/* style.css */

/* ===========================
   Design Tokens
=========================== */
:root {
  --color-bg: #f5f5f5;
  --color-surface: #ffffff;
  --color-border: #e8e8e8;

  --color-text: #1a1a1a;
  --color-text-muted: #666666;
  --color-text-light: #999999;

  --color-primary: #0d9488;
  --color-primary-dark: #0a7a71;
  --color-primary-light: #14b8a6;
  --color-primary-bg: #f0fdfb;

  --color-locked: #aaaaaa;
  --color-locked-bg: #f0f0f0;

  --font-sans: 'Inter', 'Noto Sans JP', sans-serif;

  --radius-sm: 4px;
  --radius-md: 8px;
  --radius-lg: 12px;
  --radius-full: 100px;

  --shadow-sm: 0 1px 4px rgba(0,0,0,0.08);
  --shadow-md: 0 4px 16px rgba(0,0,0,0.1);

  --transition: 0.2s ease;

  --sidebar-width: 260px;
  --header-height: 56px;
}

/* ===========================
   Reset
=========================== */
*, *::before, *::after { box-sizing: border-box; margin: 0; padding: 0; }
html { font-size: 16px; scroll-behavior: smooth; }
body {
  background: var(--color-bg);
  color: var(--color-text);
  font-family: var(--font-sans);
  line-height: 1.6;
  -webkit-font-smoothing: antialiased;
}
a { color: inherit; text-decoration: none; }
img { max-width: 100%; display: block; }

/* ===========================
   Header
=========================== */
.header {
  position: fixed;
  top: 0; left: 0; right: 0;
  z-index: 200;
  height: var(--header-height);
  background: #fff;
  border-bottom: 1px solid var(--color-border);
  display: flex;
  align-items: center;
}
.header__inner {
  width: 100%;
  padding: 0 24px;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 16px;
}
.header__logo {
  font-size: 15px;
  font-weight: 700;
  color: var(--color-text);
  display: flex;
  align-items: center;
  gap: 8px;
}
.header__logo-img {
  height: 32px;
  width: auto;
  display: block;
}
.header__actions {
  display: flex;
  align-items: center;
  gap: 10px;
}
.header__cta {
  font-size: 13px;
  font-weight: 600;
  color: #fff;
  background: var(--color-primary);
  border-radius: var(--radius-full);
  padding: 8px 20px;
  transition: background var(--transition);
  white-space: nowrap;
}
.header__cta:hover { background: var(--color-primary-dark); }
.header__signout {
  font-size: 12px;
  font-weight: 600;
  color: var(--color-text-muted);
  background: transparent;
  border: 1px solid var(--color-border);
  border-radius: var(--radius-full);
  padding: 7px 14px;
  cursor: pointer;
  transition: color var(--transition), border-color var(--transition);
  white-space: nowrap;
}
.header__signout:hover {
  color: var(--color-text);
  border-color: var(--color-text-muted);
}
.header__admin-link {
  font-size: 12px;
  font-weight: 600;
  color: var(--color-primary);
  text-decoration: none;
  padding: 7px 12px;
  border: 1px solid var(--color-primary);
  border-radius: var(--radius-full);
  white-space: nowrap;
  transition: background var(--transition), color var(--transition);
}
.header__admin-link:hover {
  background: var(--color-primary);
  color: #fff;
}

/* ===========================
   Hero
=========================== */
.hero {
  position: relative;
  background: #050b14;
  min-height: 92vh;
  display: flex;
  align-items: center;
  justify-content: center;
  padding: 120px 24px 100px;
  margin-top: var(--header-height);
  border-bottom: 1px solid rgba(127,212,216,0.08);
  overflow: hidden;
}
.hero__video {
  position: absolute;
  inset: 0;
  width: 100%;
  height: 100%;
  object-fit: cover;
  z-index: 0;
  filter: saturate(0.95) brightness(0.78) contrast(1.05);
}
.hero__overlay {
  position: absolute;
  inset: 0;
  background:
    radial-gradient(ellipse 85% 65% at 50% 42%, rgba(0,20,40,0.3) 0%, rgba(5,11,20,0.82) 80%),
    linear-gradient(180deg, rgba(5,11,20,0.45) 0%, rgba(5,11,20,0.25) 40%, rgba(5,11,20,0.82) 100%);
  z-index: 1;
}
.hero__grid-overlay {
  position: absolute;
  inset: 0;
  z-index: 2;
  background-image:
    linear-gradient(rgba(127,212,216,0.04) 1px, transparent 1px),
    linear-gradient(90deg, rgba(127,212,216,0.04) 1px, transparent 1px);
  background-size: 64px 64px;
  mask-image: radial-gradient(ellipse 70% 70% at 50% 50%, black 30%, transparent 75%);
  -webkit-mask-image: radial-gradient(ellipse 70% 70% at 50% 50%, black 30%, transparent 75%);
  pointer-events: none;
}
.hero__glow {
  position: absolute;
  top: 30%;
  left: 50%;
  transform: translate(-50%, -50%);
  width: 800px;
  height: 800px;
  z-index: 2;
  background: radial-gradient(circle, rgba(127,212,216,0.16) 0%, rgba(127,212,216,0.06) 30%, transparent 60%);
  filter: blur(40px);
  pointer-events: none;
  animation: heroGlowPulse 8s ease-in-out infinite;
}
@keyframes heroGlowPulse {
  0%, 100% { opacity: 0.7; transform: translate(-50%, -50%) scale(1); }
  50% { opacity: 1; transform: translate(-50%, -50%) scale(1.08); }
}

.hero__content {
  position: relative;
  z-index: 3;
  text-align: center;
  max-width: 760px;
  margin: 0 auto;
  text-shadow: 0 2px 16px rgba(0,0,0,0.45);
}

/* Badge */
.hero__badge {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  font-size: 11px;
  font-weight: 700;
  letter-spacing: 0.16em;
  text-transform: uppercase;
  color: rgba(255,255,255,0.95);
  background: rgba(127,212,216,0.08);
  border: 1px solid rgba(127,212,216,0.35);
  backdrop-filter: blur(12px);
  -webkit-backdrop-filter: blur(12px);
  border-radius: var(--radius-full);
  padding: 7px 16px 7px 14px;
  margin-bottom: 28px;
  box-shadow: 0 0 24px rgba(127,212,216,0.15);
}
.hero__badge-dot {
  width: 6px;
  height: 6px;
  border-radius: 50%;
  background: #7FD4D8;
  box-shadow: 0 0 8px rgba(127,212,216,0.9);
  animation: heroBadgeDotPulse 2s ease-in-out infinite;
}
@keyframes heroBadgeDotPulse {
  0%, 100% { opacity: 1; transform: scale(1); }
  50% { opacity: 0.5; transform: scale(0.75); }
}

/* Title */
.hero__title {
  font-size: clamp(2.2rem, 5.4vw, 3.8rem);
  font-weight: 800;
  letter-spacing: -0.035em;
  line-height: 1.18;
  margin-bottom: 28px;
  color: #fff;
  background: linear-gradient(180deg, #ffffff 0%, #ffffff 55%, #c8e8ea 100%);
  -webkit-background-clip: text;
  background-clip: text;
  -webkit-text-fill-color: transparent;
}
.hero__title em {
  font-style: normal;
  background: linear-gradient(135deg, #7FD4D8 0%, #b6ebee 60%, #7FD4D8 100%);
  background-size: 200% 200%;
  -webkit-background-clip: text;
  background-clip: text;
  -webkit-text-fill-color: transparent;
  animation: heroTitleShine 5s ease-in-out infinite;
}
@keyframes heroTitleShine {
  0%, 100% { background-position: 0% 50%; }
  50% { background-position: 100% 50%; }
}

/* Accent line under title */
.hero__title-line {
  width: 80px;
  height: 2px;
  margin: 0 auto 28px;
  background: linear-gradient(90deg, transparent, #7FD4D8, transparent);
  border-radius: 2px;
}

/* Subtitle */
.hero__subtitle {
  font-size: 1.02rem;
  color: rgba(255,255,255,0.78);
  line-height: 1.85;
  max-width: 520px;
  margin: 0 auto 40px;
  font-weight: 400;
}

/* Stats */
.hero__stats {
  display: inline-flex;
  align-items: center;
  gap: 20px;
  list-style: none;
  padding: 12px 28px;
  margin: 0 auto 40px;
  background: rgba(255,255,255,0.03);
  border: 1px solid rgba(127,212,216,0.12);
  border-radius: var(--radius-full);
  backdrop-filter: blur(8px);
  -webkit-backdrop-filter: blur(8px);
}
.hero__stat {
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 2px;
}
.hero__stat-num {
  font-family: 'Inter', sans-serif;
  font-size: 22px;
  font-weight: 800;
  color: #7FD4D8;
  letter-spacing: -0.02em;
  line-height: 1;
}
.hero__stat-label {
  font-family: 'Inter', sans-serif;
  font-size: 9px;
  font-weight: 700;
  letter-spacing: 0.2em;
  color: rgba(255,255,255,0.55);
  text-transform: uppercase;
}
.hero__stat-divider {
  width: 1px;
  height: 28px;
  background: rgba(127,212,216,0.2);
}

/* Actions */
.hero__actions {
  display: flex;
  justify-content: center;
  gap: 14px;
  flex-wrap: wrap;
}
.btn--hero {
  padding: 14px 32px;
  font-size: 14px;
  letter-spacing: 0.04em;
  font-weight: 700;
  border-radius: var(--radius-full);
  transition: transform 0.25s ease, box-shadow 0.25s ease, background 0.25s ease;
}
.btn--hero svg { transition: transform 0.25s ease; }
.btn--primary.btn--hero {
  background: linear-gradient(135deg, var(--color-primary) 0%, #0a8a7a 100%);
  box-shadow: 0 8px 24px rgba(4,120,87,0.4), 0 0 0 1px rgba(255,255,255,0.06) inset;
}
.btn--primary.btn--hero:hover {
  transform: translateY(-2px);
  box-shadow: 0 12px 32px rgba(4,120,87,0.55), 0 0 0 1px rgba(255,255,255,0.1) inset;
}
.btn--primary.btn--hero:hover svg { transform: translateX(4px); }
.btn--ghost {
  border: 1px solid rgba(255,255,255,0.3);
  color: #fff;
  background: rgba(255,255,255,0.04);
  backdrop-filter: blur(8px);
  -webkit-backdrop-filter: blur(8px);
}
.btn--ghost:hover {
  background: rgba(255,255,255,0.12);
  border-color: rgba(255,255,255,0.6);
  transform: translateY(-2px);
}

/* Scroll cue */
.hero__scroll-cue {
  position: absolute;
  bottom: 36px;
  left: 50%;
  transform: translateX(-50%);
  z-index: 3;
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 10px;
  text-decoration: none;
  opacity: 0;
  animation: fadeIn 1s ease 2s both;
}
.hero__scroll-cue-label {
  font-family: 'Inter', sans-serif;
  font-size: 10px;
  font-weight: 700;
  letter-spacing: 0.3em;
  color: rgba(255,255,255,0.55);
}
.hero__scroll-cue-line {
  width: 1px;
  height: 40px;
  background: linear-gradient(180deg, rgba(127,212,216,0.7), transparent);
  position: relative;
  overflow: hidden;
}
.hero__scroll-cue-line::after {
  content: '';
  position: absolute;
  top: -50%;
  left: 0;
  width: 100%;
  height: 50%;
  background: linear-gradient(180deg, transparent, #7FD4D8);
  animation: heroScrollCue 2.2s ease-in-out infinite;
}
@keyframes heroScrollCue {
  0% { transform: translateY(0); opacity: 0; }
  20% { opacity: 1; }
  100% { transform: translateY(200%); opacity: 0; }
}

/* ===========================
   Buttons
=========================== */
.btn {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  font-size: 14px;
  font-weight: 700;
  border-radius: var(--radius-md);
  padding: 12px 28px;
  cursor: pointer;
  border: none;
  transition: all var(--transition);
  font-family: var(--font-sans);
  white-space: nowrap;
}
.btn--primary {
  background: var(--color-primary);
  color: #fff;
}
.btn--primary:hover { background: var(--color-primary-dark); }
.btn--outline {
  background: #fff;
  color: var(--color-primary);
  border: 1.5px solid var(--color-primary);
}
.btn--outline:hover { background: var(--color-primary-bg); }

/* ===========================
   Page body layout
=========================== */
.page-body {
  display: grid;
  grid-template-columns: var(--sidebar-width) 1fr;
  align-items: start;
  max-width: 1280px;
  margin: 0 auto;
  padding: 32px 24px;
  gap: 24px;
}

/* ===========================
   Sidebar
=========================== */
.sidebar {
  position: sticky;
  top: calc(var(--header-height) + 24px);
  display: flex;
  flex-direction: column;
  gap: 16px;
}
.sidebar-banner {
  display: block;
  border-radius: 12px;
  overflow: hidden;
  line-height: 0;
  box-shadow: 0 2px 12px rgba(0,0,0,0.10);
  transition: transform 0.2s ease, box-shadow 0.2s ease;
  /* clip bottom ~10% to hide CTA button */
  clip-path: inset(0 0 10% 0 round 12px);
}
.sidebar-banner--full {
  clip-path: none;
  border-radius: 12px;
}
.sidebar-banner:hover {
  transform: translateY(-2px);
  box-shadow: 0 6px 20px rgba(0,0,0,0.15);
}
.sidebar-banner img {
  width: 100%;
  display: block;
}

.sidebar-card {
  background: #fff;
  border: 1px solid var(--color-border);
  border-radius: var(--radius-lg);
  overflow: hidden;
}
.sidebar-card__thumb {
  aspect-ratio: 16/9;
  background: var(--color-locked-bg);
  display: flex;
  align-items: center;
  justify-content: center;
  color: var(--color-text-light);
  font-size: 12px;
  position: relative;
}
.sidebar-card__thumb-label {
  position: absolute;
  top: 8px; left: 8px;
  font-size: 10px;
  font-weight: 700;
  letter-spacing: 0.06em;
  text-transform: uppercase;
  background: var(--color-primary);
  color: #fff;
  border-radius: var(--radius-full);
  padding: 3px 8px;
}
.sidebar-card__body {
  padding: 14px 16px 16px;
}
.sidebar-card__label {
  font-size: 10px;
  font-weight: 700;
  letter-spacing: 0.08em;
  text-transform: uppercase;
  color: var(--color-primary);
  margin-bottom: 6px;
}
.sidebar-card__title {
  font-size: 14px;
  font-weight: 700;
  line-height: 1.4;
  margin-bottom: 10px;
}
.sidebar-card__desc {
  font-size: 12px;
  color: var(--color-text-muted);
  line-height: 1.6;
  margin-bottom: 12px;
}
.sidebar-card .btn {
  width: 100%;
  justify-content: center;
  padding: 10px;
  font-size: 13px;
}

/* ===========================
   Main content
=========================== */
.main-content {
  display: flex;
  flex-direction: column;
  gap: 40px;
  min-width: 0;
}

/* ===========================
   Course Row (horizontal scroll)
=========================== */
.course-row {}
.course-row__head {
  display: flex;
  align-items: center;
  justify-content: space-between;
  margin-bottom: 14px;
}
.course-row__title {
  font-size: 18px;
  font-weight: 800;
  letter-spacing: -0.02em;
}
.course-row__more {
  font-size: 13px;
  font-weight: 600;
  color: var(--color-primary);
  display: flex;
  align-items: center;
  gap: 4px;
  transition: gap var(--transition);
}
.course-row__more:hover { gap: 8px; }

.course-scroll {
  display: flex;
  gap: 14px;
  overflow-x: auto;
  padding-bottom: 8px;
  scrollbar-width: thin;
  scrollbar-color: var(--color-border) transparent;
  scroll-snap-type: x mandatory;
}
.course-scroll::-webkit-scrollbar { height: 4px; }
.course-scroll::-webkit-scrollbar-track { background: transparent; }
.course-scroll::-webkit-scrollbar-thumb {
  background: var(--color-border);
  border-radius: 2px;
}

/* ===========================
   Course Card
=========================== */
.course-card {
  flex: 0 0 220px;
  background: #fff;
  border-radius: var(--radius-md);
  overflow: hidden;
  border: 1px solid var(--color-border);
  transition: transform var(--transition), box-shadow var(--transition);
  scroll-snap-align: start;
  cursor: pointer;
  display: block;
}
.course-card:hover {
  transform: translateY(-3px);
  box-shadow: var(--shadow-md);
}
.course-card--locked {
  cursor: default;
  opacity: 0.65;
}
.course-card--locked:hover {
  transform: none;
  box-shadow: none;
}

.course-card__thumb {
  position: relative;
  aspect-ratio: 16/9;
  background: var(--color-locked-bg);
  display: flex;
  align-items: center;
  justify-content: center;
  overflow: hidden;
}
.course-card__thumb img {
  width: 100%; height: 100%;
  object-fit: cover;
  position: absolute; inset: 0;
}
.course-card__thumb-placeholder {
  width: 100%; height: 100%;
  background: linear-gradient(135deg, #e8e8e8 25%, #d8d8d8 100%);
}

.course-card__duration {
  position: absolute;
  bottom: 6px; right: 6px;
  font-size: 10px;
  font-weight: 700;
  background: rgba(0,0,0,0.7);
  color: #fff;
  border-radius: 3px;
  padding: 2px 6px;
}
.course-card__free-badge {
  position: absolute;
  top: 6px; left: 6px;
  font-size: 10px;
  font-weight: 700;
  background: var(--color-primary);
  color: #fff;
  border-radius: 3px;
  padding: 2px 7px;
}
.course-card__lock-icon {
  position: absolute;
  top: 6px; right: 6px;
  width: 24px; height: 24px;
  background: rgba(0,0,0,0.45);
  border-radius: 50%;
  display: flex;
  align-items: center;
  justify-content: center;
}
.course-card__lock-icon svg { width: 12px; height: 12px; color: #fff; }

/* 視聴済みマーク (チェックバッジ) */
.course-card__watched {
  position: absolute;
  top: 6px; right: 6px;
  width: 22px; height: 22px;
  background: var(--color-primary);
  border-radius: 50%;
  display: flex;
  align-items: center;
  justify-content: center;
  box-shadow: 0 2px 6px rgba(0,0,0,0.25);
  z-index: 4;
}
.course-card__watched svg { width: 12px; height: 12px; color: #fff; }
.course-card.is-watched .course-card__thumb-placeholder,
.course-card.is-watched .course-card__thumb img {
  opacity: 0.75;
}
.course-card.is-watched .course-card__title {
  color: var(--color-text-muted);
}

/* Stage進捗バー (course-rowヘッダ右隣) */
.course-row__progress {
  display: flex;
  align-items: center;
  gap: 10px;
  font-family: 'Inter', sans-serif;
  font-size: 11px;
  font-weight: 600;
  color: var(--color-text-muted);
  margin-left: auto;
  margin-right: 16px;
}
.course-row__progress-bar {
  width: 80px;
  height: 4px;
  background: rgba(0,0,0,0.08);
  border-radius: 2px;
  overflow: hidden;
}
.course-row__progress-fill {
  display: block;
  height: 100%;
  background: linear-gradient(90deg, var(--color-primary), #10b981);
  border-radius: 2px;
  transition: width 0.4s ease;
}
.course-row__quiz-btn {
  font-family: 'Inter', sans-serif;
  font-size: 11px;
  font-weight: 700;
  padding: 6px 14px;
  background: rgba(4,120,87,0.08);
  color: var(--color-primary);
  border: 1px solid rgba(4,120,87,0.3);
  border-radius: var(--radius-full);
  transition: all 0.2s ease;
  text-decoration: none;
  display: inline-flex;
  align-items: center;
  gap: 4px;
  white-space: nowrap;
}
.course-row__quiz-btn:hover {
  background: var(--color-primary);
  color: #fff;
  border-color: var(--color-primary);
}
.course-row__quiz-btn.is-passed {
  background: var(--color-primary);
  color: #fff;
  border-color: var(--color-primary);
}
.course-row__head { gap: 14px; flex-wrap: wrap; }

.course-card__body {
  padding: 10px 12px 12px;
}
.course-card__title {
  font-size: 13px;
  font-weight: 700;
  line-height: 1.45;
  margin-bottom: 8px;
  display: -webkit-box;
  -webkit-line-clamp: 2;
  -webkit-box-orient: vertical;
  overflow: hidden;
}
.course-card__meta {
  display: flex;
  align-items: center;
  gap: 6px;
  flex-wrap: wrap;
}
.course-card__tag {
  font-size: 10px;
  font-weight: 600;
  color: var(--color-text-muted);
  background: var(--color-bg);
  border: 1px solid var(--color-border);
  border-radius: 3px;
  padding: 2px 7px;
}

/* ===========================
   Unlock Banner
=========================== */
.unlock-banner {
  background: var(--color-primary-bg);
  border: 1px solid #b2dfdb;
  border-radius: var(--radius-lg);
  padding: 24px 28px;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 20px;
}
.unlock-banner__text {}
.unlock-banner__title {
  font-size: 15px;
  font-weight: 700;
  margin-bottom: 4px;
}
.unlock-banner__desc {
  font-size: 13px;
  color: var(--color-text-muted);
}

/* ===========================
   Unlock Modal
=========================== */
.modal-overlay {
  position: fixed;
  inset: 0;
  z-index: 500;
  background: rgba(0,0,0,0.45);
  display: flex;
  align-items: center;
  justify-content: center;
  padding: 24px;
  opacity: 0;
  pointer-events: none;
  transition: opacity 0.2s ease;
}
.modal-overlay.is-open {
  opacity: 1;
  pointer-events: auto;
}
.modal {
  background: #fff;
  border-radius: var(--radius-lg);
  padding: 36px;
  width: 100%;
  max-width: 420px;
  box-shadow: var(--shadow-md);
  position: relative;
}
.modal__title { font-size: 1.15rem; font-weight: 800; margin-bottom: 8px; }
.modal__desc { font-size: 13px; color: var(--color-text-muted); margin-bottom: 24px; line-height: 1.6; }
.modal__input {
  width: 100%;
  border: 1.5px solid var(--color-border);
  border-radius: var(--radius-md);
  padding: 12px 14px;
  font-size: 15px;
  font-family: var(--font-sans);
  outline: none;
  margin-bottom: 10px;
  transition: border-color var(--transition);
}
.modal__input:focus { border-color: var(--color-primary); }
.modal__input.is-error { border-color: #ef4444; }
.modal__error { font-size: 12px; color: #ef4444; margin-bottom: 10px; display: none; }
.modal__error.is-visible { display: block; }
.modal__actions { display: flex; gap: 10px; }
.modal__close {
  position: absolute; top: 14px; right: 16px;
  background: none; border: none;
  font-size: 20px; color: var(--color-text-muted);
  cursor: pointer; line-height: 1; padding: 4px;
}

/* ===========================
   Course Detail Page
=========================== */
.detail-header {
  position: fixed;
  top: 0; left: 0; right: 0;
  z-index: 200;
  height: var(--header-height);
  background: #fff;
  border-bottom: 1px solid var(--color-border);
  display: flex;
  align-items: center;
  padding: 0 24px;
  gap: 16px;
}
.detail-header__back {
  display: flex;
  align-items: center;
  gap: 6px;
  font-size: 13px;
  font-weight: 600;
  color: var(--color-text-muted);
  transition: color var(--transition);
}
.detail-header__back:hover { color: var(--color-primary); }
.detail-header__back svg { width: 16px; height: 16px; }
.detail-header__title {
  font-size: 14px;
  font-weight: 700;
  flex: 1;
  overflow: hidden;
  white-space: nowrap;
  text-overflow: ellipsis;
}

.detail-main {
  margin-top: var(--header-height);
  max-width: 1000px;
  margin-left: auto;
  margin-right: auto;
  padding: 40px 24px 80px;
  display: grid;
  grid-template-columns: 1fr 300px;
  gap: 32px;
  align-items: start;
}

/* video player */
.video-player-wrap {
  background: #f0f0f0;
  border-radius: var(--radius-lg);
  aspect-ratio: 16/9;
  display: flex;
  align-items: center;
  justify-content: center;
  position: relative;
  overflow: hidden;
  margin-bottom: 24px;
}
.video-player-wrap iframe {
  position: absolute; inset: 0;
  width: 100%; height: 100%;
  border: none;
}
.video-placeholder-inner {
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 12px;
  color: var(--color-text-light);
}
.video-placeholder-inner svg { width: 48px; height: 48px; opacity: 0.3; }
.video-placeholder-inner p { font-size: 13px; }

.course-info__category {
  font-size: 11px;
  font-weight: 700;
  letter-spacing: 0.08em;
  text-transform: uppercase;
  color: var(--color-primary);
  margin-bottom: 8px;
}
.course-info__title {
  font-size: 1.5rem;
  font-weight: 800;
  letter-spacing: -0.02em;
  line-height: 1.3;
  margin-bottom: 12px;
}
.course-info__meta {
  display: flex;
  gap: 16px;
  font-size: 13px;
  color: var(--color-text-muted);
  margin-bottom: 20px;
}
.course-info__desc {
  font-size: 14px;
  line-height: 1.85;
  color: var(--color-text);
}

/* detail sidebar */
.detail-sidebar {
  position: sticky;
  top: calc(var(--header-height) + 24px);
}
.detail-sidebar__title {
  font-size: 14px;
  font-weight: 700;
  margin-bottom: 14px;
}
.detail-playlist {
  display: flex;
  flex-direction: column;
  gap: 2px;
}
.playlist-item {
  display: flex;
  align-items: center;
  gap: 10px;
  padding: 10px 12px;
  border-radius: var(--radius-md);
  cursor: pointer;
  transition: background var(--transition);
}
.playlist-item:hover { background: var(--color-bg); }
.playlist-item.is-active { background: var(--color-primary-bg); }
.playlist-item__num {
  font-size: 11px;
  font-weight: 700;
  color: var(--color-text-light);
  width: 18px;
  flex-shrink: 0;
  text-align: center;
}
.playlist-item.is-active .playlist-item__num { color: var(--color-primary); }
.playlist-item__thumb {
  width: 60px;
  aspect-ratio: 16/9;
  background: var(--color-locked-bg);
  border-radius: 4px;
  flex-shrink: 0;
  overflow: hidden;
}
.playlist-item__info { flex: 1; min-width: 0; }
.playlist-item__title {
  font-size: 12px;
  font-weight: 600;
  line-height: 1.4;
  display: -webkit-box;
  -webkit-line-clamp: 2;
  -webkit-box-orient: vertical;
  overflow: hidden;
}
.playlist-item__duration {
  font-size: 11px;
  color: var(--color-text-light);
  margin-top: 2px;
}
.playlist-item__lock {
  flex-shrink: 0;
}
.playlist-item__lock svg { width: 13px; height: 13px; color: var(--color-text-light); }

/* ===========================
   Footer
=========================== */
/* ===========================
   Welcome Video Modal
=========================== */
.video-modal-overlay {
  position: fixed;
  inset: 0;
  background: rgba(0, 0, 0, 0.75);
  display: flex;
  align-items: center;
  justify-content: center;
  z-index: 2000;
  opacity: 0;
  pointer-events: none;
  transition: opacity 0.3s ease;
  padding: 20px;
}
.video-modal-overlay.is-open {
  opacity: 1;
  pointer-events: auto;
}
.video-modal {
  position: relative;
  width: 100%;
  max-width: 800px;
  transform: translateY(16px) scale(0.97);
  transition: transform 0.3s ease;
}
.video-modal-overlay.is-open .video-modal {
  transform: translateY(0) scale(1);
}
.video-modal__close {
  position: absolute;
  top: -44px;
  right: 0;
  width: 36px;
  height: 36px;
  background: rgba(255,255,255,0.15);
  border: none;
  border-radius: 50%;
  color: #fff;
  font-size: 20px;
  cursor: pointer;
  display: flex;
  align-items: center;
  justify-content: center;
  transition: background 0.2s;
  line-height: 1;
}
.video-modal__close:hover { background: rgba(255,255,255,0.3); }
.video-modal__frame {
  position: relative;
  padding-top: 56.25%; /* 16:9 */
  border-radius: 12px;
  overflow: hidden;
  background: #000;
}
.video-modal__frame iframe {
  position: absolute;
  inset: 0;
  width: 100%;
  height: 100%;
  border: none;
}

/* ===========================
   Course Popup
=========================== */
.course-popup {
  position: absolute;
  top: 0;
  left: 0;
  width: 280px;
  background: #fff;
  border-radius: 14px;
  box-shadow: 0 8px 36px rgba(0,0,0,0.16);
  padding: 16px 18px;
  z-index: 1000;
  pointer-events: none;
  opacity: 0;
  transform: translateY(6px) scale(0.97);
  transition: opacity 0.18s ease, transform 0.18s ease;
}
.course-popup.is-visible {
  opacity: 1;
  transform: translateY(0) scale(1);
  pointer-events: auto;
}
.course-popup__label {
  font-size: 11px;
  font-weight: 700;
  letter-spacing: 0.08em;
  text-transform: uppercase;
  color: var(--color-primary);
  margin-bottom: 6px;
}
.course-popup__title {
  font-size: 14px;
  font-weight: 700;
  color: var(--color-text);
  line-height: 1.5;
  margin-bottom: 10px;
}
.course-popup__desc {
  font-size: 13px;
  line-height: 1.75;
  color: var(--color-text-muted);
  margin-bottom: 14px;
}
.course-popup__meta {
  display: flex;
  flex-wrap: wrap;
  gap: 6px;
}
.course-popup__meta span {
  font-size: 11px;
  font-weight: 600;
  background: var(--color-primary-bg);
  color: var(--color-primary);
  border-radius: 4px;
  padding: 3px 9px;
}

.footer {
  background: #fff;
  border-top: 1px solid var(--color-border);
  padding: 32px 24px;
  text-align: center;
  font-size: 12px;
  color: var(--color-text-light);
}
.footer__logo {
  font-size: 14px;
  font-weight: 700;
  color: var(--color-text);
  margin-bottom: 12px;
}

/* ===========================
   PC / Mobile 出し分けユーティリティ
=========================== */
.show-mobile { display: none; }

/* ===========================
   Responsive
=========================== */
@media (max-width: 1024px) {
  .page-body { grid-template-columns: 220px 1fr; }
}

@media (max-width: 768px) {
  .page-body { grid-template-columns: 1fr; padding: 24px 16px; }
  .sidebar { position: static; }
  .detail-main { grid-template-columns: 1fr; }
  .detail-sidebar { position: static; }

  /* テキスト出し分け */
  .show-pc { display: none; }
  .show-mobile { display: inline; }

  /* Hero スマホ最適化 */
  .hero {
    padding: 72px 20px 88px;
    min-height: 88vh;
  }
  .hero__glow { width: 480px; height: 480px; top: 35%; }
  .hero__grid-overlay { background-size: 40px 40px; }
  .hero__content { text-align: center; }
  .hero__badge {
    font-size: 10px;
    padding: 5px 14px;
    margin-bottom: 22px;
    letter-spacing: 0.14em;
  }
  .hero__title {
    font-size: 1.95rem;
    line-height: 1.28;
    margin-bottom: 20px;
  }
  .hero__title-line { margin-bottom: 20px; width: 60px; }
  .hero__subtitle {
    font-size: 0.92rem;
    line-height: 1.78;
    margin: 0 auto 28px;
    max-width: 340px;
  }
  .hero__stats {
    gap: 14px;
    padding: 10px 20px;
    margin-bottom: 30px;
  }
  .hero__stat-num { font-size: 18px; }
  .hero__stat-label { font-size: 8px; letter-spacing: 0.18em; }
  .hero__stat-divider { height: 22px; }
  .hero__actions { gap: 10px; }
  .btn--hero {
    padding: 12px 26px;
    font-size: 13px;
  }
  .hero__scroll-cue { bottom: 24px; }
  .hero__scroll-cue-line { height: 32px; }

  .unlock-banner { flex-direction: column; gap: 16px; }
}

@media (max-width: 480px) {
  .hero { padding: 64px 18px 80px; }
  .hero__title { font-size: 1.72rem; }
  .hero__subtitle {
    font-size: 0.88rem;
    max-width: 300px;
  }
  .hero__stats { gap: 10px; padding: 8px 16px; }
  .hero__stat-num { font-size: 16px; }
  .hero__stat-divider { height: 18px; }
  .hero__actions { flex-direction: column; align-items: center; }
  .btn--hero { width: 100%; max-width: 280px; justify-content: center; }
  .course-card { flex: 0 0 180px; }
}

/* ===========================
   AI診断バナー (sidebar-diagnosis)
=========================== */
.sidebar-diagnosis {
  display: block;
  background: linear-gradient(135deg, #0d9488 0%, #0a7a71 100%);
  border-radius: 12px;
  padding: 20px;
  color: #fff;
  text-decoration: none;
  transition: transform 0.2s ease, box-shadow 0.2s ease;
  box-shadow: 0 4px 16px rgba(13,148,136,0.25);
  position: relative;
  overflow: hidden;
}
.sidebar-diagnosis::before {
  content: '';
  position: absolute;
  top: -36px; right: -36px;
  width: 110px; height: 110px;
  background: rgba(255,255,255,0.08);
  border-radius: 50%;
  pointer-events: none;
}
.sidebar-diagnosis::after {
  content: '';
  position: absolute;
  bottom: -24px; right: 16px;
  width: 80px; height: 80px;
  background: rgba(255,255,255,0.05);
  border-radius: 50%;
  pointer-events: none;
}
.sidebar-diagnosis:hover {
  transform: translateY(-2px);
  box-shadow: 0 8px 24px rgba(13,148,136,0.4);
  color: #fff;
}
.sidebar-diagnosis__top {
  display: flex;
  align-items: center;
  justify-content: space-between;
  margin-bottom: 10px;
}
.sidebar-diagnosis__badge {
  font-size: 10px;
  font-weight: 700;
  letter-spacing: 0.08em;
  background: rgba(255,255,255,0.2);
  border-radius: 100px;
  padding: 3px 10px;
}
.sidebar-diagnosis__icon {
  opacity: 0.6;
  position: relative;
  z-index: 1;
}
.sidebar-diagnosis__title {
  font-size: 18px;
  font-weight: 800;
  letter-spacing: -0.02em;
  margin-bottom: 6px;
  position: relative;
  z-index: 1;
}
.sidebar-diagnosis__desc {
  font-size: 12px;
  line-height: 1.6;
  opacity: 0.85;
  margin-bottom: 16px;
  position: relative;
  z-index: 1;
}
.sidebar-diagnosis__cta {
  display: flex;
  align-items: center;
  gap: 6px;
  font-size: 13px;
  font-weight: 700;
  background: rgba(255,255,255,0.18);
  border-radius: 8px;
  padding: 9px 14px;
  transition: background 0.2s ease;
  position: relative;
  z-index: 1;
}
.sidebar-diagnosis:hover .sidebar-diagnosis__cta {
  background: rgba(255,255,255,0.26);
}