/* ==========================================================================
   AIVRA Launcher Landing Page Stylesheet
   Designed under frontend-design guidelines:
   - Palette: Obsidian, Deep Slate, Minecraft Amber / Gold
   - Typography: Clean System Font Scale, High Contrast, Precision Metrics
   - Responsive down to 360px without horizontal scroll
   - Strict keyboard focus & reduced motion support
   ========================================================================== */

:root {
  --bg-core: #090a0f;
  --bg-surface: #10121a;
  --bg-card: rgba(18, 20, 29, 0.82);
  --bg-card-hover: rgba(24, 28, 41, 0.94);
  --bg-glass: rgba(12, 14, 22, 0.72);

  --accent-amber: #f77f00;
  --accent-gold: #fcbf49;
  --accent-glow: rgba(247, 127, 0, 0.28);
  --accent-ember: #e65100;

  --text-primary: #f5f6fa;
  --text-secondary: #a2aabf;
  --text-muted: #6b7488;
  --text-dim: #4a5266;

  --border-subtle: rgba(255, 255, 255, 0.08);
  --border-accent: rgba(247, 127, 0, 0.32);
  --border-card: rgba(255, 255, 255, 0.06);

  --radius-sm: 6px;
  --radius-md: 10px;
  --radius-lg: 16px;
  --radius-pill: 9999px;

  --container-max: 1160px;
  --transition-fast: 0.18s cubic-bezier(0.16, 1, 0.3, 1);
  --transition-smooth: 0.28s cubic-bezier(0.16, 1, 0.3, 1);
}

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

html {
  font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, "Helvetica Neue", Arial, sans-serif;
  background-color: var(--bg-core);
  color: var(--text-primary);
  line-height: 1.55;
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
  scroll-behavior: smooth;
  text-rendering: optimizeLegibility;
}

body {
  min-height: 100vh;
  overflow-x: hidden;
  position: relative;
  background: var(--bg-core);
}

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

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

ul {
  list-style: none;
}

/* ---------------- Accessibility: Focus & Reduced Motion ---------------- */
:focus-visible {
  outline: 2px solid var(--accent-gold);
  outline-offset: 3px;
  border-radius: var(--radius-sm);
}

@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;
  }
}

/* ---------------- Layout Container ---------------- */
.container {
  width: 100%;
  max-width: var(--container-max);
  margin-left: auto;
  margin-right: auto;
  padding-left: 24px;
  padding-right: 24px;
}

@media (max-width: 640px) {
  .container {
    padding-left: 18px;
    padding-right: 18px;
  }
}

/* ---------------- Header ---------------- */
.site-header {
  position: sticky;
  top: 0;
  z-index: 100;
  height: 72px;
  display: flex;
  align-items: center;
  background: var(--bg-glass);
  backdrop-filter: blur(16px);
  -webkit-backdrop-filter: blur(16px);
  border-bottom: 1px solid var(--border-subtle);
}

.header-container {
  display: flex;
  align-items: center;
  justify-content: space-between;
}

.brand {
  display: inline-flex;
  align-items: center;
  gap: 10px;
  font-weight: 900;
  letter-spacing: 0.12em;
  font-size: 20px;
  color: var(--text-primary);
  transition: color var(--transition-fast);
}

.brand:hover {
  color: var(--accent-gold);
}

.brand-glyph {
  color: var(--accent-amber);
  font-size: 17px;
  line-height: 1;
}

.brand-text {
  font-weight: 900;
  letter-spacing: 0.14em;
}

.header-nav {
  display: none;
}

@media (min-width: 768px) {
  .header-nav {
    display: block;
  }
}

.nav-list {
  display: flex;
  align-items: center;
  gap: 32px;
}

.nav-list a {
  font-size: 14px;
  font-weight: 500;
  color: var(--text-secondary);
  transition: color var(--transition-fast);
}

.nav-list a:hover {
  color: var(--text-primary);
}

.btn-header {
  padding: 8px 18px;
  font-size: 13px;
  border-radius: var(--radius-pill);
}

/* ---------------- Buttons ---------------- */
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 12px;
  font-weight: 700;
  text-align: center;
  cursor: pointer;
  transition: all var(--transition-smooth);
  user-select: none;
  text-decoration: none;
}

.btn-sm {
  padding: 8px 16px;
  font-size: 13px;
  background: rgba(255, 255, 255, 0.08);
  border: 1px solid var(--border-subtle);
  color: var(--text-primary);
}

.btn-sm:hover {
  background: rgba(255, 255, 255, 0.14);
  border-color: var(--border-accent);
}

.btn-primary {
  background: linear-gradient(135deg, #f77f00 0%, #d85c00 100%);
  color: #ffffff;
  border: 1px solid rgba(255, 255, 255, 0.22);
  box-shadow: 0 8px 28px rgba(247, 127, 0, 0.28), 0 2px 6px rgba(0, 0, 0, 0.35);
  border-radius: var(--radius-md);
  padding: 16px 28px;
  font-size: 16px;
}

.btn-primary:hover {
  background: linear-gradient(135deg, #ff8d13 0%, #e86400 100%);
  transform: translateY(-2px);
  box-shadow: 0 12px 36px rgba(247, 127, 0, 0.42), 0 4px 10px rgba(0, 0, 0, 0.45);
}

.btn-primary:active {
  transform: translateY(0);
  box-shadow: 0 4px 14px rgba(247, 127, 0, 0.25);
}

.btn-large {
  padding: 18px 32px;
}

.btn-icon {
  width: 24px;
  height: 24px;
  flex-shrink: 0;
}

.btn-text-wrap {
  display: flex;
  flex-direction: column;
  text-align: left;
}

.btn-main-label {
  font-size: 17px;
  font-weight: 800;
  line-height: 1.25;
}

.btn-sub-label {
  font-size: 12px;
  font-weight: 500;
  opacity: 0.88;
  line-height: 1.25;
  margin-top: 2px;
}

/* ---------------- Hero Section ---------------- */
.hero-section {
  position: relative;
  min-height: calc(88vh - 72px);
  display: flex;
  align-items: center;
  padding: 80px 0 100px;
  overflow: hidden;
}

.hero-backdrop {
  position: absolute;
  inset: 0;
  background-image: url("assets/aivra_bg.png");
  background-size: cover;
  background-position: center 28%;
  opacity: 0.8;
  filter: contrast(1.1) brightness(0.85);
  pointer-events: none;
  z-index: 0;
}

.hero-backdrop::after {
  content: "";
  position: absolute;
  inset: 0;
  background: linear-gradient(90deg, rgba(9, 10, 15, 0.92) 0%, rgba(9, 10, 15, 0.65) 50%, rgba(9, 10, 15, 0.15) 100%),
              linear-gradient(180deg, transparent 60%, var(--bg-core) 100%);
}

.availability-note {
  color: #d5c2a3;
  font-size: 13px;
  line-height: 1.6;
  max-width: 610px;
  margin: -20px 0 30px;
  padding-left: 12px;
  border-left: 2px solid var(--accent-gold);
}

.hero-container {
  position: relative;
  z-index: 1;
}

.hero-content {
  max-width: 780px;
}

.release-badge {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  padding: 6px 14px;
  border-radius: var(--radius-pill);
  background: rgba(247, 127, 0, 0.12);
  border: 1px solid var(--border-accent);
  margin-bottom: 24px;
}

.badge-dot {
  width: 8px;
  height: 8px;
  border-radius: 50%;
  background-color: var(--accent-gold);
  box-shadow: 0 0 10px var(--accent-gold);
}

.badge-text {
  font-size: 13px;
  font-weight: 600;
  color: var(--accent-gold);
  letter-spacing: 0.02em;
}

.hero-title {
  font-size: clamp(38px, 6vw, 68px);
  font-weight: 900;
  line-height: 1.08;
  letter-spacing: -0.03em;
  color: var(--text-primary);
  margin-bottom: 24px;
}

.text-accent {
  background: linear-gradient(135deg, #fcbf49 0%, #f77f00 65%, #ff5400 100%);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
}

.hero-description {
  font-size: clamp(16px, 2.2vw, 20px);
  color: var(--text-secondary);
  line-height: 1.55;
  margin-bottom: 40px;
  max-width: 660px;
}

.hero-cta-group {
  display: flex;
  flex-direction: column;
  gap: 16px;
  align-items: flex-start;
}

.hero-secondary-meta {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 12px;
  font-size: 13px;
  color: var(--text-muted);
}

.meta-item {
  display: inline-flex;
  align-items: center;
  gap: 6px;
}

.meta-icon {
  width: 16px;
  height: 16px;
  color: var(--accent-amber);
}

.meta-separator {
  color: var(--text-dim);
}

/* ---------------- Common Section Styles ---------------- */
.section {
  padding: 100px 0;
  position: relative;
  border-top: 1px solid var(--border-subtle);
}

.section-header {
  margin-bottom: 56px;
  max-width: 680px;
}

.section-eyebrow {
  display: inline-block;
  font-size: 12px;
  font-weight: 800;
  letter-spacing: 0.14em;
  text-transform: uppercase;
  color: var(--accent-amber);
  margin-bottom: 12px;
}

.section-title {
  font-size: clamp(28px, 3.8vw, 42px);
  font-weight: 800;
  letter-spacing: -0.02em;
  line-height: 1.18;
  margin-bottom: 14px;
}

.section-subtitle {
  font-size: 16px;
  color: var(--text-secondary);
  line-height: 1.6;
}

/* ---------------- Modpacks Section ---------------- */
.modpacks-section {
  background: radial-gradient(circle at 15% 30%, rgba(247, 127, 0, 0.05) 0%, transparent 60%),
              var(--bg-core);
}

.modpacks-grid {
  display: grid;
  grid-template-columns: 1fr;
  gap: 32px;
}

@media (min-width: 880px) {
  .modpacks-grid {
    grid-template-columns: 1fr 1fr;
  }
}

.modpack-card {
  background: var(--bg-card);
  border: 1px solid var(--border-card);
  border-radius: var(--radius-lg);
  padding: 36px 32px;
  display: flex;
  flex-direction: column;
  position: relative;
  overflow: hidden;
  transition: all var(--transition-smooth);
}

.modpack-card::before {
  content: "";
  position: absolute;
  top: 0;
  left: 0;
  right: 0;
  height: 3px;
  background: transparent;
  transition: background var(--transition-fast);
}

.vanilla-card:hover::before {
  background: linear-gradient(90deg, var(--accent-gold), transparent);
}

.create-card:hover::before {
  background: linear-gradient(90deg, #d85c00, transparent);
}

.modpack-card:hover {
  background: var(--bg-card-hover);
  border-color: rgba(247, 127, 0, 0.24);
  transform: translateY(-3px);
  box-shadow: 0 20px 48px rgba(0, 0, 0, 0.4);
}

.modpack-header {
  display: flex;
  align-items: center;
  justify-content: space-between;
  margin-bottom: 20px;
}

.modpack-version-tag {
  font-size: 13px;
  font-weight: 800;
  padding: 4px 10px;
  border-radius: var(--radius-sm);
  background: rgba(247, 127, 0, 0.16);
  color: var(--accent-gold);
  border: 1px solid rgba(247, 127, 0, 0.28);
}

.modpack-category {
  font-size: 12px;
  color: var(--text-muted);
  text-transform: uppercase;
  letter-spacing: 0.08em;
  font-weight: 600;
}

.modpack-title {
  font-size: 28px;
  font-weight: 800;
  letter-spacing: -0.01em;
  margin-bottom: 16px;
  color: var(--text-primary);
}

.modpack-desc {
  font-size: 15px;
  line-height: 1.6;
  color: var(--text-secondary);
  margin-bottom: 28px;
}

.modpack-specs {
  display: flex;
  flex-direction: column;
  gap: 14px;
  margin-top: auto;
  border-top: 1px solid var(--border-subtle);
  padding-top: 24px;
}

.modpack-specs li {
  display: flex;
  align-items: flex-start;
  gap: 10px;
  font-size: 14px;
  color: var(--text-secondary);
  line-height: 1.45;
}

.spec-bullet {
  color: var(--accent-amber);
  font-size: 10px;
  margin-top: 4px;
  flex-shrink: 0;
}

.modpack-specs strong {
  color: var(--text-primary);
}

/* ---------------- Features Section ---------------- */
.features-section {
  background: var(--bg-surface);
}

.features-layout {
  display: grid;
  grid-template-columns: 1fr;
  gap: 28px;
}

@media (min-width: 680px) {
  .features-layout {
    grid-template-columns: repeat(2, 1fr);
  }
}

.feature-block {
  background: rgba(13, 15, 22, 0.65);
  border: 1px solid var(--border-card);
  border-radius: var(--radius-md);
  padding: 30px;
  display: flex;
  gap: 20px;
  align-items: flex-start;
  transition: all var(--transition-smooth);
}

.feature-block:hover {
  background: rgba(18, 22, 33, 0.85);
  border-color: rgba(255, 255, 255, 0.12);
}

.feature-icon {
  width: 44px;
  height: 44px;
  border-radius: var(--radius-sm);
  background: rgba(247, 127, 0, 0.12);
  border: 1px solid rgba(247, 127, 0, 0.22);
  color: var(--accent-gold);
  display: flex;
  align-items: center;
  justify-content: center;
  flex-shrink: 0;
}

.feature-icon svg {
  width: 22px;
  height: 22px;
}

.feature-body {
  flex: 1;
}

.feature-title {
  font-size: 18px;
  font-weight: 700;
  margin-bottom: 8px;
  color: var(--text-primary);
}

.feature-text {
  font-size: 14px;
  line-height: 1.55;
  color: var(--text-secondary);
}

/* ---------------- 3-Step Install Section ---------------- */
.install-section {
  background: var(--bg-core);
}

.install-steps {
  display: flex;
  flex-direction: column;
  gap: 24px;
  margin-bottom: 56px;
}

@media (min-width: 880px) {
  .install-steps {
    flex-direction: row;
    align-items: stretch;
    gap: 16px;
  }
}

.step-card {
  flex: 1;
  background: var(--bg-card);
  border: 1px solid var(--border-card);
  border-radius: var(--radius-md);
  padding: 32px 28px;
  display: flex;
  flex-direction: column;
  transition: all var(--transition-smooth);
}

.step-card:hover {
  border-color: rgba(247, 127, 0, 0.22);
  transform: translateY(-2px);
}

.step-number {
  font-size: 18px;
  font-weight: 900;
  color: var(--accent-gold);
  background: rgba(247, 127, 0, 0.14);
  width: 42px;
  height: 42px;
  border-radius: var(--radius-sm);
  display: flex;
  align-items: center;
  justify-content: center;
  margin-bottom: 20px;
  border: 1px solid rgba(247, 127, 0, 0.28);
}

.step-title {
  font-size: 20px;
  font-weight: 800;
  margin-bottom: 12px;
  color: var(--text-primary);
}

.step-desc {
  font-size: 14px;
  line-height: 1.55;
  color: var(--text-secondary);
}

.step-divider {
  display: none;
}

@media (min-width: 880px) {
  .step-divider {
    display: flex;
    align-items: center;
    justify-content: center;
    color: var(--text-dim);
    width: 28px;
    flex-shrink: 0;
  }

  .step-divider svg {
    width: 20px;
    height: 20px;
  }
}

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

/* ---------------- FAQ Section ---------------- */
.faq-section {
  background: var(--bg-surface);
}

.faq-container {
  max-width: 840px;
}

.faq-list {
  display: flex;
  flex-direction: column;
  gap: 14px;
}

.faq-item {
  background: rgba(14, 16, 24, 0.7);
  border: 1px solid var(--border-card);
  border-radius: var(--radius-md);
  overflow: hidden;
  transition: border-color var(--transition-fast);
}

.faq-item:hover {
  border-color: rgba(255, 255, 255, 0.14);
}

.faq-item[open] {
  border-color: var(--border-accent);
}

.faq-question {
  padding: 20px 24px;
  font-size: 16px;
  font-weight: 700;
  color: var(--text-primary);
  cursor: pointer;
  display: flex;
  align-items: center;
  justify-content: space-between;
  user-select: none;
  list-style: none;
}

.faq-question::-webkit-details-marker {
  display: none;
}

.faq-toggle {
  font-size: 22px;
  font-weight: 400;
  color: var(--accent-gold);
  transition: transform var(--transition-fast);
  line-height: 1;
}

.faq-item[open] .faq-toggle {
  transform: rotate(45deg);
}

.faq-answer {
  padding: 0 24px 22px;
  font-size: 14px;
  line-height: 1.6;
  color: var(--text-secondary);
}

/* ---------------- Footer ---------------- */
.site-footer {
  border-top: 1px solid var(--border-subtle);
  background: var(--bg-core);
  padding: 48px 0;
  font-size: 13px;
  color: var(--text-muted);
}

.footer-container {
  display: flex;
  flex-direction: column;
  gap: 24px;
  justify-content: space-between;
  align-items: flex-start;
}

@media (min-width: 768px) {
  .footer-container {
    flex-direction: row;
    align-items: center;
  }
}

.footer-meta {
  max-width: 600px;
}

.footer-brand {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  font-weight: 800;
  letter-spacing: 0.1em;
  font-size: 15px;
  color: var(--text-primary);
  margin-bottom: 8px;
}

.footer-disclaimer {
  font-size: 12px;
  line-height: 1.5;
  color: var(--text-dim);
}

.footer-system {
  display: flex;
  flex-direction: column;
  gap: 4px;
  align-items: flex-start;
}

@media (min-width: 768px) {
  .footer-system {
    align-items: flex-end;
  }
}

.system-tag {
  font-weight: 600;
  color: var(--text-secondary);
}

.system-status {
  font-size: 12px;
  color: var(--text-dim);
}

#footer-version-label {
  color: var(--accent-gold);
}