/* === Reset & Base === */
*, *::before, *::after { box-sizing: border-box; margin: 0; padding: 0; }
html { scroll-behavior: smooth; -webkit-text-size-adjust: 100%; }
body { font-family: 'Noto Sans SC', 'PingFang SC', 'Microsoft YaHei', sans-serif; font-weight: 400; line-height: 1.6; color: #333333; background: #F1FAEE; -moz-osx-font-smoothing: grayscale; -webkit-font-smoothing: antialiased; }
ul, ol { list-style: none; }
a { color: inherit; text-decoration: none; }
img, svg { display: block; max-width: 100%; }
button { font: inherit; cursor: pointer; background: none; border: none; color: inherit; }
:focus-visible { outline: 3px solid #E63946; outline-offset: 2px; border-radius: 2px; }
::selection { background: #E63946; color: #F1FAEE; }

/* === CSS Variables === */
:root {
  --c-primary: #E63946;
  --c-primary-hover: #C1121F;
  --c-tech-blue: #1D3557;
  --c-tech-blue-light: #2A4D7A;
  --c-gold: #F4A261;
  --c-gold-light: #F7B87A;
  --c-teal: #2A9D8F;
  --c-teal-dark: #1F7A6F;
  --c-off-white: #F1FAEE;
  --c-off-white-dark: #E8F0E4;
  --c-charcoal: #333333;
  --c-border: #CCCCCC;
  --c-hover: #E76F51;
  --font-heading: 'Montserrat', 'Helvetica Neue', sans-serif;
  --font-body: 'Noto Sans SC', 'PingFang SC', 'Microsoft YaHei', sans-serif;
  --font-mono: 'Courier New', 'Consolas', monospace;
  --space-xs: 0.25rem;
  --space-sm: 0.5rem;
  --space-md: 1rem;
  --space-lg: 2rem;
  --space-xl: 3rem;
  --space-2xl: 5rem;
  --max-width: 1200px;
  --header-height: 72px;
  --radius: 4px;
  --shadow-panel: 0 4px 20px rgba(0,0,0,0.08), 0 1px 4px rgba(0,0,0,0.04);
  --shadow-card: 0 2px 12px rgba(0,0,0,0.06);
}
@media (prefers-reduced-motion: reduce) {
  *, *::before, *::after { animation-duration: 0.01ms !important; transition-duration: 0.01ms !important; }
  html { scroll-behavior: auto; }
}

/* === Skip Link === */
.skip-link { position: fixed; top: -100%; left: var(--space-md); background: var(--c-tech-blue); color: var(--c-off-white); padding: var(--space-sm) var(--space-md); z-index: 10000; font-weight: 600; font-size: 0.875rem; border-radius: 0 0 var(--radius) var(--radius); transition: top 0.2s; }
.skip-link:focus { top: 0; }

/* === Scroll Progress === */
.scroll-progress { position: fixed; top: 0; left: 0; height: 4px; background: var(--c-primary); z-index: 9999; width: 0%; transition: width 0.1s linear; pointer-events: none; }
@media (prefers-reduced-motion: reduce) { .scroll-progress { transition: none; } }

/* === Header / Navigation === */
.site-header { position: fixed; top: 0; left: 0; right: 0; z-index: 9000; height: var(--header-height); transition: background 0.35s ease, box-shadow 0.35s ease; background: transparent; }
.site-header[data-scrolled] { background: var(--c-tech-blue); box-shadow: 0 2px 16px rgba(0,0,0,0.25); }
.site-header__inner { display: flex; align-items: center; justify-content: space-between; max-width: var(--max-width); margin: 0 auto; padding: 0 var(--space-lg); height: 100%; }
@media (max-width: 768px) { .site-header__inner { padding: 0 var(--space-md); } }

/* Brand */
.brand { display: flex; align-items: center; gap: var(--space-sm); flex-shrink: 0; }
.brand__icon { position: relative; display: flex; align-items: center; justify-content: center; width: 36px; height: 36px; }
.brand__icon-grid { position: absolute; width: 28px; height: 28px; border: 2px solid var(--c-gold); border-radius: 2px; background: linear-gradient(45deg, transparent 48%, var(--c-gold) 48%, var(--c-gold) 52%, transparent 52%), linear-gradient(-45deg, transparent 48%, var(--c-gold) 48%, var(--c-gold) 52%, transparent 52%); opacity: 0.8; }
.brand__icon-needle { position: absolute; width: 2px; height: 20px; background: var(--c-primary); transform: rotate(25deg); border-radius: 1px; bottom: 6px; left: 50%; margin-left: -1px; }
.brand__icon-needle::after { content: ''; position: absolute; top: -4px; left: -3px; width: 8px; height: 8px; background: var(--c-primary); border-radius: 50%; }
.brand__name { font-family: var(--font-heading); font-weight: 700; font-size: 1.35rem; letter-spacing: 0.08em; color: var(--c-off-white); text-transform: uppercase; }
.site-header[data-scrolled] .brand__name { color: var(--c-off-white); }
.site-header:not([data-scrolled]) .brand__name { color: var(--c-off-white); text-shadow: 0 1px 6px rgba(0,0,0,0.4); }
.site-header:not([data-scrolled]) .brand__icon-grid { border-color: var(--c-off-white); background-image: linear-gradient(45deg, transparent 48%, var(--c-off-white) 48%, var(--c-off-white) 52%, transparent 52%), linear-gradient(-45deg, transparent 48%, var(--c-off-white) 48%, var(--c-off-white) 52%, transparent 52%); }

/* Nav Toggle */
.nav-toggle { display: none; flex-direction: column; justify-content: center; gap: 5px; width: 40px; height: 40px; padding: 6px; background: transparent; border: none; cursor: pointer; z-index: 9100; }
.nav-toggle__bar { display: block; width: 100%; height: 3px; background: var(--c-off-white); border-radius: 2px; transition: transform 0.3s, opacity 0.3s; }
[data-open] .nav-toggle__bar:nth-child(1) { transform: translateY(8px) rotate(45deg); }
[data-open] .nav-toggle__bar:nth-child(2) { opacity: 0; }
[data-open] .nav-toggle__bar:nth-child(3) { transform: translateY(-8px) rotate(-45deg); }
@media (max-width: 768px) { .nav-toggle { display: flex; } }

/* Site Nav */
.site-nav { display: flex; align-items: center; }
.site-nav__list { display: flex; gap: var(--space-xs); }
.site-nav__item { margin: 0; }
.site-nav__link { display: block; padding: var(--space-sm) var(--space-md); font-family: var(--font-heading); font-weight: 600; font-size: 0.8rem; letter-spacing: 0.05em; text-transform: uppercase; color: var(--c-off-white); border-radius: var(--radius); transition: background 0.25s, color 0.25s; position: relative; white-space: nowrap; }
.site-header:not([data-scrolled]) .site-nav__link { text-shadow: 0 1px 6px rgba(0,0,0,0.35); }
.site-nav__link:hover, .site-nav__link:focus-visible { background: rgba(255,255,255,0.12); color: var(--c-gold); }
.site-nav__link[aria-current="page"] { background: rgba(230,57,70,0.25); color: var(--c-gold); box-shadow: inset 0 -2px 0 var(--c-primary); }
@media (max-width: 768px) {
  .site-nav { position: fixed; top: 0; left: 0; right: 0; bottom: 0; background: var(--c-tech-blue); align-items: center; justify-content: center; opacity: 0; pointer-events: none; transition: opacity 0.35s ease; z-index: 9050; }
  .site-nav[data-open] { opacity: 1; pointer-events: auto; }
  .site-nav__list { flex-direction: column; align-items: center; gap: var(--space-md); }
  .site-nav__link { font-size: 1.1rem; padding: var(--space-md) var(--space-xl); }
  .site-nav__link[aria-current="page"] { background: rgba(230,57,70,0.3); }
}

/* === Hero Frame (首框景) === */
.hero-frame { position: relative; margin: 0 auto; max-width: var(--max-width); padding: var(--space-2xl) var(--space-lg); border: 3px solid var(--c-primary); background: var(--c-off-white); box-shadow: var(--shadow-panel); }
.hero-frame::before { content: ''; position: absolute; inset: -8px; border: 1px solid var(--c-gold); pointer-events: none; }
.hero-frame__inner { position: relative; z-index: 1; }
.hero-frame__label { display: inline-block; font-family: var(--font-mono); font-weight: 600; font-size: 0.85rem; color: var(--c-gold); background: var(--c-tech-blue); padding: var(--space-xs) var(--space-sm); letter-spacing: 0.1em; margin-bottom: var(--space-md); }
@media (max-width: 768px) { .hero-frame { padding: var(--space-xl) var(--space-md); } }

/* === Stack Panel === */
.stack-panel { padding: var(--space-2xl) var(--space-lg); background: var(--c-off-white); box-shadow: var(--shadow-panel); margin-bottom: var(--space-md); position: relative; }
.stack-panel--alt { background: var(--c-teal); color: var(--c-off-white); }
.stack-panel--alt .section-label { color: var(--c-gold); }
.stack-panel--alt .index-tag { background: var(--c-off-white); color: var(--c-teal-dark); }
.stack-panel--dark { background: var(--c-tech-blue); color: var(--c-off-white); }
@media (max-width: 768px) { .stack-panel { padding: var(--space-xl) var(--space-md); } }

/* === Section Label & Index Tag === */
.section-label { display: flex; align-items: center; gap: var(--space-sm); font-family: var(--font-heading); font-weight: 700; font-size: 1.6rem; letter-spacing: 0.05em; text-transform: uppercase; color: var(--c-tech-blue); margin-bottom: var(--space-lg); }
.section-label .index-tag { font-size: 1rem; padding: var(--space-xs) var(--space-sm); }
.index-tag { display: inline-block; font-family: var(--font-mono); font-weight: 600; font-size: 0.85rem; color: var(--c-off-white); background: var(--c-gold); padding: 2px 10px; letter-spacing: 0.05em; border-radius: 2px; }
.stack-panel--alt .section-label { color: var(--c-off-white); }

/* === Buttons === */
.btn { display: inline-flex; align-items: center; justify-content: center; padding: var(--space-sm) var(--space-lg); font-family: var(--font-heading); font-weight: 600; font-size: 0.85rem; letter-spacing: 0.05em; text-transform: uppercase; border-radius: var(--radius); transition: background 0.25s, color 0.25s, transform 0.2s, box-shadow 0.25s; border: 2px solid transparent; cursor: pointer; }
.btn:hover { transform: translateY(-1px); box-shadow: 0 4px 12px rgba(0,0,0,0.15); }
.btn:active { transform: translateY(0); }
.btn--primary { background: var(--c-primary); color: var(--c-off-white); border-color: var(--c-primary); }
.btn--primary:hover { background: var(--c-primary-hover); border-color: var(--c-primary-hover); }
.btn--secondary { background: transparent; color: var(--c-gold); border-color: var(--c-gold); }
.btn--secondary:hover { background: var(--c-gold); color: var(--c-tech-blue); }
.btn--ghost { background: transparent; color: var(--c-off-white); border-color: rgba(255,255,255,0.3); }
.btn--ghost:hover { border-color: var(--c-off-white); background: rgba(255,255,255,0.08); }

/* === Data Card === */
.data-card { background: var(--c-off-white); border-left: 4px solid var(--c-primary); padding: var(--space-md) var(--space-lg); box-shadow: var(--shadow-card); border-radius: 0 var(--radius) var(--radius) 0; transition: transform 0.25s, box-shadow 0.25s; }
.data-card:hover { transform: translateY(-2px); box-shadow: 0 6px 20px rgba(0,0,0,0.1); }
.data-card__value { font-family: var(--font-heading); font-weight: 700; font-size: 2rem; color: var(--c-tech-blue); line-height: 1.2; }
.data-card__label { font-size: 0.85rem; color: var(--c-charcoal); opacity: 0.75; margin-top: var(--space-xs); }
.data-card--alt { border-left-color: var(--c-gold); }
.data-card--alt .data-card__value { color: var(--c-teal-dark); }

/* === Filter Bar === */
.filter-bar { display: flex; flex-wrap: wrap; gap: var(--space-sm); padding: var(--space-md) 0; margin-bottom: var(--space-lg); border-bottom: 2px solid var(--c-border); }
.filter-btn { padding: var(--space-sm) var(--space-md); font-family: var(--font-heading); font-weight: 600; font-size: 0.75rem; letter-spacing: 0.05em; text-transform: uppercase; color: var(--c-charcoal); background: transparent; border: 2px solid var(--c-border); border-radius: var(--radius); cursor: pointer; transition: background 0.25s, color 0.25s, border-color 0.25s; }
.filter-btn:hover { border-color: var(--c-primary); color: var(--c-primary); }
.filter-btn[aria-pressed="true"] { background: var(--c-primary); color: var(--c-off-white); border-color: var(--c-primary); }

/* === Coord Index === */
.coord-index { display: flex; align-items: center; gap: var(--space-sm); font-family: var(--font-mono); font-weight: 600; font-size: 0.8rem; color: var(--c-gold); letter-spacing: 0.05em; }
.coord-index::before { content: '◆'; color: var(--c-primary); font-size: 0.6rem; }

/* === Back to Top === */
.back-to-top { position: fixed; bottom: var(--space-lg); right: var(--space-lg); z-index: 8000; width: 48px; height: 48px; background: var(--c-tech-blue); color: var(--c-off-white); border: 2px solid var(--c-gold); border-radius: 50%; display: flex; align-items: center; justify-content: center; font-size: 1.4rem; opacity: 0; pointer-events: none; transition: opacity 0.35s, transform 0.35s; transform: translateY(20px); cursor: pointer; box-shadow: 0 4px 16px rgba(0,0,0,0.2); }
.back-to-top[data-visible] { opacity: 1; pointer-events: auto; transform: translateY(0); }
.back-to-top:hover { background: var(--c-primary); border-color: var(--c-primary); }
.back-to-top::after { content: '↑'; font-weight: 700; }

/* === Footer === */
.site-footer { background: var(--c-tech-blue); color: var(--c-off-white); padding: var(--space-2xl) var(--space-lg) var(--space-lg); margin-top: var(--space-2xl); border-top: 4px solid var(--c-primary); position: relative; }
.site-footer::before { content: ''; position: absolute; top: 0; left: 0; right: 0; height: 2px; background: linear-gradient(90deg, var(--c-primary), var(--c-gold), var(--c-teal)); }
.site-footer__inner { max-width: var(--max-width); margin: 0 auto; }
.footer__grid { display: grid; grid-template-columns: 1.4fr 1fr 1.2fr 1fr; gap: var(--space-xl); margin-bottom: var(--space-xl); }
.footer__col { min-width: 0; }
.footer__col--brand .brand__name { color: var(--c-off-white); font-size: 1.2rem; }
.footer__col--brand .brand__icon-grid { border-color: var(--c-gold); background-image: linear-gradient(45deg, transparent 48%, var(--c-gold) 48%, var(--c-gold) 52%, transparent 52%), linear-gradient(-45deg, transparent 48%, var(--c-gold) 48%, var(--c-gold) 52%, transparent 52%); }
.footer__tagline { font-size: 0.9rem; margin-top: var(--space-sm); opacity: 0.85; font-weight: 300; }
.footer__trust { font-size: 0.8rem; margin-top: var(--space-md); opacity: 0.6; font-style: italic; border-left: 2px solid var(--c-gold); padding-left: var(--space-sm); }
.footer__heading { font-family: var(--font-heading); font-weight: 700; font-size: 0.8rem; letter-spacing: 0.1em; text-transform: uppercase; color: var(--c-gold); margin-bottom: var(--space-md); padding-bottom: var(--space-sm); border-bottom: 1px solid rgba(255,255,255,0.15); }
.footer__list { display: flex; flex-direction: column; gap: var(--space-sm); }
.footer__link { font-size: 0.9rem; color: var(--c-off-white); opacity: 0.8; transition: opacity 0.25s, color 0.25s; padding: var(--space-xs) 0; }
.footer__link:hover { opacity: 1; color: var(--c-gold); }
.footer__address { font-size: 0.85rem; opacity: 0.65; font-style: normal; margin-top: var(--space-xs); }
.footer__note { font-size: 0.78rem; opacity: 0.55; margin-top: var(--space-md); }
.footer__bottom { display: flex; justify-content: space-between; align-items: center; padding-top: var(--space-lg); border-top: 1px solid rgba(255,255,255,0.12); font-size: 0.8rem; opacity: 0.7; }
.footer__copyright, .footer__icp { font-size: 0.78rem; }
@media (max-width: 1024px) {
  .footer__grid { grid-template-columns: 1fr 1fr; gap: var(--space-lg); }
}
@media (max-width: 640px) {
  .footer__grid { grid-template-columns: 1fr; gap: var(--space-lg); }
  .footer__bottom { flex-direction: column; gap: var(--space-sm); text-align: center; }
  .site-footer { padding: var(--space-xl) var(--space-md) var(--space-md); }
}

/* === Utility === */
.container { max-width: var(--max-width); margin: 0 auto; padding: 0 var(--space-lg); }
@media (max-width: 768px) { .container { padding: 0 var(--space-md); } }
.text-gold { color: var(--c-gold); }
.text-primary { color: var(--c-primary); }
.text-tech-blue { color: var(--c-tech-blue); }
.bg-off-white { background: var(--c-off-white); }
.bg-teal { background: var(--c-teal); }
.bg-tech-blue { background: var(--c-tech-blue); color: var(--c-off-white); }
.mono { font-family: var(--font-mono); }
.uppercase { text-transform: uppercase; letter-spacing: 0.05em; }
.grid-2 { display: grid; grid-template-columns: 1fr 1fr; gap: var(--space-lg); }
.grid-3 { display: grid; grid-template-columns: repeat(3, 1fr); gap: var(--space-lg); }
.grid-4 { display: grid; grid-template-columns: repeat(4, 1fr); gap: var(--space-lg); }
@media (max-width: 768px) { .grid-2, .grid-3, .grid-4 { grid-template-columns: 1fr; } }
@media (max-width: 1024px) { .grid-4 { grid-template-columns: 1fr 1fr; } }

/* === Image Placeholder Container === */
.img-placeholder { position: relative; background: var(--c-tech-blue-light); overflow: hidden; min-height: 200px; display: flex; align-items: center; justify-content: center; color: var(--c-off-white); font-family: var(--font-mono); font-size: 0.8rem; opacity: 0.7; border: 1px dashed var(--c-gold); border-radius: var(--radius); }
.img-placeholder::before { content: '📷 赛事影像'; opacity: 0.5; }
.img-placeholder--chart { background: linear-gradient(135deg, var(--c-tech-blue) 0%, var(--c-teal-dark) 100%); border-style: solid; }
.img-placeholder--chart::before { content: '📊 数据图表'; }
.img-placeholder--badge { background: var(--c-off-white-dark); border: 2px solid var(--c-border); min-height: 120px; }
.img-placeholder--badge::before { content: '🏷️ 球队徽章'; color: var(--c-charcoal); }

/* === Responsive for header spacing === */
#main-content { padding-top: var(--header-height); }