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

html {
  scroll-behavior: smooth;
  -webkit-text-size-adjust: 100%;
  font-size: 16px;
}

body {
  font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", "PingFang SC", "Microsoft YaHei", "Helvetica Neue", Arial, sans-serif;
  font-weight: 400;
  line-height: 1.7;
  color: var(--color-text-primary);
  background-color: var(--color-bg-dark);
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
}

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

a {
  color: var(--color-link);
  text-decoration: none;
  transition: color 0.25s ease;
}

a:hover {
  color: var(--color-accent1);
}

ul,
ol {
  list-style: none;
}

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

:focus-visible {
  outline: 2px solid var(--color-accent1);
  outline-offset: 2px;
  border-radius: 2px;
}

/* ===== CSS Variables ===== */
:root {
  --color-primary: #0A1F3F;
  --color-accent1: #D4AF37;
  --color-accent2: #39FF14;
  --color-bg-dark: #0A1F3F;
  --color-bg-card: rgba(10, 31, 63, 0.8);
  --color-bg-light: #1A2F4F;
  --color-text-primary: #FFFFFF;
  --color-text-secondary: #B0C4DE;
  --color-text-accent: #D4AF37;
  --color-link: #39FF14;
  --font-mono: "SF Mono", "Source Code Pro", "Consolas", "Courier New", monospace;
  --header-height: 72px;
  --content-max-width: 1200px;
  --spacing-xs: 4px;
  --spacing-sm: 8px;
  --spacing-md: 16px;
  --spacing-lg: 32px;
  --spacing-xl: 64px;
}

/* ===== Scroll Progress ===== */
.scroll-progress {
  position: fixed;
  top: 0;
  left: 0;
  width: 0%;
  height: 3px;
  background: linear-gradient(90deg, var(--color-accent1), var(--color-accent2));
  z-index: 1001;
  transition: width 0.08s linear;
  pointer-events: none;
}

@media (prefers-reduced-motion: reduce) {
  .scroll-progress {
    transition: none;
  }
}

/* ===== Skip Link ===== */
.skip-link {
  position: absolute;
  top: -100%;
  left: 0;
  z-index: 1002;
  padding: 8px 16px;
  background: var(--color-accent1);
  color: var(--color-bg-dark);
  font-weight: 600;
  font-size: 0.875rem;
  border-radius: 0 0 4px 0;
  transition: top 0.2s ease;
}

.skip-link:focus {
  top: 0;
  outline: none;
}

/* ===== Header ===== */
.header {
  position: fixed;
  top: 0;
  left: 0;
  right: 0;
  z-index: 1000;
  height: var(--header-height);
  background: transparent;
  transition: background 0.4s ease, box-shadow 0.4s ease;
}

.header--solid {
  background: rgba(10, 31, 63, 0.92);
  backdrop-filter: blur(12px);
  -webkit-backdrop-filter: blur(12px);
  box-shadow: 0 1px 0 rgba(212, 175, 55, 0.12);
}

@media (prefers-reduced-motion: reduce) {
  .header {
    transition: none;
  }
  .header--solid {
    background: var(--color-bg-dark);
  }
}

.header__inner {
  display: flex;
  align-items: center;
  justify-content: space-between;
  max-width: var(--content-max-width);
  margin: 0 auto;
  padding: 0 var(--spacing-lg);
  height: 100%;
  position: relative;
}

/* Logo */
.header__logo {
  display: flex;
  align-items: center;
  gap: var(--spacing-sm);
  color: var(--color-accent1);
  font-size: 1.625rem;
  font-weight: 800;
  letter-spacing: 0.02em;
  flex-shrink: 0;
  transition: color 0.25s ease;
}

.header__logo:hover {
  color: var(--color-accent1);
  opacity: 0.85;
}

.header__logo-icon {
  font-size: 1.25rem;
  color: var(--color-accent2);
  line-height: 1;
}

.header__logo-text {
  line-height: 1;
}

/* Navigation */
.header__nav {
  display: flex;
  align-items: center;
}

.header__nav-list {
  display: flex;
  align-items: center;
  gap: var(--spacing-xs);
}

.header__nav-item {
  position: relative;
}

.header__nav-link {
  display: flex;
  align-items: center;
  gap: 6px;
  padding: 6px 14px;
  color: var(--color-text-secondary);
  font-size: 0.9375rem;
  font-weight: 500;
  border-radius: 4px;
  transition: color 0.25s ease, background 0.25s ease;
  white-space: nowrap;
}

.header__nav-link:hover {
  color: var(--color-text-primary);
  background: rgba(212, 175, 55, 0.08);
}

.header__nav-link[aria-current="page"] {
  color: var(--color-accent1);
}

.header__nav-link[aria-current="page"]::after {
  content: "";
  position: absolute;
  bottom: 0;
  left: 14px;
  right: 14px;
  height: 2px;
  background: var(--color-accent1);
  border-radius: 1px;
}

.header__nav-index {
  font-family: var(--font-mono);
  font-size: 0.7rem;
  color: var(--color-accent2);
  opacity: 0.6;
  font-weight: 400;
  letter-spacing: 0.04em;
}

.header__nav-label {
  line-height: 1.2;
}

/* CTA Button */
.header__cta {
  display: inline-flex;
  align-items: center;
  padding: 6px 18px;
  margin-left: var(--spacing-md);
  font-size: 0.8125rem;
  font-weight: 600;
  color: var(--color-accent1);
  border: 1px solid var(--color-accent1);
  border-radius: 4px;
  letter-spacing: 0.04em;
  transition: background 0.25s ease, color 0.25s ease;
  flex-shrink: 0;
  white-space: nowrap;
}

.header__cta:hover {
  background: var(--color-accent1);
  color: var(--color-bg-dark);
}

/* Mobile Toggle */
.header__toggle {
  display: none;
  flex-direction: column;
  justify-content: center;
  align-items: center;
  width: 40px;
  height: 40px;
  gap: 5px;
  background: transparent;
  border: none;
  cursor: pointer;
  flex-shrink: 0;
  z-index: 1001;
}

.header__toggle-bar {
  display: block;
  width: 24px;
  height: 2px;
  background: var(--color-text-primary);
  border-radius: 1px;
  transition: transform 0.3s ease, opacity 0.3s ease;
}

@media (prefers-reduced-motion: reduce) {
  .header__toggle-bar {
    transition: none;
  }
}

/* ===== Mobile Nav Open State ===== */
@media (max-width: 768px) {
  .header__toggle {
    display: flex;
  }

  .header__nav {
    position: fixed;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    background: rgba(10, 31, 63, 0.98);
    backdrop-filter: blur(16px);
    -webkit-backdrop-filter: blur(16px);
    display: flex;
    align-items: center;
    justify-content: center;
    opacity: 0;
    visibility: hidden;
    transition: opacity 0.35s ease, visibility 0.35s ease;
    z-index: 999;
  }

  .header__nav[data-open] {
    opacity: 1;
    visibility: visible;
  }

  .header__nav-list {
    flex-direction: column;
    gap: var(--spacing-lg);
    text-align: center;
  }

  .header__nav-link {
    font-size: 1.25rem;
    padding: 8px 24px;
    justify-content: center;
  }

  .header__nav-link[aria-current="page"]::after {
    left: 50%;
    transform: translateX(-50%);
    width: 40%;
  }

  .header__nav-index {
    font-size: 0.85rem;
  }

  .header__cta {
    display: none;
  }

  /* Toggle animation when open */
  .header__toggle[aria-expanded="true"] .header__toggle-bar:nth-child(1) {
    transform: translateY(7px) rotate(45deg);
  }

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

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

/* ===== Footer ===== */
.footer {
  background: var(--color-bg-dark);
  border-top: 1px solid rgba(212, 175, 55, 0.1);
  padding: var(--spacing-xl) 0 var(--spacing-lg);
}

.footer__inner {
  max-width: var(--content-max-width);
  margin: 0 auto;
  padding: 0 var(--spacing-lg);
  display: grid;
  grid-template-columns: 2fr 1fr 1.5fr;
  gap: var(--spacing-xl);
}

.footer__logo {
  display: inline-flex;
  align-items: center;
  gap: var(--spacing-sm);
  color: var(--color-accent1);
  font-size: 1.5rem;
  font-weight: 800;
  letter-spacing: 0.02em;
  transition: opacity 0.25s ease;
}

.footer__logo:hover {
  color: var(--color-accent1);
  opacity: 0.85;
}

.footer__logo-icon {
  font-size: 1.125rem;
  color: var(--color-accent2);
  line-height: 1;
}

.footer__logo-text {
  line-height: 1;
}

.footer__tagline {
  margin-top: var(--spacing-sm);
  color: var(--color-text-secondary);
  font-size: 0.9375rem;
  line-height: 1.6;
  max-width: 300px;
}

.footer__heading {
  color: var(--color-accent1);
  font-size: 0.9375rem;
  font-weight: 700;
  text-transform: uppercase;
  letter-spacing: 0.06em;
  margin-bottom: var(--spacing-md);
  padding-bottom: var(--spacing-sm);
  border-bottom: 1px solid rgba(212, 175, 55, 0.15);
}

.footer__link-list {
  display: flex;
  flex-direction: column;
  gap: var(--spacing-sm);
}

.footer__link {
  color: var(--color-text-secondary);
  font-size: 0.9rem;
  transition: color 0.25s ease, padding-left 0.25s ease;
  padding-left: 0;
}

.footer__link:hover {
  color: var(--color-accent1);
  padding-left: 4px;
}

.footer__contact-list {
  display: flex;
  flex-direction: column;
  gap: var(--spacing-sm);
}

.footer__contact-item {
  display: flex;
  flex-direction: column;
  gap: 2px;
}

.footer__contact-label {
  font-size: 0.75rem;
  color: var(--color-accent2);
  font-family: var(--font-mono);
  text-transform: uppercase;
  letter-spacing: 0.06em;
  opacity: 0.7;
}

.footer__contact-value {
  color: var(--color-text-secondary);
  font-size: 0.9rem;
  word-break: break-all;
}

a.footer__contact-value:hover {
  color: var(--color-accent1);
}

/* Footer Bottom */
.footer__bottom {
  max-width: var(--content-max-width);
  margin: var(--spacing-xl) auto 0;
  padding: var(--spacing-lg) var(--spacing-lg) 0;
  border-top: 1px solid rgba(176, 196, 222, 0.08);
  display: flex;
  flex-wrap: wrap;
  justify-content: space-between;
  align-items: center;
  gap: var(--spacing-md);
}

.footer__copyright {
  color: var(--color-text-secondary);
  font-size: 0.8125rem;
  opacity: 0.7;
}

.footer__trust {
  color: var(--color-text-secondary);
  font-size: 0.75rem;
  opacity: 0.5;
  font-family: var(--font-mono);
  letter-spacing: 0.03em;
}

/* Footer Responsive */
@media (max-width: 768px) {
  .footer__inner {
    grid-template-columns: 1fr;
    gap: var(--spacing-lg);
    text-align: center;
  }

  .footer__tagline {
    max-width: 100%;
    margin-left: auto;
    margin-right: auto;
  }

  .footer__heading {
    text-align: center;
  }

  .footer__link-list {
    align-items: center;
  }

  .footer__contact-list {
    align-items: center;
  }

  .footer__contact-item {
    align-items: center;
  }

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

/* ===== Shared Utilities ===== */
.container {
  max-width: var(--content-max-width);
  margin: 0 auto;
  padding: 0 var(--spacing-lg);
  width: 100%;
}

/* Buttons */
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  padding: 10px 28px;
  font-size: 0.9375rem;
  font-weight: 600;
  border-radius: 4px;
  transition: background 0.3s ease, color 0.3s ease, border-color 0.3s ease;
  cursor: pointer;
  border: 1px solid transparent;
  line-height: 1.4;
  text-decoration: none;
}

.btn--primary {
  background: var(--color-accent1);
  color: var(--color-bg-dark);
  border-color: var(--color-accent1);
}

.btn--primary:hover {
  background: transparent;
  color: var(--color-accent1);
}

.btn--outline {
  background: transparent;
  color: var(--color-accent1);
  border-color: var(--color-accent1);
}

.btn--outline:hover {
  background: var(--color-accent1);
  color: var(--color-bg-dark);
}

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

.btn--ghost:hover {
  color: var(--color-text-primary);
  background: rgba(255, 255, 255, 0.05);
}

/* Breadcrumb */
.breadcrumb {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: var(--spacing-sm);
  padding: var(--spacing-md) 0;
  font-size: 0.85rem;
  color: var(--color-text-secondary);
}

.breadcrumb li {
  display: flex;
  align-items: center;
  gap: var(--spacing-sm);
}

.breadcrumb li + li::before {
  content: "/";
  color: var(--color-text-secondary);
  opacity: 0.4;
  font-family: var(--font-mono);
  font-size: 0.75rem;
}

.breadcrumb a {
  color: var(--color-text-secondary);
  transition: color 0.25s ease;
}

.breadcrumb a:hover {
  color: var(--color-accent1);
}

.breadcrumb [aria-current="page"] {
  color: var(--color-accent1);
  font-weight: 500;
}

/* Section Titles */
.section-title {
  font-size: 2.5rem;
  font-weight: 800;
  color: var(--color-accent1);
  line-height: 1.15;
  letter-spacing: -0.02em;
  margin-bottom: var(--spacing-sm);
}

.section-subtitle {
  font-size: 1.125rem;
  color: var(--color-text-secondary);
  line-height: 1.6;
  max-width: 640px;
}

@media (max-width: 768px) {
  .section-title {
    font-size: 1.875rem;
  }
  .section-subtitle {
    font-size: 1rem;
  }
}

/* Monospace data text */
.data-text {
  font-family: var(--font-mono);
  color: var(--color-accent2);
  font-size: 0.9375rem;
  letter-spacing: 0.02em;
}

/* Card base */
.card {
  background: var(--color-bg-card);
  border: 1px solid rgba(212, 175, 55, 0.08);
  border-radius: 6px;
  padding: var(--spacing-lg);
  backdrop-filter: blur(4px);
  -webkit-backdrop-filter: blur(4px);
  transition: border-color 0.3s ease, box-shadow 0.3s ease;
}

.card:hover {
  border-color: rgba(212, 175, 55, 0.25);
  box-shadow: 0 4px 24px rgba(10, 31, 63, 0.5);
}

/* Responsive spacing */
@media (max-width: 480px) {
  .header__inner,
  .footer__inner,
  .footer__bottom {
    padding-left: var(--spacing-md);
    padding-right: var(--spacing-md);
  }

  .container {
    padding-left: var(--spacing-md);
    padding-right: var(--spacing-md);
  }
}

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