/* ========== CSS Variables ========== */
:root {
  --c-deep: #0D1B3E;
  --c-orange: #FF7A00;
  --c-lime: #39FF14;
  --c-light: #F5F5F5;
  --c-white: #FFFFFF;
  --c-text: #222222;
  --c-gray: #666666;
  --c-border: #DDDDDD;

  --font-heading: 'Noto Sans SC', 'Source Han Sans SC', 'PingFang SC', 'Microsoft YaHei', sans-serif;
  --font-body: 'Source Han Sans SC', 'Noto Sans SC', 'PingFang SC', 'Microsoft YaHei', sans-serif;

  --container-w: 1280px;
  --container-pad: 32px;

  --shadow-card: 4px 4px 0 rgba(13, 27, 62, 0.14);
  --shadow-btn: 3px 3px 0 rgba(13, 27, 62, 0.25);
}

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

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

body {
  margin: 0;
  font-family: var(--font-body);
  font-size: 16px;
  line-height: 1.75;
  color: var(--c-text);
  background: var(--c-light);
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
}

h1, h2, h3, h4, h5, h6 {
  font-family: var(--font-heading);
  font-weight: 900;
  line-height: 1.25;
  margin: 0 0 16px;
  color: var(--c-deep);
  letter-spacing: 0.02em;
}

p {
  margin: 0 0 16px;
}

ul, ol {
  margin: 0;
  padding: 0;
}

a {
  color: var(--c-orange);
  text-decoration: none;
  transition: color 0.2s ease;
}

a:hover {
  color: #d46400;
  text-decoration: underline;
}

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

address {
  font-style: normal;
}

button {
  font-family: inherit;
  font-size: inherit;
  line-height: inherit;
}

main {
  display: block;
}

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

/* ========== Accessibility ========== */
.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: 12px;
  left: 12px;
  z-index: 3000;
  display: inline-block;
  padding: 10px 20px;
  background: var(--c-orange);
  color: #fff;
  font-family: var(--font-heading);
  font-weight: 700;
  font-size: 14px;
  letter-spacing: 0.04em;
  border: 2px solid #fff;
  box-shadow: 4px 4px 0 rgba(13, 27, 62, 0.4);
  transform: translateY(-220%);
  transition: transform 0.2s ease;
}

.skip-link:focus {
  transform: translateY(0);
  color: #fff;
  text-decoration: none;
}

#main-content {
  min-height: 60vh;
}

#main-content:focus {
  outline: none;
}

/* ========== Layout Helpers ========== */
.container {
  max-width: var(--container-w);
  margin: 0 auto;
  padding: 0 var(--container-pad);
}

.prose ul,
.prose ol {
  margin-bottom: 16px;
  padding-left: 1.5em;
}

.prose li + li {
  margin-top: 4px;
}

/* ========== Buttons ========== */
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 8px;
  padding: 12px 28px;
  font-family: var(--font-heading);
  font-weight: 700;
  font-size: 15px;
  line-height: 1.4;
  letter-spacing: 0.06em;
  border: 2px solid transparent;
  cursor: pointer;
  text-decoration: none;
  transition: background 0.2s ease, color 0.2s ease, border-color 0.2s ease,
              box-shadow 0.2s ease, transform 0.2s ease;
}

.btn:hover {
  text-decoration: none;
}

.btn-primary {
  background: var(--c-orange);
  color: #fff;
  border-color: var(--c-orange);
  box-shadow: var(--shadow-btn);
}

.btn-primary:hover {
  background: #e06a00;
  border-color: #e06a00;
  color: #fff;
  box-shadow: 1px 1px 0 rgba(13, 27, 62, 0.25);
  transform: translate(2px, 2px);
}

.btn-outline {
  background: transparent;
  color: var(--c-deep);
  border-color: var(--c-deep);
  box-shadow: none;
}

.btn-outline:hover {
  background: var(--c-deep);
  color: #fff;
}

/* ========== Scroll Progress ========== */
.scroll-progress {
  position: fixed;
  top: 0;
  left: 0;
  height: 4px;
  width: 0%;
  z-index: 2500;
  pointer-events: none;
  background: linear-gradient(90deg, var(--c-orange) 0%, var(--c-lime) 100%);
  box-shadow: 0 0 10px rgba(57, 255, 20, 0.45);
}

/* ========== Header ========== */
.site-header {
  background:
    radial-gradient(ellipse 520px 180px at 12% -30%, rgba(57, 255, 20, 0.16), transparent 70%),
    radial-gradient(ellipse 560px 200px at 88% -25%, rgba(255, 122, 0, 0.14), transparent 70%),
    var(--c-deep);
  color: #fff;
  position: sticky;
  top: 0;
  z-index: 1200;
  border-bottom: 3px solid var(--c-orange);
}

.header-topbar {
  max-width: var(--container-w);
  margin: 0 auto;
  padding: 10px var(--container-pad);
  display: flex;
  justify-content: space-between;
  align-items: center;
  gap: 16px;
  border-bottom: 1px solid rgba(255, 255, 255, 0.08);
}

.header-slogan {
  margin: 0;
  font-family: var(--font-heading);
  font-size: 12px;
  font-weight: 400;
  letter-spacing: 0.16em;
  text-transform: uppercase;
  color: rgba(255, 255, 255, 0.55);
}

.header-status {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  font-family: var(--font-heading);
  font-size: 12px;
  font-weight: 500;
  letter-spacing: 0.08em;
  color: rgba(255, 255, 255, 0.65);
}

.status-dot {
  display: inline-block;
  width: 7px;
  height: 7px;
  border-radius: 50%;
  background: var(--c-lime);
  box-shadow: 0 0 8px rgba(57, 255, 20, 0.7);
  animation: status-pulse 2s ease-in-out infinite;
}

@keyframes status-pulse {
  0%, 100% {
    opacity: 1;
    transform: scale(1);
  }
  50% {
    opacity: 0.5;
    transform: scale(0.75);
  }
}

.header-masthead {
  max-width: var(--container-w);
  margin: 0 auto;
  padding: 24px var(--container-pad) 18px;
  display: flex;
  justify-content: center;
  align-items: center;
  position: relative;
}

.brand {
  display: inline-flex;
  align-items: center;
  gap: 14px;
  color: #fff;
  text-decoration: none;
}

.brand:hover {
  color: #fff;
  text-decoration: none;
}

.brand-mark {
  width: 42px;
  height: 42px;
  flex-shrink: 0;
  filter: drop-shadow(0 2px 6px rgba(255, 122, 0, 0.35));
}

.brand-name {
  font-family: var(--font-heading);
  font-weight: 900;
  font-size: 30px;
  letter-spacing: 0.06em;
  line-height: 1.15;
  color: #fff;
  text-shadow: 0 2px 12px rgba(13, 27, 62, 0.5);
}

.header-cta {
  position: absolute;
  right: var(--container-pad);
  top: 50%;
  transform: translateY(-50%);
  display: inline-flex;
  align-items: center;
  gap: 6px;
  padding: 10px 22px;
  background: var(--c-orange);
  color: #fff;
  font-family: var(--font-heading);
  font-weight: 700;
  font-size: 14px;
  letter-spacing: 0.06em;
  border: 2px solid var(--c-orange);
  box-shadow: 3px 3px 0 rgba(0, 0, 0, 0.25);
  transition: background 0.2s ease, box-shadow 0.2s ease;
}

.header-cta:hover {
  background: #e06a00;
  border-color: #e06a00;
  color: #fff;
  text-decoration: none;
  box-shadow: 1px 1px 0 rgba(0, 0, 0, 0.25);
}

.header-navbar {
  max-width: var(--container-w);
  margin: 0 auto;
  padding: 0 var(--container-pad);
  display: flex;
  flex-wrap: wrap;
  justify-content: center;
  align-items: center;
}

.site-nav {
  flex: 1;
}

.nav-list {
  list-style: none;
  display: flex;
  justify-content: center;
  align-items: center;
  gap: 0;
  margin: 0;
  padding: 0;
}

.nav-item {
  margin: 0;
  padding: 0;
}

.nav-link {
  display: block;
  padding: 16px 26px;
  color: rgba(255, 255, 255, 0.85);
  font-family: var(--font-heading);
  font-size: 15px;
  font-weight: 500;
  letter-spacing: 0.08em;
  text-decoration: none;
  border-bottom: 3px solid transparent;
  transition: color 0.2s ease, background 0.2s ease, border-color 0.2s ease;
}

.nav-link:hover {
  color: #fff;
  text-decoration: none;
  background: rgba(255, 255, 255, 0.06);
  border-bottom-color: rgba(255, 255, 255, 0.25);
}

.nav-link[aria-current="page"] {
  color: #fff;
  font-weight: 700;
  background: rgba(255, 122, 0, 0.14);
  border-bottom-color: var(--c-orange);
}

.nav-toggle {
  display: none;
}

.nav-toggle-text {
  font-family: var(--font-heading);
  font-size: 14px;
  font-weight: 700;
  letter-spacing: 0.08em;
}

/* ========== Footer ========== */
.site-footer {
  margin-top: 96px;
  background:
    radial-gradient(ellipse 620px 220px at 100% -40%, rgba(255, 122, 0, 0.07), transparent 70%),
    radial-gradient(ellipse 480px 180px at 0% 120%, rgba(57, 255, 20, 0.04), transparent 70%),
    var(--c-deep);
  color: rgba(255, 255, 255, 0.75);
  border-top: 4px solid var(--c-orange);
  position: relative;
}

.site-footer::before {
  content: '';
  display: block;
  position: absolute;
  top: 4px;
  left: 0;
  width: 28%;
  height: 2px;
  background: var(--c-lime);
  pointer-events: none;
}

.footer-main {
  max-width: var(--container-w);
  margin: 0 auto;
  padding: 64px var(--container-pad) 48px;
  display: grid;
  grid-template-columns: 1.6fr 1fr 1fr;
  gap: 48px;
}

.footer-brand-col {
  display: flex;
  flex-direction: column;
  align-items: flex-start;
}

.footer-brand {
  display: inline-flex;
  align-items: center;
  gap: 12px;
  color: #fff;
  text-decoration: none;
}

.footer-brand:hover {
  color: #fff;
  text-decoration: none;
}

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

.footer-brand .brand-name {
  font-size: 24px;
}

.footer-slogan {
  margin: 16px 0 0;
  font-family: var(--font-heading);
  font-size: 14px;
  font-weight: 500;
  letter-spacing: 0.12em;
  color: var(--c-orange);
}

.footer-trust {
  margin: 16px 0 0;
  font-size: 13px;
  line-height: 1.7;
  color: rgba(255, 255, 255, 0.5);
  max-width: 34em;
}

.footer-contact {
  margin-top: 20px;
  display: flex;
  flex-direction: column;
  gap: 4px;
  font-size: 13px;
  line-height: 1.6;
  color: rgba(255, 255, 255, 0.6);
}

.contact-item {
  display: inline-block;
}

.footer-col {
  padding-top: 4px;
}

.footer-col-title {
  margin: 0 0 16px;
  color: #fff;
  font-family: var(--font-heading);
  font-size: 16px;
  font-weight: 700;
  letter-spacing: 0.08em;
  padding-bottom: 8px;
  border-bottom: 2px solid var(--c-orange);
  display: inline-block;
}

.footer-links {
  list-style: none;
  margin: 0;
  padding: 0;
  display: flex;
  flex-direction: column;
  gap: 10px;
}

.footer-links a {
  color: rgba(255, 255, 255, 0.65);
  font-size: 14px;
  text-decoration: none;
  position: relative;
  padding-left: 16px;
  transition: color 0.2s ease;
}

.footer-links a::before {
  content: '→';
  position: absolute;
  left: 0;
  top: 0;
  color: var(--c-lime);
  font-size: 13px;
  opacity: 0.7;
}

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

.footer-bottom {
  max-width: var(--container-w);
  margin: 0 auto;
  padding: 20px var(--container-pad);
  display: flex;
  justify-content: space-between;
  align-items: center;
  gap: 16px;
  border-top: 1px solid rgba(255, 255, 255, 0.08);
  font-size: 13px;
  letter-spacing: 0.04em;
  color: rgba(255, 255, 255, 0.45);
}

.footer-icp {
  font-family: var(--font-heading);
  letter-spacing: 0.08em;
}

/* ========== Back to Top ========== */
.back-to-top {
  position: fixed;
  right: 24px;
  bottom: 24px;
  width: 50px;
  height: 50px;
  display: flex;
  align-items: center;
  justify-content: center;
  background: var(--c-deep);
  color: var(--c-orange);
  border: 2px solid var(--c-orange);
  cursor: pointer;
  box-shadow: 4px 4px 0 rgba(13, 27, 62, 0.25);
  opacity: 0;
  visibility: hidden;
  transform: translateY(8px);
  transition: opacity 0.25s ease, transform 0.25s ease, visibility 0.25s ease,
              background 0.2s ease;
  z-index: 1100;
}

.back-to-top[data-visible] {
  opacity: 1;
  visibility: visible;
  transform: translateY(0);
}

.back-to-top:hover {
  background: var(--c-orange);
  color: var(--c-deep);
}

.back-to-top svg {
  width: 20px;
  height: 20px;
}

/* ========== Shared Content Components ========== */
.section-label {
  display: inline-flex;
  align-items: center;
  gap: 10px;
  font-family: var(--font-heading);
  font-size: 13px;
  font-weight: 500;
  letter-spacing: 0.16em;
  text-transform: uppercase;
  color: var(--c-orange);
}

.section-label::before {
  content: '';
  display: inline-block;
  width: 28px;
  height: 3px;
  background: var(--c-orange);
}

.card {
  background: var(--c-white);
  border: 2px solid var(--c-deep);
  box-shadow: var(--shadow-card);
  padding: 24px;
}

.breadcrumbs {
  list-style: none;
  display: flex;
  flex-wrap: wrap;
  gap: 0;
  padding: 0;
  margin: 24px 0 0;
  font-family: var(--font-heading);
  font-size: 13px;
  letter-spacing: 0.06em;
  color: var(--c-gray);
}

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

.breadcrumbs li + li::before {
  content: '/';
  margin: 0 10px;
  color: var(--c-border);
}

.breadcrumbs a {
  color: var(--c-deep);
  text-decoration: none;
}

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

.breadcrumbs [aria-current="page"] {
  color: var(--c-gray);
}

.image-container {
  position: relative;
  overflow: hidden;
  background: linear-gradient(135deg, #14264f 0%, #0D1B3E 100%);
  border: 2px solid var(--c-deep);
}

.image-container::before {
  content: '';
  display: block;
  padding-top: 56.25%;
}

.image-container--portrait::before {
  padding-top: 133.33%;
}

.image-container--square::before {
  padding-top: 100%;
}

.image-container img,
.image-container-media {
  position: absolute;
  top: 0;
  left: 0;
  width: 100%;
  height: 100%;
  object-fit: cover;
}

/* ========== Responsive ========== */
@media (max-width: 1024px) {
  :root {
    --container-pad: 24px;
  }

  .brand-name {
    font-size: 26px;
  }

  .nav-link {
    padding: 14px 18px;
    font-size: 14px;
  }

  .footer-main {
    grid-template-columns: 1.4fr 1fr 1fr;
    gap: 32px;
  }
}

@media (max-width: 860px) {
  .header-topbar {
    padding-top: 8px;
    padding-bottom: 8px;
  }

  .header-masthead {
    padding: 20px var(--container-pad) 14px;
  }

  .brand-name {
    font-size: 24px;
  }

  .header-cta {
    padding: 8px 16px;
    font-size: 13px;
  }

  .header-navbar {
    justify-content: flex-end;
    padding-top: 6px;
    padding-bottom: 6px;
  }

  .nav-toggle {
    display: inline-flex;
    align-items: center;
    gap: 8px;
    padding: 10px 0;
    background: none;
    border: none;
    cursor: pointer;
    color: #fff;
    font-family: var(--font-heading);
    font-size: 14px;
    font-weight: 700;
    letter-spacing: 0.08em;
    -webkit-tap-highlight-color: transparent;
  }

  .nav-toggle-box {
    display: flex;
    flex-direction: column;
    gap: 4px;
    width: 20px;
  }

  .nav-toggle-bar {
    display: block;
    width: 20px;
    height: 2px;
    background: #fff;
    border-radius: 1px;
    transition: transform 0.2s ease, opacity 0.2s ease;
  }

  .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);
  }

  .site-nav {
    order: 3;
    flex-basis: 100%;
    display: none;
  }

  .site-nav[data-open] {
    display: block;
  }

  .nav-list {
    flex-direction: column;
    align-items: stretch;
    gap: 0;
    padding: 4px 0 8px;
  }

  .nav-link {
    padding: 13px 16px;
    border-bottom: 1px solid rgba(255, 255, 255, 0.08);
    border-left: 3px solid transparent;
  }

  .nav-link[aria-current="page"] {
    border-left-color: var(--c-orange);
    border-bottom-color: rgba(255, 255, 255, 0.08);
  }

  .footer-main {
    grid-template-columns: 1fr 1fr;
    padding: 48px var(--container-pad) 32px;
  }

  .footer-brand-col {
    grid-column: 1 / -1;
  }

  .footer-bottom {
    flex-direction: column;
    align-items: flex-start;
    gap: 8px;
  }
}

@media (max-width: 560px) {
  :root {
    --container-pad: 18px;
  }

  .header-slogan {
    display: none;
  }

  .header-topbar {
    justify-content: center;
  }

  .brand {
    gap: 8px;
  }

  .brand-mark {
    width: 32px;
    height: 32px;
  }

  .brand-name {
    font-size: 20px;
    letter-spacing: 0.04em;
  }

  .header-cta {
    padding: 8px 14px;
    font-size: 12px;
  }

  .footer-main {
    grid-template-columns: 1fr;
    gap: 24px;
    padding: 40px var(--container-pad) 24px;
  }

  .footer-brand-col {
    grid-column: 1;
  }

  .back-to-top {
    right: 16px;
    bottom: 16px;
    width: 44px;
    height: 44px;
  }
}

@media (max-width: 400px) {
  .brand-mark {
    width: 28px;
    height: 28px;
  }

  .brand-name {
    font-size: 16px;
    letter-spacing: 0.02em;
  }

  .header-cta {
    padding: 6px 8px;
    font-size: 12px;
    right: 12px;
  }

  .header-masthead {
    padding: 16px 12px 12px;
  }

  .header-topbar {
    padding: 8px 12px;
  }

  .header-navbar {
    padding: 0 12px;
  }
}

/* ========== 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;
    transition-delay: 0ms !important;
  }

  .status-dot {
    animation: none !important;
  }
}