/* ================================================
   KAIYUN 开户平台 · Site Kit
   文件：/assets/site.css
   ================================================ */

/* ---------- 1. Design Tokens ---------- */
:root {
  --color-primary: #0A6CFF;
  --color-accent: #FF6B00;
  --color-bg: #121318;
  --color-bg-deep: #0B0C10;
  --color-surface: #1E2027;
  --color-surface-2: #242732;
  --color-surface-3: #2A2D38;
  --color-text: #FFFFFF;
  --color-muted: #A0A4B0;
  --color-cyan: #00E5FF;
  --color-gold: #FFB300;

  --gradient-brand: linear-gradient(135deg, #0A6CFF 0%, #FF6B00 100%);
  --gradient-blue: linear-gradient(135deg, #0A6CFF 0%, #00E5FF 100%);
  --gradient-orange: linear-gradient(135deg, #FF6B00 0%, #FFB300 100%);
  --gradient-scan: linear-gradient(90deg, #0A6CFF, #00E5FF, #FF6B00);

  --font-heading: "Noto Serif SC", "Source Han Serif SC", "Songti SC", serif;
  --font-body: "Noto Sans SC", "Source Han Sans SC", "PingFang SC", "Microsoft YaHei", sans-serif;
  --font-code: "JetBrains Mono", "SF Mono", Consolas, monospace;

  --text-xs: 0.75rem;
  --text-sm: 0.875rem;
  --text-base: 1rem;
  --text-lg: 1.125rem;
  --text-xl: 1.5rem;
  --text-3xl: clamp(1.5rem, 4vw, 3.5rem);

  --sp-1: 0.25rem;
  --sp-2: 0.5rem;
  --sp-3: 0.75rem;
  --sp-4: 1rem;
  --sp-5: 1.5rem;
  --sp-6: 2rem;
  --sp-7: 3rem;
  --sp-8: 4rem;

  --header-w: 280px;
  --header-h-mobile: 64px;

  --radius: 12px;
  --radius-sm: 8px;
  --ease: cubic-bezier(0.4, 0, 0.2, 1);
  --dur: 200ms;
  --container-w: 1120px;
}

/* ---------- 2. Reset & Base ---------- */
*,
*::before,
*::after {
  box-sizing: border-box;
  margin: 0;
  padding: 0;
}

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

body {
  background: var(--color-bg);
  color: var(--color-text);
  font-family: var(--font-body);
  font-size: var(--text-base);
  line-height: 1.7;
  min-height: 100vh;
  -webkit-font-smoothing: antialiased;
}

h1,
h2,
h3,
h4,
h5,
h6 {
  font-family: var(--font-heading);
  line-height: 1.2;
  font-weight: 700;
}

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

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

ul,
ol {
  list-style: none;
}

button {
  font: inherit;
  color: inherit;
  background: none;
  border: 0;
  cursor: pointer;
}

::selection {
  background: rgba(255, 107, 0, 0.35);
  color: var(--color-text);
}

/* ---------- 3. Accessibility ---------- */
.visually-hidden {
  position: absolute;
  width: 1px;
  height: 1px;
  padding: 0;
  margin: -1px;
  overflow: hidden;
  clip: rect(0, 0, 0, 0);
  white-space: nowrap;
  border: 0;
}

:focus-visible {
  outline: 3px solid var(--color-accent);
  outline-offset: 3px;
  border-radius: 2px;
}

#main-content {
  outline: none;
}

#main-content:focus-visible {
  outline: 3px solid var(--color-accent);
  outline-offset: -3px;
}

.skip-link {
  position: fixed;
  top: -100%;
  left: var(--sp-4);
  z-index: 2000;
  padding: 12px 20px;
  background: var(--color-bg);
  color: var(--color-text);
  border: 1px solid var(--color-primary);
  border-radius: var(--radius-sm);
  font-size: var(--text-sm);
  font-weight: 600;
  transition: top var(--dur) var(--ease);
}

.skip-link:focus-visible {
  top: var(--sp-4);
}

/* ---------- 4. Buttons ---------- */
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: var(--sp-2);
  padding: 0.75rem 1.5rem;
  border-radius: 999px;
  font-family: var(--font-body);
  font-size: var(--text-sm);
  font-weight: 700;
  letter-spacing: 0.05em;
  line-height: 1;
  cursor: pointer;
  transition: transform var(--dur) var(--ease), box-shadow var(--dur) var(--ease),
    border-color var(--dur) var(--ease), background-color var(--dur) var(--ease);
}

.btn--gradient {
  background: var(--gradient-brand);
  color: #fff;
  box-shadow: 0 4px 20px rgba(255, 107, 0, 0.3);
}

.btn--gradient:hover {
  transform: translateY(-2px);
  box-shadow: 0 8px 28px rgba(10, 108, 255, 0.38);
}

.btn--ghost {
  background: transparent;
  border: 1px solid rgba(255, 255, 255, 0.22);
  color: var(--color-text);
}

.btn--ghost:hover {
  border-color: var(--color-accent);
  background: rgba(255, 107, 0, 0.08);
}

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

/* ---------- 5. Layout Utilities ---------- */
.main-content {
  margin-left: var(--header-w);
  min-height: 55vh;
  position: relative;
}

.container {
  max-width: var(--container-w);
  margin: 0 auto;
  padding: 0 var(--sp-5);
}

.page-section {
  padding: var(--sp-8) 0;
}

.section-heading {
  margin-bottom: var(--sp-6);
}

.section-heading__label {
  display: inline-flex;
  align-items: center;
  gap: var(--sp-2);
  font-family: var(--font-code);
  font-size: var(--text-xs);
  font-weight: 500;
  letter-spacing: 0.16em;
  text-transform: uppercase;
  color: var(--color-accent);
  margin-bottom: var(--sp-3);
  transform: skewX(-8deg);
}

.section-heading__label::before {
  content: "";
  width: 28px;
  height: 2px;
  background: var(--gradient-brand);
  transform: skewX(-12deg);
}

.section-heading__title {
  font-family: var(--font-heading);
  font-size: var(--text-3xl);
  font-weight: 900;
  font-style: italic;
  line-height: 1.15;
  letter-spacing: 0.01em;
  max-width: 22em;
}

.breadcrumb {
  margin-bottom: var(--sp-5);
  font-size: var(--text-sm);
  color: var(--color-muted);
}

.breadcrumb__list {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: var(--sp-2);
}

.breadcrumb__item {
  display: inline-flex;
  align-items: center;
  gap: var(--sp-2);
}

.breadcrumb__item + .breadcrumb__item::before {
  content: "/";
  color: rgba(255, 255, 255, 0.3);
}

.breadcrumb__link {
  color: var(--color-muted);
  transition: color var(--dur) var(--ease);
}

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

.breadcrumb__item[aria-current="page"] {
  color: var(--color-text);
  font-weight: 500;
}

.divider {
  height: 1px;
  border: 0;
  background: linear-gradient(90deg, rgba(10, 108, 255, 0.4), rgba(0, 229, 255, 0.2), rgba(255, 107, 0, 0.4));
}

.prose {
  max-width: 65ch;
  font-size: var(--text-lg);
  line-height: 1.9;
  color: var(--color-muted);
}

.prose h1,
.prose h2,
.prose h3 {
  color: var(--color-text);
  margin-top: 1.5em;
  margin-bottom: 0.5em;
}

.prose p + p {
  margin-top: 1em;
}

.prose a {
  color: var(--color-primary);
  text-decoration: underline;
  text-underline-offset: 3px;
}

/* ---------- 6. Header ---------- */
.site-header {
  position: fixed;
  top: 0;
  left: 0;
  bottom: 0;
  width: var(--header-w);
  z-index: 1000;
  display: flex;
  flex-direction: column;
  background: #17181F;
  border-right: 1px solid rgba(255, 255, 255, 0.06);
  box-shadow: 24px 0 64px rgba(0, 0, 0, 0.25);
}

.site-header::after {
  content: "";
  position: absolute;
  top: 0;
  right: -1px;
  width: 2px;
  height: 100%;
  background: linear-gradient(180deg, #0A6CFF, #00E5FF 50%, #FF6B00);
  opacity: 0.35;
}

.header-progress {
  position: fixed;
  top: 0;
  left: 0;
  right: 0;
  height: 3px;
  z-index: 1500;
  background: rgba(255, 255, 255, 0.04);
  pointer-events: none;
}

.header-progress__bar {
  display: block;
  width: 0%;
  height: 100%;
  background: var(--gradient-scan);
  box-shadow: 0 0 12px rgba(10, 108, 255, 0.6);
  transition: width 80ms linear;
}

.site-header__top {
  flex-shrink: 0;
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: var(--sp-6) var(--sp-5) var(--sp-5);
}

.brand {
  display: inline-flex;
  align-items: center;
  gap: var(--sp-4);
}

.brand__mark {
  flex-shrink: 0;
  filter: drop-shadow(0 0 8px rgba(10, 108, 255, 0.3));
}

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

.brand__name {
  font-family: var(--font-body);
  font-size: var(--text-lg);
  font-weight: 800;
  letter-spacing: 0.12em;
  color: var(--color-text);
}

.brand__sub {
  font-size: var(--text-xs);
  font-weight: 500;
  color: var(--color-muted);
  letter-spacing: 0.3em;
}

.site-nav {
  flex: 1;
  min-height: 0;
  display: flex;
  flex-direction: column;
  padding: var(--sp-2) var(--sp-5) 0;
}

.site-nav__list {
  display: grid;
  gap: 2px;
}

.site-nav__item {
  position: relative;
}

.site-nav__link {
  position: relative;
  display: flex;
  align-items: center;
  gap: var(--sp-3);
  min-height: 48px;
  padding: var(--sp-4) var(--sp-3);
  border-radius: var(--radius-sm);
  color: var(--color-muted);
  font-size: var(--text-sm);
  font-weight: 500;
  transition: color var(--dur) var(--ease), background-color var(--dur) var(--ease);
}

.site-nav__link::before {
  content: "";
  position: absolute;
  left: 0;
  top: 26%;
  bottom: 26%;
  width: 3px;
  border-radius: 0 4px 4px 0;
  background: rgba(255, 255, 255, 0.12);
  opacity: 0;
  transition: opacity var(--dur) var(--ease);
}

.site-nav__link:hover {
  color: var(--color-text);
  background: rgba(255, 255, 255, 0.05);
}

.site-nav__link:hover::before {
  opacity: 1;
}

.site-nav__link[aria-current="page"] {
  color: var(--color-text);
  background: linear-gradient(90deg, rgba(10, 108, 255, 0.16), rgba(255, 107, 0, 0.04));
  font-weight: 600;
}

.site-nav__link[aria-current="page"]::before {
  background: var(--gradient-brand);
  box-shadow: 0 0 10px rgba(10, 108, 255, 0.6);
  opacity: 1;
}

.site-nav__index {
  font-family: var(--font-code);
  font-size: var(--text-xs);
  color: rgba(160, 164, 176, 0.6);
  letter-spacing: 0.05em;
  min-width: 22px;
  transition: color var(--dur) var(--ease);
}

.site-nav__link:hover .site-nav__index {
  color: var(--color-cyan);
}

.site-nav__link[aria-current="page"] .site-nav__index {
  color: var(--color-accent);
}

.site-nav__aside {
  margin-top: auto;
  padding: var(--sp-5) 0 var(--sp-6);
  border-top: 1px solid rgba(255, 255, 255, 0.06);
}

.header__meta {
  display: flex;
  align-items: center;
  justify-content: center;
  gap: var(--sp-2);
  margin-top: var(--sp-4);
  font-size: var(--text-xs);
  color: var(--color-muted);
  letter-spacing: 0.08em;
}

.header__meta-dot {
  width: 6px;
  height: 6px;
  border-radius: 50%;
  background: var(--color-accent);
  box-shadow: 0 0 8px rgba(255, 107, 0, 0.9);
  animation: pulse-dot 2s var(--ease) infinite;
}

@keyframes pulse-dot {
  0%, 100% { opacity: 1; }
  50% { opacity: 0.35; }
}

.nav-toggle {
  display: none;
  align-items: center;
  justify-content: center;
  gap: 4px;
  padding: 10px 12px;
  border-radius: var(--radius-sm);
  background: rgba(255, 255, 255, 0.04);
  border: 1px solid rgba(255, 255, 255, 0.08);
}

.nav-toggle__box {
  width: 20px;
  height: 14px;
  display: grid;
  gap: 4px;
}

.nav-toggle__bar {
  display: block;
  height: 2px;
  width: 100%;
  border-radius: 2px;
  background: var(--color-text);
  transition: transform var(--dur) var(--ease);
}

.nav-toggle[aria-expanded="true"] .nav-toggle__bar:nth-child(1) {
  transform: translateY(3px) rotate(45deg);
}

.nav-toggle[aria-expanded="true"] .nav-toggle__bar:nth-child(2) {
  transform: translateY(-3px) rotate(-45deg);
}

/* ---------- 7. Footer ---------- */
.site-footer {
  position: relative;
  margin-left: var(--header-w);
  padding: var(--sp-8) var(--sp-6) var(--sp-5);
  background: linear-gradient(180deg, #101116, #0B0C10 45%);
  color: var(--color-muted);
  font-size: var(--text-sm);
}

.site-footer::before {
  content: "";
  position: absolute;
  inset: 0;
  background:
    radial-gradient(560px 240px at 85% 0%, rgba(10, 108, 255, 0.12), transparent 65%),
    radial-gradient(420px 200px at 10% 100%, rgba(255, 107, 0, 0.07), transparent 60%);
  pointer-events: none;
}

.site-footer__decoration {
  position: absolute;
  top: 0;
  left: 0;
  right: 0;
  height: 2px;
  background: linear-gradient(90deg, transparent 0%, #0A6CFF 20%, #00E5FF 45%, #FF6B00 75%, transparent 100%);
  opacity: 0.5;
}

.site-footer__inner {
  position: relative;
  max-width: var(--container-w);
  margin: 0 auto;
  display: grid;
  grid-template-columns: minmax(0, 1.6fr) repeat(3, minmax(0, 1fr));
  gap: var(--sp-7);
}

.site-footer__brand {
  display: grid;
  gap: var(--sp-4);
  align-content: start;
}

.brand--footer .brand__name {
  font-size: var(--text-lg);
}

.brand--footer .brand__mark svg {
  width: 36px;
  height: 36px;
}

.site-footer__intro {
  max-width: 32em;
  line-height: 1.8;
}

.footer-col__title {
  font-family: var(--font-body);
  font-size: var(--text-xs);
  font-weight: 700;
  color: var(--color-text);
  letter-spacing: 0.16em;
  text-transform: uppercase;
  margin-bottom: var(--sp-4);
  position: relative;
  padding-left: var(--sp-4);
}

.footer-col__title::before {
  content: "";
  position: absolute;
  left: 0;
  top: 50%;
  width: 9px;
  height: 9px;
  background: var(--gradient-brand);
  transform: translateY(-50%) skewX(-14deg);
  border-radius: 2px;
}

.footer-col__list {
  display: grid;
  gap: var(--sp-3);
}

.footer-col__list a {
  color: var(--color-muted);
  transition: color var(--dur) var(--ease), padding-left var(--dur) var(--ease);
  overflow-wrap: anywhere;
}

.footer-col__list a:hover {
  color: var(--color-text);
  padding-left: 4px;
}

.footer-col__address {
  display: block;
  line-height: 1.7;
}

.site-footer__bottom {
  position: relative;
  max-width: var(--container-w);
  margin: var(--sp-7) auto 0;
  padding-top: var(--sp-5);
  border-top: 1px solid rgba(255, 255, 255, 0.06);
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  justify-content: space-between;
  gap: var(--sp-3);
  font-size: var(--text-xs);
  color: rgba(160, 164, 176, 0.8);
}

/* ---------- 8. Shared Page Components ---------- */
.card {
  background: var(--color-surface);
  border: 1px solid rgba(255, 255, 255, 0.06);
  border-radius: var(--radius);
  padding: var(--sp-5);
  transition: border-color var(--dur) var(--ease), box-shadow var(--dur) var(--ease);
}

.card:hover {
  border-color: rgba(255, 255, 255, 0.14);
  box-shadow: 0 8px 32px rgba(0, 0, 0, 0.25);
}

.data-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(260px, 1fr));
  gap: var(--sp-5);
}

.tag {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  padding: 4px 12px;
  border-radius: 999px;
  background: rgba(10, 108, 255, 0.15);
  color: var(--color-cyan);
  font-size: var(--text-xs);
  font-weight: 600;
  letter-spacing: 0.06em;
  border: 1px solid rgba(10, 108, 255, 0.25);
}

.media {
  position: relative;
  overflow: hidden;
  border-radius: var(--radius);
  background: linear-gradient(135deg, rgba(10, 108, 255, 0.08), rgba(255, 107, 0, 0.08));
  border: 1px solid rgba(255, 255, 255, 0.06);
  aspect-ratio: 16 / 9;
}

.media > img,
.media > svg {
  width: 100%;
  height: 100%;
  object-fit: cover;
}

.media--wide { aspect-ratio: 21 / 9; }
.media--tall { aspect-ratio: 3 / 4; }
.media--square { aspect-ratio: 1 / 1; }

.legend {
  display: flex;
  flex-wrap: wrap;
  gap: var(--sp-3);
  padding: var(--sp-4);
  background: rgba(255, 255, 255, 0.02);
  border: 1px solid rgba(255, 255, 255, 0.06);
  border-radius: var(--radius);
}

.legend__item {
  display: inline-flex;
  align-items: center;
  gap: var(--sp-2);
  font-size: var(--text-xs);
  color: var(--color-muted);
}

.legend__dot {
  width: 8px;
  height: 8px;
  border-radius: 2px;
  transform: skewX(-10deg);
  flex-shrink: 0;
}

.legend__dot--primary { background: var(--color-primary); }
.legend__dot--accent { background: var(--color-accent); }
.legend__dot--cyan { background: var(--color-cyan); }
.legend__dot--gold { background: var(--color-gold); }

/* ---------- 9. Reveal on Scroll ---------- */
[data-reveal] {
  opacity: 0;
  transform: translateY(24px);
  transition: opacity 600ms var(--ease), transform 600ms var(--ease);
}

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

/* ---------- 10. Responsive ---------- */
@media (min-width: 961px) and (max-width: 1200px) {
  :root {
    --header-w: 250px;
  }

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

  .site-footer__brand {
    grid-column: 1 / -1;
  }
}

@media (max-width: 960px) {
  .main-content {
    margin-left: 0;
    padding-top: var(--header-h-mobile);
  }

  .site-header {
    width: 100%;
    height: var(--header-h-mobile);
    bottom: auto;
    flex-direction: row;
    align-items: center;
    border-right: none;
    border-bottom: 1px solid rgba(255, 255, 255, 0.06);
    box-shadow: 0 8px 32px rgba(0, 0, 0, 0.3);
  }

  .site-header::after {
    display: none;
  }

  .site-header__top {
    flex: 1;
    height: 100%;
    padding: 0 var(--sp-4);
  }

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

  .brand__sub {
    font-size: 0.65rem;
    letter-spacing: 0.2em;
  }

  .brand__mark svg {
    width: 36px;
    height: 36px;
  }

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

  .site-nav {
    position: fixed;
    top: var(--header-h-mobile);
    right: 0;
    bottom: 0;
    z-index: 1000;
    width: min(320px, 88vw);
    display: flex;
    flex-direction: column;
    padding: var(--sp-5);
    background: #1A1B23;
    border-left: 1px solid rgba(255, 255, 255, 0.08);
    box-shadow: -24px 0 48px rgba(0, 0, 0, 0.4);
    overflow-y: auto;
    visibility: hidden;
    transform: translateX(103%);
    transition: transform 260ms var(--ease), visibility 260ms;
  }

  .site-nav[data-open="true"] {
    visibility: visible;
    transform: translateX(0);
  }

  .site-nav__link {
    min-height: 52px;
  }

  .site-footer {
    margin-left: 0;
    padding: var(--sp-7) var(--sp-4) var(--sp-5);
  }

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

  .site-footer__bottom {
    flex-direction: column;
    align-items: flex-start;
  }
}

/* ---------- 11. 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;
  }

  .header-progress__bar {
    transition: none;
  }

  .header__meta-dot {
    animation: none;
  }

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

/* ---------- 12. Scrollbar ---------- */
::-webkit-scrollbar {
  width: 10px;
  height: 10px;
}

::-webkit-scrollbar-track {
  background: var(--color-bg);
}

::-webkit-scrollbar-thumb {
  background: var(--color-surface-3);
  border-radius: 5px;
}

::-webkit-scrollbar-thumb:hover {
  background: var(--color-surface-2);
}

/* ---------- 13. Focus Visible Base ---------- */
a:focus-visible,
button:focus-visible {
  outline: 3px solid var(--color-accent);
  outline-offset: 3px;
}