/* =========================================================
   KAIYUN Site Kit — Shared Stylesheet
   Deep Space Blue / Gold Highlight / Technical Blueprint
   ========================================================= */

/* ---------- 1. Reset ---------- */
*,
*::before,
*::after {
  box-sizing: border-box;
  margin: 0;
  padding: 0;
}

/* ---------- 2. Design Tokens ---------- */
:root {
  --clr-navy: #0B1B3A;
  --clr-gold: #F2C94C;
  --clr-gold-light: #FFE37E;
  --clr-red: #9E2B25;
  --clr-lake: #3BB0DB;
  --clr-white: #F5F7FA;
  --clr-slate: #6C7A89;
  --clr-grid: #1E3A5F;
  --clr-ink: #071326;
  --clr-card: #2C3E5A;
  --font-heading: 'Arial Black', 'Impact', 'Noto Sans SC', sans-serif;
  --font-body: 'Helvetica Neue', 'PingFang SC', 'Microsoft YaHei', sans-serif;
  --max-width: 1200px;
  --ease-fast: 0.2s ease;
  --shadow-soft: 0 8px 32px rgba(0, 0, 0, 0.3);
}

/* ---------- 3. Base ---------- */
html {
  -webkit-text-size-adjust: 100%;
}

body {
  font-family: var(--font-body);
  font-size: 16px;
  line-height: 1.6;
  color: var(--clr-white);
  background-color: var(--clr-navy);
  background-image:
    linear-gradient(rgba(30, 58, 95, 0.18) 1px, transparent 1px),
    linear-gradient(90deg, rgba(30, 58, 95, 0.18) 1px, transparent 1px);
  background-size: 48px 48px;
  min-height: 100vh;
}

a {
  color: var(--clr-lake);
  text-decoration: none;
  transition: color var(--ease-fast);
}

a:hover {
  color: var(--clr-gold);
}

ul,
ol {
  list-style: none;
}

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

:focus-visible {
  outline: 2px solid var(--clr-gold);
  outline-offset: 3px;
}

::selection {
  background: var(--clr-gold);
  color: var(--clr-ink);
}

#main-content {
  display: block;
  outline: none;
  min-height: 50vh;
}

/* ---------- 4. Layout Utilities ---------- */
.container {
  width: 100%;
  max-width: var(--max-width);
  margin-inline: auto;
  padding-inline: 20px;
}

@media (min-width: 768px) {
  .container {
    padding-inline: 24px;
  }
}

.grid {
  display: grid;
  gap: 24px;
}

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

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

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

@media (min-width: 992px) {
  .grid--4 {
    grid-template-columns: repeat(4, 1fr);
  }
}

.grid-bg {
  position: relative;
  background-image:
    linear-gradient(rgba(30, 58, 95, 0.3) 1px, transparent 1px),
    linear-gradient(90deg, rgba(30, 58, 95, 0.3) 1px, transparent 1px);
  background-size: 48px 48px;
}

/* ---------- 5. Skip Link ---------- */
.skip-link {
  position: fixed;
  top: -100px;
  left: 20px;
  z-index: 9999;
  display: inline-block;
  padding: 10px 20px;
  background: var(--clr-gold);
  color: var(--clr-ink);
  font-family: var(--font-body);
  font-weight: 800;
  font-size: 14px;
  line-height: 1.2;
  text-decoration: none;
  box-shadow: var(--shadow-soft);
  transition: top var(--ease-fast);
}

.skip-link:focus {
  top: 16px;
}

/* ---------- 6. Shared Header ---------- */
.site-header {
  position: relative;
  z-index: 1100;
  background-color: var(--clr-navy);
  border-bottom: 1px solid var(--clr-grid);
  box-shadow: 0 4px 20px rgba(0, 0, 0, 0.15);
}

.scroll-progress {
  position: fixed;
  top: 0;
  left: 0;
  z-index: 1200;
  height: 3px;
  width: 0;
  background: linear-gradient(90deg, var(--clr-gold), var(--clr-lake));
  pointer-events: none;
}

.scroll-progress::after {
  content: '';
  position: absolute;
  top: 0;
  right: 0;
  width: 72px;
  height: 100%;
  background: linear-gradient(90deg, transparent, var(--clr-red));
  opacity: 0.45;
}

.masthead {
  position: relative;
  overflow: hidden;
}

.masthead__grid {
  position: absolute;
  inset: 0;
  z-index: 0;
  pointer-events: none;
  background-image:
    linear-gradient(var(--clr-grid) 1px, transparent 1px),
    linear-gradient(90deg, var(--clr-grid) 1px, transparent 1px);
  background-size: 36px 36px;
  opacity: 0.28;
  -webkit-mask-image: linear-gradient(to bottom, transparent, black 35%, black 85%, transparent);
  mask-image: linear-gradient(to bottom, transparent, black 35%, black 85%, transparent);
}

.masthead__grid::before,
.masthead__grid::after {
  content: '';
  position: absolute;
  width: 20px;
  height: 20px;
  opacity: 0.55;
}

.masthead__grid::before {
  top: 14px;
  left: 14px;
  border-top: 2px solid var(--clr-gold);
  border-left: 2px solid var(--clr-gold);
}

.masthead__grid::after {
  bottom: 14px;
  right: 14px;
  border-bottom: 2px solid var(--clr-gold);
  border-right: 2px solid var(--clr-gold);
}

.masthead__inner {
  position: relative;
  z-index: 1;
  max-width: var(--max-width);
  margin-inline: auto;
  padding: 10px 20px 0;
}

@media (min-width: 768px) {
  .masthead__inner {
    padding: 12px 24px 0;
  }
}

.masthead__top {
  display: flex;
  align-items: center;
  justify-content: flex-end;
  gap: 16px;
  padding-bottom: 8px;
  border-bottom: 1px solid rgba(242, 201, 76, 0.22);
  font-size: 11px;
  letter-spacing: 0.16em;
  text-transform: uppercase;
  color: var(--clr-slate);
}

.masthead__coord {
  display: none;
  font-size: 11px;
  letter-spacing: 0.2em;
  text-transform: uppercase;
  color: var(--clr-slate);
  white-space: nowrap;
}

.masthead__live {
  display: inline-block;
  font-size: 11px;
  font-weight: 800;
  letter-spacing: 0.14em;
  text-transform: uppercase;
  color: #f2c9c4;
  background: rgba(158, 43, 37, 0.32);
  border: 1px solid rgba(158, 43, 37, 0.7);
  padding: 3px 10px;
  line-height: 1.4;
}

.masthead__edition {
  font-size: 12px;
  font-weight: 700;
  color: var(--clr-gold);
  white-space: nowrap;
}

@media (min-width: 768px) {
  .masthead__top {
    justify-content: space-between;
  }

  .masthead__coord {
    display: inline;
  }
}

.masthead__main {
  display: flex;
  align-items: flex-end;
  justify-content: space-between;
  gap: 24px;
  padding: 14px 0 12px;
}

@media (min-width: 768px) {
  .masthead__main {
    padding: 18px 0 14px;
  }
}

.brand-lockup {
  display: inline-flex;
  flex-direction: column;
  gap: 3px;
  text-decoration: none;
}

.brand-lockup__mark {
  font-family: var(--font-heading);
  font-size: clamp(34px, 8vw, 52px);
  font-style: italic;
  font-weight: 900;
  line-height: 1;
  letter-spacing: 0.04em;
  color: transparent;
  background: linear-gradient(135deg, var(--clr-gold-light), var(--clr-gold));
  -webkit-background-clip: text;
  background-clip: text;
  text-shadow: 0 0 36px rgba(242, 201, 76, 0.22);
}

.brand-lockup__tagline {
  font-size: 12px;
  letter-spacing: 0.18em;
  color: var(--clr-slate);
  text-transform: uppercase;
}

.masthead__meta {
  display: none;
  flex-direction: column;
  align-items: flex-end;
  gap: 5px;
  text-align: right;
  font-size: 12px;
  letter-spacing: 0.14em;
  text-transform: uppercase;
  color: var(--clr-slate);
}

.masthead__label {
  font-size: 11px;
  color: var(--clr-slate);
  border: 1px solid rgba(30, 58, 95, 0.9);
  padding: 4px 10px;
  background: rgba(7, 19, 38, 0.4);
  white-space: nowrap;
}

.masthead__label:first-child {
  color: var(--clr-lake);
  border-color: rgba(59, 176, 219, 0.3);
}

@media (min-width: 768px) {
  .masthead__meta {
    display: flex;
  }
}

.masthead__navrow {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  border-top: 2px solid var(--clr-gold);
  border-bottom: 1px solid rgba(30, 58, 95, 0.7);
}

/* ---------- 7. Navigation ---------- */
.nav-toggle {
  display: inline-flex;
  align-items: center;
  gap: 10px;
  margin-left: auto;
  padding: 13px 2px;
  background: none;
  border: none;
  cursor: pointer;
  color: var(--clr-white);
  font-family: var(--font-body);
  font-size: 14px;
  font-weight: 700;
  line-height: 1;
  letter-spacing: 0.1em;
}

.nav-toggle__icon {
  display: inline-flex;
  flex-direction: column;
  gap: 4px;
  width: 20px;
  flex-shrink: 0;
}

.nav-toggle__bar {
  display: block;
  height: 2px;
  background: currentColor;
  transition: transform var(--ease-fast), opacity var(--ease-fast);
}

.nav-toggle[aria-expanded="true"] .nav-toggle__bar:nth-child(1) {
  transform: translateY(6px) rotate(45deg);
}

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

.nav-toggle[aria-expanded="true"] .nav-toggle__bar:nth-child(3) {
  transform: translateY(-6px) rotate(-45deg);
}

.nav-toggle__label {
  letter-spacing: 0.08em;
  font-size: 14px;
}

.site-nav {
  flex: 1 1 100%;
  display: none;
  background-color: rgba(11, 27, 58, 0.98);
}

.site-nav[data-open] {
  display: block;
  border-top: 1px solid rgba(242, 201, 76, 0.16);
  padding: 8px 0 12px;
}

.site-nav__list {
  display: flex;
  flex-direction: column;
}

.site-nav__link {
  position: relative;
  display: block;
  padding: 13px 20px;
  border-left: 3px solid transparent;
  font-size: 15px;
  font-weight: 700;
  color: var(--clr-white);
  text-decoration: none;
  transition: color var(--ease-fast), border-color var(--ease-fast), background-color var(--ease-fast);
}

.site-nav__link:hover {
  color: var(--clr-gold);
  background: rgba(59, 176, 219, 0.06);
}

.site-nav__link[aria-current="page"] {
  color: var(--clr-gold);
  background: rgba(242, 201, 76, 0.06);
  border-left-color: var(--clr-gold);
}

@media (min-width: 992px) {
  .nav-toggle {
    display: none;
  }

  .masthead__navrow {
    justify-content: center;
  }

  .site-nav,
  .site-nav[data-open] {
    flex: 0 0 auto;
    display: flex;
    border-top: none;
    padding: 0;
    background: transparent;
  }

  .site-nav__list {
    flex-direction: row;
  }

  .site-nav__link {
    padding: 15px 28px;
    border-left: none;
    text-align: center;
  }

  .site-nav__link::after {
    content: '';
    position: absolute;
    left: 24px;
    right: 24px;
    bottom: -1px;
    height: 2px;
    background: transparent;
    transition: background-color var(--ease-fast);
  }

  .site-nav__link:hover,
  .site-nav__link[aria-current="page"] {
    background: transparent;
    border-left: none;
  }

  .site-nav__link:hover::after,
  .site-nav__link[aria-current="page"]::after {
    background: var(--clr-gold);
  }

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

/* ---------- 8. Shared Footer ---------- */
.site-footer {
  position: relative;
  margin-top: 80px;
  background-color: var(--clr-ink);
  border-top: 4px solid var(--clr-gold);
  box-shadow: 0 -10px 32px rgba(0, 0, 0, 0.2);
}

.site-footer__grid {
  display: grid;
  grid-template-columns: 1fr;
  gap: 32px;
  max-width: var(--max-width);
  margin-inline: auto;
  padding: 48px 20px 32px;
}

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

@media (min-width: 992px) {
  .site-footer__grid {
    grid-template-columns: 1.4fr 1fr 1fr 1.2fr;
    gap: 40px;
    padding: 56px 24px 36px;
  }
}

.footer-brand,
.footer-nav,
.footer-contact {
  min-width: 0;
}

.footer-brand__mark {
  font-family: var(--font-heading);
  font-size: 28px;
  font-style: italic;
  font-weight: 900;
  line-height: 1;
  letter-spacing: 0.04em;
  color: var(--clr-gold);
  margin-bottom: 8px;
}

.footer-brand__tagline {
  font-size: 13px;
  letter-spacing: 0.18em;
  text-transform: uppercase;
  color: var(--clr-slate);
  margin-bottom: 16px;
}

.footer-brand__trust {
  font-size: 14px;
  line-height: 1.7;
  color: rgba(245, 247, 250, 0.72);
  max-width: 34ch;
}

.footer-title {
  font-size: 14px;
  font-weight: 800;
  letter-spacing: 0.12em;
  text-transform: uppercase;
  color: var(--clr-gold);
  border-bottom: 1px solid rgba(30, 58, 95, 0.8);
  padding-bottom: 8px;
  margin-bottom: 14px;
}

.footer-links {
  display: flex;
  flex-direction: column;
  gap: 2px;
}

.footer-link {
  display: inline-block;
  padding: 4px 0;
  font-size: 14px;
  color: rgba(245, 247, 250, 0.8);
  transition: color var(--ease-fast), padding-left var(--ease-fast);
}

.footer-link:hover {
  color: var(--clr-gold);
  padding-left: 4px;
}

.footer-contact__line {
  font-size: 14px;
  line-height: 1.7;
  color: rgba(245, 247, 250, 0.8);
  margin-bottom: 6px;
}

.site-footer__bottom {
  border-top: 1px solid rgba(30, 58, 95, 0.7);
}

.site-footer__bottom-inner {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  justify-content: space-between;
  gap: 8px 24px;
  max-width: var(--max-width);
  margin-inline: auto;
  padding: 16px 20px;
}

.site-footer__icp,
.site-footer__copyright {
  margin: 0;
  font-size: 12px;
  color: var(--clr-slate);
}

.scroll-top {
  position: fixed;
  right: 24px;
  bottom: 24px;
  z-index: 1000;
  display: inline-flex;
  align-items: center;
  gap: 8px;
  padding: 10px 18px;
  background: var(--clr-gold);
  color: var(--clr-ink);
  border: none;
  font-family: var(--font-body);
  font-size: 13px;
  font-weight: 800;
  letter-spacing: 0.04em;
  cursor: pointer;
  box-shadow: var(--shadow-soft);
  opacity: 0;
  visibility: hidden;
  transform: translateY(12px);
  transition: opacity var(--ease-fast), transform var(--ease-fast), visibility var(--ease-fast);
}

.scroll-top:hover {
  background: var(--clr-gold-light);
}

.scroll-top.is-visible {
  opacity: 1;
  visibility: visible;
  transform: translateY(0);
}

@media (max-width: 767px) {
  .scroll-top {
    right: 16px;
    bottom: 16px;
    padding: 10px 14px;
  }

  .site-footer__bottom-inner {
    justify-content: center;
    text-align: center;
  }
}

/* ---------- 9. Shared Components ---------- */
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 8px;
  padding: 12px 28px;
  font-family: var(--font-body);
  font-size: 15px;
  font-weight: 800;
  line-height: 1.2;
  text-decoration: none;
  border: 2px solid transparent;
  cursor: pointer;
  transition: background-color var(--ease-fast), color var(--ease-fast), border-color var(--ease-fast), transform var(--ease-fast);
}

.btn--gold {
  background: linear-gradient(135deg, var(--clr-gold), var(--clr-gold-light));
  color: var(--clr-ink);
  border-color: var(--clr-gold);
}

.btn--gold:hover {
  background: var(--clr-gold-light);
  border-color: var(--clr-gold-light);
  color: var(--clr-ink);
  transform: translateY(-2px);
}

.btn--ghost {
  background: transparent;
  color: var(--clr-white);
  border-color: var(--clr-grid);
}

.btn--ghost:hover {
  border-color: var(--clr-gold);
  color: var(--clr-gold);
  transform: translateY(-2px);
}

.tag {
  display: inline-block;
  padding: 4px 12px;
  font-size: 12px;
  font-weight: 700;
  letter-spacing: 0.08em;
  text-transform: uppercase;
  color: var(--clr-gold);
  background: rgba(242, 201, 76, 0.1);
  border: 1px solid rgba(242, 201, 76, 0.35);
}

.section-heading {
  display: flex;
  align-items: center;
  flex-wrap: wrap;
  gap: 12px;
  margin-bottom: 28px;
}

.section-heading__index {
  font-size: 13px;
  font-weight: 800;
  letter-spacing: 0.1em;
  color: var(--clr-gold);
  border: 1px solid rgba(242, 201, 76, 0.4);
  padding: 3px 10px;
  line-height: 1.4;
}

.section-heading__title {
  font-family: var(--font-heading);
  font-size: clamp(26px, 4vw, 36px);
  font-weight: 900;
  line-height: 1.1;
  color: var(--clr-white);
  margin: 0;
}

.section-heading__caption {
  font-size: 12px;
  letter-spacing: 0.18em;
  text-transform: uppercase;
  color: var(--clr-slate);
  white-space: nowrap;
}

.caption-vertical {
  display: inline-block;
  writing-mode: vertical-rl;
  text-orientation: mixed;
  font-size: 12px;
  letter-spacing: 0.2em;
  text-transform: uppercase;
  color: var(--clr-slate);
  line-height: 1.4;
}

.breadcrumb {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 4px;
  padding: 12px 0;
  font-size: 13px;
  color: var(--clr-slate);
}

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

.breadcrumb__item + .breadcrumb__item::before {
  content: '→';
  color: var(--clr-grid);
  margin: 0 8px;
}

.breadcrumb__link {
  color: var(--clr-lake);
  text-decoration: none;
  transition: color var(--ease-fast);
}

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

.breadcrumb__current {
  color: var(--clr-white);
}

.figure-frame {
  position: relative;
  margin: 0;
  background: linear-gradient(145deg, var(--clr-card), var(--clr-ink));
  border: 1px solid rgba(30, 58, 95, 0.8);
  overflow: hidden;
  box-shadow: inset 0 0 30px rgba(7, 19, 38, 0.5);
}

.figure-frame::before {
  content: '';
  display: block;
  padding-bottom: 62.5%;
}

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

.figure-frame::after {
  content: '+';
  position: absolute;
  top: 8px;
  right: 10px;
  color: var(--clr-gold);
  font-size: 16px;
  font-weight: 700;
  opacity: 0.6;
  line-height: 1;
}

.figure-frame__label {
  position: absolute;
  left: 0;
  bottom: 0;
  z-index: 2;
  padding: 6px 12px;
  background: rgba(7, 19, 38, 0.85);
  color: var(--clr-white);
  font-size: 12px;
  letter-spacing: 0.08em;
  border-top: 1px solid rgba(242, 201, 76, 0.4);
}

.prose {
  max-width: 72ch;
  color: rgba(245, 247, 250, 0.88);
  font-size: 16px;
  line-height: 1.8;
}

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

.prose a {
  color: var(--clr-lake);
  text-decoration: underline;
  text-underline-offset: 4px;
  text-decoration-color: rgba(59, 176, 219, 0.4);
}

.prose a:hover {
  color: var(--clr-gold);
  text-decoration-color: var(--clr-gold);
}

.prose h2,
.prose h3,
.prose h4 {
  font-family: var(--font-heading);
  color: var(--clr-white);
  line-height: 1.25;
  margin-top: 1.5em;
}

.prose strong {
  color: var(--clr-gold);
}

.prose ul {
  list-style: none;
  padding-left: 0;
}

.prose li {
  position: relative;
  padding-left: 18px;
}

.prose li::before {
  content: '';
  position: absolute;
  left: 0;
  top: 0.62em;
  width: 6px;
  height: 6px;
  background: var(--clr-gold);
  transform: rotate(45deg);
}

.page-header {
  position: relative;
  padding: 48px 0 32px;
  border-bottom: 1px solid var(--clr-grid);
  margin-bottom: 40px;
}

.page-header__index {
  display: inline-block;
  font-size: 13px;
  font-weight: 800;
  letter-spacing: 0.14em;
  text-transform: uppercase;
  color: var(--clr-gold);
  margin-bottom: 8px;
}

.page-header__title {
  font-family: var(--font-heading);
  font-size: clamp(32px, 5vw, 48px);
  font-weight: 900;
  line-height: 1.1;
  color: var(--clr-white);
  margin: 0 0 8px;
}

.page-header__desc {
  font-size: 16px;
  color: var(--clr-slate);
  max-width: 60ch;
  line-height: 1.7;
}

/* ---------- 10. Reduced Motion ---------- */
@media (prefers-reduced-motion: reduce) {
  *,
  *::before,
  *::after {
    animation-duration: 0.01ms !important;
    animation-iteration-count: 1 !important;
    transition-duration: 0.01ms !important;
  }
}