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

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

body {
  font-family: 'Inter Variable', -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, Helvetica, Arial, sans-serif;
  font-weight: 400;
  line-height: 1.6;
  color: #1E293B;
  background: #F5F0EB;
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
}

ul, ol {
  list-style: none;
}

a {
  color: #F0B90B;
  text-decoration: none;
  transition: color 0.25s ease, border-color 0.25s ease, box-shadow 0.25s ease;
}

a:hover {
  color: #D4A309;
}

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

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

:focus-visible {
  outline: 3px solid #F0B90B;
  outline-offset: 2px;
  border-radius: 4px;
}

@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;
  }
  html {
    scroll-behavior: auto;
  }
}

/* ===== CSS Variables ===== */
:root {
  --color-deep-blue: #0B1A33;
  --color-deep-blue-2: #112240;
  --color-deep-blue-3: #1A2D4A;
  --color-cyber-gold: #F0B90B;
  --color-cyber-gold-dark: #D4A309;
  --color-cyber-gold-light: #FCD34D;
  --color-neon-purple: #7C3AED;
  --color-neon-purple-light: #A855F7;
  --color-mist-white: #F5F0EB;
  --color-dark-charcoal: #1E293B;
  --color-mid-gray: #64748B;
  --color-light-gray: #E2E8F0;
  --color-border: #CBD5E1;
  --color-success: #10B981;
  --font-heading: 'Inter Variable', -apple-system, BlinkMacSystemFont, 'Segoe UI', sans-serif;
  --font-body: 'Inter Variable', -apple-system, BlinkMacSystemFont, 'Segoe UI', sans-serif;
  --radius-sm: 8px;
  --radius-md: 16px;
  --radius-lg: 24px;
  --radius-full: 999px;
  --shadow-card: 0 4px 16px rgba(11, 26, 51, 0.08);
  --shadow-card-hover: 0 8px 32px rgba(11, 26, 51, 0.14);
  --transition-fast: 0.2s ease;
  --transition-normal: 0.3s ease;
  --header-height: 72px;
  --max-width: 1200px;
  --grid-gap: 24px;
}

/* ===== Typography ===== */
h1, h2, h3, h4, h5, h6 {
  font-family: var(--font-heading);
  font-weight: 700;
  line-height: 1.25;
  color: var(--color-dark-charcoal);
}

h1 {
  font-size: clamp(2.2rem, 5vw, 3.6rem);
  font-weight: 800;
  letter-spacing: -0.02em;
}

h2 {
  font-size: clamp(1.6rem, 3.5vw, 2.6rem);
  font-weight: 700;
  letter-spacing: -0.01em;
}

h3 {
  font-size: clamp(1.2rem, 2.5vw, 1.8rem);
  font-weight: 600;
}

h4 {
  font-size: clamp(1rem, 1.8vw, 1.3rem);
  font-weight: 600;
}

p {
  margin-bottom: 1rem;
  color: var(--color-mid-gray);
}

small {
  font-size: 0.875rem;
}

/* ===== Container ===== */
.container {
  max-width: var(--max-width);
  margin: 0 auto;
  padding-left: 24px;
  padding-right: 24px;
}

/* ===== Skip Link ===== */
.skip-link {
  position: absolute;
  top: -100%;
  left: 16px;
  z-index: 10000;
  padding: 12px 24px;
  background: var(--color-cyber-gold);
  color: var(--color-deep-blue);
  font-weight: 600;
  border-radius: var(--radius-sm);
  box-shadow: 0 4px 12px rgba(0,0,0,0.2);
  transition: top 0.25s ease;
}

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

/* ===== Header ===== */
.site-header {
  position: fixed;
  top: 0;
  left: 0;
  width: 100%;
  height: var(--header-height);
  background: linear-gradient(135deg, #0B1A33 0%, #112240 60%, #1A2D4A 100%);
  border-bottom: 2px solid rgba(240, 185, 11, 0.25);
  box-shadow: 0 2px 24px rgba(11, 26, 51, 0.5);
  z-index: 1000;
  display: flex;
  align-items: center;
}

.header-inner {
  display: flex;
  align-items: center;
  justify-content: space-between;
  width: 100%;
  height: 100%;
  gap: 16px;
}

/* Brand */
.site-brand {
  display: flex;
  align-items: baseline;
  gap: 10px;
  flex-shrink: 0;
  text-decoration: none;
  transition: opacity 0.2s ease;
}

.site-brand:hover {
  opacity: 0.88;
}

.brand-name {
  font-family: var(--font-heading);
  font-size: 1.5rem;
  font-weight: 800;
  letter-spacing: -0.02em;
  color: var(--color-cyber-gold);
  text-shadow: 0 0 20px rgba(240, 185, 11, 0.25), 0 0 60px rgba(124, 58, 237, 0.15);
  line-height: 1;
}

.brand-tagline {
  font-size: 0.75rem;
  font-weight: 500;
  color: rgba(255,255,255,0.6);
  letter-spacing: 0.08em;
  text-transform: uppercase;
  display: none;
}

@media (min-width: 560px) {
  .brand-tagline {
    display: inline;
  }
}

/* Navigation */
.main-nav {
  display: none;
}

.main-nav[data-open] {
  display: block;
  position: fixed;
  top: var(--header-height);
  left: 0;
  width: 100%;
  height: calc(100vh - var(--header-height));
  background: linear-gradient(160deg, #0B1A33 0%, #112240 70%, #1A2D4A 100%);
  z-index: 999;
  padding: 32px 24px;
  overflow-y: auto;
  border-top: 1px solid rgba(240, 185, 11, 0.15);
}

.nav-list {
  display: flex;
  flex-direction: column;
  gap: 8px;
}

.main-nav[data-open] .nav-list {
  gap: 4px;
}

.main-nav[data-open] .nav-list a {
  display: block;
  padding: 14px 20px;
  font-size: 1.05rem;
  font-weight: 500;
  color: rgba(255,255,255,0.85);
  border-radius: var(--radius-sm);
  transition: background 0.2s ease, color 0.2s ease;
  border-left: 3px solid transparent;
}

.main-nav[data-open] .nav-list a:hover {
  background: rgba(240, 185, 11, 0.1);
  color: var(--color-cyber-gold);
  border-left-color: var(--color-cyber-gold);
}

.main-nav[data-open] .nav-list a[aria-current="page"] {
  color: var(--color-cyber-gold);
  background: rgba(240, 185, 11, 0.08);
  border-left-color: var(--color-cyber-gold);
  font-weight: 600;
}

@media (min-width: 900px) {
  .main-nav {
    display: flex;
    position: static;
    height: auto;
    background: none;
    border: none;
    padding: 0;
    overflow: visible;
  }

  .nav-list {
    flex-direction: row;
    gap: 4px;
  }

  .nav-list a {
    display: block;
    padding: 8px 16px;
    font-size: 0.9rem;
    font-weight: 500;
    color: rgba(255,255,255,0.8);
    border-radius: var(--radius-sm);
    transition: color 0.2s ease, background 0.2s ease;
    border-left: none;
    letter-spacing: 0.02em;
  }

  .nav-list a:hover {
    color: var(--color-cyber-gold);
    background: rgba(240, 185, 11, 0.08);
  }

  .nav-list a[aria-current="page"] {
    color: var(--color-cyber-gold);
    background: rgba(240, 185, 11, 0.1);
    font-weight: 600;
    border-left: none;
    position: relative;
  }

  .nav-list a[aria-current="page"]::after {
    content: '';
    position: absolute;
    bottom: 2px;
    left: 16px;
    right: 16px;
    height: 2px;
    background: var(--color-cyber-gold);
    border-radius: 2px;
  }
}

/* Header Actions */
.header-actions {
  display: flex;
  align-items: center;
  gap: 12px;
  flex-shrink: 0;
}

.btn-legacy {
  display: inline-flex;
  align-items: center;
  padding: 8px 18px;
  background: var(--color-cyber-gold);
  color: var(--color-deep-blue);
  font-weight: 700;
  font-size: 0.85rem;
  border-radius: var(--radius-full);
  letter-spacing: 0.03em;
  transition: background 0.25s ease, transform 0.2s ease, box-shadow 0.25s ease;
  box-shadow: 0 2px 12px rgba(240, 185, 11, 0.3);
  border: none;
  line-height: 1.4;
}

.btn-legacy:hover {
  background: var(--color-cyber-gold-dark);
  color: var(--color-deep-blue);
  transform: translateY(-1px);
  box-shadow: 0 4px 20px rgba(240, 185, 11, 0.4);
}

.btn-calendar {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  font-size: 1.3rem;
  color: var(--color-cyber-gold);
  padding: 6px;
  border-radius: var(--radius-sm);
  transition: transform 0.2s ease, color 0.2s ease;
  line-height: 1;
}

.btn-calendar:hover {
  transform: scale(1.1);
  color: var(--color-cyber-gold-light);
}

/* Hamburger */
.nav-toggle {
  display: flex;
  flex-direction: column;
  justify-content: center;
  align-items: center;
  width: 40px;
  height: 40px;
  border-radius: var(--radius-sm);
  background: rgba(255,255,255,0.06);
  transition: background 0.2s ease;
  gap: 5px;
  padding: 8px;
}

.nav-toggle:hover {
  background: rgba(255,255,255,0.12);
}

.hamburger-line {
  display: block;
  width: 22px;
  height: 2px;
  background: rgba(255,255,255,0.85);
  border-radius: 2px;
  transition: transform 0.3s ease, opacity 0.3s ease;
}

.nav-toggle[aria-expanded="true"] .hamburger-line:nth-child(1) {
  transform: rotate(45deg) translate(5px, 5px);
}

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

.nav-toggle[aria-expanded="true"] .hamburger-line:nth-child(3) {
  transform: rotate(-45deg) translate(5px, -5px);
}

@media (min-width: 900px) {
  .nav-toggle {
    display: none;
  }
}

/* ===== Footer ===== */
.site-footer {
  background: linear-gradient(160deg, #0B1A33 0%, #0A1628 60%, #112240 100%);
  color: rgba(255,255,255,0.8);
  padding-top: 56px;
  position: relative;
  border-top: 3px solid transparent;
  border-image: linear-gradient(90deg, var(--color-cyber-gold), var(--color-neon-purple), var(--color-cyber-gold)) 1;
}

.footer-inner {
  display: grid;
  grid-template-columns: 1fr;
  gap: 40px;
  padding-bottom: 40px;
}

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

@media (min-width: 900px) {
  .footer-inner {
    grid-template-columns: 1.4fr 1fr 1.2fr;
    gap: 48px;
  }
}

.footer-col {
  display: flex;
  flex-direction: column;
  gap: 16px;
}

.footer-brand-name {
  font-family: var(--font-heading);
  font-size: 1.4rem;
  font-weight: 800;
  color: var(--color-cyber-gold);
  text-shadow: 0 0 12px rgba(240, 185, 11, 0.15);
  margin-bottom: 4px;
}

.footer-desc {
  font-size: 0.9rem;
  line-height: 1.7;
  color: rgba(255,255,255,0.6);
  margin-bottom: 0;
}

.footer-heading {
  font-size: 1rem;
  font-weight: 600;
  color: var(--color-cyber-gold);
  letter-spacing: 0.05em;
  text-transform: uppercase;
  margin-bottom: 4px;
  position: relative;
  padding-bottom: 8px;
}

.footer-heading::after {
  content: '';
  position: absolute;
  bottom: 0;
  left: 0;
  width: 32px;
  height: 2px;
  background: var(--color-neon-purple);
  border-radius: 2px;
}

.footer-link-list {
  display: flex;
  flex-direction: column;
  gap: 8px;
}

.footer-link-list a {
  color: rgba(255,255,255,0.65);
  font-size: 0.9rem;
  transition: color 0.2s ease, padding-left 0.2s ease;
  padding-left: 0;
}

.footer-link-list a:hover {
  color: var(--color-cyber-gold);
  padding-left: 6px;
}

.footer-contact-list {
  display: flex;
  flex-direction: column;
  gap: 10px;
}

.footer-contact-list li {
  font-size: 0.9rem;
  color: rgba(255,255,255,0.65);
  line-height: 1.5;
}

.footer-contact-list a {
  color: rgba(255,255,255,0.75);
  border-bottom: 1px solid rgba(240,185,11,0.2);
  transition: color 0.2s ease, border-color 0.2s ease;
}

.footer-contact-list a:hover {
  color: var(--color-cyber-gold);
  border-bottom-color: var(--color-cyber-gold);
}

.footer-note {
  font-size: 0.8rem;
  color: rgba(255,255,255,0.45);
  padding-top: 4px;
  border-top: 1px solid rgba(255,255,255,0.08);
}

.footer-bottom {
  border-top: 1px solid rgba(255,255,255,0.08);
  padding: 16px 0;
  background: rgba(0,0,0,0.2);
}

.footer-bottom-inner {
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 6px;
  text-align: center;
}

@media (min-width: 640px) {
  .footer-bottom-inner {
    flex-direction: row;
    justify-content: space-between;
    text-align: left;
  }
}

.footer-icp,
.footer-copyright {
  font-size: 0.8rem;
  color: rgba(255,255,255,0.45);
  margin-bottom: 0;
}

.footer-icp a,
.footer-copyright a {
  color: rgba(255,255,255,0.55);
}

.footer-icp a:hover,
.footer-copyright a:hover {
  color: var(--color-cyber-gold);
}

/* ===== Buttons ===== */
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  padding: 12px 28px;
  font-family: var(--font-heading);
  font-weight: 600;
  font-size: 0.95rem;
  border-radius: var(--radius-full);
  transition: background 0.25s ease, color 0.25s ease, transform 0.2s ease, box-shadow 0.25s ease;
  border: 2px solid transparent;
  line-height: 1.4;
  text-decoration: none;
  cursor: pointer;
}

.btn:hover {
  transform: translateY(-1px);
}

.btn:active {
  transform: translateY(0);
}

.btn-primary {
  background: var(--color-cyber-gold);
  color: var(--color-deep-blue);
  border-color: var(--color-cyber-gold);
  box-shadow: 0 4px 16px rgba(240, 185, 11, 0.3);
}

.btn-primary:hover {
  background: var(--color-cyber-gold-dark);
  border-color: var(--color-cyber-gold-dark);
  color: var(--color-deep-blue);
  box-shadow: 0 6px 24px rgba(240, 185, 11, 0.4);
}

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

.btn-outline:hover {
  background: rgba(240, 185, 11, 0.1);
  color: var(--color-cyber-gold-light);
  border-color: var(--color-cyber-gold-light);
}

.btn-lg {
  padding: 16px 36px;
  font-size: 1.1rem;
}

/* ===== Card ===== */
.card {
  background: #FFFFFF;
  border-radius: var(--radius-md);
  padding: 24px;
  box-shadow: var(--shadow-card);
  border: 1px solid var(--color-border);
  transition: transform 0.25s ease, box-shadow 0.25s ease, border-color 0.25s ease;
}

.card:hover {
  transform: translateY(-4px);
  box-shadow: var(--shadow-card-hover);
  border-color: var(--color-cyber-gold);
}

.card-title {
  font-size: 1.15rem;
  font-weight: 600;
  color: var(--color-dark-charcoal);
  margin-bottom: 8px;
}

.card-text {
  font-size: 0.9rem;
  color: var(--color-mid-gray);
  margin-bottom: 0;
}

/* ===== Tag ===== */
.tag {
  display: inline-flex;
  align-items: center;
  padding: 4px 14px;
  font-size: 0.78rem;
  font-weight: 500;
  border-radius: var(--radius-full);
  background: rgba(240, 185, 11, 0.12);
  color: var(--color-cyber-gold-dark);
  border: 1px solid rgba(240, 185, 11, 0.2);
}

.tag-blue {
  background: rgba(124, 58, 237, 0.1);
  color: var(--color-neon-purple);
  border-color: rgba(124, 58, 237, 0.2);
}

.tag-green {
  background: rgba(16, 185, 129, 0.1);
  color: #047857;
  border-color: rgba(16, 185, 129, 0.2);
}

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

.grid-col-1 { grid-column: span 1; }
.grid-col-2 { grid-column: span 2; }
.grid-col-3 { grid-column: span 3; }
.grid-col-4 { grid-column: span 4; }
.grid-col-5 { grid-column: span 5; }
.grid-col-6 { grid-column: span 6; }
.grid-col-7 { grid-column: span 7; }
.grid-col-8 { grid-column: span 8; }
.grid-col-9 { grid-column: span 9; }
.grid-col-10 { grid-column: span 10; }
.grid-col-11 { grid-column: span 11; }
.grid-col-12 { grid-column: span 12; }

@media (max-width: 768px) {
  .grid {
    gap: 16px;
  }
  .grid-col-1, .grid-col-2, .grid-col-3, .grid-col-4,
  .grid-col-5, .grid-col-6, .grid-col-7, .grid-col-8,
  .grid-col-9, .grid-col-10, .grid-col-11 {
    grid-column: span 12;
  }
  .grid-col-6 {
    grid-column: span 12;
  }
}

@media (min-width: 769px) and (max-width: 1024px) {
  .grid-col-1, .grid-col-2, .grid-col-3 { grid-column: span 4; }
  .grid-col-4, .grid-col-5 { grid-column: span 6; }
  .grid-col-7, .grid-col-8 { grid-column: span 8; }
  .grid-col-9, .grid-col-10, .grid-col-11 { grid-column: span 12; }
}

/* ===== Breadcrumb ===== */
.breadcrumb {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 6px;
  padding: 12px 0;
  font-size: 0.85rem;
  color: var(--color-mid-gray);
}

.breadcrumb a {
  color: var(--color-deep-blue);
  text-decoration: none;
  transition: color 0.2s ease;
}

.breadcrumb a:hover {
  color: var(--color-cyber-gold-dark);
}

.breadcrumb .separator {
  color: var(--color-mid-gray);
  font-size: 0.75rem;
  user-select: none;
}

.breadcrumb .current {
  color: var(--color-mid-gray);
  font-weight: 500;
}

/* ===== Section Title ===== */
.section-title {
  font-size: clamp(1.4rem, 3vw, 2rem);
  font-weight: 700;
  color: var(--color-dark-charcoal);
  margin-bottom: 16px;
  padding-bottom: 12px;
  position: relative;
}

.section-title::after {
  content: '';
  position: absolute;
  bottom: 0;
  left: 0;
  width: 48px;
  height: 3px;
  background: var(--color-cyber-gold);
  border-radius: 3px;
  box-shadow: 0 0 12px rgba(240, 185, 11, 0.3);
}

.section-title-center {
  text-align: center;
}

.section-title-center::after {
  left: 50%;
  transform: translateX(-50%);
}

/* ===== Progress Bar ===== */
.progress-bar {
  position: fixed;
  top: var(--header-height);
  left: 0;
  width: 100%;
  height: 3px;
  background: rgba(255,255,255,0.1);
  z-index: 999;
  pointer-events: none;
}

.progress-bar-fill {
  height: 100%;
  width: 0%;
  background: linear-gradient(90deg, var(--color-cyber-gold), var(--color-neon-purple));
  transition: width 0.1s linear;
  border-radius: 0 2px 2px 0;
}

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

/* ===== Back to Top ===== */
.back-to-top {
  position: fixed;
  bottom: 32px;
  right: 32px;
  width: 48px;
  height: 48px;
  border-radius: 50%;
  background: linear-gradient(135deg, var(--color-cyber-gold), var(--color-neon-purple));
  color: #fff;
  font-size: 1.3rem;
  display: flex;
  align-items: center;
  justify-content: center;
  box-shadow: 0 4px 20px rgba(240, 185, 11, 0.3);
  opacity: 0;
  visibility: hidden;
  transform: translateY(16px);
  transition: opacity 0.3s ease, visibility 0.3s ease, transform 0.3s ease;
  z-index: 998;
  border: none;
  cursor: pointer;
}

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

.back-to-top:hover {
  transform: translateY(-3px);
  box-shadow: 0 6px 28px rgba(240, 185, 11, 0.45);
}

@media (prefers-reduced-motion: reduce) {
  .back-to-top {
    transition: none;
  }
  .back-to-top.visible {
    transform: none;
  }
}

/* ===== Content Main ===== */
.main-content {
  min-height: 60vh;
  padding-top: calc(var(--header-height) + 24px);
  padding-bottom: 56px;
}

/* ===== Utility ===== */
.text-gold {
  color: var(--color-cyber-gold);
}

.text-purple {
  color: var(--color-neon-purple);
}

.text-center {
  text-align: center;
}

.mt-8 { margin-top: 8px; }
.mt-16 { margin-top: 16px; }
.mt-24 { margin-top: 24px; }
.mt-32 { margin-top: 32px; }
.mt-48 { margin-top: 48px; }
.mb-8 { margin-bottom: 8px; }
.mb-16 { margin-bottom: 16px; }
.mb-24 { margin-bottom: 24px; }
.mb-32 { margin-bottom: 32px; }
.mb-48 { margin-bottom: 48px; }

/* ===== Responsive Images Placeholder ===== */
.img-placeholder {
  width: 100%;
  background: var(--color-light-gray);
  border-radius: var(--radius-sm);
  aspect-ratio: 16 / 9;
  display: flex;
  align-items: center;
  justify-content: center;
  color: var(--color-mid-gray);
  font-size: 0.85rem;
  border: 2px dashed var(--color-border);
}

.img-placeholder.ratio-4-3 {
  aspect-ratio: 4 / 3;
}

.img-placeholder.ratio-1-1 {
  aspect-ratio: 1 / 1;
}

.img-placeholder.ratio-21-9 {
  aspect-ratio: 21 / 9;
}

/* ===== Horizontal Rule with Gradient ===== */
hr.gradient-hr {
  border: none;
  height: 2px;
  background: linear-gradient(90deg, var(--color-cyber-gold), var(--color-neon-purple), var(--color-cyber-gold));
  margin: 32px 0;
  border-radius: 2px;
}

/* ===== Grid Background Pattern (Tech Blueprint) ===== */
.tech-grid-bg {
  position: relative;
}

.tech-grid-bg::before {
  content: '';
  position: absolute;
  inset: 0;
  background-image:
    linear-gradient(rgba(240, 185, 11, 0.04) 1px, transparent 1px),
    linear-gradient(90deg, rgba(240, 185, 11, 0.04) 1px, transparent 1px);
  background-size: 48px 48px;
  pointer-events: none;
  z-index: 0;
}

.tech-grid-bg > * {
  position: relative;
  z-index: 1;
}