/* ================================================
   K1 棋牌竞技台 — 共享样式
   File: /assets/site.css
   ================================================ */

/* ---------- CSS Variables ---------- */
:root {
  --color-bg: #0A0A0F;
  --color-card: #1A1A24;
  --color-card-2: #14141E;
  --color-primary: #00FF88;
  --color-secondary: #B026FF;
  --color-gold: #FFD700;
  --color-steel: #C0C0C8;
  --color-white: #FFFFFF;
  --color-light: #E0E0E6;

  --font-heading: Impact, "Arial Black", "Haettenschweiler", "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei", sans-serif;
  --font-body: -apple-system, BlinkMacSystemFont, "Segoe UI", "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei", sans-serif;
  --font-mono: "SF Mono", "JetBrains Mono", "Fira Code", "Cascadia Code", Consolas, "Liberation Mono", monospace;

  --text-xs: 0.75rem;
  --text-sm: 0.875rem;
  --text-base: 1rem;
  --text-md: 1.125rem;
  --text-lg: 1.5rem;
  --text-xl: 2rem;
  --text-2xl: 3rem;
  --text-3xl: 4rem;

  --space-1: 0.25rem;
  --space-2: 0.5rem;
  --space-3: 0.75rem;
  --space-4: 1rem;
  --space-5: 1.5rem;
  --space-6: 2rem;
  --space-8: 3rem;
  --space-10: 4rem;
  --space-12: 5rem;

  --container-width: 1320px;
  --header-height: 4.5rem;

  --transition-fast: 0.2s ease;
  --transition-base: 0.3s ease;

  --z-header: 1000;
  --z-progress: 1200;
  --z-skip: 1100;
}

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

html {
  scroll-behavior: smooth;
  scroll-padding-top: calc(var(--header-height) + var(--space-4));
}

body {
  min-height: 100vh;
  display: flex;
  flex-direction: column;
  background-color: var(--color-bg);
  color: var(--color-white);
  font-family: var(--font-body);
  font-size: var(--text-base);
  line-height: 1.7;
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
}

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

a {
  color: var(--color-primary);
  text-decoration: none;
  transition: color var(--transition-fast);
}

a:hover {
  color: var(--color-secondary);
}

ul,
ol {
  list-style: none;
}

button {
  font: inherit;
  border: none;
  background: none;
  cursor: pointer;
  color: inherit;
}

p {
  margin: 0;
}

hr {
  border: none;
}

#main-content {
  flex: 1;
  padding-top: var(--header-height);
}

/* ---------- Focus Visible ---------- */
:focus-visible {
  outline: 2px solid var(--color-secondary);
  outline-offset: 3px;
  border-radius: 2px;
}

.skip-link:focus {
  outline: none;
}

/* ---------- Skip Link ---------- */
.skip-link {
  position: fixed;
  top: 0;
  left: 0;
  z-index: var(--z-skip);
  padding: var(--space-3) var(--space-5);
  background: var(--color-primary);
  color: var(--color-bg);
  font-family: var(--font-mono);
  font-size: var(--text-sm);
  font-weight: 700;
  letter-spacing: 0.08em;
  text-transform: uppercase;
  clip-path: polygon(0 0, 100% 0, 100% calc(100% - 8px), calc(100% - 8px) 100%, 0 100%);
  transform: translateY(-120%);
  transition: transform var(--transition-base);
}

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

/* ---------- Scroll Progress ---------- */
.scroll-progress {
  position: fixed;
  top: 0;
  left: 0;
  height: 3px;
  width: 0%;
  background: linear-gradient(90deg, var(--color-primary), var(--color-secondary));
  z-index: var(--z-progress);
  transition: width 0.08s linear;
}

/* ---------- Container ---------- */
.container {
  width: 100%;
  max-width: var(--container-width);
  margin-inline: auto;
  padding-inline: var(--space-5);
}

/* ---------- Header ---------- */
.site-header {
  position: fixed;
  top: 0;
  left: 0;
  right: 0;
  z-index: var(--z-header);
  height: var(--header-height);
  background: rgba(10, 10, 15, 0.55);
  border-bottom: 1px solid rgba(192, 192, 200, 0.1);
  backdrop-filter: blur(0px);
  -webkit-backdrop-filter: blur(0px);
  transition:
    background var(--transition-base),
    border-color var(--transition-base),
    backdrop-filter var(--transition-base);
}

.site-header[data-scrolled] {
  background: rgba(10, 10, 15, 0.92);
  backdrop-filter: blur(14px);
  -webkit-backdrop-filter: blur(14px);
  border-bottom-color: rgba(176, 38, 255, 0.25);
}

.site-header__inner {
  max-width: var(--container-width);
  margin: 0 auto;
  padding: 0 var(--space-5);
  height: 100%;
  display: flex;
  align-items: center;
  gap: var(--space-5);
}

/* ---------- Brand ---------- */
.brand {
  display: inline-flex;
  align-items: center;
  gap: var(--space-3);
  color: var(--color-white);
  flex-shrink: 0;
}

.brand:hover {
  color: var(--color-white);
}

.brand__mark {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  width: 2.5rem;
  height: 2.5rem;
  background: var(--color-primary);
  color: var(--color-bg);
  font-family: var(--font-heading);
  font-size: 1.1rem;
  font-weight: 700;
  letter-spacing: 0.03em;
  line-height: 1;
  clip-path: polygon(100% 0, 100% 72%, 72% 100%, 0 100%, 0 0);
  transition:
    background var(--transition-fast),
    transform var(--transition-fast);
}

.brand:hover .brand__mark {
  background: var(--color-secondary);
  transform: translateY(-2px);
}

.brand__text {
  font-family: var(--font-heading);
  font-size: var(--text-md);
  font-weight: 700;
  letter-spacing: 0.06em;
  text-transform: uppercase;
  white-space: nowrap;
}

.brand--footer .brand__mark {
  width: 2.75rem;
  height: 2.75rem;
  font-size: 1.15rem;
}

/* ---------- Navigation ---------- */
.main-nav {
  margin-left: auto;
}

.main-nav__list {
  display: flex;
  align-items: center;
  gap: var(--space-1);
}

.main-nav__link {
  display: inline-block;
  padding: var(--space-2) var(--space-3);
  color: var(--color-light);
  font-family: var(--font-mono);
  font-size: var(--text-xs);
  font-weight: 500;
  letter-spacing: 0.05em;
  text-transform: uppercase;
  position: relative;
  transition: color var(--transition-fast);
  white-space: nowrap;
}

.main-nav__link::after {
  content: "";
  position: absolute;
  bottom: 0;
  left: var(--space-3);
  right: var(--space-3);
  height: 2px;
  background: var(--color-primary);
  transform: scaleX(0);
  transform-origin: left;
  transition: transform var(--transition-base);
}

.main-nav__link:hover,
.main-nav__link[aria-current="page"] {
  color: var(--color-white);
}

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

.main-nav__link[aria-current="page"] {
  color: var(--color-primary);
}

.main-nav__link[aria-current="page"]::after {
  background: var(--color-secondary);
}

/* ---------- Header Actions ---------- */
.site-header__actions {
  display: flex;
  align-items: center;
  gap: var(--space-3);
  flex-shrink: 0;
}

.header__search {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  width: 2.25rem;
  height: 2.25rem;
  color: var(--color-light);
  border: 1px solid transparent;
  border-radius: 0;
  transition:
    color var(--transition-fast),
    border-color var(--transition-fast),
    background var(--transition-fast);
}

.header__search:hover {
  color: var(--color-primary);
  border-color: rgba(0, 255, 136, 0.35);
  background: rgba(0, 255, 136, 0.06);
}

/* ---------- Buttons ---------- */
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: var(--space-2);
  padding: var(--space-3) var(--space-5);
  font-family: var(--font-mono);
  font-size: var(--text-sm);
  font-weight: 500;
  letter-spacing: 0.04em;
  line-height: 1;
  text-transform: uppercase;
  cursor: pointer;
  white-space: nowrap;
  transition:
    background var(--transition-fast),
    color var(--transition-fast),
    border-color var(--transition-fast),
    box-shadow var(--transition-fast);
}

.btn--primary {
  background: var(--color-primary);
  color: var(--color-bg);
  border: 1px solid var(--color-primary);
  clip-path: polygon(0 0, 100% 0, 100% calc(100% - 8px), calc(100% - 8px) 100%, 0 100%);
}

.btn--primary:hover {
  background: var(--color-secondary);
  border-color: var(--color-secondary);
  color: var(--color-white);
  box-shadow: 0 0 20px rgba(176, 38, 255, 0.3);
}

.btn--ghost {
  background: transparent;
  color: var(--color-light);
  border: 1px solid var(--color-steel);
}

.btn--ghost:hover {
  border-color: var(--color-secondary);
  color: var(--color-secondary);
  background: rgba(176, 38, 255, 0.08);
}

.btn--sm {
  padding: var(--space-2) var(--space-4);
  font-size: var(--text-xs);
}

.btn__dot {
  display: inline-block;
  width: 6px;
  height: 6px;
  flex-shrink: 0;
  border-radius: 50%;
  background: var(--color-gold);
  box-shadow: 0 0 8px rgba(255, 215, 0, 0.6);
}

/* ---------- Nav Toggle ---------- */
.nav-toggle {
  display: none;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  gap: var(--space-1);
  padding: var(--space-2);
  min-width: 2.75rem;
  min-height: 2.75rem;
}

.nav-toggle__box {
  display: flex;
  flex-direction: column;
  gap: 5px;
  width: 1.5rem;
}

.nav-toggle__line {
  display: block;
  height: 2px;
  width: 100%;
  background: var(--color-primary);
  border-radius: 0;
  transition:
    transform var(--transition-base),
    opacity var(--transition-base),
    background var(--transition-fast);
}

.nav-toggle__text {
  font-family: var(--font-mono);
  font-size: var(--text-xs);
  color: var(--color-light);
  line-height: 1;
  letter-spacing: 0.04em;
}

.nav-toggle:hover .nav-toggle__line {
  background: var(--color-secondary);
}

.nav-toggle[aria-expanded="true"] .nav-toggle__line:nth-child(1) {
  transform: translateY(7px) rotate(45deg);
}

.nav-toggle[aria-expanded="true"] .nav-toggle__line:nth-child(2) {
  opacity: 0;
}

.nav-toggle[aria-expanded="true"] .nav-toggle__line:nth-child(3) {
  transform: translateY(-7px) rotate(-45deg);
}

/* ---------- Breadcrumb ---------- */
.breadcrumb {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: var(--space-2);
  font-family: var(--font-mono);
  font-size: var(--text-xs);
  text-transform: uppercase;
  letter-spacing: 0.04em;
  margin-bottom: var(--space-5);
}

.breadcrumb__link {
  color: var(--color-light);
  transition: color var(--transition-fast);
}

.breadcrumb__link:hover {
  color: var(--color-primary);
}

.breadcrumb__separator {
  color: var(--color-secondary);
  margin: 0 var(--space-1);
}

.breadcrumb__current {
  color: var(--color-primary);
}

/* ---------- Section Heading ---------- */
.section-heading {
  margin-bottom: var(--space-6);
}

.section-heading__eyebrow {
  display: flex;
  align-items: center;
  gap: var(--space-2);
  font-family: var(--font-mono);
  font-size: var(--text-xs);
  color: var(--color-secondary);
  text-transform: uppercase;
  letter-spacing: 0.08em;
  margin-bottom: var(--space-3);
}

.section-heading__eyebrow::before {
  content: "";
  display: inline-block;
  width: 1.5rem;
  height: 2px;
  background: var(--color-primary);
  flex-shrink: 0;
}

.section-heading__title {
  font-family: var(--font-heading);
  font-size: var(--text-2xl);
  font-weight: 700;
  line-height: 1.1;
  color: var(--color-white);
  text-transform: uppercase;
  letter-spacing: 0.02em;
}

@media (max-width: 767px) {
  .section-heading__title {
    font-size: var(--text-xl);
  }
}

/* ---------- Data Display ---------- */
.data-display {
  font-family: var(--font-mono);
  font-size: var(--text-sm);
  color: var(--color-light);
  display: inline-flex;
  align-items: baseline;
  gap: var(--space-2);
}

.data-display__value {
  font-size: var(--text-lg);
  font-weight: 500;
  color: var(--color-primary);
}

.data-display__tag {
  font-size: var(--text-xs);
  color: var(--color-gold);
  text-transform: uppercase;
  letter-spacing: 0.08em;
}

/* ---------- Card ---------- */
.card {
  background: var(--color-card);
  border: 1px solid rgba(192, 192, 200, 0.08);
}

.card--accent {
  border-top: 2px solid var(--color-secondary);
}

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

.card__title {
  font-family: var(--font-heading);
  font-size: var(--text-md);
  font-weight: 700;
  text-transform: uppercase;
  letter-spacing: 0.04em;
  margin-bottom: var(--space-3);
  color: var(--color-white);
}

.card__text {
  color: var(--color-light);
  font-size: var(--text-sm);
  line-height: 1.7;
}

/* ---------- Grid ---------- */
.grid {
  display: grid;
  gap: var(--space-5);
}

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

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

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

/* ---------- Divider ---------- */
.divider {
  height: 1px;
  background: linear-gradient(90deg, var(--color-primary), var(--color-secondary), transparent);
  border: none;
  margin: var(--space-6) 0;
}

/* ---------- Footer ---------- */
.site-footer {
  background: var(--color-card);
  border-top: 1px solid rgba(0, 255, 136, 0.2);
  position: relative;
}

.site-footer::before {
  content: "";
  position: absolute;
  top: 0;
  left: 0;
  right: 0;
  height: 3px;
  background: linear-gradient(90deg, var(--color-primary), var(--color-secondary), var(--color-gold));
  opacity: 0.65;
}

.site-footer__inner {
  max-width: var(--container-width);
  margin: 0 auto;
  padding: var(--space-10) var(--space-5) var(--space-8);
  display: grid;
  grid-template-columns: 2fr 1fr 1.5fr;
  gap: var(--space-8);
}

.site-footer__col--brand {
  display: flex;
  flex-direction: column;
  gap: var(--space-4);
}

.brand--footer {
  margin-bottom: var(--space-2);
}

.site-footer__desc {
  color: var(--color-light);
  font-size: var(--text-sm);
  line-height: 1.8;
  max-width: 28rem;
}

.site-footer__trust {
  color: var(--color-steel);
  font-size: var(--text-sm);
  line-height: 1.7;
  border-left: 2px solid var(--color-gold);
  padding-left: var(--space-4);
  margin-top: var(--space-2);
}

.site-footer__trust-mark {
  color: var(--color-gold);
  margin-right: var(--space-1);
}

.site-footer__heading {
  font-family: var(--font-heading);
  font-size: var(--text-md);
  font-weight: 700;
  letter-spacing: 0.06em;
  text-transform: uppercase;
  color: var(--color-white);
  margin-bottom: var(--space-5);
  padding-bottom: var(--space-3);
  position: relative;
}

.site-footer__heading::after {
  content: "";
  position: absolute;
  bottom: 0;
  left: 0;
  width: 2rem;
  height: 2px;
  background: var(--color-primary);
}

.site-footer__list {
  display: flex;
  flex-direction: column;
  gap: var(--space-2);
}

.site-footer__list a {
  display: inline-flex;
  align-items: center;
  gap: var(--space-2);
  color: var(--color-light);
  font-size: var(--text-sm);
  padding: var(--space-1) 0;
  transition:
    color var(--transition-fast),
    padding-left var(--transition-fast);
}

.site-footer__list a::before {
  content: "";
  width: 4px;
  height: 4px;
  background: var(--color-secondary);
  flex-shrink: 0;
}

.site-footer__list a:hover {
  color: var(--color-primary);
  padding-left: var(--space-1);
}

.site-footer__contact {
  display: flex;
  flex-direction: column;
  gap: var(--space-3);
}

.site-footer__contact li {
  padding-bottom: var(--space-2);
  border-bottom: 1px solid rgba(192, 192, 200, 0.08);
}

.site-footer__contact li:last-child {
  border-bottom: none;
}

.site-footer__label {
  display: block;
  font-family: var(--font-mono);
  font-size: var(--text-xs);
  color: var(--color-secondary);
  text-transform: uppercase;
  letter-spacing: 0.06em;
  margin-bottom: var(--space-1);
}

.site-footer__value {
  color: var(--color-light);
  font-size: var(--text-sm);
  line-height: 1.5;
  word-break: break-word;
}

.site-footer__bottom {
  border-top: 1px solid rgba(192, 192, 200, 0.12);
  padding: var(--space-4) 0;
}

.site-footer__bottom-inner {
  max-width: var(--container-width);
  margin: 0 auto;
  padding: 0 var(--space-5);
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: var(--space-4);
  flex-wrap: wrap;
}

.site-footer__copyright {
  color: var(--color-steel);
  font-size: var(--text-xs);
  font-family: var(--font-mono);
  letter-spacing: 0.04em;
}

.site-footer__legal {
  display: flex;
  align-items: center;
  gap: var(--space-3);
}

.site-footer__legal a {
  color: var(--color-light);
  font-size: var(--text-xs);
  font-family: var(--font-mono);
  letter-spacing: 0.03em;
  text-transform: uppercase;
  transition: color var(--transition-fast);
}

.site-footer__legal a:hover {
  color: var(--color-primary);
}

.site-footer__divider {
  color: var(--color-steel);
}

/* ---------- Responsive ---------- */

/* ≤991px: Nav collapses to hamburger */
@media (max-width: 991px) {
  .main-nav {
    position: absolute;
    top: 100%;
    left: 0;
    right: 0;
    margin-left: 0;
    background: rgba(10, 10, 15, 0.98);
    border-bottom: 1px solid rgba(176, 38, 255, 0.3);
    border-top: 1px solid rgba(0, 255, 136, 0.2);
    padding: var(--space-4) var(--space-5) var(--space-5);
    visibility: hidden;
    opacity: 0;
    transform: translateY(-10px);
    transition:
      transform var(--transition-base),
      opacity var(--transition-base),
      visibility var(--transition-base);
  }

  .main-nav[data-open] {
    visibility: visible;
    opacity: 1;
    transform: translateY(0);
  }

  .main-nav__list {
    flex-direction: column;
    align-items: stretch;
    gap: 0;
  }

  .main-nav__item {
    border-bottom: 1px solid rgba(192, 192, 200, 0.08);
  }

  .main-nav__item:last-child {
    border-bottom: none;
  }

  .main-nav__link {
    display: block;
    padding: var(--space-4) var(--space-3);
    font-size: var(--text-sm);
  }

  .main-nav__link::after {
    display: none;
  }

  .nav-toggle {
    display: inline-flex;
  }

  .grid--3,
  .grid--4 {
    grid-template-columns: repeat(2, 1fr);
  }

  .site-footer__inner {
    grid-template-columns: 1fr 1fr;
    gap: var(--space-6);
  }

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

/* ≤767px: Tablet / Mobile adjustments */
@media (max-width: 767px) {
  .site-header__inner {
    padding: 0 var(--space-4);
    gap: var(--space-3);
  }

  .brand__text {
    font-size: var(--text-base);
  }

  .brand__mark {
    width: 2.25rem;
    height: 2.25rem;
    font-size: 1rem;
  }

  .site-footer__inner {
    padding: var(--space-8) var(--space-5) var(--space-6);
  }

  .site-footer__bottom-inner {
    flex-direction: column;
    text-align: center;
  }
}

/* ≤480px: Compact header actions */
@media (max-width: 480px) {
  .site-header__collect {
    padding: var(--space-2);
  }

  .site-header__collect .btn__dot {
    width: 5px;
    height: 5px;
  }

  .header__search {
    width: 2rem;
    height: 2rem;
  }

  .site-footer__inner {
    grid-template-columns: 1fr;
    padding: var(--space-8) var(--space-4) var(--space-6);
    gap: var(--space-6);
  }

  .site-footer__col--brand {
    grid-column: auto;
  }

  .grid--2,
  .grid--3,
  .grid--4 {
    grid-template-columns: 1fr;
  }
}

/* ---------- Reduced Motion ---------- */
@media (prefers-reduced-motion: reduce) {
  *,
  *::before,
  *::after {
    animation-duration: 0.01ms !important;
    animation-iteration-count: 1 !important;
    transition-duration: 0.01ms !important;
    scroll-behavior: auto !important;
  }

  .scroll-progress {
    transition: none;
  }

  .site-header {
    backdrop-filter: blur(0px);
    -webkit-backdrop-filter: blur(0px);
  }

  .site-header[data-scrolled] {
    backdrop-filter: none;
    -webkit-backdrop-filter: none;
  }
}