transparent;
  transition: background 0.22s ease, border-color 0.22s ease, transform 0.22s ease;
}

.btn-primary {
  background: var(--c-accent);
  color: var(--c-white);
  box-shadow: 0 10px 26px rgba(255, 107, 44, 0.28);
}

.btn-primary:hover {
  background: #ff5724;
  transform: translateY(-2px);
}

.btn-outline {
  border-color: rgba(255, 255, 255, 0.46);
  color: var(--c-white);
}

.btn-outline:hover {
  border-color: var(--c-accent);
  color: var(--c-accent);
}

.tag {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  padding: 4px 12px;
  border: 1px solid var(--c-line);
  background: transparent;
  font-family: var(--font-mono);
  font-size: 0.72rem;
  font-weight: 700;
  letter-spacing: 0.08em;
  text-transform: uppercase;
  color: var(--c-muted);
}

.tag-accent {
  color: var(--c-accent);
  border-color: rgba(255, 107, 44, 0.42);
  background: rgba(255, 107, 44, 0.08);
}

.tag-success {
  color: var(--c-green);
  border-color: rgba(31, 168, 107, 0.4);
  background: rgba(31, 168, 107, 0.08);
}

.tag-danger {
  color: var(--c-red);
  border-color: rgba(214, 64, 64, 0.38);
  background: rgba(214, 64, 64, 0.08);
}

.breadcrumb {
  padding: 20px 0 8px;
  font-size: 0.82rem;
  color: var(--c-muted);
}

.breadcrumb-list {
  list-style: none;
  display: flex;
  flex-wrap: wrap;
  gap: 8px;
}

.breadcrumb-item {
  display: inline-flex;
  align-items: center;
}

.breadcrumb-item + .breadcrumb-item::before {
  content: "/";
  margin-right: 8px;
  color: var(--c-line);
}

.breadcrumb-item a {
  color: var(--c-muted);
  text-decoration: none;
}

.breadcrumb-item a:hover {
  color: var(--c-accent);
}

.breadcrumb-current {
  color: var(--c-primary);
  font-weight: 700;
}

.data-stat {
  display: flex;
  flex-direction: column;
  gap: 6px;
  padding-left: 18px;
  border-left: 3px solid var(--c-accent);
}

.stat-value {
  font-family: var(--font-mono);
  font-size: clamp(1.9rem, 4vw, 3.1rem);
  font-weight: 700;
  line-height: 1;
  letter-spacing: -0.03em;
}

.stat-value.is-accent {
  color: var(--c-accent);
}

.stat-value.is-green {
  color: var(--c-green);
}

.stat-label {
  font-size: 0.8rem;
  font-weight: 700;
  letter-spacing: 0.1em;
  text-transform: uppercase;
  color: var(--c-muted);
}

.section-dark .stat-label {
  color: rgba(255, 255, 255, 0.62);
}

.media-frame {
  position: relative;
  overflow: hidden;
  aspect-ratio: 16 / 9;
  background: var(--c-primary-soft);
  border: 1px solid rgba(255, 255, 255, 0.14);
}

.media-frame.is-tall {
  aspect-ratio: 4 / 5;
}

.media-frame.is-wide {
  aspect-ratio: 21 / 9;
}

.image-placeholder {
  position: relative;
  display: flex;
  align-items: flex-end;
  min-height: 240px;
  padding: 18px;
  overflow: hidden;
  background:
    linear-gradient(135deg, rgba(255, 107, 44, 0.22), transparent 38%),
    radial-gradient(160% 100% at 80% 0%, rgba(255, 255, 255, 0.12), transparent 52%),
    linear-gradient(145deg, var(--c-primary) 0%, var(--c-primary-soft) 100%);
  border: 1px solid rgba(255, 255, 255, 0.14);
}

.image-placeholder::after {
  content: "SPORTS DATA / 赛后统计";
  position: absolute;
  right: 16px;
  bottom: 12px;
  font-family: var(--font-mono);
  font-size: 0.64rem;
  letter-spacing: 0.26em;
  color: rgba(255, 255, 255, 0.3);
  pointer-events: none;
}

.image-object {
  position: absolute;
  inset: 0;
  width: 100%;
  height: 100%;
  object-fit: cover;
}

.image-caption {
  position: relative;
  z-index: 1;
  margin-top: auto;
  max-width: 80%;
  padding: 8px 12px;
  background: rgba(10, 27, 61, 0.72);
  border-left: 3px solid var(--c-accent);
  color: var(--c-white);
  font-size: 0.78rem;
}

.research-board {
  border: 1px solid var(--c-line);
  background: var(--c-white);
  box-shadow: var(--shadow-sm);
}

.research-summary {
  padding: clamp(22px, 4vw, 36px);
  border-bottom: 1px solid var(--c-line);
}

.proof-list {
  list-style: none;
  counter-reset: proof;
  display: grid;
  gap: 10px;
  padding: 20px clamp(22px, 4vw, 36px);
}

.proof-list li {
  counter-increment: proof;
  display: flex;
  align-items: baseline;
  gap: 14px;
  padding: 12px 0;
  border-bottom: 1px solid var(--c-line);
  font-size: 0.92rem;
}

.proof-list li::before {
  content: counter(proof, decimal-leading-zero);
  font-family: var(--font-mono);
  font-size: 0.7rem;
  color: var(--c-accent);
}

.term-chip {
  display: inline-flex;
  padding: 4px 12px;
  margin: 0 8px 8px 0;
  border: 1px solid var(--c-line);
  background: var(--c-bg);
  font-size: 0.78rem;
  color: var(--c-muted);
}

.further-reading {
  padding: 16px clamp(22px, 4vw, 36px) 32px;
}

.further-reading a {
  color: var(--c-primary);
  font-weight: 700;
  text-decoration: none;
  border-bottom: 2px solid var(--c-accent);
}

@media (max-width: 1100px) {
  .footer-inner {
    grid-template-columns: 1.4fr 1fr 1fr;
  }

  .footer-contact {
    grid-column: span 3;
  }
}

@media (max-width: 900px) {
  .site-nav {
    display: block;
    position: fixed;
    top: 0;
    right: 0;
    height: 100vh;
    width: min(84vw, 360px);
    padding: 96px 28px 32px;
    background: var(--c-primary);
    box-shadow: -30px 0 60px rgba(0, 0, 0, 0.3);
    transform: translateX(104%);
    visibility: hidden;
    transition: transform 0.25s ease, visibility 0.25s ease;
    z-index: 1200;
    overflow-y: auto;
  }

  .site-nav[data-open] {
    transform: translateX(0);
    visibility: visible;
  }

  .nav-close {
    display: inline-flex;
    margin-bottom: 24px;
  }

  .nav-links {
    flex-direction: column;
    align-items: stretch;
    gap: 0;
  }

  .nav-link {
    padding: 15px 0;
    border-bottom: 1px solid rgba(255, 255, 255, 0.12);
    font-size: 1.05rem;
  }

  .nav-link::after {
    display: none;
  }

  .nav-link[aria-current="page"] {
    color: var(--c-accent);
    border-left: 4px solid var(--c-accent);
    padding-left: 14px;
  }

  .nav-toggle {
    display: inline-flex;
  }

  .header-ribbon {
    padding: 8px 16px;
  }

  .brand-sub {
    display: none;
  }

  .quick-nav {
    gap: 6px;
  }

  .quick-link {
    font-size: 0.7rem;
    padding: 6px 4px;
  }

  .quick-index {
    font-size: 0.55rem;
  }

  .header-navbar {
    min-height: 48px;
    padding: 0 16px;
  }

  .grid {
    gap: 16px;
  }

  .grid-2 > *,
  .grid-3 > *,
  .g-col-4,
  .g-col-5,
  .g-col-6,
  .g-col-7,
  .g-col-8 {
    grid-column: span 12;
  }

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

  .footer-brand {
    grid-column: span 2;
  }

  .footer-contact {
    grid-column: span 2;
  }

  .to-top {
    right: 18px;
    bottom: 18px;
    width: 50px;
    height: 50px;
  }
}

@media (max-width: 640px) {
  .header-ribbon {
    flex-direction: column;
    align-items: stretch;
    gap: 4px;
  }

  .brand {
    align-self: flex-start;
  }

  .quick-nav {
    width: 100%;
    justify-content: space-between;
  }

  .quick-link {
    flex: 1;
    justify-content: center;
    border-right: 1px solid rgba(255, 255, 255, 0.14);
  }

  .quick-link:last-child {
    border-right: 0;
  }

  .footer-inner {
    grid-template-columns: 1fr;
    gap: 36px;
  }

  .footer-brand,
  .footer-contact {
    grid-column: span 1;
  }

  .footer-bottom-inner {
    gap: 8px 18px;
    font-size: 0.72rem;
  }
}

@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;
  }
}