/* ===== RESET & BASE ===== */
*, *::before, *::after { box-sizing: border-box; margin: 0; padding: 0; }
html { font-size: 16px; scroll-behavior: smooth; -webkit-text-size-adjust: 100%; }
body { font-family: 'Helvetica Neue', 'Arial', 'PingFang SC', 'Microsoft YaHei', sans-serif; font-weight: 400; line-height: 1.6; color: #FFFFFF; background-color: #0D0D0D; min-height: 100vh; overflow-x: hidden; }
img, svg { display: block; max-width: 100%; height: auto; }
a { color: #00BFFF; text-decoration: none; transition: color 0.2s ease; }
a:hover { color: #FFD700; }
a:focus-visible { outline: 2px solid #FFD700; outline-offset: 2px; border-radius: 2px; }
ul, ol { list-style: none; }
button { cursor: pointer; font: inherit; border: none; background: none; color: inherit; }
button:focus-visible { outline: 2px solid #FFD700; outline-offset: 2px; }

/* ===== CSS VARIABLES ===== */
:root {
  --color-primary: #FF4500;
  --color-primary-hover: #E03D00;
  --color-secondary: #00BFFF;
  --color-secondary-hover: #009ACD;
  --color-accent: #FFD700;
  --color-bg-dark: #0D0D0D;
  --color-bg-card: #1A1A1A;
  --color-text-primary: #FFFFFF;
  --color-text-secondary: #B0B0B0;
  --color-text-on-color: #000000;
  --color-border: #333333;
  --color-border-active: #FF4500;
  --font-heading: 'Impact', 'Arial Black', 'PingFang SC', sans-serif;
  --font-body: 'Helvetica Neue', 'Arial', 'PingFang SC', 'Microsoft YaHei', sans-serif;
  --font-numeric: 'Courier New', monospace;
  --weight-heading: 900;
  --weight-body: 400;
  --scale-h1: 4rem;
  --scale-h2: 2.5rem;
  --scale-h3: 1.75rem;
  --scale-body: 1rem;
  --scale-small: 0.875rem;
  --spacing-xs: 0.25rem;
  --spacing-sm: 0.5rem;
  --spacing-md: 1rem;
  --spacing-lg: 2rem;
  --spacing-xl: 3rem;
  --spacing-2xl: 4rem;
  --border-width-thick: 4px;
  --border-width-thin: 1px;
  --shadow-heavy: 0 8px 32px rgba(0,0,0,0.6);
  --shadow-glow: 0 0 20px rgba(255,69,0,0.3);
  --transition-fast: 0.15s ease;
  --transition-base: 0.25s ease;
  --max-width: 1280px;
  --header-left-width: 280px;
}

/* ===== TYPOGRAPHY ===== */
h1, h2, h3, h4, h5, h6 { font-family: var(--font-heading); font-weight: var(--weight-heading); text-transform: uppercase; line-height: 1.1; letter-spacing: 0.02em; color: var(--color-text-primary); }
h1 { font-size: var(--scale-h1); }
h2 { font-size: var(--scale-h2); }
h3 { font-size: var(--scale-h3); }
body, p, li, .text-body { font-family: var(--font-body); font-weight: var(--weight-body); line-height: 1.6; color: var(--color-text-primary); }
.numeric, [data-numeric] { font-family: var(--font-numeric); color: var(--color-accent); font-weight: 700; }
small, .text-small { font-size: var(--scale-small); color: var(--color-text-secondary); }

/* ===== SKIP LINK ===== */
.skip-link { position: absolute; top: -100%; left: 0; z-index: 10000; padding: var(--spacing-sm) var(--spacing-md); background: var(--color-primary); color: var(--color-text-on-color); font-weight: 700; text-decoration: none; border-radius: 0 0 4px 0; transition: top 0.2s ease; }
.skip-link:focus { top: 0; }

/* ===== SCROLL PROGRESS ===== */
.scroll-progress { position: fixed; top: 0; left: 0; width: 0%; height: 4px; background: linear-gradient(90deg, var(--color-primary), var(--color-accent)); z-index: 9999; transition: width 0.1s linear; will-change: width; pointer-events: none; }
@media (prefers-reduced-motion: reduce) { .scroll-progress { display: none; } }

/* ===== HEADER ===== */
.site-header { position: relative; z-index: 1000; background: var(--color-bg-dark); border-bottom: var(--border-width-thick) solid var(--color-border); box-shadow: var(--shadow-heavy); display: flex; flex-direction: column; }
.header-inner { display: flex; align-items: center; justify-content: space-between; padding: var(--spacing-md) var(--spacing-lg); max-width: var(--max-width); margin: 0 auto; width: 100%; gap: var(--spacing-md); }
.header-brand { display: flex; flex-direction: column; align-items: flex-start; gap: var(--spacing-xs); }
.header-brand .logo { font-family: var(--font-heading); font-size: 2.2rem; font-weight: var(--weight-heading); text-transform: uppercase; color: var(--color-primary); letter-spacing: 0.06em; line-height: 1; text-shadow: 2px 2px 0 rgba(255,69,0,0.3); }
.header-brand .slogan { font-family: var(--font-body); font-size: var(--scale-small); color: var(--color-text-secondary); letter-spacing: 0.08em; text-transform: uppercase; border-left: 2px solid var(--color-primary); padding-left: var(--spacing-sm); }
.header-actions { display: flex; align-items: center; gap: var(--spacing-lg); }
.action-link { font-family: var(--font-body); font-size: var(--scale-small); font-weight: 700; color: var(--color-text-secondary); text-transform: uppercase; letter-spacing: 0.05em; padding: var(--spacing-xs) var(--spacing-sm); border: 1px solid transparent; transition: all var(--transition-fast); }
.action-link:hover { color: var(--color-accent); border-color: var(--color-accent); border-radius: 2px; }
.action-link:focus-visible { outline: 2px solid var(--color-accent); outline-offset: 2px; }
.mobile-nav-toggle { display: none; font-size: 1.8rem; color: var(--color-primary); padding: var(--spacing-xs); line-height: 1; }

/* ===== NAVIGATION ===== */
.nav-main { background: var(--color-bg-dark); border-top: var(--border-width-thin) solid var(--color-border); }
.nav-list { display: flex; flex-direction: row; gap: 0; max-width: var(--max-width); margin: 0 auto; padding: 0 var(--spacing-lg); }
.nav-item { position: relative; }
.nav-link { display: block; padding: var(--spacing-md) var(--spacing-lg); font-family: var(--font-heading); font-size: 1.05rem; font-weight: var(--weight-heading); text-transform: uppercase; color: var(--color-text-secondary); letter-spacing: 0.04em; border-bottom: 3px solid transparent; transition: all var(--transition-base); }
.nav-link:hover { color: var(--color-primary); border-bottom-color: var(--color-primary); background: rgba(255,69,0,0.05); }
.nav-link:focus-visible { outline: 2px solid var(--color-accent); outline-offset: -2px; }
.nav-link[aria-current="page"] { color: var(--color-primary); border-bottom-color: var(--color-primary); background: rgba(255,69,0,0.08); }

/* ===== FOOTER ===== */
.site-footer { background: var(--color-bg-dark); border-top: var(--border-width-thick) solid var(--color-border); box-shadow: 0 -8px 32px rgba(0,0,0,0.4); padding: var(--spacing-xl) var(--spacing-lg) var(--spacing-lg); margin-top: var(--spacing-2xl); }
.footer-inner { max-width: var(--max-width); margin: 0 auto; display: grid; grid-template-columns: 1fr 1fr 1fr; gap: var(--spacing-lg) var(--spacing-xl); }
.footer-brand { display: flex; flex-direction: column; gap: var(--spacing-sm); }
.footer-brand .logo { font-family: var(--font-heading); font-size: 1.6rem; font-weight: var(--weight-heading); text-transform: uppercase; color: var(--color-primary); }
.footer-brand .slogan { font-family: var(--font-body); font-size: var(--scale-small); color: var(--color-text-secondary); text-transform: uppercase; letter-spacing: 0.06em; }
.footer-links { display: flex; flex-direction: column; gap: var(--spacing-sm); }
.footer-link { font-family: var(--font-body); font-size: var(--scale-body); color: var(--color-text-secondary); padding: var(--spacing-xs) 0; transition: color var(--transition-fast); }
.footer-link:hover { color: var(--color-accent); }
.footer-contact { display: flex; flex-direction: column; gap: var(--spacing-sm); }
.footer-contact .footer-email,
.footer-contact .footer-hours,
.footer-contact .footer-address { font-size: var(--scale-small); color: var(--color-text-secondary); }
.footer-icp { grid-column: 1 / -1; text-align: center; padding-top: var(--spacing-md); border-top: var(--border-width-thin) solid var(--color-border); font-size: var(--scale-small); color: var(--color-text-secondary); letter-spacing: 0.03em; }

/* ===== BUTTONS ===== */
.btn { display: inline-flex; align-items: center; justify-content: center; padding: var(--spacing-sm) var(--spacing-lg); font-family: var(--font-heading); font-size: var(--scale-body); font-weight: var(--weight-heading); text-transform: uppercase; letter-spacing: 0.04em; border: var(--border-width-thick) solid transparent; transition: all var(--transition-base); cursor: pointer; text-decoration: none; }
.btn-primary { background: var(--color-primary); color: var(--color-text-on-color); border-color: var(--color-primary); }
.btn-primary:hover { background: var(--color-primary-hover); border-color: var(--color-primary-hover); color: var(--color-text-on-color); box-shadow: var(--shadow-glow); }
.btn-primary:focus-visible { outline: 2px solid var(--color-accent); outline-offset: 2px; }
.btn-outline { background: transparent; color: var(--color-primary); border-color: var(--color-primary); }
.btn-outline:hover { background: var(--color-primary); color: var(--color-text-on-color); }

/* ===== CONTAINER ===== */
.container { max-width: var(--max-width); margin: 0 auto; padding: 0 var(--spacing-lg); }

/* ===== SECTION DIVIDER ===== */
.section-divider { width: 100%; height: var(--border-width-thick); background: var(--color-border); margin: var(--spacing-2xl) 0; border: none; }

/* ===== IMAGE CONTAINER (reusable) ===== */
.img-container { position: relative; overflow: hidden; background: var(--color-bg-card); border: var(--border-width-thin) solid var(--color-border); aspect-ratio: 16 / 9; display: flex; align-items: center; justify-content: center; color: var(--color-text-secondary); font-size: var(--scale-small); text-transform: uppercase; letter-spacing: 0.04em; }
.img-container::before { content: "📷 赛事影像"; opacity: 0.5; }
.img-container img { width: 100%; height: 100%; object-fit: cover; }

/* ===== CARD BASE ===== */
.card { background: var(--color-bg-card); border: var(--border-width-thin) solid var(--color-border); padding: var(--spacing-lg); box-shadow: var(--shadow-heavy); transition: all var(--transition-base); }
.card:hover { border-color: var(--color-border-active); box-shadow: var(--shadow-glow); transform: translateY(-2px); }
.card:focus-visible { outline: 2px solid var(--color-accent); outline-offset: 2px; }

/* ===== GRID BASE ===== */
.grid { display: grid; gap: var(--spacing-lg); }
.grid-2 { grid-template-columns: repeat(2, 1fr); }
.grid-3 { grid-template-columns: repeat(3, 1fr); }
.grid-4 { grid-template-columns: repeat(4, 1fr); }

/* ===== BREADCRUMB ===== */
.breadcrumb { display: flex; align-items: center; gap: var(--spacing-sm); padding: var(--spacing-md) 0; font-size: var(--scale-small); color: var(--color-text-secondary); text-transform: uppercase; letter-spacing: 0.04em; }
.breadcrumb a { color: var(--color-secondary); }
.breadcrumb a:hover { color: var(--color-accent); }
.breadcrumb .sep { color: var(--color-border); margin: 0 var(--spacing-xs); }

/* ===== RESPONSIVE ===== */
@media (max-width: 1024px) {
  :root { --header-left-width: 220px; --scale-h1: 3rem; --scale-h2: 2rem; --scale-h3: 1.5rem; }
  .footer-inner { grid-template-columns: 1fr 1fr; }
  .nav-link { padding: var(--spacing-sm) var(--spacing-md); font-size: 0.95rem; }
}

@media (max-width: 768px) {
  :root { --scale-h1: 2.2rem; --scale-h2: 1.6rem; --scale-h3: 1.25rem; --spacing-lg: 1.2rem; --spacing-xl: 2rem; }
  .header-inner { padding: var(--spacing-sm) var(--spacing-md); }
  .header-brand .logo { font-size: 1.6rem; }
  .header-brand .slogan { font-size: 0.75rem; }
  .header-actions { gap: var(--spacing-md); }
  .action-link { font-size: 0.75rem; }
  .mobile-nav-toggle { display: block; }
  .nav-main { position: fixed; top: 0; left: -100%; width: 280px; height: 100vh; height: 100dvh; background: var(--color-bg-dark); border-right: var(--border-width-thick) solid var(--color-border); box-shadow: var(--shadow-heavy); transition: left 0.3s ease; overflow-y: auto; z-index: 9998; padding-top: 60px; }
  .nav-main[data-open] { left: 0; }
  .nav-list { flex-direction: column; padding: var(--spacing-md); gap: var(--spacing-xs); }
  .nav-link { padding: var(--spacing-md); border-bottom: 1px solid var(--color-border); font-size: 1rem; }
  .nav-link[aria-current="page"] { border-left: 4px solid var(--color-primary); }
  .footer-inner { grid-template-columns: 1fr; gap: var(--spacing-lg); }
  .footer-icp { text-align: left; }
  .grid-2, .grid-3, .grid-4 { grid-template-columns: 1fr; }
  .img-container { aspect-ratio: 4 / 3; }
}

@media (max-width: 480px) {
  .header-brand .logo { font-size: 1.3rem; }
  .nav-main { width: 100%; left: -100%; }
  .header-actions .action-link { font-size: 0.7rem; padding: var(--spacing-xs); }
}

/* ===== REDUCED MOTION ===== */
@media (prefers-reduced-motion: reduce) {
  *, *::before, *::after { transition: none !important; animation: none !important; scroll-behavior: auto !important; }
  .scroll-progress { display: none; }
  .nav-main { transition: none; }
  .card:hover { transform: none; }
}

/* ===== FOCUS VISIBLE (global) ===== */
:focus-visible { outline: 2px solid var(--color-accent); outline-offset: 2px; }