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

:root {
  --color-deep: #0B1E3A;
  --color-orange: #FF6A00;
  --color-silver: #C0C0C8;
  --color-night: #1C1C1E;
  --color-rock: #4A4A4A;
  --color-moss: #6B8E23;
  --color-terra: #D2691E;
  --color-cream: #F5F5DC;

  --font-display: 'Anton', Impact, 'Arial Black', 'Microsoft YaHei', sans-serif;
  --font-body: 'Open Sans', Roboto, 'Helvetica Neue', 'PingFang SC', 'Microsoft YaHei', sans-serif;

  --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;

  --radius-sm: 6px;
  --radius-md: 12px;
  --radius-lg: 20px;
  --radius-pill: 999px;

  --container-max: 1100px;
  --rail-width: 240px;
  --header-h-mobile: 64px;

  --transition-fast: 200ms ease-out;
  --transition-base: 300ms ease-out;
}

html {
  scroll-behavior: smooth;
}

body {
  font-family: var(--font-body);
  font-size: 1rem;
  line-height: 1.75;
  background: var(--color-deep);
  color: var(--color-night);
  -webkit-font-smoothing: antialiased;
  min-height: 100vh;
}

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

ul,
ol {
  list-style: none;
}

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

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

input,
textarea,
select {
  font: inherit;
}

/* ===== 2. Base Typography ===== */
h1,
h2,
h3,
h4 {
  font-family: var(--font-display);
  font-weight: 400;
  line-height: 1.15;
  letter-spacing: 0.02em;
  color: var(--color-deep);
}

h1 {
  font-size: 3.5rem;
  text-transform: uppercase;
}

h2 {
  font-size: 2.5rem;
}

h3 {
  font-size: 1.5rem;
}

p {
  margin-bottom: var(--space-4);
}

/* ===== 3. Layout & Container ===== */
#main-content {
  display: block;
  min-height: 70vh;
  background: var(--color-cream);
}

.container {
  width: min(100% - 2rem, var(--container-max));
  margin-inline: auto;
}

@media (min-width: 1024px) {
  #main-content {
    margin-left: var(--rail-width);
  }
  .site-footer {
    margin-left: var(--rail-width);
  }
}

/* ===== 4. Header ===== */
.site-header {
  position: fixed;
  top: 0;
  left: 0;
  right: 0;
  z-index: 2000;
  height: var(--header-h-mobile);
  background: var(--color-deep);
  box-shadow: 0 2px 16px rgba(0, 0, 0, 0.35);
  display: flex;
  flex-direction: column;
  justify-content: center;
}

.header-top {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 0 var(--space-5);
  position: relative;
  z-index: 2;
}

.site-header::before {
  content: '';
  position: absolute;
  inset: 0;
  pointer-events: none;
  background:
    linear-gradient(180deg, rgba(255, 106, 0, 0.05), transparent 40%),
    repeating-linear-gradient(
      -45deg,
      rgba(192, 192, 200, 0.04) 0,
      rgba(192, 192, 200, 0.04) 1px,
      transparent 1px,
      transparent 8px
    );
}

/* ===== 4a. Brand ===== */
.brand {
  display: inline-flex;
  align-items: center;
  gap: var(--space-3);
}

.brand-mark {
  position: relative;
  display: inline-flex;
  align-items: center;
  justify-content: center;
  width: 40px;
  height: 40px;
  border-radius: var(--radius-md);
  background: linear-gradient(135deg, var(--color-orange), #FF9A33);
  color: var(--color-deep);
  font-family: var(--font-display);
  font-size: 1.5rem;
  font-weight: 700;
  line-height: 1;
  flex-shrink: 0;
}

.brand-mark::after {
  content: '';
  position: absolute;
  top: -2px;
  right: -2px;
  width: 8px;
  height: 8px;
  background: var(--color-orange);
  border-radius: 50%;
  border: 2px solid var(--color-deep);
  animation: brand-pulse 2.4s ease-out infinite;
}

@keyframes brand-pulse {
  0%, 100% {
    box-shadow: 0 0 0 0 rgba(255, 106, 0, 0.6);
  }
  60% {
    box-shadow: 0 0 0 8px rgba(255, 106, 0, 0);
  }
}

.brand-copy {
  display: flex;
  align-items: baseline;
  gap: var(--space-2);
  line-height: 1.2;
}

.brand-title {
  font-family: var(--font-display);
  font-size: 1.125rem;
  letter-spacing: 0.06em;
  color: #fff;
  text-transform: uppercase;
  white-space: nowrap;
  font-weight: 400;
}

.brand-tagline {
  font-size: 0.625rem;
  letter-spacing: 0.2em;
  color: var(--color-silver);
  text-transform: uppercase;
  white-space: nowrap;
}

/* ===== 4b. Toggle Button ===== */
.nav-toggle {
  display: inline-flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  width: 44px;
  height: 44px;
  border: 1px solid rgba(192, 192, 200, 0.25);
  border-radius: var(--radius-md);
  gap: 4px;
  transition: border-color var(--transition-fast);
  background: rgba(11, 30, 58, 0.5);
  position: relative;
  z-index: 2;
}

.nav-toggle:hover {
  border-color: var(--color-orange);
}

.nav-bars {
  display: flex;
  flex-direction: column;
  gap: 4px;
}

.nav-bar {
  display: block;
  width: 20px;
  height: 2px;
  border-radius: 2px;
  background: var(--color-silver);
  transition: transform var(--transition-base), opacity var(--transition-base), background var(--transition-fast);
}

.nav-toggle[aria-expanded="true"] {
  border-color: var(--color-orange);
}

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

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

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

/* ===== 4c. Navigation ===== */
.site-nav {
  position: fixed;
  top: 0;
  left: 0;
  bottom: 0;
  width: min(80vw, 320px);
  background: var(--color-deep);
  padding: calc(var(--header-h-mobile) + var(--space-4)) var(--space-5) var(--space-5);
  transform: translateX(-100%);
  transition: transform 0.35s cubic-bezier(0.22, 1, 0.36, 1);
  z-index: 1990;
  overflow-y: auto;
  display: flex;
  flex-direction: column;
}

.site-nav[data-open] {
  transform: translateX(0);
  box-shadow: 6px 0 32px rgba(0, 0, 0, 0.5);
}

.site-nav::before {
  content: '';
  position: absolute;
  inset: 0;
  pointer-events: none;
  background: repeating-linear-gradient(
    -45deg,
    rgba(192, 192, 200, 0.03) 0,
    rgba(192, 192, 200, 0.03) 1px,
    transparent 1px,
    transparent 10px
  );
}

.nav-list {
  display: flex;
  flex-direction: column;
  gap: var(--space-1);
  flex: 1;
  position: relative;
  z-index: 1;
}

.nav-link {
  display: flex;
  align-items: center;
  gap: var(--space-3);
  padding: var(--space-3) var(--space-4);
  color: var(--color-silver);
  font-size: 0.9375rem;
  font-weight: 600;
  border-radius: var(--radius-md);
  transition: background var(--transition-fast), color var(--transition-fast);
}

.nav-link::before {
  content: '';
  width: 6px;
  height: 6px;
  border-radius: 50%;
  background: currentColor;
  opacity: 0.3;
  transition: all var(--transition-fast);
  flex-shrink: 0;
}

.nav-link:hover {
  color: #fff;
  background: rgba(255, 255, 255, 0.06);
}

.nav-link:hover::before {
  background: var(--color-orange);
  opacity: 1;
}

.nav-link[aria-current="page"] {
  color: var(--color-orange);
  background: rgba(255, 106, 0, 0.1);
}

.nav-link[aria-current="page"]::before {
  background: var(--color-orange);
  opacity: 1;
  box-shadow: 0 0 10px var(--color-orange);
}

.nav-cta-btn {
  margin-top: var(--space-4);
  position: relative;
  z-index: 1;
}

.btn-dot {
  width: 8px;
  height: 8px;
  border-radius: 50%;
  background: #fff;
  animation: dot-blink 1.8s ease-in-out infinite;
  flex-shrink: 0;
}

@keyframes dot-blink {
  0%, 100% { opacity: 1; }
  50% { opacity: 0.45; }
}

/* ===== 5. Buttons ===== */
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: var(--space-2);
  padding: var(--space-3) var(--space-6);
  border-radius: var(--radius-pill);
  font-family: var(--font-body);
  font-size: 0.9375rem;
  font-weight: 700;
  line-height: 1.4;
  text-decoration: none;
  border: 2px solid transparent;
  cursor: pointer;
  white-space: nowrap;
  transition: background var(--transition-base), color var(--transition-base), border-color var(--transition-base), box-shadow var(--transition-base), transform var(--transition-fast);
}

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

.btn-primary:hover,
.btn-primary:focus-visible {
  background: #FF7D22;
  border-color: #FF7D22;
  box-shadow: 0 6px 24px rgba(255, 106, 0, 0.35);
  transform: translateY(-2px);
}

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

/* ===== 6. Footer ===== */
.site-footer {
  background:
    repeating-linear-gradient(
      -45deg,
      rgba(192, 192, 200, 0.03) 0,
      rgba(192, 192, 200, 0.03) 1px,
      transparent 1px,
      transparent 12px
    ),
    var(--color-night);
  color: var(--color-silver);
  padding: var(--space-8) 0 0;
}

.footer-grid {
  display: grid;
  gap: var(--space-6);
  grid-template-columns: 1fr;
  width: min(100% - 2.5rem, var(--container-max));
  margin-inline: auto;
}

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

.footer-brand {
  display: inline-flex;
  align-items: center;
  gap: var(--space-3);
}

.footer-brand-mark {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  width: 34px;
  height: 34px;
  border-radius: var(--radius-sm);
  background: linear-gradient(135deg, var(--color-orange), #FF9A33);
  color: var(--color-deep);
  font-family: var(--font-display);
  font-size: 1.25rem;
  font-weight: 700;
  line-height: 1;
}

.footer-brand-copy {
  display: flex;
  flex-direction: column;
  line-height: 1.2;
  gap: 2px;
}

.footer-brand-title {
  font-family: var(--font-display);
  font-size: 1.125rem;
  color: #fff;
  letter-spacing: 0.06em;
  text-transform: uppercase;
}

.footer-brand-tag {
  font-size: 0.625rem;
  letter-spacing: 0.22em;
  color: var(--color-silver);
  text-transform: uppercase;
}

.footer-trust {
  font-size: 0.8125rem;
  line-height: 1.7;
  color: rgba(192, 192, 200, 0.65);
  max-width: 38ch;
  margin: 0;
}

.footer-heading {
  font-family: var(--font-display);
  font-size: 1rem;
  font-weight: 400;
  letter-spacing: 0.08em;
  text-transform: uppercase;
  color: #fff;
  margin-bottom: var(--space-4);
  position: relative;
  padding-bottom: var(--space-2);
}

.footer-heading::after {
  content: '';
  position: absolute;
  left: 0;
  bottom: 0;
  width: 24px;
  height: 2px;
  background: var(--color-orange);
  border-radius: 2px;
}

.footer-nav-list,
.footer-contact-list,
.footer-legal-list {
  display: flex;
  flex-direction: column;
  gap: var(--space-2);
  font-size: 0.875rem;
}

.footer-nav-list a,
.footer-legal-list a {
  color: var(--color-silver);
  transition: color var(--transition-fast);
  display: inline-block;
  padding: 2px 0;
}

.footer-nav-list a:hover,
.footer-legal-list a:hover {
  color: var(--color-orange);
}

.footer-contact-list li {
  display: flex;
  flex-direction: column;
  gap: 2px;
}

.contact-label {
  font-size: 0.6875rem;
  letter-spacing: 0.12em;
  text-transform: uppercase;
  color: var(--color-moss);
  font-weight: 700;
}

.contact-value {
  color: rgba(192, 192, 200, 0.8);
  font-size: 0.875rem;
  word-break: break-all;
}

.footer-bottom {
  border-top: 1px solid rgba(192, 192, 200, 0.12);
  margin-top: var(--space-6);
  padding: var(--space-5) var(--space-5);
  display: flex;
  flex-direction: column;
  gap: var(--space-2);
  align-items: center;
  justify-content: center;
  text-align: center;
  width: min(100% - 2.5rem, var(--container-max));
  margin-left: auto;
  margin-right: auto;
}

.footer-copyright,
.footer-icp {
  font-size: 0.8125rem;
  color: rgba(192, 192, 200, 0.55);
  margin: 0;
}

/* ===== 7. Scroll Progress ===== */
.scroll-progress {
  position: fixed;
  top: 0;
  left: 0;
  height: 3px;
  width: 0%;
  background: linear-gradient(90deg, var(--color-orange), #FFB84D);
  z-index: 5000;
  transition: width 0.1s linear;
  pointer-events: none;
}

/* ===== 8. Skip Link ===== */
.skip-link {
  position: fixed;
  top: -100%;
  left: var(--space-4);
  z-index: 6000;
  background: var(--color-orange);
  color: #fff;
  padding: var(--space-3) var(--space-5);
  border-radius: var(--radius-pill);
  font-weight: 700;
  font-size: 0.875rem;
  text-decoration: none;
  box-shadow: 0 4px 20px rgba(255, 106, 0, 0.4);
  transition: top var(--transition-fast);
}

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

/* ===== 9. Breadcrumbs ===== */
.breadcrumb {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: var(--space-2);
  padding: var(--space-4) 0;
  font-size: 0.875rem;
  color: var(--color-rock);
}

.breadcrumb li {
  display: flex;
  align-items: center;
  gap: var(--space-2);
}

.breadcrumb li:not(:last-child)::after {
  content: '▸';
  color: var(--color-silver);
  font-size: 0.75rem;
}

.breadcrumb a {
  color: var(--color-rock);
  text-decoration: none;
  transition: color var(--transition-fast);
}

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

.breadcrumb .breadcrumb-current {
  color: var(--color-orange);
  font-weight: 600;
}

/* ===== 10. Base Components ===== */
.page-title {
  font-size: 3rem;
  text-transform: uppercase;
  color: var(--color-deep);
  line-height: 1.1;
  margin-bottom: var(--space-2);
}

.page-intro {
  font-size: 1.125rem;
  color: var(--color-rock);
  max-width: 60ch;
}

.section-heading {
  display: flex;
  align-items: baseline;
  gap: var(--space-4);
  margin-bottom: var(--space-5);
  flex-wrap: wrap;
}

.section-num {
  font-family: var(--font-display);
  font-size: 3rem;
  line-height: 1;
  color: var(--color-orange);
  letter-spacing: 0.02em;
}

.section-title {
  font-family: var(--font-display);
  font-size: 2rem;
  line-height: 1.15;
  color: var(--color-deep);
  letter-spacing: 0.04em;
  text-transform: uppercase;
}

.section-desc {
  flex-basis: 100%;
  color: var(--color-rock);
  font-size: 0.9375rem;
  margin: 0;
  max-width: 65ch;
}

.card {
  background: #fff;
  border: 1px solid rgba(192, 192, 200, 0.35);
  border-radius: var(--radius-lg);
  padding: var(--space-5);
  transition: transform var(--transition-base), box-shadow var(--transition-base), border-color var(--transition-base);
}

.card:hover {
  transform: translateY(-3px);
  box-shadow: 0 12px 32px rgba(11, 30, 58, 0.12);
  border-color: rgba(255, 106, 0, 0.25);
}

.tag {
  display: inline-flex;
  align-items: center;
  gap: var(--space-1);
  padding: 3px 12px;
  border-radius: var(--radius-pill);
  font-size: 0.75rem;
  font-weight: 700;
  letter-spacing: 0.05em;
  line-height: 1.5;
}

.tag-hot {
  background: rgba(210, 105, 30, 0.12);
  color: var(--color-terra);
  border: 1px solid rgba(210, 105, 30, 0.35);
}

.tag-new {
  background: rgba(107, 142, 35, 0.12);
  color: var(--color-moss);
  border: 1px solid rgba(107, 142, 35, 0.35);
}

/* ===== 11. Grid ===== */
.grid {
  display: grid;
  grid-template-columns: repeat(12, 1fr);
  gap: var(--space-5);
}

.grid-2 > * {
  grid-column: span 12;
}

.grid-3 > * {
  grid-column: span 12;
}

@media (min-width: 768px) {
  .grid-2 > * {
    grid-column: span 6;
  }
  .grid-3 > * {
    grid-column: span 6;
  }
}

@media (min-width: 1024px) {
  .grid-3 > * {
    grid-column: span 4;
  }
}

/* ===== 12. Header Desktop Rail ===== */
@media (min-width: 1024px) {
  .site-header {
    top: 0;
    left: 0;
    right: auto;
    bottom: 0;
    width: var(--rail-width);
    height: 100vh;
    box-shadow: none;
    border-right: 1px solid rgba(192, 192, 200, 0.12);
    justify-content: flex-start;
  }

  .header-top {
    padding: var(--space-8) var(--space-5) var(--space-6);
    justify-content: flex-start;
    border-bottom: 1px solid rgba(192, 192, 200, 0.1);
    margin-bottom: var(--space-4);
  }

  .brand-copy {
    flex-direction: column;
    gap: 2px;
  }

  .brand-title {
    font-size: 1.375rem;
  }

  .nav-toggle {
    display: none;
  }

  .site-nav {
    position: static;
    width: auto;
    height: auto;
    transform: none;
    padding: var(--space-3) var(--space-3) var(--space-5);
    transition: none;
    box-shadow: none;
    overflow-y: auto;
    flex: 1;
    display: flex;
    flex-direction: column;
  }

  .site-nav[data-open] {
    transform: none;
    box-shadow: none;
  }

  .nav-list {
    gap: var(--space-1);
    flex: 1;
  }

  .nav-link {
    font-size: 1rem;
    padding: var(--space-3) var(--space-4);
  }

  .nav-cta-btn {
    margin-top: var(--space-4);
  }

  .scroll-progress {
    left: var(--rail-width);
    right: 0;
  }
}

/* ===== 13. Footer Desktop ===== */
@media (min-width: 768px) {
  .footer-grid {
    grid-template-columns: 1.2fr 0.8fr 1fr 0.8fr;
    gap: var(--space-8);
  }

  .footer-bottom {
    flex-direction: row;
    justify-content: space-between;
  }
}

/* ===== 14. Focus Visible ===== */
:focus-visible {
  outline: 2px solid var(--color-orange);
  outline-offset: 3px;
  border-radius: 4px;
}

/* ===== 15. 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;
  }

  .brand-mark::after,
  .btn-dot {
    animation: none !important;
  }

  .scroll-progress {
    transition: none;
  }
}