/* ============================================
   买球体育 WELCOMEKAIYUN — Site Kit
   /assets/site.css
   ============================================ */

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

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

body,
h1, h2, h3, h4, p, figure, blockquote, dl, dd,
ul, ol, li, fieldset, legend {
  margin: 0;
  padding: 0;
}

ul,
ol {
  list-style: none;
}

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

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

button {
  background: none;
  border: 0;
  padding: 0;
  cursor: pointer;
}

a {
  color: inherit;
  text-decoration: none;
}

/* ---------- Root Variables ---------- */
:root {
  --paper: #F5F2ED;
  --ink: #111111;
  --white: #FFFFFF;
  --orange: #FF4D00;
  --blue: #0A2540;
  --gray-light: #E5E5E5;
  --gray-mid: #888888;
  --soft-red: #FF6B35;

  --font-sans: "Noto Sans SC", "Source Han Sans SC", "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei", system-ui, "Helvetica Neue", Arial, sans-serif;

  --container: 1200px;
  --header-h: 72px;
  --text-main: #333333;
  --ease-out: cubic-bezier(0.22, 1, 0.36, 1);
}

/* ---------- Base ---------- */
html,
body {
  min-height: 100vh;
}

body {
  display: flex;
  flex-direction: column;
  font-family: var(--font-sans);
  font-size: 16px;
  line-height: 1.75;
  color: var(--ink);
  background: var(--paper);
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
  text-rendering: optimizeLegibility;
}

main {
  flex: 1 0 auto;
}

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

/* ---------- Focus ---------- */
:focus-visible {
  outline: 3px solid var(--orange);
  outline-offset: 2px;
}

/* ---------- Utilities ---------- */
.container {
  width: 100%;
  max-width: var(--container);
  margin-inline: auto;
  padding-inline: clamp(1rem, 4vw, 2rem);
}

.sr-only {
  position: absolute;
  width: 1px;
  height: 1px;
  padding: 0;
  margin: -1px;
  overflow: hidden;
  clip: rect(0 0 0 0);
  white-space: nowrap;
  border: 0;
}

.skip-link {
  position: fixed;
  top: 0;
  left: 0;
  z-index: 900;
  transform: translateY(-150%);
  background: var(--orange);
  color: var(--white);
  font-weight: 600;
  font-size: 0.875rem;
  letter-spacing: 0.06em;
  padding: 0.75rem 1.25rem;
  transition: transform 0.2s var(--ease-out);
}

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

/* ---------- Scroll Progress ---------- */
.scroll-progress {
  position: fixed;
  top: 0;
  left: 0;
  right: 0;
  height: 3px;
  z-index: 400;
  pointer-events: none;
}

.scroll-progress span {
  display: block;
  height: 100%;
  background: var(--orange);
  transform: scaleX(0);
  transform-origin: left top;
  will-change: transform;
}

/* ---------- Buttons ---------- */
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 0.5rem;
  min-height: 44px;
  padding: 0.625rem 1.75rem;
  font-family: var(--font-sans);
  font-size: 0.9375rem;
  font-weight: 600;
  letter-spacing: 0.08em;
  text-decoration: none;
  border: 2px solid var(--ink);
  transition: color 0.2s ease, background-color 0.2s ease, border-color 0.2s ease;
}

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

.btn--primary:hover {
  background: var(--ink);
  border-color: var(--ink);
}

.btn--outline {
  background: transparent;
  color: var(--ink);
}

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

.btn--ghost {
  background: transparent;
  border-color: var(--paper);
  color: var(--paper);
}

.btn--ghost:hover {
  background: var(--paper);
  border-color: var(--paper);
  color: var(--blue);
}

/* ---------- Breadcrumbs ---------- */
.breadcrumbs {
  display: flex;
  flex-wrap: wrap;
  gap: 0.5rem;
  padding: 0.875rem 0;
  font-size: 0.8125rem;
  letter-spacing: 0.04em;
  color: var(--gray-mid);
}

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

.breadcrumbs li + li::before {
  content: "／";
  margin-right: 0.5rem;
  color: var(--gray-light);
}

.breadcrumbs a {
  color: var(--gray-mid);
  transition: color 0.2s ease;
}

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

.breadcrumbs [aria-current="page"] {
  color: var(--ink);
  font-weight: 600;
}

/* ---------- Page Head ---------- */
.page-head {
  padding: clamp(3rem, 7vw, 5.5rem) 0 clamp(2rem, 5vw, 3.5rem);
}

.page-head__label {
  display: inline-flex;
  align-items: center;
  gap: 0.5rem;
  font-size: 0.75rem;
  letter-spacing: 0.22em;
  color: var(--orange);
  margin-bottom: 1rem;
}

.page-head__label::before {
  content: "";
  width: 2rem;
  height: 2px;
  background: currentColor;
}

.page-head__title {
  font-size: clamp(2.375rem, 6vw, 4.5rem);
  font-weight: 300;
  line-height: 1.12;
  letter-spacing: -0.02em;
  max-width: 12em;
}

.page-head__lede {
  margin-top: 1.125rem;
  font-size: 1rem;
  color: var(--gray-mid);
  max-width: 34em;
}

/* ---------- Section ---------- */
.section {
  padding-block: clamp(3rem, 8vw, 6rem);
}

.section--paper {
  background: var(--paper);
}

.section--white {
  background: var(--white);
  border-block: 1px solid var(--gray-light);
}

.section--blue {
  background: var(--blue);
  color: var(--paper);
}

.section--blue .section-title {
  color: var(--paper);
}

.section--blue .section-lede {
  color: rgba(245, 242, 237, 0.72);
}

.section--blue .section-label {
  color: var(--soft-red);
}

.section--blue .section-label::before {
  background: var(--soft-red);
}

.section-label {
  display: inline-flex;
  align-items: center;
  gap: 0.6rem;
  font-size: 0.75rem;
  letter-spacing: 0.22em;
  color: var(--orange);
  margin-bottom: 1rem;
}

.section-label::before {
  content: "";
  width: 2rem;
  height: 2px;
  background: var(--orange);
  flex-shrink: 0;
}

.section-title {
  font-size: clamp(2rem, 5vw, 3.375rem);
  font-weight: 300;
  line-height: 1.18;
  letter-spacing: -0.01em;
  margin-bottom: 1rem;
}

.section-lede {
  font-size: 1rem;
  line-height: 1.9;
  color: var(--gray-mid);
  max-width: 36em;
}

/* ---------- Grid ---------- */
.grid {
  display: grid;
  gap: 1.5rem;
}

.grid--2 {
  grid-template-columns: minmax(0, 1fr);
}

.grid--3 {
  grid-template-columns: minmax(0, 1fr);
}

@media (min-width: 640px) {
  .grid--2 {
    grid-template-columns: repeat(2, minmax(0, 1fr));
  }

  .grid--3 {
    grid-template-columns: repeat(2, minmax(0, 1fr));
  }
}

@media (min-width: 1024px) {
  .grid--3 {
    grid-template-columns: repeat(3, minmax(0, 1fr));
  }
}

/* ---------- Sheet ---------- */
.sheet {
  background: var(--white);
  border: 1px solid var(--gray-light);
  border-top: 3px solid var(--ink);
  padding: clamp(1.375rem, 3vw, 2.5rem);
  position: relative;
  transition: border-top-color 0.2s ease, border-color 0.2s ease, transform 0.3s var(--ease-out);
}

.sheet:hover {
  border-color: var(--orange);
  border-top-color: var(--orange);
  transform: translateY(-3px);
}

.sheet__title {
  font-size: 1.25rem;
  font-weight: 700;
  letter-spacing: 0.02em;
  margin-bottom: 0.625rem;
}

.sheet__text {
  font-size: 0.9375rem;
  color: var(--text-main);
}

/* ---------- Tag ---------- */
.tag {
  display: inline-block;
  border: 1px solid var(--ink);
  padding: 0.3125rem 0.625rem;
  font-size: 0.6875rem;
  letter-spacing: 0.16em;
  text-transform: uppercase;
  color: var(--ink);
  background: transparent;
  transition: background-color 0.2s ease, color 0.2s ease, border-color 0.2s ease;
}

.tag--orange {
  border-color: var(--orange);
  color: var(--orange);
}

a.tag:hover {
  background: var(--orange);
  color: var(--white);
  border-color: var(--orange);
}

/* ---------- Prose ---------- */
.prose {
  font-size: 0.9375rem;
  line-height: 1.95;
  color: var(--text-main);
}

.prose p {
  margin-bottom: 1.25em;
}

.prose a {
  color: var(--orange);
  text-decoration: underline;
  text-decoration-thickness: 1px;
  text-underline-offset: 3px;
  transition: text-decoration-thickness 0.2s ease;
}

.prose a:hover {
  text-decoration-thickness: 2px;
}

.prose h2 {
  font-size: 1.5rem;
  font-weight: 700;
  margin-top: 2.2em;
  margin-bottom: 0.6em;
}

.prose h3 {
  font-size: 1.125rem;
  font-weight: 600;
  margin-top: 1.6em;
  margin-bottom: 0.5em;
}

.prose ul {
  list-style: disc;
  padding-left: 1.25em;
  margin-bottom: 1.25em;
}

.prose ol {
  list-style: decimal;
  padding-left: 1.25em;
  margin-bottom: 1.25em;
}

.prose li {
  margin-bottom: 0.5em;
}

.prose blockquote {
  border-left: 3px solid var(--orange);
  padding-left: 1rem;
  margin: 1.75em 0;
  color: var(--gray-mid);
}

.prose address {
  font-style: normal;
  line-height: 2;
}

/* ---------- Image Frame ---------- */
.image-frame {
  position: relative;
  overflow: hidden;
  background: var(--gray-light);
  aspect-ratio: 4 / 3;
}

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

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

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

.image-frame__placeholder {
  display: flex;
  align-items: center;
  justify-content: center;
  background:
    linear-gradient(135deg, rgba(10, 37, 64, 0.06) 25%, transparent 25%) 0 0 / 24px 24px,
    linear-gradient(315deg, rgba(10, 37, 64, 0.06) 25%, transparent 25%) 0 0 / 24px 24px,
    var(--gray-light);
  color: var(--gray-mid);
  font-size: 0.75rem;
  letter-spacing: 0.18em;
}

.image-frame__label {
  position: absolute;
  left: 0;
  bottom: 0;
  background: var(--ink);
  color: var(--paper);
  font-size: 0.75rem;
  letter-spacing: 0.1em;
  padding: 0.3125rem 0.75rem;
}

/* ---------- Reveal ---------- */
[data-reveal] {
  opacity: 0;
  transform: translateY(1.5rem);
  transition: opacity 0.55s var(--ease-out), transform 0.55s var(--ease-out);
}

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

/* ---------- Header ---------- */
.site-header {
  position: sticky;
  top: 0;
  z-index: 200;
  background: var(--paper);
  border-bottom: 1px solid var(--ink);
}

.site-header::after {
  content: "";
  position: absolute;
  top: 0;
  right: 0;
  width: 0;
  height: 0;
  border-top: 22px solid var(--orange);
  border-left: 22px solid transparent;
  pointer-events: none;
}

.header-main {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 1rem;
  min-height: var(--header-h);
  position: relative;
}

/* Brand */
.brand-logo {
  display: inline-flex;
  align-items: center;
  gap: 0.625rem;
  min-height: 44px;
  color: var(--ink);
}

.brand-logo__mark {
  color: var(--orange);
  width: 38px;
  height: 38px;
  flex-shrink: 0;
  transition: transform 0.3s var(--ease-out);
}

.brand-logo:hover .brand-logo__mark {
  transform: rotate(-10deg);
}

.brand-logo__text {
  display: flex;
  flex-direction: column;
  line-height: 1.15;
}

.brand-logo__name {
  font-size: 1.25rem;
  font-weight: 700;
  letter-spacing: 0.04em;
}

.brand-logo__sub {
  font-size: 0.5625rem;
  font-weight: 500;
  letter-spacing: 0.2em;
  color: var(--gray-mid);
  text-transform: uppercase;
}

/* Navigation */
.site-nav {
  position: fixed;
  top: var(--header-h);
  right: 0;
  bottom: 0;
  width: min(340px, 88vw);
  z-index: 210;
  visibility: hidden;
  transform: translateX(100%);
  transition: transform 0.3s var(--ease-out), visibility 0s linear 0.3s;
}

.site-nav[data-open="true"] {
  visibility: visible;
  transform: translateX(0);
  transition: transform 0.3s var(--ease-out), visibility 0s;
}

.site-nav[data-open="true"]::before {
  content: "";
  position: absolute;
  top: 0;
  bottom: 0;
  left: -100vw;
  width: 200vw;
  z-index: -1;
  background: rgba(10, 37, 64, 0.5);
}

.site-nav__inner {
  height: 100%;
  display: flex;
  flex-direction: column;
  background: var(--paper);
  border-left: 1px solid var(--ink);
  padding: 2rem 1.75rem 1.5rem;
  overflow-y: auto;
}

.nav-list {
  display: flex;
  flex-direction: column;
  gap: 0.125rem;
}

.nav-link {
  position: relative;
  display: flex;
  align-items: center;
  justify-content: space-between;
  min-height: 46px;
  padding: 0.625rem 0.25rem;
  font-size: 0.9375rem;
  font-weight: 500;
  letter-spacing: 0.1em;
  color: var(--ink);
  transition: color 0.2s ease;
}

.nav-link::before {
  content: "";
  position: absolute;
  left: 0;
  top: 12px;
  bottom: 12px;
  width: 3px;
  background: var(--orange);
  transform: scaleY(0);
  transform-origin: bottom center;
  transition: transform 0.2s ease;
}

.nav-link::after {
  content: "→";
  font-size: 0.75rem;
  color: var(--gray-mid);
  transition: color 0.2s ease;
}

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

.nav-link:hover::before,
.nav-link[aria-current="page"]::before {
  transform: scaleY(1);
}

.nav-link:hover::after,
.nav-link[aria-current="page"]::after {
  color: var(--orange);
}

.nav-link[aria-current="page"] {
  font-weight: 700;
}

.site-nav__footer {
  margin-top: auto;
  padding-top: 1.75rem;
  border-top: 1px solid var(--gray-light);
  font-size: 0.6875rem;
  letter-spacing: 0.18em;
  color: var(--gray-mid);
  text-transform: uppercase;
}

/* Nav Toggle */
.nav-toggle {
  display: inline-flex;
  align-items: center;
  gap: 0.625rem;
  min-height: 44px;
  padding: 0.5rem 0.875rem;
  border: 1px solid var(--ink);
  background: transparent;
  color: var(--ink);
  font-size: 0.875rem;
  letter-spacing: 0.1em;
  transition: border-color 0.2s ease, color 0.2s ease;
}

.nav-toggle:hover,
.nav-toggle[aria-expanded="true"] {
  border-color: var(--orange);
  color: var(--orange);
}

.nav-toggle__icon {
  position: relative;
  width: 20px;
  height: 14px;
}

.nav-toggle__icon::before,
.nav-toggle__icon::after {
  content: "";
  position: absolute;
  left: 0;
  width: 100%;
  height: 2px;
  background: currentColor;
  transition: top 0.2s ease, bottom 0.2s ease, transform 0.2s ease;
}

.nav-toggle__icon::before {
  top: 0;
}

.nav-toggle__icon::after {
  top: auto;
  bottom: 0;
}

.nav-toggle[aria-expanded="true"] .nav-toggle__icon::before {
  top: 6px;
  transform: rotate(45deg);
}

.nav-toggle[aria-expanded="true"] .nav-toggle__icon::after {
  bottom: 6px;
  transform: rotate(-45deg);
}

/* Desktop Nav */
@media (min-width: 768px) {
  .site-nav {
    position: static;
    top: auto;
    right: auto;
    bottom: auto;
    height: auto;
    width: auto;
    background: transparent;
    visibility: visible;
    transform: none;
    transition: none;
  }

  .site-nav[data-open="true"]::before {
    display: none;
  }

  .site-nav__inner {
    display: block;
    height: auto;
    padding: 0;
    border-left: 0;
    background: transparent;
    overflow: visible;
  }

  .nav-list {
    flex-direction: row;
    gap: 0.25rem;
  }

  .nav-link {
    display: inline-flex;
    justify-content: center;
    min-height: 44px;
    padding: 0.5rem 0.625rem;
    font-size: 0.875rem;
  }

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

  .nav-link::after {
    content: "";
    position: absolute;
    left: 0.625rem;
    right: 0.625rem;
    bottom: 0.375rem;
    height: 2px;
    background: var(--orange);
    transform: scaleX(0);
    transform-origin: left center;
    transition: transform 0.2s ease;
  }

  .nav-link:hover::after,
  .nav-link[aria-current="page"]::after {
    transform: scaleX(1);
  }

  .site-nav__footer {
    display: none;
  }

  .nav-toggle {
    display: none;
  }
}

/* ---------- Footer ---------- */
.site-footer {
  margin-top: auto;
  background: var(--blue);
  color: var(--paper);
  border-top: 4px solid var(--orange);
}

.site-footer a {
  color: var(--paper);
  transition: color 0.2s ease;
}

.site-footer a:hover {
  color: var(--orange);
}

.footer-statement {
  padding: clamp(3rem, 8vw, 5.5rem) 0 2rem;
  border-bottom: 1px solid rgba(245, 242, 237, 0.16);
}

.footer-statement__label {
  display: flex;
  align-items: center;
  gap: 0.6rem;
  font-size: 0.75rem;
  letter-spacing: 0.22em;
  color: var(--orange);
  margin-bottom: 0.875rem;
}

.footer-statement__label::before {
  content: "";
  width: 2rem;
  height: 2px;
  background: var(--orange);
}

.footer-statement__text {
  font-size: clamp(1.875rem, 4.5vw, 3.25rem);
  font-weight: 300;
  line-height: 1.25;
  max-width: 18em;
  letter-spacing: -0.01em;
}

.footer-grid {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: 2.5rem;
  padding: 3rem 0 2rem;
}

@media (min-width: 640px) {
  .footer-grid {
    grid-template-columns: 1.4fr 1fr 1fr;
  }
}

@media (min-width: 1024px) {
  .footer-grid {
    grid-template-columns: 1.6fr 1fr 1fr 1fr;
  }
}

.footer-brand__desc {
  margin-top: 1rem;
  font-size: 0.875rem;
  line-height: 1.9;
  color: rgba(245, 242, 237, 0.72);
  max-width: 30em;
}

.brand-logo--footer .brand-logo__name {
  color: var(--paper);
}

.brand-logo--footer .brand-logo__sub {
  color: rgba(245, 242, 237, 0.55);
}

.footer-col__title {
  margin-bottom: 1rem;
  padding-bottom: 0.5rem;
  border-bottom: 1px solid rgba(245, 242, 237, 0.16);
  font-size: 0.8125rem;
  font-weight: 600;
  letter-spacing: 0.18em;
  color: var(--soft-red);
  text-transform: uppercase;
}

.footer-col__list {
  display: grid;
  gap: 0.625rem;
}

.footer-col__item {
  font-size: 0.875rem;
  line-height: 1.7;
  color: rgba(245, 242, 237, 0.72);
  overflow-wrap: anywhere;
}

.footer-bottom {
  display: flex;
  flex-wrap: wrap;
  gap: 0.375rem 1.75rem;
  justify-content: space-between;
  align-items: center;
  padding: 1.375rem 0 2rem;
  border-top: 1px solid rgba(245, 242, 237, 0.16);
  font-size: 0.75rem;
  color: rgba(245, 242, 237, 0.55);
}

/* ---------- Reduced Motion ---------- */
@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;
  }

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

  .site-nav,
  .skip-link,
  .nav-link::before,
  .nav-link::after {
    transition: none;
  }
}