/* ==========================================================================
   K-POP Timeline - Timeline Layout
   ========================================================================== */

/* ===== Hero Section ===== */

/* Initial state for hero animation (prevents FOUC) */
.hero__book {
  opacity: 0;
  transform: translateY(50px);
}

.hero__buy-link {
  opacity: 0;
}

.hero__description {
  opacity: 0;
  transform: translateY(30px);
}

.hero__scroll-hint {
  opacity: 0;
}

.hero {
  height: 100vh;
  height: 100dvh; /* Dynamic viewport height for mobile */
  display: flex;
  align-items: center;
  justify-content: center;
  background: var(--color-accent-primary);
  position: relative;
  overflow: hidden;
}

.hero__content {
  text-align: center;
  padding: var(--spacing-xl);
  max-width: 100%;
}

/* Book Cover */
.hero__book {
  margin-bottom: var(--spacing-xl);
  display: flex;
  justify-content: center;
}

.hero__book-wrapper {
  position: relative;
  display: inline-block;
}

/* Buy Link Badge */
.hero__buy-link {
  position: absolute;
  top: 0;
  right: 0;
  transform: translate(50%, -50%) rotate(15deg);
  width: 88px;
  height: 88px;
  background: var(--color-accent-secondary);
  color: white;
  border: 2px solid var(--color-accent-secondary);
  border-radius: var(--radius-full);
  display: flex;
  align-items: center;
  justify-content: center;
  text-align: center;
  font-family: var(--font-family-ja);
  font-size: 1rem;
  font-weight: var(--font-weight-bold);
  line-height: 1.4;
  text-decoration: none;
  transition: transform var(--transition-normal),
              background var(--transition-fast),
              color var(--transition-fast);
  z-index: 10;
  animation: wiggle 2.5s ease-in-out infinite;
}

@keyframes wiggle {
  0%, 100% { transform: translate(50%, -50%) rotate(15deg); }
  25% { transform: translate(50%, -50%) rotate(20deg); }
  75% { transform: translate(50%, -50%) rotate(10deg); }
}

.hero__buy-link:hover {
  transform: translate(50%, -50%) rotate(15deg) scale(1.15);
  background: white;
  color: var(--color-accent-secondary);
  animation: none;
}

.hero__buy-link:active {
  transform: translate(50%, -50%) rotate(15deg) scale(0.95);
}

.hero__book-image {
  max-width: min(340px, 80vw);
  max-height: 50vh;
  width: auto;
  height: auto;
  object-fit: contain;
  box-shadow: 0 20px 60px rgba(0, 0, 0, 0.2);
  display: block;
}

.hero__description {
  font-family: var(--font-family-ja);
  font-feature-settings: 'palt' 1;
  font-size: 1rem;
  font-weight: var(--font-weight-regular);
  color: white;
  line-height: 1.8;
  margin-top: var(--spacing-3xl);
  margin-bottom: 0;
}

.hero__scroll-hint {
  position: absolute;
  bottom: var(--spacing-xl);
  left: 50%;
  transform: translateX(-50%);
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: var(--spacing-sm);
}

.hero__scroll-text {
  font-family: var(--font-family-en);
  font-size: 0.75rem;
  color: white;
  letter-spacing: 0.15em;
  text-transform: uppercase;
}

.hero__scroll-arrow {
  width: 20px;
  height: 20px;
  stroke: var(--color-accent-secondary);
  stroke-width: 2;
  stroke-linecap: round;
  stroke-linejoin: round;
  fill: none;
  animation: scrollBounce 2s ease-in-out infinite;
}

@keyframes scrollBounce {
  0%, 100% {
    transform: translateY(0);
  }
  50% {
    transform: translateY(6px);
  }
}

/* ===== Timeline Container - 12 Column Grid ===== */
.timeline-container {
  background: var(--color-bg-secondary);
  padding: var(--spacing-section) var(--grid-padding);
  min-height: 100vh;
}

.timeline {
  max-width: var(--max-width-content);
  margin: 0 auto;
}

/* ===== Year Section - Grid Row ===== */
.timeline__year {
  display: grid;
  grid-template-columns: repeat(12, 1fr);
  gap: var(--grid-gap);
  padding: var(--spacing-section) 0;
  position: relative;
}

/* Divider line - 1 column margin on each side */
.timeline__year::before {
  content: '';
  position: absolute;
  top: 0;
  left: calc(100% / 12);      /* 1 column from left */
  right: calc(100% / 12);     /* 1 column from right */
  height: 2px;
  background: var(--color-accent-primary);
}

.timeline__year:first-of-type {
  padding-top: 0;
}

.timeline__year:first-of-type::before {
  display: none;
}

/* ===== Year Marker - Sticky Left ===== */
.timeline__year-marker {
  grid-column: 2 / 4;
  position: sticky;
  top: 2rem;
  align-self: start;
  height: fit-content;
  z-index: var(--z-year-marker);
  text-align: left;
  padding-left: 1em;
}

.timeline__year-text {
  font-family: var(--font-family-display);
  font-size: 1.75rem;
  font-weight: 500;
  color: var(--color-accent-secondary);
  line-height: 1.3;
}

/* ===== Tracks Grid - 8 Columns ===== */
.timeline__tracks {
  grid-column: 4 / 12;
  display: flex;
  flex-direction: column;
  gap: var(--spacing-section);
}

/* Track wrapper - no longer needs positioning */
.timeline__track-wrapper {
  position: relative;
}

/* ===== Preface Section ===== */
.timeline__preface {
  display: grid;
  grid-template-columns: repeat(12, 1fr);
  gap: var(--grid-gap);
  padding: var(--spacing-section) 0;
  position: relative;
}

.preface__marker {
  grid-column: 2 / 4;
  position: sticky;
  top: 2rem;
  align-self: start;
  height: fit-content;
  z-index: var(--z-year-marker);
  text-align: left;
  padding-left: 1em;
}

.preface__marker-text {
  font-family: var(--font-family-display);
  font-size: 1.75rem;
  font-weight: 500;
  color: var(--color-accent-secondary);
  line-height: 1.3;
}

.preface__content {
  grid-column: 4 / 12;
}

.preface__title {
  font-size: 1.5rem;
  font-weight: var(--font-weight-bold);
  font-feature-settings: 'palt' 1;
  color: var(--color-accent-primary);
  line-height: 1.4;
  letter-spacing: 0.02em;
  margin-bottom: var(--spacing-sm);
}

.preface__subtitle {
  font-size: var(--font-size-body);
  color: var(--color-accent-primary);
  margin-bottom: var(--spacing-md);
}

.preface__author {
  font-size: 0.875rem;
  color: var(--color-accent-primary);
  letter-spacing: 0.05em;
  margin-bottom: var(--spacing-2xl);
}

.preface__body {
  font-family: var(--font-family-ja);
  font-feature-settings: 'palt' 1, 'kern' 1;
  color: var(--color-accent-secondary);
  font-size: 1rem;
  line-height: 1.9;
  text-align: justify;

  /* 最適な行長（35〜45文字/行） */
  max-width: 40em;

  /* 禁則処理 */
  word-break: normal;
  overflow-wrap: break-word;
  line-break: strict;

  /* 約物処理（Safari対応） */
  hanging-punctuation: first last;
}

.preface__body p {
  margin-bottom: 1.5em;
  text-indent: 1em;
}

/* 最初の段落は字下げなし */
.preface__body p:first-child {
  text-indent: 0;
}

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

/* ===== Event Banner ===== */
.event-banner {
  position: relative;
  max-width: 40em;
  margin-top: 2em;
  display: grid;
  grid-template-columns: 1fr auto;
  background: var(--color-accent-secondary);
  color: white;
  text-decoration: none;
  transition: background var(--transition-fast);
  font-feature-settings: 'palt' 1;
}

.event-banner:hover {
  background: var(--color-accent-primary);
  color: white;
}

/* EVENT label - absolute top-left */
.event-banner__label {
  position: absolute;
  top: var(--spacing-sm);
  left: var(--spacing-md);
  font-family: var(--font-family-display);
  font-size: 0.625rem;
  letter-spacing: 0.2em;
}

/* Content */
.event-banner__content {
  min-width: 0;
  padding: var(--spacing-lg);
  padding-top: calc(var(--spacing-lg) + 0.5rem);
  display: flex;
  flex-direction: column;
  justify-content: center;
}

.event-banner__headline {
  margin: 0 0 var(--spacing-xs);
  line-height: var(--line-height-tight);
}

.event-banner__date {
  font-family: var(--font-family-en);
  font-size: 1.125rem;
  font-weight: var(--font-weight-bold);
  letter-spacing: 0.02em;
  margin-right: 0.5em;
}

.event-banner__title {
  font-family: var(--font-family-ja);
  font-size: 1.125rem;
  font-weight: var(--font-weight-bold);
}

.event-banner__venue {
  font-family: var(--font-family-ja);
  font-size: 1.125rem;
  font-weight: var(--font-weight-bold);
  margin: 0 0 var(--spacing-xs);
}

.event-banner__cta {
  font-family: var(--font-family-ja);
  font-size: 0.8125rem;
  margin: 0;
}

/* Latin text in banner uses Geist */
.event-banner .typesetting-latin {
  font-family: var(--font-family-en);
}

/* Photo - grid item, square via aspect-ratio */
.event-banner__photo {
  position: relative;
  aspect-ratio: 1;
  max-width: 140px;
  overflow: hidden;
}

.event-banner__image {
  width: 100%;
  height: 100%;
  object-fit: cover;
  object-position: center top;
  transition: filter var(--transition-normal);
}

/* Duotone hover effect */
.event-banner__photo::after {
  content: '';
  position: absolute;
  inset: 0;
  background: var(--color-accent-primary);
  mix-blend-mode: screen;
  opacity: 0;
  transition: opacity var(--transition-normal);
}

.event-banner:hover .event-banner__image {
  filter: grayscale(100%) contrast(1.1);
}

.event-banner:hover .event-banner__photo::after {
  opacity: 1;
}

/* ===== Mobile Hint Banner ===== */
.mobile-hint-banner {
  position: fixed;
  top: 0;
  left: 0;
  right: 0;
  height: 44px;
  background: var(--color-accent-primary);
  color: white;
  display: none; /* デスクトップでは非表示 */
  align-items: center;
  justify-content: center;
  gap: var(--spacing-sm);
  font-family: var(--font-family-ja);
  font-size: 0.875rem;
  font-weight: var(--font-weight-medium);
  z-index: var(--z-header);
  opacity: 0;
  transform: translateY(-100%);
  transition: opacity var(--transition-normal),
              transform var(--transition-normal);
}

.mobile-hint-banner.is-visible {
  opacity: 1;
  transform: translateY(0);
}

/* ===== Footer ===== */
.footer {
  background: var(--color-accent-secondary);
  padding: var(--spacing-3xl) var(--spacing-lg);
  text-align: center;
}

.footer__content {
  max-width: var(--max-width-content);
  margin: 0 auto;
}

.footer__text {
  font-family: var(--font-family-en);
  font-size: 0.875rem;
  color: white;
  margin-bottom: var(--spacing-sm);
}

.footer__copyright {
  font-family: var(--font-family-en);
  font-size: 0.75rem;
  color: rgba(255, 255, 255, 0.7);
}

/* ===== YouTube Modal ===== */
.youtube-modal {
  position: fixed;
  inset: 0;
  z-index: var(--z-modal);
  display: flex;
  align-items: center;
  justify-content: center;
  opacity: 0;
  visibility: hidden;
  transition: opacity 0.3s ease, visibility 0.3s ease;
}

.youtube-modal.is-open {
  opacity: 1;
  visibility: visible;
}

.youtube-modal__backdrop {
  position: absolute;
  inset: 0;
  background: rgba(255, 255, 255, 0.95);
  cursor: pointer;
}

.youtube-modal__content {
  position: relative;
  width: 90vw;
  max-width: 1200px;
  transform: scale(0.9);
  transition: transform 0.3s ease;
}

.youtube-modal.is-open .youtube-modal__content {
  transform: scale(1);
}

/* Hide close button in error state */
.youtube-modal.is-error .youtube-modal__close {
  display: none !important;
}

.youtube-modal__close {
  position: absolute;
  top: -50px;
  right: 0;
  width: 40px;
  height: 40px;
  background: transparent;
  border: none;
  cursor: pointer;
  padding: 0;
  z-index: 10;
}

.youtube-modal__close svg {
  width: 32px;
  height: 32px;
  fill: var(--color-text-primary);
  transition: fill 0.2s ease;
}

.youtube-modal__close:hover svg {
  fill: var(--color-accent-primary);
}

.youtube-modal__video-container {
  position: relative;
  width: 100%;
  padding-bottom: 56.25%; /* 16:9 aspect ratio */
  background: #000;
}

.youtube-modal__video-container iframe {
  position: absolute;
  top: 0;
  left: 0;
  width: 100%;
  height: 100%;
}

/* YouTube Error Fallback UI */
.youtube-modal__error {
  /* Same dimensions as video container */
  position: relative;
  width: 100%;
  padding-bottom: 56.25%; /* 16:9 aspect ratio */
  background: var(--color-bg-primary);
  z-index: 10;
}

.youtube-modal__error-inner {
  position: absolute;
  top: 0;
  left: 0;
  width: 100%;
  height: 100%;
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  gap: var(--spacing-lg);
  text-align: center;
}

.youtube-modal__error-text {
  font-family: var(--font-family-ja);
  font-size: 1.125rem;
  color: var(--color-text-secondary);
  margin: 0;
}

.youtube-modal__fallback-link {
  display: inline-flex;
  align-items: center;
  gap: var(--spacing-sm);
  padding: var(--spacing-md) var(--spacing-xl);
  background: var(--color-youtube);
  color: white;
  font-family: var(--font-family-en);
  font-size: 0.875rem;
  font-weight: var(--font-weight-medium);
  border-radius: var(--radius-md);
  text-decoration: none;
  transition: background var(--transition-fast), transform var(--transition-fast);
}

.youtube-modal__fallback-link:hover {
  background: #cc0000;
  color: white;
  transform: translateY(-2px);
}

.youtube-modal__fallback-link::before {
  content: '';
  display: inline-block;
  width: 24px;
  height: 24px;
  background-image: url("data:image/svg+xml,%3Csvg xmlns='http://www.w3.org/2000/svg' viewBox='0 0 24 24' fill='white'%3E%3Cpath d='M19.615 3.184c-3.604-.246-11.631-.245-15.23 0-3.897.266-4.356 2.62-4.385 8.816.029 6.185.484 8.549 4.385 8.816 3.6.245 11.626.246 15.23 0 3.897-.266 4.356-2.62 4.385-8.816-.029-6.185-.484-8.549-4.385-8.816zm-10.615 12.816v-8l8 3.993-8 4.007z'/%3E%3C/svg%3E");
  background-size: contain;
  background-repeat: no-repeat;
}

/* ===== Back to Top Button ===== */
.back-to-top {
  position: fixed;
  right: 24px;
  bottom: 24px;
  width: 40px;
  height: 40px;
  background: transparent;
  backdrop-filter: blur(4px);
  -webkit-backdrop-filter: blur(4px);
  border: 2px solid var(--color-accent-secondary);
  border-radius: var(--radius-full);
  cursor: pointer;
  display: flex;
  align-items: center;
  justify-content: center;
  opacity: 0;
  visibility: hidden;
  transform: translateY(20px);
  transition: opacity var(--transition-normal),
              visibility var(--transition-normal),
              transform var(--transition-normal),
              background var(--transition-fast);
  z-index: var(--z-header);
}

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

.back-to-top:hover {
  transform: translateY(0) scale(1.1);
  background: var(--color-accent-secondary);
}

.back-to-top:hover svg {
  stroke: white;
}

.back-to-top:active {
  transform: translateY(0) scale(0.95);
}

.back-to-top svg {
  width: 20px;
  height: 20px;
  stroke: var(--color-accent-secondary);
  stroke-width: 2;
  stroke-linecap: round;
  stroke-linejoin: round;
  fill: none;
  transition: stroke var(--transition-fast);
}

/* Back to top button on footer - invert colors */
.back-to-top.is-on-footer {
  border-color: white;
}

.back-to-top.is-on-footer svg {
  stroke: white;
}

.back-to-top.is-on-footer:hover {
  background: white;
}

.back-to-top.is-on-footer:hover svg {
  stroke: var(--color-accent-secondary);
}