/* ==========================================================================
   Karui Landing Page
   Design Guide Colors + Elegant Animations
   ========================================================================== */

/* --------------------------------------------------------------------------
   Variables - Design Guide Colors
   -------------------------------------------------------------------------- */
:root {
  /* Primary Colors */
  --glacier: #A0D3D9;
  --sunset: #F29441;
  --ember: #F2600C;
  --flame: #F2380F;

  /* Neutral Palette - 締まった黒 */
  --obsidian: #0C0C0F;
  --charcoal: #141418;
  --graphite: #28282F;
  --slate: #5A5A66;
  --silver: #9A9AA6;
  --snow: #F7F7FC;

  /* Semantic */
  --success: #34D399;

  /* Fonts */
  --font: "Inter", "Noto Sans JP", system-ui, sans-serif;
  --mono: "SF Mono", "JetBrains Mono", monospace;

  /* Animation */
  --ease: cubic-bezier(0.25, 0.1, 0.25, 1);
  --ease-out: cubic-bezier(0.16, 1, 0.3, 1);
  --ease-slow: cubic-bezier(0.4, 0, 0.2, 1);
  --duration-slow: 1s;
  --duration-medium: 0.6s;
  --duration-fast: 0.3s;
}

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

html {
  scroll-behavior: smooth;
  -webkit-font-smoothing: antialiased;
}

body {
  font-family: var(--font);
  font-size: 16px;
  line-height: 1.6;
  color: var(--silver);
  background: var(--obsidian);
  overflow-x: hidden;
}

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

ul { list-style: none; }
img { display: block; max-width: 100%; }
button { font: inherit; cursor: pointer; border: none; background: none; }

::selection {
  background: rgba(160, 211, 217, 0.3);
}

/* --------------------------------------------------------------------------
   Background with Image
   -------------------------------------------------------------------------- */
.bg {
  position: fixed;
  inset: 0;
  z-index: -1;
  overflow: hidden;
}

.bg-image {
  width: 100%;
  height: 100%;
  object-fit: cover;
  object-position: center;
  opacity: 0;
  animation: bgFadeIn 2.5s var(--ease-slow) 0.3s forwards;
}

@keyframes bgFadeIn {
  from {
    opacity: 0;
    transform: scale(1.05);
  }
  to {
    opacity: 1;
    transform: scale(1);
  }
}

.bg-overlay {
  position: absolute;
  inset: 0;
  background: linear-gradient(
    to bottom,
    rgba(12, 12, 15, 0.1) 0%,
    rgba(12, 12, 15, 0.4) 60%,
    rgba(12, 12, 15, 0.9) 100%
  );
}

/* --------------------------------------------------------------------------
   Navigation
   -------------------------------------------------------------------------- */
.nav {
  position: fixed;
  top: 0;
  left: 0;
  right: 0;
  z-index: 100;
  padding: 20px 0;
  transition: all var(--duration-medium) var(--ease);
}

.nav.scrolled {
  background: rgba(12, 12, 15, 0.95);
  backdrop-filter: blur(12px);
  -webkit-backdrop-filter: blur(12px);
  border-bottom: 1px solid var(--graphite);
}

.nav-inner {
  max-width: 1100px;
  margin: 0 auto;
  padding: 0 24px;
  display: flex;
  align-items: center;
  justify-content: space-between;
}

.logo {
  display: flex;
  align-items: center;
  gap: 10px;
}

.logo-img {
  width: 36px;
  height: 36px;
  border-radius: 8px;
  transition: transform var(--duration-fast) var(--ease);
}

.logo:hover .logo-img {
  transform: scale(1.05);
}

.logo-text {
  font-size: 20px;
  font-weight: 600;
  letter-spacing: -0.02em;
  color: var(--snow);
}

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

.nav-link {
  font-size: 14px;
  font-weight: 500;
  color: var(--snow);
  opacity: 0.8;
  transition: opacity var(--duration-fast) var(--ease);
}

.nav-link:hover {
  opacity: 1;
}

.nav-btn {
  font-size: 14px;
  font-weight: 500;
  color: var(--obsidian);
  background: var(--snow);
  padding: 8px 20px;
  border-radius: 8px;
  transition: all var(--duration-fast) var(--ease);
}

.nav-btn:hover {
  background: var(--glacier);
  transform: translateY(-1px);
}

/* --------------------------------------------------------------------------
   Animation Classes
   -------------------------------------------------------------------------- */
.anim-fade {
  opacity: 0;
  transform: translateY(30px);
}

.anim-fade.visible {
  animation: animFade var(--duration-slow) var(--ease-out) forwards;
}

@keyframes animFade {
  from {
    opacity: 0;
    transform: translateY(30px);
  }
  to {
    opacity: 1;
    transform: translateY(0);
  }
}

.anim-slide {
  opacity: 0;
  transform: translateY(40px);
}

.anim-slide.visible {
  animation: animSlide var(--duration-slow) var(--ease-out) forwards;
}

@keyframes animSlide {
  from {
    opacity: 0;
    transform: translateY(40px);
  }
  to {
    opacity: 1;
    transform: translateY(0);
  }
}

.anim-scale {
  opacity: 0;
  transform: scale(0.95);
}

.anim-scale.visible {
  animation: animScale var(--duration-slow) var(--ease-out) forwards;
}

@keyframes animScale {
  from {
    opacity: 0;
    transform: scale(0.95);
  }
  to {
    opacity: 1;
    transform: scale(1);
  }
}

/* --------------------------------------------------------------------------
   Hero
   -------------------------------------------------------------------------- */
.hero {
  min-height: 100vh;
  display: flex;
  align-items: center;
  padding: 120px 24px;
}

.hero-inner {
  max-width: 700px;
  margin: 0 auto;
  text-align: center;
}

.hero-logo {
  margin-bottom: 40px;
  display: flex;
  justify-content: center;
}

.hero-logo-img {
  width: 120px;
  height: 120px;
  border-radius: 28px;
  box-shadow: 0 12px 40px rgba(0, 0, 0, 0.5);
}

.hero-eyebrow {
  font-size: 13px;
  font-weight: 500;
  letter-spacing: 0.12em;
  text-transform: uppercase;
  color: var(--glacier);
  margin-bottom: 24px;
}

.hero-title {
  font-size: clamp(40px, 8vw, 64px);
  font-weight: 600;
  line-height: 1.15;
  letter-spacing: -0.03em;
  color: var(--snow);
  margin-bottom: 24px;
}

.hero-lead {
  font-size: 18px;
  line-height: 1.8;
  color: var(--snow);
  opacity: 0.85;
  margin-bottom: 40px;
}

.hero-actions {
  display: flex;
  gap: 16px;
  justify-content: center;
  flex-wrap: wrap;
}

/* --------------------------------------------------------------------------
   Buttons
   -------------------------------------------------------------------------- */
.btn-primary {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  font-size: 15px;
  font-weight: 500;
  color: var(--obsidian);
  background: var(--snow);
  padding: 14px 28px;
  border-radius: 10px;
  transition: all var(--duration-fast) var(--ease);
}

.btn-primary:hover {
  background: var(--glacier);
  transform: translateY(-2px);
  box-shadow: 0 8px 24px rgba(160, 211, 217, 0.25);
}

.btn-ghost {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  font-size: 15px;
  font-weight: 500;
  color: var(--silver);
  padding: 14px 28px;
  border: 1px solid var(--graphite);
  border-radius: 10px;
  transition: all var(--duration-fast) var(--ease);
}

.btn-ghost:hover {
  color: var(--snow);
  border-color: var(--slate);
  background: rgba(61, 61, 86, 0.3);
}

.btn-secondary {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  width: 100%;
  font-size: 15px;
  font-weight: 500;
  color: var(--silver);
  padding: 14px 28px;
  border: 1px solid var(--graphite);
  border-radius: 10px;
  transition: all var(--duration-fast) var(--ease);
}

.btn-secondary:hover {
  color: var(--snow);
  border-color: var(--slate);
  background: rgba(61, 61, 86, 0.3);
}

/* --------------------------------------------------------------------------
   Values
   -------------------------------------------------------------------------- */
.values {
  padding: 0 24px 100px;
}

.values-inner {
  max-width: 700px;
  margin: 0 auto;
  display: flex;
  align-items: center;
  justify-content: center;
  gap: 48px;
  padding: 40px 0;
  border-top: 1px solid var(--graphite);
  border-bottom: 1px solid var(--graphite);
}

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

.value-number {
  font-size: 56px;
  font-weight: 700;
  font-family: var(--mono);
  letter-spacing: -0.02em;
  color: var(--sunset);
}

.value-suffix {
  font-size: 32px;
  font-weight: 700;
  font-family: var(--mono);
  color: var(--sunset);
}

.value-label {
  display: block;
  font-size: 14px;
  font-weight: 600;
  color: var(--snow);
  margin-top: 10px;
  letter-spacing: 0.02em;
}

.value-divider {
  width: 1px;
  height: 50px;
  background: var(--graphite);
}

/* --------------------------------------------------------------------------
   Sections Common
   -------------------------------------------------------------------------- */
.section-title {
  font-size: clamp(32px, 6vw, 44px);
  font-weight: 700;
  letter-spacing: -0.02em;
  color: var(--snow);
  margin-bottom: 16px;
}

.section-subtitle {
  font-size: 16px;
  color: var(--snow);
  opacity: 0.7;
}

/* --------------------------------------------------------------------------
   Philosophy
   -------------------------------------------------------------------------- */
.philosophy {
  padding: 100px 24px;
}

.philosophy-inner {
  max-width: 700px;
  margin: 0 auto;
  text-align: center;
}

.philosophy-text {
  margin-top: 48px;
}

.philosophy-text p {
  font-size: 17px;
  font-weight: 600;
  line-height: 2;
  color: var(--snow);
  opacity: 0.85;
  margin-bottom: 32px;
}

.philosophy-text p:last-child {
  margin-bottom: 0;
}

/* --------------------------------------------------------------------------
   Comparison
   -------------------------------------------------------------------------- */
.comparison {
  padding: 100px 24px;
}

.comparison-inner {
  max-width: 1000px;
  margin: 0 auto;
  text-align: center;
}

.comparison-viewer {
  margin: 60px 0;
}

.comparison-container {
  position: relative;
  aspect-ratio: 16 / 10;
  border-radius: 16px;
  overflow: hidden;
  background: var(--charcoal);
  box-shadow: 0 24px 48px rgba(0, 0, 0, 0.4);
}

.comparison-before,
.comparison-after {
  position: absolute;
  inset: 0;
}

.comparison-img {
  width: 100%;
  height: 100%;
  object-fit: cover;
  transition: transform 0.8s var(--ease-slow);
}

.comparison-container:hover .comparison-img {
  transform: scale(1.02);
}

.comparison-after {
  clip-path: inset(0 50% 0 0);
}

.comparison-label {
  position: absolute;
  bottom: 20px;
  padding: 10px 18px;
  background: rgba(12, 12, 15, 0.85);
  backdrop-filter: blur(8px);
  border-radius: 8px;
  border: 1px solid var(--graphite);
  display: flex;
  align-items: center;
  gap: 12px;
}

.comparison-before .comparison-label { left: 20px; }
.comparison-after .comparison-label { right: 20px; }

.label-title {
  font-size: 11px;
  font-weight: 600;
  text-transform: uppercase;
  letter-spacing: 0.08em;
  color: var(--slate);
}

.label-size {
  font-size: 14px;
  font-weight: 600;
  font-family: var(--mono);
  color: var(--snow);
}

.comparison-slider {
  position: absolute;
  top: 0;
  bottom: 0;
  left: 50%;
  width: 3px;
  background: var(--snow);
  cursor: ew-resize;
  transform: translateX(-50%);
  transition: background var(--duration-fast) var(--ease);
}

.comparison-slider:hover {
  background: var(--glacier);
}

.slider-handle {
  position: absolute;
  top: 50%;
  left: 50%;
  transform: translate(-50%, -50%);
  width: 48px;
  height: 48px;
  background: var(--snow);
  border-radius: 50%;
  display: flex;
  align-items: center;
  justify-content: center;
  color: var(--obsidian);
  box-shadow: 0 4px 24px rgba(0, 0, 0, 0.4);
  transition: all var(--duration-fast) var(--ease);
}

.comparison-slider:hover .slider-handle {
  background: var(--glacier);
  transform: translate(-50%, -50%) scale(1.1);
}

.comparison-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 24px;
  margin-top: 48px;
}

.comparison-card {
  position: relative;
  aspect-ratio: 4 / 3;
  border-radius: 12px;
  overflow: hidden;
  background: var(--charcoal);
}

.card-img {
  width: 100%;
  height: 100%;
  object-fit: cover;
  transition: transform 0.6s var(--ease-slow);
}

.comparison-card:hover .card-img {
  transform: scale(1.05);
}

.card-info {
  position: absolute;
  bottom: 0;
  left: 0;
  right: 0;
  padding: 20px;
  background: linear-gradient(to top, rgba(12, 12, 15, 0.95), transparent);
  display: flex;
  align-items: baseline;
  gap: 12px;
}

.card-reduction {
  font-size: 22px;
  font-weight: 600;
  font-family: var(--mono);
  color: var(--glacier);
}

.card-detail {
  font-size: 13px;
  color: var(--snow);
  opacity: 0.7;
  font-family: var(--mono);
}

/* --------------------------------------------------------------------------
   Features
   -------------------------------------------------------------------------- */
.features {
  padding: 100px 24px;
  background: var(--charcoal);
}

.features-inner {
  max-width: 900px;
  margin: 0 auto;
}

.feature-block {
  padding: 48px 0;
  border-bottom: 1px solid var(--graphite);
}

.feature-block:last-child {
  border-bottom: none;
}

.feature-content {
  max-width: 600px;
}

.feature-title {
  font-size: 24px;
  font-weight: 600;
  color: var(--snow);
  margin-bottom: 16px;
}

.feature-text {
  font-size: 16px;
  font-weight: 600;
  line-height: 1.8;
  color: var(--snow);
  opacity: 0.8;
}

/* --------------------------------------------------------------------------
   Pricing
   -------------------------------------------------------------------------- */
.pricing {
  padding: 100px 24px;
}

.pricing-inner {
  max-width: 800px;
  margin: 0 auto;
  text-align: center;
}

.pricing-cards {
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: 24px;
  margin-top: 60px;
}

.price-card {
  background: var(--charcoal);
  border: 1px solid var(--graphite);
  border-radius: 16px;
  padding: 40px 32px;
  text-align: left;
  transition: all var(--duration-medium) var(--ease);
}

.price-card:hover {
  transform: translateY(-4px);
  box-shadow: 0 16px 40px rgba(0, 0, 0, 0.3);
}

.price-card.featured {
  border-color: var(--sunset);
  background: linear-gradient(
    to bottom,
    rgba(242, 148, 65, 0.08),
    var(--charcoal)
  );
}

.price-header {
  margin-bottom: 24px;
}

.price-name {
  font-size: 20px;
  font-weight: 600;
  color: var(--snow);
}

.price-desc {
  font-size: 14px;
  color: var(--snow);
  opacity: 0.7;
  margin-top: 4px;
}

.price-amount {
  display: flex;
  align-items: baseline;
  gap: 8px;
  margin-bottom: 32px;
  padding-bottom: 32px;
  border-bottom: 1px solid var(--graphite);
}

.price-value {
  font-size: 44px;
  font-weight: 600;
  font-family: var(--mono);
  color: var(--snow);
}

.price-once {
  font-size: 14px;
  color: var(--snow);
  opacity: 0.7;
}

.price-features {
  margin-bottom: 32px;
}

.price-features li {
  font-size: 15px;
  font-weight: 600;
  color: var(--snow);
  opacity: 0.85;
  padding: 12px 0;
  border-bottom: 1px solid var(--graphite);
}

.price-features li:last-child {
  border-bottom: none;
}

.price-card .btn-primary,
.price-card .btn-secondary {
  width: 100%;
  justify-content: center;
}

/* --------------------------------------------------------------------------
   Download
   -------------------------------------------------------------------------- */
.download {
  padding: 100px 24px;
  background: var(--charcoal);
}

.download-inner {
  max-width: 600px;
  margin: 0 auto;
  text-align: center;
}

.download-title {
  font-size: 36px;
  font-weight: 600;
  color: var(--snow);
  margin-bottom: 8px;
}

.download-subtitle {
  font-size: 16px;
  color: var(--slate);
  margin-bottom: 48px;
}

.download-buttons {
  display: flex;
  gap: 16px;
  justify-content: center;
}

.dl-btn {
  display: flex;
  align-items: center;
  gap: 14px;
  padding: 18px 28px;
  background: var(--obsidian);
  border: 1px solid var(--graphite);
  border-radius: 12px;
  transition: all var(--duration-fast) var(--ease);
  min-width: 200px;
}

.dl-btn:hover {
  border-color: var(--glacier);
  background: rgba(26, 26, 46, 0.8);
  transform: translateY(-2px);
  box-shadow: 0 8px 24px rgba(0, 0, 0, 0.3);
}

.dl-icon {
  width: 32px;
  height: 32px;
  color: var(--snow);
}

.dl-label {
  display: block;
  font-size: 11px;
  color: var(--slate);
  text-transform: uppercase;
  letter-spacing: 0.05em;
}

.dl-platform {
  display: block;
  font-size: 17px;
  font-weight: 600;
  color: var(--snow);
}

/* --------------------------------------------------------------------------
   Footer
   -------------------------------------------------------------------------- */
.footer {
  padding: 40px 24px;
  border-top: 1px solid var(--graphite);
}

.footer-inner {
  max-width: 1100px;
  margin: 0 auto;
  display: flex;
  align-items: center;
  justify-content: space-between;
}

.footer-brand {
  display: flex;
  align-items: center;
  gap: 10px;
}

.footer-logo-img {
  width: 28px;
  height: 28px;
  border-radius: 6px;
}

.footer-logo {
  font-size: 16px;
  font-weight: 600;
  color: var(--snow);
}

.footer-copy {
  font-size: 13px;
  color: var(--snow);
  opacity: 0.5;
}

.footer-link {
  font-size: 14px;
  color: var(--slate);
  transition: color var(--duration-fast) var(--ease);
}

.footer-link:hover {
  color: var(--glacier);
}

/* --------------------------------------------------------------------------
   Responsive
   -------------------------------------------------------------------------- */
@media (max-width: 768px) {
  .nav-links {
    gap: 16px;
  }

  .nav-link {
    display: none;
  }

  .nav-link:last-of-type {
    display: block;
  }

  .values-inner {
    gap: 32px;
  }

  .value-number {
    font-size: 44px;
  }

  .value-suffix {
    font-size: 26px;
  }

  .comparison-grid {
    grid-template-columns: 1fr;
    gap: 16px;
  }

  .pricing-cards {
    grid-template-columns: 1fr;
  }

  .download-buttons {
    flex-direction: column;
    align-items: center;
  }

  .dl-btn {
    width: 100%;
    max-width: 280px;
    justify-content: center;
  }

  .footer-inner {
    flex-direction: column;
    gap: 16px;
    text-align: center;
  }
}

@media (max-width: 480px) {
  .hero-actions {
    flex-direction: column;
  }

  .btn-primary, .btn-ghost {
    width: 100%;
    justify-content: center;
  }

  .values-inner {
    flex-direction: column;
    gap: 24px;
  }

  .value-divider {
    width: 40px;
    height: 1px;
  }
}

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

  .anim-fade,
  .anim-slide,
  .anim-scale {
    opacity: 1;
    transform: none;
  }
}