/* ==========================================================================
   M6体育 · 共享 Site Kit  /assets/site.css
   坐标蓝图 · 切角面板 · 数据流动
   ========================================================================== */

/* ---------- 01 Design Tokens ---------- */
:root {
  --c-deep: #0B1B3A;
  --c-electric: #1E3A8A;
  --c-orange: #FF6B35;
  --c-lime: #C8FF00;
  --c-light: #F5F7FA;
  --c-dark: #081020;
  --c-white: #FFFFFF;
  --c-dim: #B0C4DE;
  --c-ink: #1A2B3C;
  --c-soft: #4A5C6E;
  --c-line: #3A5A8C;

  --font-heading: 'Rajdhani', 'Noto Sans SC', 'PingFang SC', 'Microsoft YaHei', 'Helvetica Neue', Arial, sans-serif;
  --font-body: 'Inter', 'Noto Sans SC', 'PingFang SC', 'Microsoft YaHei', 'Helvetica Neue', Arial, sans-serif;

  --container-w: min(1180px, 92vw);
  --header-h: 76px;
  --ease-out: cubic-bezier(.22, .68, 0, 1);
  --clip-corner: polygon(0 0, 100% 0, calc(100% - 14px) 100%, 0 100%);
}

/* ---------- 02 Reset & Base ---------- */
*,
*::before,
*::after {
  box-sizing: border-box;
}

html {
  -webkit-text-size-adjust: 100%;
  scroll-behavior: smooth;
  scroll-padding-top: calc(var(--header-h) + 14px);
}

body {
  margin: 0;
  min-height: 100vh;
  overflow-x: hidden;
  background: var(--c-light);
  color: var(--c-ink);
  font-family: var(--font-body);
  font-weight: 400;
  font-size: 16px;
  line-height: 1.6;
}

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

button,
input,
select,
textarea {
  font: inherit;
}

ul,
ol {
  margin: 0;
  padding: 0;
  list-style: none;
}

h1,
h2,
h3,
h4,
p,
figure {
  margin: 0;
}

a {
  color: inherit;
}

::selection {
  background: var(--c-lime);
  color: var(--c-dark);
}

:focus-visible {
  outline: 3px solid var(--c-lime);
  outline-offset: 3px;
}

/* ---------- 03 Typography ---------- */
h1,
h2,
h3,
h4 {
  font-family: var(--font-heading);
  font-weight: 700;
  font-style: italic;
  letter-spacing: .02em;
  line-height: 1.15;
  color: var(--c-ink);
}

h1 {
  font-size: clamp(2.375rem, 5vw, 4rem);
  line-height: 1.08;
  margin-bottom: 16px;
}

h2 {
  font-size: clamp(1.75rem, 3.2vw, 2.5rem);
  margin-bottom: 14px;
}

h3 {
  font-size: 1.5rem;
  margin-bottom: 12px;
}

p {
  margin-bottom: 1em;
}

/* ---------- 04 Shared Layout ---------- */
.site-container {
  width: var(--container-w);
  margin-inline: auto;
}

.site-main {
  min-height: 60vh;
}

#main-content {
  scroll-margin-top: calc(var(--header-h) + 8px);
}

.surface-grid {
  background-image:
    linear-gradient(to right, rgba(30, 58, 138, .07) 1px, transparent 1px),
    linear-gradient(to bottom, rgba(30, 58, 138, .07) 1px, transparent 1px);
  background-size: 32px 32px;
}

/* ---------- 05 Buttons ---------- */
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: .5rem;
  min-height: 44px;
  padding: .7rem 1.4rem;
  border: 0;
  background: none;
  cursor: pointer;
  font-family: var(--font-heading);
  font-weight: 700;
  font-style: italic;
  font-size: 1rem;
  line-height: 1;
  letter-spacing: .06em;
  text-decoration: none;
  clip-path: polygon(0 0, calc(100% - 14px) 0, 100% 100%, 0 100%);
  transition: transform .2s var(--ease-out), background-color .2s ease, color .2s ease, box-shadow .2s ease;
}

.btn:hover {
  transform: translateY(-2px);
}

.btn:active {
  transform: translateY(0);
}

.btn--primary {
  background: var(--c-orange);
  color: var(--c-dark);
}

.btn--primary:hover {
  background: #ff8354;
}

.btn--lime {
  background: var(--c-lime);
  color: var(--c-dark);
}

.btn--lime:hover {
  background: #d9ff3b;
}

.btn--ghost {
  color: var(--c-white);
  box-shadow: inset 0 0 0 2px var(--c-line);
}

.btn--ghost:hover {
  color: var(--c-lime);
  box-shadow: inset 0 0 0 2px var(--c-lime);
}

/* ---------- 06 Breadcrumb ---------- */
.breadcrumb {
  margin: 26px 0 6px;
}

.breadcrumb ol {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 6px 0;
  font-family: var(--font-heading);
  font-size: .875rem;
  font-weight: 600;
  letter-spacing: .06em;
  color: var(--c-soft);
}

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

.breadcrumb li + li::before {
  content: '/';
  margin-inline: 12px;
  color: var(--c-line);
}

.breadcrumb a {
  color: var(--c-soft);
  text-decoration: none;
  transition: color .2s ease;
}

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

.breadcrumb [aria-current='page'] {
  color: var(--c-orange);
}

/* ---------- 07 Section Head ---------- */
.section-head {
  display: flex;
  align-items: baseline;
  flex-wrap: wrap;
  gap: 16px;
  margin-bottom: 28px;
}

.section-head__index {
  flex: 0 0 auto;
  padding: 6px 12px 4px;
  background: var(--c-lime);
  color: var(--c-dark);
  font-family: var(--font-heading);
  font-weight: 700;
  font-style: italic;
  font-size: clamp(1.25rem, 3vw, 1.75rem);
  line-height: 1;
  clip-path: polygon(0 0, 100% 0, calc(100% - 10px) 100%, 0 100%);
}

.section-head__title {
  margin: 0;
}

.section-head__note {
  margin-inline-start: auto;
  font-family: var(--font-heading);
  font-size: .8125rem;
  letter-spacing: .12em;
  color: var(--c-soft);
}

/* ---------- 08 Grid ---------- */
.grid {
  display: grid;
  gap: 24px;
}

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

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

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

/* ---------- 09 Media Frame ---------- */
.media-frame {
  position: relative;
  overflow: hidden;
  background-color: var(--c-deep);
  clip-path: polygon(0 0, 100% 0, calc(100% - 20px) 100%, 0 100%);
}

.media-frame::after {
  content: '';
  position: absolute;
  inset: 0;
  z-index: 1;
  pointer-events: none;
  background-image: linear-gradient(135deg, rgba(200, 255, 0, .1) 25%, transparent 25%, transparent 75%, rgba(200, 255, 0, .1) 75%);
  background-size: 18px 18px;
  mix-blend-mode: screen;
}

.media-frame img {
  position: relative;
  z-index: 0;
  width: 100%;
  height: 100%;
  object-fit: cover;
}

.media-frame--16x9 {
  aspect-ratio: 16 / 9;
}

.media-frame--4x3 {
  aspect-ratio: 4 / 3;
}

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

/* ---------- 10 Prose ---------- */
.prose {
  font-size: 1rem;
  line-height: 1.75;
  color: var(--c-ink);
}

.prose p {
  margin-bottom: 1.2em;
}

.prose a {
  color: var(--c-electric);
  text-decoration-thickness: 2px;
  text-underline-offset: 4px;
}

.prose h2,
.prose h3 {
  margin-top: 2em;
}

.prose ul {
  list-style: disc;
  padding-left: 1.4em;
}

.prose ol {
  list-style: decimal;
  padding-left: 1.4em;
}

.prose li {
  margin-bottom: .4em;
}

/* ---------- 11 Scroll Reveal ---------- */
[data-scroll-reveal] {
  opacity: 0;
  transform: translateY(24px);
  transition: opacity .5s ease, transform .5s var(--ease-out);
  will-change: opacity, transform;
}

[data-scroll-reveal].is-visible {
  opacity: 1;
  transform: none;
}

/* ---------- 12 Header ---------- */
.skip-link {
  position: fixed;
  top: -120px;
  inset-inline-start: 16px;
  z-index: 300;
  padding: 10px 18px;
  background: var(--c-lime);
  color: var(--c-dark);
  font-family: var(--font-heading);
  font-weight: 700;
  font-size: .9375rem;
  letter-spacing: .08em;
  text-decoration: none;
  clip-path: var(--clip-corner);
  transition: top .22s ease;
}

.skip-link:focus-visible {
  top: 16px;
}

.site-header {
  position: sticky;
  top: 0;
  z-index: 100;
  isolation: isolate;
  background: var(--c-deep);
  color: var(--c-white);
  border-bottom: 1px solid var(--c-line);
  box-shadow: 0 8px 28px rgba(8, 16, 32, .32);
}

.site-header::before {
  content: '';
  position: absolute;
  inset: 0;
  z-index: -1;
  pointer-events: none;
  background-image:
    linear-gradient(to right, rgba(58, 90, 140, .3) 1px, transparent 1px),
    linear-gradient(to bottom, rgba(58, 90, 140, .3) 1px, transparent 1px);
  background-size: 36px 36px;
}

.site-header__progress {
  position: absolute;
  top: 0;
  left: 0;
  right: 0;
  height: 3px;
  z-index: 3;
  background: rgba(58, 90, 140, .38);
  pointer-events: none;
}

.site-header__progress-bar {
  display: block;
  height: 100%;
  width: 0;
  background: linear-gradient(90deg, var(--c-orange) 0%, var(--c-lime) 100%);
  will-change: width;
}

.site-header__inner {
  position: relative;
  z-index: 1;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 18px;
  width: var(--container-w);
  min-height: var(--header-h);
  margin-inline: auto;
}

.site-header__brand {
  position: relative;
  display: inline-flex;
  align-items: center;
  gap: 12px;
  flex: 0 0 auto;
  padding-block: 20px;
  text-decoration: none;
}

.site-header__brand::after {
  content: '';
  position: absolute;
  left: calc(100% + 4px);
  top: 50%;
  width: 12px;
  height: 2px;
  background: repeating-linear-gradient(90deg, var(--c-lime) 0 3px, transparent 3px 6px);
  opacity: .75;
}

.site-header__brand-name {
  font-family: var(--font-heading);
  font-style: italic;
  font-weight: 700;
  font-size: 1.75rem;
  line-height: 1;
  letter-spacing: .02em;
  color: var(--c-orange);
}

.site-header__brand-name em {
  font-style: normal;
  color: var(--c-white);
  margin-inline-start: 3px;
}

.site-header__brand-meta {
  font-family: var(--font-heading);
  font-size: .625rem;
  font-weight: 700;
  letter-spacing: .24em;
  color: var(--c-lime);
  border: 1px solid rgba(200, 255, 0, .45);
  padding: 4px 7px 3px;
  transform: skewX(-8deg);
  transition: background .2s ease, color .2s ease;
}

.site-header__brand:hover .site-header__brand-meta {
  background: var(--c-lime);
  color: var(--c-dark);
}

.site-header__coord {
  display: inline-flex;
  align-items: center;
  gap: 10px;
  margin: 0;
  padding-inline: 20px;
  border-inline: 1px solid var(--c-line);
  font-family: var(--font-heading);
  font-size: .75rem;
  font-weight: 600;
  letter-spacing: .2em;
  white-space: nowrap;
  color: var(--c-dim);
}

.site-header__coord-pulse {
  flex: 0 0 8px;
  width: 8px;
  height: 8px;
  background: var(--c-lime);
  clip-path: polygon(50% 0, 100% 50%, 50% 100%, 0 50%);
  animation: coord-pulse 2s ease-in-out infinite;
}

@keyframes coord-pulse {
  0%,
  100% {
    transform: scale(1);
    opacity: 1;
  }
  50% {
    transform: scale(1.5);
    opacity: .5;
  }
}

.site-header__nav {
  position: relative;
  z-index: 1;
  display: flex;
  align-items: center;
}

.site-header__nav-list {
  display: flex;
  align-items: center;
  gap: 2px;
}

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

.site-header__nav-link {
  position: relative;
  display: inline-flex;
  align-items: baseline;
  gap: 6px;
  padding: 26px 11px 22px;
  font-family: var(--font-heading);
  font-weight: 700;
  font-size: .9375rem;
  line-height: 1.2;
  letter-spacing: .08em;
  white-space: nowrap;
  color: var(--c-white);
  text-decoration: none;
  transition: color .2s ease;
}

.site-header__nav-link::after {
  content: '';
  position: absolute;
  left: 11px;
  right: 11px;
  bottom: 16px;
  height: 2px;
  background: var(--c-lime);
  transform: scaleX(0);
  transform-origin: left center;
  transition: transform .25s var(--ease-out);
}

.site-header__nav-link:hover,
.site-header__nav-link:focus-visible {
  color: var(--c-lime);
}

.site-header__nav-link:hover::after,
.site-header__nav-link:focus-visible::after,
.site-header__nav-link[aria-current='page']::after {
  transform: scaleX(1);
}

.site-header__nav-link[aria-current='page'] {
  color: var(--c-lime);
}

.site-header__nav-index {
  font-size: .625rem;
  font-weight: 700;
  letter-spacing: .12em;
  color: var(--c-lime);
  opacity: .7;
  transition: color .2s ease, opacity .2s ease;
}

.site-header__nav-link:hover .site-header__nav-index,
.site-header__nav-link[aria-current='page'] .site-header__nav-index {
  color: var(--c-orange);
  opacity: 1;
}

.site-header__toggle {
  display: none;
  position: relative;
  z-index: 2;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  gap: 5px;
  width: 48px;
  height: 48px;
  padding: 0;
  border: 1px solid var(--c-line);
  border-radius: 0;
  background: transparent;
  cursor: pointer;
  transition: border-color .2s ease;
}

.site-header__toggle:hover {
  border-color: var(--c-lime);
}

.site-header__toggle-line {
  display: block;
  width: 20px;
  height: 2px;
  background: var(--c-white);
  transition: transform .24s ease, opacity .18s ease;
}

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

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

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

.site-header__scrim {
  display: none;
  position: fixed;
  inset: 0;
  z-index: 110;
  background: rgba(8, 16, 32, .58);
  backdrop-filter: blur(2px);
}

/* ---------- 13 Footer ---------- */
.site-footer {
  position: relative;
  margin-top: 88px;
  background: var(--c-dark);
  color: var(--c-white);
  overflow: hidden;
}

.site-footer::before {
  content: '';
  position: absolute;
  inset: 0;
  pointer-events: none;
  background-image:
    linear-gradient(to right, rgba(58, 90, 140, .18) 1px, transparent 1px),
    linear-gradient(to bottom, rgba(58, 90, 140, .18) 1px, transparent 1px);
  background-size: 44px 44px;
}

.site-footer::after {
  content: '';
  position: absolute;
  top: 0;
  left: 8%;
  width: 128px;
  height: 5px;
  background: var(--c-lime);
  clip-path: polygon(0 0, 100% 0, calc(100% - 16px) 100%, 16px 100%);
  pointer-events: none;
}

.site-footer__inner {
  position: relative;
  width: var(--container-w);
  margin-inline: auto;
  padding-block: 60px 26px;
}

.site-footer__grid {
  display: grid;
  grid-template-columns: 1.6fr 1fr 1.2fr;
  gap: 44px 48px;
  padding-bottom: 36px;
  border-bottom: 1px solid var(--c-line);
}

.site-footer__brand {
  display: flex;
  align-items: baseline;
  gap: 4px;
  margin-bottom: 12px;
  font-family: var(--font-heading);
  font-style: italic;
  font-weight: 700;
  font-size: 2.125rem;
  line-height: 1;
  letter-spacing: .04em;
}

.site-footer__brand span {
  color: var(--c-orange);
}

.site-footer__brand em {
  font-style: normal;
  color: var(--c-white);
}

.site-footer__tagline {
  display: inline-flex;
  align-items: center;
  margin-bottom: 16px;
  padding: 5px 12px 4px;
  background: var(--c-lime);
  color: var(--c-dark);
  font-family: var(--font-heading);
  font-weight: 700;
  font-style: italic;
  font-size: .75rem;
  letter-spacing: .14em;
  transform: skewX(-8deg);
  box-shadow: 4px 4px 0 rgba(200, 255, 0, .16);
}

.site-footer__trust {
  max-width: 34em;
  margin: 0;
  font-size: .9375rem;
  line-height: 1.7;
  color: var(--c-dim);
}

.site-footer__heading {
  display: flex;
  align-items: baseline;
  gap: 8px;
  margin-bottom: 18px;
  font-family: var(--font-heading);
  font-style: italic;
  font-weight: 700;
  font-size: 1.0625rem;
  letter-spacing: .16em;
  text-transform: uppercase;
  color: var(--c-white);
}

.site-footer__heading::before {
  content: '/';
  color: var(--c-lime);
  font-size: 1.25rem;
  line-height: 1;
}

.site-footer__links,
.site-footer__contact {
  display: grid;
  gap: 8px;
}

.site-footer__links a {
  display: inline-flex;
  align-items: center;
  gap: 10px;
  padding: 4px 0;
  color: var(--c-dim);
  font-size: .9375rem;
  text-decoration: none;
  transition: color .2s ease;
}

.site-footer__links a::before {
  content: '';
  flex: 0 0 12px;
  height: 2px;
  background: var(--c-orange);
  transition: transform .2s ease, background-color .2s ease;
}

.site-footer__links a:hover {
  color: var(--c-lime);
}

.site-footer__links a:hover::before {
  transform: translateX(4px);
  background: var(--c-lime);
}

.site-footer__contact li {
  display: flex;
  align-items: center;
  gap: 10px;
  padding: 4px 0;
  color: var(--c-dim);
  font-size: .9375rem;
}

.site-footer__contact li::before {
  content: '';
  flex: 0 0 12px;
  height: 2px;
  background: var(--c-lime);
}

.site-footer__contact li a {
  color: inherit;
  text-decoration: none;
  transition: color .2s ease;
}

.site-footer__contact li a:hover {
  color: var(--c-lime);
}

.site-footer__meta {
  display: flex;
  flex-wrap: wrap;
  justify-content: space-between;
  gap: 8px 28px;
  padding-top: 20px;
  font-family: var(--font-heading);
  font-size: .8125rem;
  font-weight: 600;
  letter-spacing: .1em;
  color: var(--c-dim);
}

/* ---------- 14 Responsive ---------- */
@media (max-width: 1180px) {
  .grid--4 {
    grid-template-columns: repeat(2, 1fr);
  }

  .site-header__brand-name {
    font-size: 1.5rem;
  }

  .site-header__nav-link {
    padding-inline: 8px;
    font-size: .875rem;
  }
}

@media (max-width: 1080px) {
  .site-header__coord {
    display: none;
  }

  .site-header__brand-meta {
    display: none;
  }

  .site-header__brand::after {
    display: none;
  }
}

@media (max-width: 960px) {
  :root {
    --header-h: 64px;
  }

  .site-header__inner {
    min-height: var(--header-h);
    gap: 12px;
  }

  .site-header__brand {
    padding-block: 14px;
  }

  .site-header__toggle {
    display: inline-flex;
    margin-inline-start: auto;
  }

  [data-nav] {
    display: block;
    position: fixed;
    top: 0;
    right: 0;
    z-index: 120;
    width: min(80vw, 360px);
    height: 100vh;
    height: 100dvh;
    overflow-y: auto;
    background: var(--c-dark);
    border-left: 1px solid var(--c-line);
    box-shadow: -20px 0 44px rgba(8, 16, 32, .46);
    transform: translateX(105%);
    visibility: hidden;
    transition: transform .3s var(--ease-out), visibility .3s linear;
  }

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

  [data-nav]::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    width: 5px;
    height: 100%;
    background: linear-gradient(180deg, var(--c-orange), var(--c-lime));
  }

  [data-nav]::after {
    content: 'NAV / 坐标索引';
    position: absolute;
    top: 24px;
    left: 26px;
    font-family: var(--font-heading);
    font-size: .625rem;
    font-weight: 700;
    letter-spacing: .3em;
    color: var(--c-dim);
  }

  .site-header__nav-list {
    flex-direction: column;
    align-items: stretch;
    gap: 0;
    padding: 84px 22px 30px;
  }

  .site-header__nav-item {
    border-bottom: 1px dashed rgba(58, 90, 140, .7);
  }

  .site-header__nav-item:first-child {
    border-top: 1px dashed rgba(58, 90, 140, .7);
  }

  .site-header__nav-link {
    width: 100%;
    align-items: center;
    justify-content: space-between;
    padding: 16px 6px;
    font-size: 1.0625rem;
  }

  .site-header__nav-link::after {
    display: none;
  }

  .site-header__nav-label {
    order: 1;
  }

  .site-header__nav-index {
    order: 2;
    font-size: .6875rem;
  }

  .site-header__scrim {
    display: block;
    opacity: 0;
    visibility: hidden;
    transition: opacity .28s ease, visibility .28s ease;
  }

  .site-header__scrim[data-open] {
    opacity: 1;
    visibility: visible;
  }

  .grid--3 {
    grid-template-columns: 1fr 1fr;
  }
}

@media (max-width: 760px) {
  .site-footer__grid {
    grid-template-columns: 1fr 1fr;
    gap: 32px 24px;
  }

  .site-footer__block--brand {
    grid-column: 1 / -1;
  }
}

@media (max-width: 560px) {
  .grid--2,
  .grid--3,
  .grid--4 {
    grid-template-columns: 1fr;
  }

  .section-head {
    flex-wrap: wrap;
    gap: 10px 14px;
  }

  .section-head__note {
    margin-inline-start: 0;
    width: 100%;
  }

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

/* ---------- 15 Reduced Motion ---------- */
@media (prefers-reduced-motion: reduce) {
  html {
    scroll-behavior: auto;
  }

  *,
  *::before,
  *::after {
    animation-duration: .01ms !important;
    animation-iteration-count: 1 !important;
    transition-duration: .01ms !important;
    transition-delay: 0ms !important;
  }

  [data-scroll-reveal] {
    opacity: 1;
    transform: none;
  }
}