/* ==========================================================================
   大江体育 / site.css
   共享样式：reset、变量、中文排版、头部、页脚、通用组件
   ========================================================================== */

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

/* ---------------------------------- Variables ----------------------------- */
:root {
  --color-red: #E60012;
  --color-blue: #0072BC;
  --color-black: #0A0A0A;
  --color-silver: #C0C0C0;
  --color-fog: #F5F5F5;
  --color-smoke: #333333;
  --color-white: #FFFFFF;
  --color-coolgray: #8A8A8A;

  --font-sans: 'Noto Sans SC', 'PingFang SC', 'Hiragino Sans GB',
               'Microsoft YaHei', 'Heiti SC', sans-serif;
  --font-mono: 'IBM Plex Mono', 'SF Mono', 'JetBrains Mono',
               'Cascadia Mono', Consolas, monospace;

  --header-w: 280px;
  --container-w: 1200px;
  --space-1: 8px;
  --space-2: 16px;
  --space-3: 32px;
  --space-4: 64px;
  --space-5: 96px;
}

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

body {
  font-family: var(--font-sans);
  font-size: 16px;
  line-height: 1.8;
  color: var(--color-smoke);
  background-color: var(--color-white);
  background-image:
    linear-gradient(rgba(10, 10, 10, 0.04) 1px, transparent 1px),
    linear-gradient(90deg, rgba(10, 10, 10, 0.04) 1px, transparent 1px);
  background-size: 48px 48px;
  background-attachment: fixed;
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
}

@media (min-width: 768px) {
  body {
    margin-left: var(--header-w);
  }
}

@media (max-width: 767px) {
  body {
    background-attachment: scroll;
  }
}

h1, h2, h3, h4, h5, h6 {
  font-family: var(--font-sans);
  font-weight: 300;
  line-height: 1.3;
  color: var(--color-black);
  letter-spacing: 0.02em;
}

a {
  color: var(--color-blue);
  text-decoration: none;
}

a:hover {
  text-decoration: underline;
}

::selection {
  background: var(--color-red);
  color: var(--color-white);
}

:focus-visible {
  outline: 2px solid var(--color-blue);
  outline-offset: 2px;
}

/* ------------------------------- Skip link --------------------------------- */
.skip-link {
  position: fixed;
  top: -100px;
  left: 16px;
  z-index: 2000;
  padding: 12px 24px;
  background: var(--color-red);
  color: var(--color-white);
  font-weight: 700;
  font-size: 14px;
  letter-spacing: 1px;
  text-decoration: none;
  transition: top 0.2s ease;
}

.skip-link:hover {
  text-decoration: none;
}

.skip-link:focus-visible {
  top: 8px;
  outline: 2px solid var(--color-white);
  outline-offset: -2px;
  box-shadow: 0 0 0 4px rgba(230, 0, 18, 0.4);
}

@media (max-width: 767px) {
  .skip-link:focus-visible {
    top: 60px;
  }
}

/* ------------------------------- Progress bar ----------------------------- */
.progress-track {
  position: fixed;
  top: 0;
  left: 0;
  z-index: 1600;
  width: 100%;
  height: 3px;
  background: rgba(192, 192, 192, 0.25);
  pointer-events: none;
}

.progress-bar {
  width: 0%;
  height: 100%;
  background: var(--color-red);
  transition: width 0.1s linear;
}

/* -------------------------------- Header ---------------------------------- */
.site-header {
  position: fixed;
  top: 0;
  left: 0;
  z-index: 1000;
  width: var(--header-w);
  height: 100vh;
  background: var(--color-black);
  color: var(--color-white);
  border-right: 1px solid rgba(192, 192, 192, 0.25);
}

.header-inner {
  display: flex;
  flex-direction: column;
  height: 100%;
  overflow-y: auto;
  overflow-x: hidden;
}

/* Brand */
.brand {
  display: flex;
  align-items: center;
  gap: 14px;
  padding: 28px 24px 20px;
  text-decoration: none;
}

.brand:hover {
  text-decoration: none;
}

.brand-mark {
  display: flex;
  align-items: center;
  justify-content: center;
  flex-shrink: 0;
  width: 48px;
  height: 48px;
  background: var(--color-red);
  color: var(--color-white);
  font-size: 15px;
  font-weight: 700;
  letter-spacing: 2px;
  line-height: 1;
}

.brand-text {
  display: flex;
  flex-direction: column;
  min-width: 0;
}

.brand-name {
  font-size: 20px;
  font-weight: 100;
  letter-spacing: 6px;
  color: var(--color-white);
  white-space: nowrap;
  line-height: 1.2;
}

.brand-tagline {
  font-size: 11px;
  letter-spacing: 2px;
  color: var(--color-silver);
  white-space: nowrap;
  margin-top: 4px;
}

.header-divider {
  height: 1px;
  margin: 0 24px;
  background: linear-gradient(90deg, var(--color-red) 32px, rgba(192, 192, 192, 0.25) 32px);
}

/* Navigation */
.site-nav {
  flex: 1;
  padding: 24px 0;
}

.nav-list {
  list-style: none;
}

.nav-item + .nav-item .nav-link {
  border-top: 1px solid rgba(192, 192, 192, 0.12);
}

.nav-link {
  display: flex;
  align-items: center;
  gap: 14px;
  padding: 13px 24px;
  color: var(--color-silver);
  text-decoration: none;
  font-size: 15px;
  font-weight: 400;
  letter-spacing: 1px;
  border-left: 2px solid transparent;
  transition: background 0.2s ease, color 0.2s ease, border-color 0.2s ease;
}

.nav-link:hover {
  color: var(--color-white);
  background: rgba(255, 255, 255, 0.04);
  text-decoration: none;
}

.nav-link[aria-current="page"] {
  color: var(--color-red);
  border-left-color: var(--color-red);
  background: linear-gradient(90deg, rgba(230, 0, 18, 0.12), transparent);
}

.nav-index {
  font-family: var(--font-mono);
  font-size: 12px;
  color: var(--color-coolgray);
  letter-spacing: 1px;
  min-width: 24px;
}

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

.nav-label {
  white-space: nowrap;
}

/* Header bottom */
.header-bottom {
  padding: 20px 24px 24px;
  border-top: 1px solid rgba(192, 192, 192, 0.15);
  position: relative;
}

.header-bottom::before {
  content: "";
  position: absolute;
  top: -1px;
  left: 24px;
  width: 32px;
  height: 1px;
  background: var(--color-red);
}

.header-contact,
.header-note {
  margin-top: 14px;
}

.header-contact-label,
.header-note-label {
  display: block;
  font-family: var(--font-mono);
  font-size: 10px;
  letter-spacing: 2px;
  text-transform: uppercase;
  color: var(--color-coolgray);
  margin-bottom: 2px;
}

.header-contact-value,
.header-note-value {
  display: block;
  color: var(--color-silver);
  font-size: 13px;
  word-break: break-all;
}

.header-coord {
  margin-top: 16px;
  padding-top: 12px;
  border-top: 1px dashed rgba(192, 192, 192, 0.2);
  font-family: var(--font-mono);
  font-size: 10px;
  color: var(--color-coolgray);
  letter-spacing: 1px;
}

/* ------------------------------- Nav toggle ------------------------------- */
.nav-toggle {
  display: none;
  align-items: center;
  gap: 10px;
  padding: 12px 16px;
  background: rgba(10, 10, 10, 0.92);
  border: 1px solid rgba(192, 192, 192, 0.3);
  border-radius: 0;
  cursor: pointer;
  color: var(--color-white);
  box-shadow: 0 2px 12px rgba(0, 0, 0, 0.35);
  z-index: 1400;
}

.nav-toggle:hover {
  background: #1A1A1A;
  border-color: var(--color-silver);
}

.nav-toggle-box {
  display: flex;
  flex-direction: column;
  gap: 5px;
  width: 22px;
}

.nav-toggle-bar {
  display: block;
  width: 22px;
  height: 2px;
  background: var(--color-silver);
  transition: transform 0.3s ease, opacity 0.3s ease;
}

.nav-toggle.is-active .nav-toggle-bar:nth-child(1) {
  transform: translateY(7px) rotate(45deg);
}

.nav-toggle.is-active .nav-toggle-bar:nth-child(2) {
  opacity: 0;
}

.nav-toggle.is-active .nav-toggle-bar:nth-child(3) {
  transform: translateY(-7px) rotate(-45deg);
}

.nav-toggle-label {
  font-size: 13px;
  letter-spacing: 2px;
  color: var(--color-silver);
}

/* Mobile overlay */
.nav-overlay {
  position: fixed;
  top: 0;
  left: 0;
  z-index: 900;
  width: 100%;
  height: 100%;
  background: rgba(10, 10, 10, 0.6);
  -webkit-backdrop-filter: blur(2px);
  backdrop-filter: blur(2px);
}

body.nav-is-open {
  overflow: hidden;
}

/* -------------------------------- Footer ---------------------------------- */
.site-footer {
  background: var(--color-black);
  color: var(--color-silver);
  border-top: 3px solid var(--color-red);
}

.footer-top {
  display: grid;
  grid-template-columns: 2fr 1fr 1fr 1.5fr;
  gap: 48px;
  max-width: var(--container-w);
  margin: 0 auto;
  padding: 64px 32px 48px;
}

.footer-brand-col .brand {
  padding: 0;
  margin-bottom: 20px;
}

.footer-brand-col .brand-mark {
  width: 44px;
  height: 44px;
  font-size: 14px;
}

.footer-brand-col .brand-name {
  font-size: 18px;
  letter-spacing: 5px;
}

.footer-brand-col .brand-tagline {
  font-size: 11px;
}

.trust-statement {
  font-size: 13px;
  color: var(--color-coolgray);
  line-height: 1.8;
  border-left: 2px solid var(--color-red);
  padding-left: 16px;
  margin-top: 16px;
}

.footer-heading {
  font-family: var(--font-mono);
  font-size: 12px;
  font-weight: 400;
  letter-spacing: 3px;
  text-transform: uppercase;
  color: var(--color-white);
  margin-bottom: 16px;
  padding-bottom: 8px;
  border-bottom: 1px solid rgba(192, 192, 192, 0.2);
  position: relative;
}

.footer-heading::after {
  content: "";
  position: absolute;
  left: 0;
  bottom: -1px;
  width: 32px;
  height: 1px;
  background: var(--color-red);
}

.footer-nav-list {
  list-style: none;
}

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

.footer-nav-list a {
  color: var(--color-silver);
  text-decoration: none;
  font-size: 14px;
  transition: color 0.2s ease, padding-left 0.2s ease;
}

.footer-nav-list a:hover {
  color: var(--color-white);
  padding-left: 4px;
  text-decoration: none;
}

.footer-contact-item {
  font-size: 14px;
  color: var(--color-silver);
  margin-bottom: 10px;
  line-height: 1.6;
  word-break: break-all;
}

.footer-bottom {
  max-width: var(--container-w);
  margin: 0 auto;
  padding: 24px 32px;
  border-top: 1px solid rgba(192, 192, 192, 0.15);
  display: flex;
  flex-wrap: wrap;
  gap: 12px 32px;
  justify-content: space-between;
  align-items: center;
}

.footer-copyright,
.footer-icp,
.footer-update {
  font-family: var(--font-mono);
  font-size: 12px;
  color: var(--color-coolgray);
}

.footer-update {
  display: inline-flex;
  align-items: center;
  gap: 8px;
}

.footer-update::before {
  content: "";
  display: inline-block;
  width: 6px;
  height: 6px;
  flex-shrink: 0;
  border-radius: 50%;
  background: var(--color-red);
}

/* ------------------------------- Layout containers ------------------------ */
.container {
  max-width: var(--container-w);
  margin: 0 auto;
  padding: 0 32px;
}

.container-narrow {
  max-width: 780px;
  margin: 0 auto;
  padding: 0 32px;
}

.section {
  padding: var(--space-5) 0;
}

.section-dark {
  background: var(--color-black);
  color: var(--color-white);
}

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

.section-light {
  background: var(--color-fog);
}

.section-label {
  display: inline-flex;
  align-items: center;
  gap: 12px;
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: 3px;
  text-transform: uppercase;
  color: var(--color-red);
  margin-bottom: 16px;
}

.section-label::before {
  content: "";
  width: 24px;
  height: 1px;
  background: var(--color-red);
}

/* ---------------------------------- Grid ---------------------------------- */
.grid {
  display: grid;
  gap: 32px;
}

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

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

/* -------------------------------- Buttons --------------------------------- */
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 8px;
  padding: 14px 36px;
  font-family: var(--font-sans);
  font-size: 15px;
  font-weight: 700;
  line-height: 1;
  text-decoration: none;
  border: 1px solid transparent;
  cursor: pointer;
  letter-spacing: 1px;
  transition: background 0.2s ease, color 0.2s ease,
              border-color 0.2s ease, transform 0.2s ease;
}

.btn:hover {
  text-decoration: none;
  transform: translateY(-1px);
}

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

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

.btn-primary:hover {
  background: #C50010;
  border-color: #C50010;
}

.btn-secondary {
  background: transparent;
  color: var(--color-black);
  border-color: var(--color-black);
}

.btn-secondary:hover {
  background: var(--color-black);
  color: var(--color-white);
}

.btn-silver {
  background: transparent;
  color: var(--color-white);
  border-color: var(--color-silver);
}

.btn-silver:hover {
  background: var(--color-silver);
  color: var(--color-black);
}

.btn-block {
  display: flex;
  width: 100%;
}

/* ------------------------------- Breadcrumb -------------------------------- */
.breadcrumb {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 8px;
  padding: 16px 0;
  font-family: var(--font-mono);
  font-size: 12px;
  color: var(--color-coolgray);
}

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

.breadcrumb a:hover {
  text-decoration: underline;
}

.breadcrumb-sep {
  color: var(--color-silver);
}

.breadcrumb-current {
  color: var(--color-smoke);
}

/* ------------------------------- Image frame ------------------------------- */
.img-frame {
  position: relative;
  display: block;
  overflow: hidden;
  background: var(--color-fog);
  border: 1px solid var(--color-silver);
}

.img-frame img {
  display: block;
  width: 100%;
  height: 100%;
  object-fit: cover;
}

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

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

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

.img-frame .img-caption {
  position: absolute;
  left: 0;
  bottom: 0;
  padding: 6px 14px;
  background: rgba(10, 10, 10, 0.8);
  color: var(--color-white);
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: 1px;
  z-index: 1;
}

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

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

/* ------------------------------ Responsive -------------------------------- */
@media (max-width: 991px) {
  .footer-top {
    grid-template-columns: 1fr 1fr;
  }

  .footer-brand-col {
    grid-column: 1 / -1;
  }

  .grid-cols-3 {
    grid-template-columns: repeat(2, 1fr);
  }
}

@media (max-width: 767px) {
  body {
    margin-left: 0;
  }

  .site-header {
    transform: translateX(-100%);
    transition: transform 0.35s ease,
                visibility 0s 0.35s;
    visibility: hidden;
  }

  .site-header[data-open] {
    transform: translateX(0);
    visibility: visible;
    box-shadow: 0 0 40px rgba(0, 0, 0, 0.5);
    transition: transform 0.35s ease;
  }

  .nav-toggle {
    display: flex;
    position: fixed;
    top: 12px;
    left: 12px;
  }

  .grid-cols-2,
  .grid-cols-3 {
    grid-template-columns: 1fr;
  }

  .footer-top {
    grid-template-columns: 1fr;
    gap: 32px;
    padding: 48px 24px 32px;
  }

  .footer-brand-col {
    grid-column: auto;
  }

  .footer-bottom {
    padding: 20px 24px;
    flex-direction: column;
    align-items: flex-start;
  }

  .section {
    padding: 64px 0;
  }

  .container,
  .container-narrow {
    padding: 0 20px;
  }
}

/* ------------------------------ 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;
    scroll-behavior: auto !important;
  }

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

  .progress-bar {
    transition: none;
  }

  .nav-toggle.is-active .nav-toggle-bar {
    transition: none;
  }
}