/* ==========================================================================
   Kura Personal Site - Styles
   Design: 黒基調・洗練・シック・余白多め・タイポグラフィ重視
   ========================================================================== */

@import url('https://fonts.googleapis.com/css2?family=Inter:wght@300;400;500;600&family=Noto+Sans+JP:wght@300;400;500;600&family=Noto+Serif+JP:wght@400;700&display=swap');

/* --------------------------------------------------------------------------
   CSS Custom Properties
   -------------------------------------------------------------------------- */
:root {
  /* Colors - 黒・白・茶基調のシックで明るいテーマ */
  --color-bg-primary: #1a1816;
  --color-bg-secondary: #242220;
  --color-bg-tertiary: #2e2c2a;
  --color-bg-light: #f5f3f0;
  --color-text-primary: #ffffff;
  --color-text-secondary: #c4beb6;
  --color-text-muted: #8a847c;
  --color-accent: #c9a55a;
  --color-accent-hover: #deb96e;
  --color-accent-light: #f0e6d3;
  --color-border: #3d3a36;
  --color-border-light: #524e48;

  /* Typography */
  --font-sans: 'Inter', 'Noto Sans JP', -apple-system, BlinkMacSystemFont, sans-serif;
  --font-size-xs: 0.75rem;
  --font-size-sm: 0.875rem;
  --font-size-base: 1rem;
  --font-size-lg: 1.125rem;
  --font-size-xl: 1.25rem;
  --font-size-2xl: 1.5rem;
  --font-size-3xl: 2rem;
  --font-size-4xl: 2.5rem;
  --font-size-5xl: 3.5rem;

  /* Spacing */
  --spacing-xs: 0.5rem;
  --spacing-sm: 1rem;
  --spacing-md: 1.5rem;
  --spacing-lg: 2rem;
  --spacing-xl: 3rem;
  --spacing-2xl: 4rem;
  --spacing-3xl: 6rem;
  --spacing-4xl: 8rem;

  /* Layout */
  --max-width: 1100px;
  --max-width-narrow: 800px;

  /* Transitions */
  --transition-fast: 150ms ease;
  --transition-base: 250ms ease;
}

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

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

body {
  font-family: var(--font-sans);
  font-size: var(--font-size-base);
  font-weight: 400;
  line-height: 1.7;
  color: var(--color-text-primary);
  background-color: var(--color-bg-primary);
}

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

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

ul,
ol {
  list-style: none;
}

/* --------------------------------------------------------------------------
   Typography
   -------------------------------------------------------------------------- */
h1,
h2,
h3,
h4,
h5,
h6 {
  font-weight: 500;
  line-height: 1.3;
  letter-spacing: -0.02em;
}

h1 {
  font-size: var(--font-size-5xl);
}

h2 {
  font-size: var(--font-size-3xl);
}

h3 {
  font-size: var(--font-size-xl);
}

h4 {
  font-size: var(--font-size-lg);
}

p {
  color: var(--color-text-secondary);
}

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

.container--narrow {
  max-width: var(--max-width-narrow);
}

section {
  padding: var(--spacing-4xl) 0;
}

/* --------------------------------------------------------------------------
   Navigation
   -------------------------------------------------------------------------- */
.nav {
  position: fixed;
  top: 0;
  left: 0;
  right: 0;
  z-index: 100;
  background: rgba(10, 10, 10, 0.9);
  backdrop-filter: blur(10px);
  border-bottom: 1px solid var(--color-border);
}

.nav__inner {
  display: flex;
  justify-content: space-between;
  align-items: center;
  height: 70px;
}

.nav__logo {
  font-size: var(--font-size-lg);
  font-weight: 600;
  color: var(--color-text-primary);
}

.nav__menu {
  display: flex;
  gap: var(--spacing-lg);
}

.nav__link {
  font-size: var(--font-size-sm);
  color: var(--color-text-secondary);
  transition: color var(--transition-fast);
}

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

/* --------------------------------------------------------------------------
   Hero Section
   -------------------------------------------------------------------------- */
.hero {
  min-height: 100vh;
  display: flex;
  align-items: center;
  justify-content: center;
  text-align: center;
  padding-top: 70px;
  background-image: linear-gradient(135deg, rgba(26, 24, 22, 0.95), rgba(46, 44, 42, 0.5), rgba(26, 24, 22, 0.95)), url('assets/hero-bg.png');
  background-size: 200% 200%, cover;
  background-position: 0% 50%, center;
  background-attachment: scroll, fixed;
  animation: gradientShift 20s ease infinite alternate;
  position: relative;
}

@keyframes gradientShift {
  0% { background-position: 0% 50%, center; }
  100% { background-position: 100% 50%, center; }
}

.hero__content {
  max-width: 700px;
}

.hero__name {
  font-family: 'Noto Serif JP', serif;
  font-size: 3.5rem;
  /* サイズ調整 */
  font-weight: 700;
  margin-bottom: var(--spacing-sm);
  letter-spacing: 0.05em;
  text-shadow: 0 4px 10px rgba(0, 0, 0, 0.7);
  background: linear-gradient(to right, #ffffff, #e0d0b0);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
  display: inline-block;
  /* グラデーション用 */
}

.hero__tagline {
  font-size: var(--font-size-lg);
  color: var(--color-text-secondary);
  margin-bottom: var(--spacing-md);
  text-shadow: 0 1px 2px rgba(0, 0, 0, 0.5);
}



.hero__cta {
  display: flex;
  gap: var(--spacing-md);
  justify-content: center;
  flex-wrap: wrap;
}

.hero__scroll-indicator {
  position: absolute;
  bottom: 2rem;
  left: 50%;
  transform: translateX(-50%);
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 0.5rem;
  opacity: 0.7;
}
.hero__scroll-indicator span {
  font-size: 0.75rem;
  letter-spacing: 0.1em;
  color: var(--color-text-secondary);
}
.hero__scroll-indicator .line {
  width: 1px;
  height: 40px;
  background: var(--color-text-secondary);
  animation: scrollLine 2s infinite;
}
@keyframes scrollLine {
  0% { transform: scaleY(0); transform-origin: top; }
  50% { transform: scaleY(1); transform-origin: top; }
  50.1% { transform: scaleY(1); transform-origin: bottom; }
  100% { transform: scaleY(0); transform-origin: bottom; }
}

/* Animations */
.fade-in-up {
  opacity: 0;
  transform: translateY(20px);
  transition: opacity 0.6s ease-out, transform 0.6s ease-out;
}
.is-visible {
  opacity: 1;
  transform: translateY(0);
}

@media (prefers-reduced-motion: reduce) {
  .fade-in-up {
    transition: none;
    opacity: 1;
    transform: none;
  }
  .hero {
    animation: none;
  }
  .hero__scroll-indicator .line {
    animation: none;
  }
}

/* --------------------------------------------------------------------------
   Buttons
   -------------------------------------------------------------------------- */
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: var(--spacing-xs);
  padding: var(--spacing-sm) var(--spacing-lg);
  font-size: var(--font-size-sm);
  font-weight: 500;
  border-radius: 6px;
  border: none;
  cursor: pointer;
  transition: all var(--transition-base);
}

.btn--primary {
  background: var(--color-accent);
  color: var(--color-bg-primary);
}

.btn--primary:hover {
  background: var(--color-accent-hover);
  transform: translateY(-4px);
  box-shadow: 0 4px 20px rgba(222, 185, 110, 0.4);
}

.btn--secondary {
  background: transparent;
  color: var(--color-text-primary);
  border: 1px solid var(--color-border);
}

.btn--secondary:hover {
  border-color: var(--color-accent);
  color: var(--color-accent);
  background: rgba(222, 185, 110, 0.05);
  transform: translateY(-4px);
  box-shadow: 0 4px 20px rgba(0, 0, 0, 0.3);
}

.btn--large {
  padding: var(--spacing-md) var(--spacing-xl);
  font-size: var(--font-size-base);
}

/* --------------------------------------------------------------------------
   Section Header
   -------------------------------------------------------------------------- */
.section-header {
  text-align: center;
  margin-bottom: var(--spacing-3xl);
}

.section-header__title {
  font-size: var(--font-size-3xl);
  margin-bottom: var(--spacing-sm);
}

.section-header__subtitle {
  color: var(--color-text-secondary);
  max-width: 600px;
  margin: 0 auto;
}

/* --------------------------------------------------------------------------
   Latest Video Section
   -------------------------------------------------------------------------- */
.latest-video {
  background: var(--color-bg-secondary);
}

.video-container {
  position: relative;
  width: 100%;
  max-width: 800px;
  margin: 0 auto;
}

.latest-video__link {
  display: block;
  background: var(--color-bg-tertiary);
  border-radius: 12px;
  overflow: hidden;
  border: 1px solid var(--color-border);
  transition: transform var(--transition-base), border-color var(--transition-base), box-shadow var(--transition-base);
  text-align: left;
}
.latest-video__link:hover {
  transform: translateY(-4px);
  border-color: var(--color-accent);
  box-shadow: 0 8px 30px rgba(222, 185, 110, 0.15);
}
.latest-video__thumbnail {
  position: relative;
  aspect-ratio: 16/9;
  overflow: hidden;
}
.latest-video__thumbnail img {
  width: 100%;
  height: 100%;
  object-fit: cover;
  transition: transform 0.5s ease;
}
.latest-video__link:hover .latest-video__thumbnail img {
  transform: scale(1.02);
}
.latest-video__play {
  position: absolute;
  top: 50%;
  left: 50%;
  transform: translate(-50%, -50%);
  width: 64px;
  height: 64px;
  background: rgba(0, 0, 0, 0.7);
  border-radius: 50%;
  display: flex;
  align-items: center;
  justify-content: center;
  transition: transform var(--transition-base), background var(--transition-base);
}
.latest-video__link:hover .latest-video__play {
  transform: translate(-50%, -50%) scale(1.1);
  background: rgba(201, 165, 90, 0.9);
}
.latest-video__play svg {
  width: 28px;
  height: 28px;
  fill: white;
  margin-left: 4px;
}
.latest-video__info {
  padding: var(--spacing-lg);
  display: flex;
  justify-content: space-between;
  align-items: center;
  gap: var(--spacing-md);
}
.latest-video__title {
  font-size: var(--font-size-lg);
  color: var(--color-text-primary);
  margin: 0;
  font-weight: 500;
}
@media (max-width: 600px) {
  .latest-video__info {
    flex-direction: column;
    align-items: flex-start;
  }
}

.video-placeholder {
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  aspect-ratio: 16/9;
  background: var(--color-bg-tertiary);
  border-radius: 12px;
  border: 1px dashed var(--color-border);
  text-align: center;
  padding: var(--spacing-xl);
}

.video-placeholder__icon {
  font-size: 4rem;
  margin-bottom: var(--spacing-md);
  opacity: 0.5;
}

.video-placeholder__text {
  color: var(--color-text-muted);
  margin-bottom: var(--spacing-lg);
}

/* Popular Videos */
.popular-videos {
  margin-top: var(--spacing-3xl);
}

.popular-videos__title {
  font-size: var(--font-size-xl);
  text-align: center;
  margin-bottom: var(--spacing-xl);
  color: var(--color-text-secondary);
}

.popular-videos__grid {
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: var(--spacing-lg);
  max-width: 800px;
  margin: 0 auto;
}

@media (max-width: 600px) {
  .popular-videos__grid {
    grid-template-columns: 1fr;
  }
}

.popular-video-card {
  background: var(--color-bg-tertiary);
  border-radius: 12px;
  overflow: hidden;
  border: 1px solid var(--color-border);
  transition: transform var(--transition-base), border-color var(--transition-base);
}

.popular-video-card:hover {
  transform: translateY(-4px);
  border-color: var(--color-accent);
  box-shadow: 0 4px 20px rgba(0, 0, 0, 0.4);
}

.popular-video-card__thumbnail {
  position: relative;
  aspect-ratio: 16/9;
  overflow: hidden;
}

.popular-video-card__thumbnail img {
  width: 100%;
  height: 100%;
  object-fit: cover;
  transition: transform 0.3s ease;
}

.popular-video-card:hover .popular-video-card__thumbnail img {
  transform: scale(1.02);
}

.popular-video-card__play {
  position: absolute;
  top: 50%;
  left: 50%;
  transform: translate(-50%, -50%);
  width: 60px;
  height: 60px;
  background: rgba(0, 0, 0, 0.7);
  border-radius: 50%;
  display: flex;
  align-items: center;
  justify-content: center;
  opacity: 0;
  transition: opacity var(--transition-base);
}

.popular-video-card:hover .popular-video-card__play {
  opacity: 1;
}

.popular-video-card__play svg {
  width: 24px;
  height: 24px;
  fill: white;
  margin-left: 4px;
}

.popular-video-card__info {
  padding: var(--spacing-md);
}

.popular-video-card__title {
  font-size: var(--font-size-sm);
  font-weight: 500;
  color: var(--color-text-primary);
  line-height: 1.4;
  display: -webkit-box;
  -webkit-line-clamp: 2;
  line-clamp: 2;
  -webkit-box-orient: vertical;
  overflow: hidden;
  margin-bottom: var(--spacing-xs);
}

.popular-video-card__sub {
  font-size: var(--font-size-xs);
  color: var(--color-text-muted);
}

/* --------------------------------------------------------------------------
   Collaboration Videos
   -------------------------------------------------------------------------- */
.collaboration-videos {
  margin-top: var(--spacing-4xl);
}

.collaboration-videos .section-header__title {
  text-align: center;
  margin-top: 6rem;
  font-size: 2rem;
}

/* --------------------------------------------------------------------------
   YouTube Section
   -------------------------------------------------------------------------- */
.youtube {
  text-align: center;
}

.youtube__cta {
  margin-top: var(--spacing-xl);
}

/* --------------------------------------------------------------------------
   About Section
   -------------------------------------------------------------------------- */
.about {
  text-align: center;
}

.about__content {
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: var(--spacing-xl);
}

.about__image-wrapper {
  width: 180px;
  height: 180px;
  border-radius: 50%;
  overflow: hidden;
  background: var(--color-bg-tertiary);
  border: 3px solid var(--color-border);
}

.about__image {
  width: 100%;
  height: 100%;
  object-fit: cover;
}

.about__image-placeholder {
  width: 100%;
  height: 100%;
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 4rem;
  color: var(--color-text-muted);
}

.about__name {
  font-size: var(--font-size-2xl);
  margin-bottom: var(--spacing-sm);
}

.about__bio {
  max-width: 600px;
  color: var(--color-text-secondary);
}

/* --------------------------------------------------------------------------
   Footer
   -------------------------------------------------------------------------- */
.footer {
  background: var(--color-bg-secondary);
  border-top: 1px solid var(--color-border);
  padding: var(--spacing-xl) 0;
}

.footer__inner {
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: var(--spacing-md);
}

.footer__social {
  display: flex;
  gap: var(--spacing-md);
}

.footer__social-link {
  display: flex;
  align-items: center;
  justify-content: center;
  width: 44px;
  height: 44px;
  border-radius: 50%;
  background: var(--color-bg-tertiary);
  color: var(--color-text-secondary);
  transition: all var(--transition-base);
  border: 1px solid var(--color-border);
}

.footer__social-link:hover {
  background: var(--color-accent);
  color: var(--color-bg-primary);
  border-color: var(--color-accent);
}

.footer__social-link svg {
  width: 20px;
  height: 20px;
}

.footer__copyright {
  font-size: var(--font-size-sm);
  color: var(--color-text-muted);
}

/* --------------------------------------------------------------------------
   Responsive
   -------------------------------------------------------------------------- */
@media (max-width: 768px) {
  :root {
    --font-size-5xl: 2.5rem;
    --font-size-3xl: 1.75rem;
    --spacing-4xl: 5rem;
    --spacing-3xl: 4rem;
  }

  .nav__menu {
    display: none;
  }

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

  .hero__cta .btn {
    width: 100%;
    max-width: 280px;
  }

  .pricing-example {
    flex-direction: column;
    align-items: flex-start;
    gap: var(--spacing-xs);
  }
}

/* --------------------------------------------------------------------------
   Animations
   -------------------------------------------------------------------------- */
@keyframes fadeInUp {
  from {
    opacity: 0;
    transform: translateY(20px);
  }

  to {
    opacity: 1;
    transform: translateY(0);
  }
}

.fade-in-up {
  animation: fadeInUp 0.6s ease forwards;
}

/* --------------------------------------------------------------------------
   Utility Classes
   -------------------------------------------------------------------------- */
.sr-only {
  position: absolute;
  width: 1px;
  height: 1px;
  padding: 0;
  margin: -1px;
  overflow: hidden;
  clip: rect(0, 0, 0, 0);
  white-space: nowrap;
  border: 0;
}

/* --------------------------------------------------------------------------
   Hero Logo
   -------------------------------------------------------------------------- */
.hero__logo {
  max-width: 650px;
  width: 100%;
  height: auto;
  margin: 0 auto;
  filter: drop-shadow(0 4px 10px rgba(0, 0, 0, 0.5));
}

@media (max-width: 768px) {
  .hero__logo {
    max-width: 350px;
  }
}
/* --------------------------------------------------------------------------
   HP Creation Section
   -------------------------------------------------------------------------- */
.hp-create {
  background: var(--color-bg-primary);
  text-align: center;
  scroll-margin-top: 80px;
}

.hp-create__content {
  display: flex;
  flex-direction: column;
  align-items: center;
  max-width: 700px;
  margin: 0 auto;
}

.hp-create__description {
  font-size: var(--font-size-base);
  color: var(--color-text-secondary);
  line-height: 1.8;
  margin-bottom: var(--spacing-xl);
}

.hp-create__cta {
  width: 100%;
  display: flex;
  justify-content: center;
}

/* --------------------------------------------------------------------------
   Listen Agency Section
   -------------------------------------------------------------------------- */
.listen-agency {
  background: var(--color-bg-secondary);
  text-align: center;
  scroll-margin-top: 80px;
  border-top: 1px solid var(--color-border);
  border-bottom: 1px solid var(--color-border);
}

.listen-agency__content {
  display: flex;
  flex-direction: column;
  align-items: center;
  max-width: 700px;
  margin: 0 auto;
}

.listen-agency__description {
  font-size: var(--font-size-base);
  color: var(--color-text-secondary);
  line-height: 1.8;
  margin-bottom: var(--spacing-xl);
}

.listen-agency__cta {
  width: 100%;
  display: flex;
  justify-content: center;
}