/* === Theme tokens === */

:root,
:root[data-theme="light"],
:root[data-theme="auto"] {
  color-scheme: light;
  --bg-1: #f7fffd;
  --bg-2: #d7f9f4;
  --bg-radial-1: #ffffff;
  --bg-radial-2: #ffe2f3;
  --surface: #ffffff;
  --surface-2: #f2fffc;
  --surface-3: #e5faf6;
  --surface-glass: rgba(255, 255, 255, 0.85);
  --border: #a9ece8;
  --border-soft: #d4f2ef;
  --border-strong: #18d6d1;
  --ink: #173957;
  --ink-soft: #3f687f;
  --ink-mute: #6d8ca0;
  --primary: #18dcd6;
  --primary-strong: #08a9b2;
  --primary-soft: #d8fbf7;
  --accent: #ff72b6;
  --accent-strong: #e84f9d;
  --accent-soft: #ffe1f1;
  --gold: #ffe575;
  --silver: #b8c9d4;
  --bronze: #d49a6a;
  --green-bg: #d8f5e0;
  --green-text: #3a8553;
  --orange-bg: #fde7d8;
  --orange-text: #b56730;
  --red: #e23939;
  --shadow-sm: 0 2px 8px rgba(23, 57, 87, 0.10);
  --shadow: 0 8px 24px rgba(23, 57, 87, 0.14);
  --shadow-lg: 0 16px 40px rgba(23, 57, 87, 0.18);
  --radius-sm: 12px;
  --radius: 18px;
  --radius-lg: 28px;
  --tnum: "tnum";
}

@media (prefers-color-scheme: dark) {
  :root[data-theme="auto"] {
    color-scheme: dark;
    --bg-1: #173957;
    --bg-2: #102b45;
    --bg-radial-1: #1f4a68;
    --bg-radial-2: #3e1f46;
    --surface: #183957;
    --surface-2: #1d4663;
    --surface-3: #233f5b;
    --surface-glass: rgba(23, 57, 87, 0.90);
    --border: #2c5b74;
    --border-soft: #244d68;
    --border-strong: #18dcd6;
    --ink: #effcff;
    --ink-soft: #c8e8ef;
    --ink-mute: #94b9c6;
    --primary: #18dcd6;
    --primary-strong: #69f6ee;
    --primary-soft: #133f55;
    --accent: #ff72b6;
    --accent-strong: #ff9bd0;
    --accent-soft: #53304f;
    --gold: #ffe575;
    --silver: #d0d8e0;
    --bronze: #d49a6a;
    --green-bg: #1f4030;
    --green-text: #7ad99c;
    --orange-bg: #4a2c1a;
    --orange-text: #ffb084;
    --red: #ff7575;
    --shadow-sm: 0 2px 8px rgba(0, 0, 0, 0.4);
    --shadow: 0 8px 24px rgba(0, 0, 0, 0.5);
    --shadow-lg: 0 16px 40px rgba(0, 0, 0, 0.6);
  }
}

:root[data-theme="dark"] {
  color-scheme: dark;
  --bg-1: #173957;
  --bg-2: #102b45;
  --bg-radial-1: #1f4a68;
  --bg-radial-2: #3e1f46;
  --surface: #183957;
  --surface-2: #1d4663;
  --surface-3: #233f5b;
  --surface-glass: rgba(23, 57, 87, 0.90);
  --border: #2c5b74;
  --border-soft: #244d68;
  --border-strong: #18dcd6;
  --ink: #e5f0f9;
  --ink-soft: #b0c5d8;
  --ink-mute: #7a92ad;
  --primary: #18dcd6;
  --primary-strong: #69f6ee;
  --primary-soft: #133f55;
  --accent: #ff72b6;
  --accent-strong: #ff9bd0;
  --accent-soft: #4a2540;
  --gold: #ffe575;
  --silver: #d0d8e0;
  --bronze: #d49a6a;
  --green-bg: #1f4030;
  --green-text: #7ad99c;
  --orange-bg: #4a2c1a;
  --orange-text: #ffb084;
  --red: #ff7575;
  --shadow-sm: 0 2px 8px rgba(0, 0, 0, 0.4);
  --shadow: 0 8px 24px rgba(0, 0, 0, 0.5);
  --shadow-lg: 0 16px 40px rgba(0, 0, 0, 0.6);
}

/* === Reset / base === */

* { box-sizing: border-box; margin: 0; padding: 0; }
html { scroll-behavior: smooth; }
body {
  font-family: "Noto Sans JP", "Noto Sans CJK JP", "Source Han Sans JP", "Hiragino Sans", "Hiragino Kaku Gothic ProN", "BIZ UDPGothic", "Yu Gothic", "Meiryo", system-ui, sans-serif;
  background:
    radial-gradient(circle at 15% 5%, var(--bg-radial-1) 0%, transparent 38%),
    radial-gradient(circle at 85% 95%, var(--bg-radial-2) 0%, transparent 32%),
    linear-gradient(180deg, var(--bg-1) 0%, var(--bg-2) 100%);
  background-attachment: fixed;
  color: var(--ink);
  min-height: 100vh;
  line-height: 1.7;
  -webkit-font-smoothing: antialiased;
  transition: background 0.3s ease, color 0.2s ease;
}

a { color: var(--primary-strong); text-decoration: none; }
a:hover { text-decoration: underline; }
button { font-family: inherit; }
input, select, textarea { font-family: inherit; color: inherit; }

::selection { background: var(--primary-soft); color: var(--ink); }

/* === Background bubbles === */

.bubbles { display: none; }
.bubble.b1 { width: 180px; height: 60px; top: 12%;    left: -50px;  animation: drift 32s linear infinite; }
.bubble.b2 { width: 120px; height: 40px; top: 38%;    right: -40px; animation: drift-rev 38s linear infinite; }
.bubble.b3 { width: 220px; height: 70px; bottom: 12%; left: 10%;    animation: drift 44s linear infinite; }
.bubble.b4 { width: 90px;  height: 30px; bottom: 30%; right: 20%;   animation: drift-rev 50s linear infinite; }

:root[data-theme="dark"] .bubble { opacity: 0.10; }
@media (prefers-color-scheme: dark) {
  :root[data-theme="auto"] .bubble { opacity: 0.10; }
}

@keyframes drift     { from { transform: translateX(0); } to { transform: translateX(110vw); } }
@keyframes drift-rev { from { transform: translateX(0); } to { transform: translateX(-110vw); } }

/* === Layout primitives === */

.container {
  position: relative;
  z-index: 1;
  max-width: 1180px;
  margin: 0 auto;
  padding: 0 20px;
}

main.container { padding-top: 28px; padding-bottom: 80px; }

/* === Topbar === */

.topbar {
  position: sticky;
  top: 0;
  z-index: 50;
  background: var(--surface-glass);
  backdrop-filter: saturate(140%) blur(10px);
  -webkit-backdrop-filter: saturate(140%) blur(10px);
  border-bottom: 1px solid var(--border-soft);
}
.topbar-inner {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 12px;
  height: 56px;
}
.brand {
  display: flex;
  align-items: center;
  gap: 10px;
  color: var(--ink);
  text-decoration: none;
}
.brand:hover { text-decoration: none; opacity: 0.85; }
.brand-icon {
  width: 28px;
  height: 28px;
  flex: 0 0 auto;
  border-radius: 50%;
  box-shadow: var(--shadow-sm);
}
.brand-text { display: flex; flex-direction: column; line-height: 1.15; }
.brand-title { font-size: 15px; font-weight: 700; letter-spacing: 0.02em; }
.brand-dim { color: var(--ink-mute); font-weight: 500; }
.brand-sub { font-size: 10.5px; color: var(--accent-strong); letter-spacing: 0.1em; font-weight: 600; }

.topbar-actions {
  display: flex;
  align-items: center;
  gap: 8px;
}
.topbar-actions .topbar-official-links {
  margin-left: 4px;
  padding-left: 8px;
  border-left: 1px solid var(--border-soft);
}
.mobile-menu-state {
  display: none;
}
.mobile-menu-toggle {
  display: none;
}

/* === Footer === */

.site-footer {
  position: relative;
  z-index: 1;
  text-align: center;
  margin-top: 56px;
  padding: 24px 16px 32px;
  color: var(--ink-mute);
  font-size: 12px;
}
.site-footer .heart { color: var(--accent); }
.site-footer a { color: var(--primary-strong); }

/* === Help modal === */

.modal-backdrop {
  position: fixed;
  inset: 0;
  z-index: 100;
  display: grid;
  place-items: center;
  padding: 20px;
  background: rgba(31, 72, 97, 0.28);
  backdrop-filter: blur(8px);
  -webkit-backdrop-filter: blur(8px);
}
.modal-backdrop[hidden] { display: none; }

.help-dialog {
  width: min(720px, 100%);
  max-height: min(760px, calc(100vh - 40px));
  overflow: auto;
  background: var(--surface);
  border: 2px solid var(--border);
  border-radius: var(--radius-lg);
  box-shadow: var(--shadow-lg);
  padding: 22px;
  animation: fadeIn 0.18s ease;
}
.help-head {
  display: flex;
  align-items: flex-start;
  justify-content: space-between;
  gap: 16px;
  margin-bottom: 18px;
}
.help-kicker {
  color: var(--accent-strong);
  font-size: 11px;
  font-weight: 700;
  letter-spacing: 0.12em;
  text-transform: uppercase;
}
.help-head h2 {
  font-size: 22px;
  color: var(--ink);
  line-height: 1.25;
}
.help-lead {
  margin-top: 6px;
  color: var(--ink-soft);
  font-size: 13px;
  line-height: 1.65;
}
.help-grid {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 12px;
}
.guide-flow {
  display: grid;
  grid-template-columns: repeat(3, minmax(0, 1fr));
  gap: 10px;
  margin-bottom: 14px;
}
.guide-step {
  display: grid;
  grid-template-columns: 28px 1fr;
  gap: 4px 9px;
  align-items: start;
  padding: 12px;
  border: 1px solid var(--border-soft);
  border-radius: var(--radius-sm);
  background: linear-gradient(180deg, var(--surface-2), var(--surface));
}
.guide-step span {
  grid-row: span 2;
  display: inline-flex;
  align-items: center;
  justify-content: center;
  width: 26px;
  height: 26px;
  border-radius: 999px;
  background: var(--primary-soft);
  color: var(--primary-strong);
  font-size: 12px;
  font-weight: 900;
}
.guide-step strong {
  color: var(--ink);
  font-size: 12.5px;
}
.guide-step p {
  color: var(--ink-soft);
  font-size: 11.5px;
  line-height: 1.55;
}
.guide-sections {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 12px;
}
.guide-section {
  background: var(--surface-2);
  border: 1px solid var(--border-soft);
  border-radius: var(--radius-sm);
  padding: 14px 16px;
}
.guide-section h3 {
  color: var(--ink);
  font-size: 14px;
  margin-bottom: 8px;
}
.guide-section ul {
  margin: 0;
  padding-left: 18px;
  color: var(--ink-soft);
  font-size: 12.5px;
  line-height: 1.75;
}
.help-item {
  display: grid;
  grid-template-columns: 34px 1fr;
  gap: 10px;
  align-items: start;
  background: var(--surface-2);
  border: 1px solid var(--border-soft);
  border-radius: var(--radius-sm);
  padding: 14px;
}
.help-mark {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  width: 28px;
  height: 28px;
  border-radius: 50%;
  background: var(--primary-soft);
  color: var(--primary-strong);
  font-size: 13px;
  font-weight: 800;
}
.help-item h3 {
  font-size: 14px;
  color: var(--ink);
  margin-bottom: 3px;
}
.help-item p {
  color: var(--ink-soft);
  font-size: 12.5px;
  line-height: 1.65;
}
.song-dialog {
  width: min(760px, 100%);
}
.song-detail-main {
  display: grid;
  grid-template-columns: 1fr minmax(220px, 280px);
  gap: 18px;
  align-items: start;
}
.song-detail-artist {
  color: var(--ink-soft);
  font-size: 14px;
  margin-bottom: 10px;
  appearance: none;
  border: 0;
  background: transparent;
  cursor: pointer;
  padding: 0;
  text-align: left;
}
.song-detail-artist:hover {
  color: var(--primary-strong);
  text-decoration: underline;
}
.song-detail-tags {
  display: flex;
  flex-wrap: wrap;
  gap: 6px;
}
.song-detail-stats {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 8px;
}
.song-detail-stats.no-key {
  grid-template-columns: repeat(2, 1fr);
}
.song-detail-stats div {
  background: var(--surface-2);
  border: 1px solid var(--border-soft);
  border-radius: var(--radius-sm);
  padding: 10px;
  text-align: center;
}
.song-detail-stats strong {
  display: block;
  color: var(--primary-strong);
  font-size: 18px;
  line-height: 1.2;
}
.song-detail-stats span {
  color: var(--ink-mute);
  font-size: 10.5px;
}
.song-detail-actions {
  display: flex;
  flex-wrap: wrap;
  gap: 8px;
  margin: 18px 0;
}
.song-detail-history h3 {
  color: var(--ink);
  font-size: 14px;
  margin-bottom: 8px;
}
.song-detail-stream {
  display: grid;
  grid-template-columns: 58px 1fr;
  gap: 10px;
  align-items: center;
  padding: 9px 0;
  border-top: 1px dashed var(--border);
  color: var(--ink);
}
.song-detail-thumb-link {
  display: block;
  border-radius: 6px;
}
.song-detail-thumb {
  width: 58px;
  aspect-ratio: 16 / 9;
  object-fit: cover;
  border-radius: 6px;
  background: var(--surface-2);
  border: 1px solid var(--border-soft);
}
.song-detail-thumb.placeholder {
  display: block;
}
.song-detail-frame {
  appearance: none;
  border: 0;
  background: transparent;
  color: inherit;
  cursor: pointer;
  display: grid;
  gap: 2px;
  min-width: 0;
  padding: 4px 6px;
  text-align: left;
  border-radius: 6px;
}
.song-detail-frame:hover {
  background: var(--surface-2);
}
.song-detail-frame span {
  color: var(--primary-strong);
  font-size: 12px;
  font-weight: 700;
}
.song-detail-frame strong {
  font-size: 12.5px;
  color: var(--ink-soft);
  font-weight: 600;
  overflow: hidden;
  text-overflow: ellipsis;
  white-space: nowrap;
}
.song-detail-empty {
  color: var(--ink-mute);
  font-size: 13px;
}
.welcome-tip {
  position: fixed;
  right: 18px;
  bottom: 18px;
  z-index: 80;
  display: flex;
  align-items: flex-start;
  gap: 12px;
  width: min(420px, calc(100vw - 36px));
  background: var(--surface);
  border: 2px solid var(--border);
  border-radius: var(--radius);
  box-shadow: var(--shadow-lg);
  padding: 14px;
}
.welcome-tip[hidden] { display: none; }
.welcome-tip strong,
.welcome-tip span {
  display: block;
}
.welcome-tip strong {
  color: var(--ink);
  font-size: 13px;
  margin-bottom: 2px;
}
.welcome-tip span {
  color: var(--ink-soft);
  font-size: 12px;
  line-height: 1.55;
}

.page-top-toast {
  position: fixed;
  right: max(16px, env(safe-area-inset-right));
  bottom: max(18px, calc(env(safe-area-inset-bottom) + 18px));
  z-index: 45;
  display: inline-flex;
  align-items: center;
  gap: 6px;
  min-height: 38px;
  padding: 7px 12px;
  border: 2px solid var(--border);
  border-radius: 999px;
  background: var(--surface-glass);
  color: var(--primary-strong);
  box-shadow: var(--shadow);
  font-family: inherit;
  font-size: 11px;
  font-weight: 900;
  letter-spacing: 0.04em;
  cursor: pointer;
  opacity: 0;
  pointer-events: none;
  transform: translateY(10px);
  transition: opacity 0.18s ease, transform 0.18s ease, border-color 0.18s ease;
  backdrop-filter: saturate(140%) blur(10px);
  -webkit-backdrop-filter: saturate(140%) blur(10px);
}
.page-top-toast[hidden] {
  display: inline-flex;
}
.page-top-toast span {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  width: 20px;
  height: 20px;
  border-radius: 999px;
  background: var(--primary-soft);
  font-size: 14px;
  line-height: 1;
}
.page-top-toast.is-visible {
  opacity: 0.94;
  pointer-events: auto;
  transform: translateY(0);
}
.page-top-toast:hover {
  border-color: var(--primary);
  transform: translateY(-1px);
}

@media (max-width: 700px) {
  html,
  body {
    overflow-x: hidden;
  }
  .container {
    width: 100%;
    padding: 0 clamp(12px, 3vw, 20px);
  }
  .brand-dim,
  .brand-sub,
  .theme-label { display: none; }
  .topbar-inner {
    align-items: flex-start;
    flex-wrap: wrap;
    height: auto;
    min-height: 56px;
    padding-top: 8px;
    padding-bottom: 8px;
  }
  .topbar-inner { gap: 8px; }
  .brand {
    flex: 1 1 calc(100% - 46px);
    max-width: calc(100% - 46px);
    min-width: 0;
  }
  .brand-title {
    max-width: 100%;
    overflow: hidden;
    text-overflow: ellipsis;
    white-space: nowrap;
  }
  .mobile-menu-toggle {
    appearance: none;
    display: inline-flex;
    align-items: center;
    justify-content: space-between;
    gap: 8px;
    width: 100%;
    min-height: 36px;
    padding: 5px 12px;
    border: 2px solid var(--border);
    border-radius: 999px;
    background: var(--surface);
    color: var(--ink-soft);
    font-family: inherit;
    font-size: 12px;
    font-weight: 800;
    line-height: 1.2;
    box-shadow: var(--shadow-sm);
    cursor: pointer;
    position: relative;
    z-index: 2;
    touch-action: manipulation;
  }
  .mobile-menu-state:checked + .mobile-menu-toggle,
  .mobile-menu-toggle[aria-expanded="true"] {
    border-color: var(--primary-strong);
    color: var(--primary-strong);
    background: var(--primary-soft);
  }
  .mobile-menu-icon {
    font-size: 14px;
    line-height: 1;
  }
  .topbar-actions {
    flex: 1 1 100%;
    width: 100%;
    display: none;
    gap: 5px;
    flex-wrap: wrap;
    justify-content: flex-start;
    min-width: 0;
    padding: 8px;
    border: 1px solid var(--border-soft);
    border-radius: 18px;
    background: var(--surface-glass);
    box-shadow: var(--shadow-sm);
  }
  .topbar-actions.is-open {
    display: grid !important;
    grid-template-columns: 1fr auto auto auto;
    align-items: center;
    justify-content: end;
    position: relative;
    z-index: 1;
  }
  .mobile-menu-state:checked ~ .topbar-actions {
    display: grid !important;
    grid-template-columns: 1fr auto auto auto;
    align-items: center;
    justify-content: end;
    position: relative;
    z-index: 1;
  }
  .topbar-actions .channel-switch {
    grid-column: 1 / -1;
  }
  .topbar-actions .audience-switch {
    grid-column: 1 / -1;
  }
  .topbar-actions .topbar-official-links {
    grid-column: 1;
    display: grid;
    grid-template-columns: repeat(3, minmax(0, auto));
    gap: 5px;
    justify-content: flex-start;
    align-self: center;
    padding-left: 0;
    padding-top: 0;
    border-left: 0;
    border-top: 0;
  }
  .topbar-actions .topbar-official-label {
    grid-column: 1 / -1;
  }
  .topbar-actions .theme-toggle,
  .topbar-actions .icon-btn {
    justify-self: end;
    width: 36px;
    height: 36px;
    min-width: 36px;
    padding: 0;
  }
  .topbar-actions .theme-toggle {
    grid-column: 2;
  }
  .theme-toggle { width: 36px; padding: 0; justify-content: center; }
  .help-grid { grid-template-columns: 1fr; }
  .guide-flow,
  .guide-sections {
    grid-template-columns: 1fr;
  }
  .help-dialog { padding: 18px; }
  .welcome-tip {
    right: 12px;
    bottom: 78px;
    width: calc(100vw - 24px);
  }
  .song-detail-main {
    grid-template-columns: minmax(0, 1fr);
  }
  .song-detail-stats {
    grid-template-columns: repeat(3, minmax(0, 1fr));
  }
  .song-detail-stats div {
    min-width: 0;
  }
  .song-detail-stats strong {
    overflow-wrap: anywhere;
  }
  .song-detail-stream {
    grid-template-columns: 58px 1fr;
    gap: 6px 10px;
  }
  .song-detail-thumb-link {
    width: 58px;
    aspect-ratio: 16 / 9;
    background: var(--surface-2);
  }
  .song-detail-thumb-link.thumb-missing {
    border: 1px solid var(--border-soft);
    opacity: 0.7;
    pointer-events: none;
  }
  .song-detail-thumb-link.thumb-missing .song-detail-thumb {
    display: none;
  }
}

@media (max-width: 480px) {
  .topbar-actions .theme-toggle,
  .topbar-actions .icon-btn {
    width: 36px;
    min-width: 36px;
  }
  .modal-backdrop {
    align-items: end;
    padding: 8px;
  }
  .help-dialog {
    width: 100%;
    max-height: calc(100dvh - 16px);
    border-radius: 18px;
    padding: 16px;
  }
  .help-head {
    gap: 10px;
  }
  .help-head h2 {
    font-size: 19px;
  }
  .song-detail-stats {
    gap: 6px;
  }
  .song-detail-stats div {
    padding: 8px 5px;
  }
  .song-detail-stats strong {
    font-size: 15px;
  }
  .song-detail-stats span {
    font-size: 10px;
  }
  .song-detail-actions .btn {
    flex: 1 1 130px;
    justify-content: center;
  }
}

/* === Animations === */

@keyframes fadeIn {
  from { opacity: 0; transform: translateY(8px); }
  to   { opacity: 1; transform: translateY(0); }
}

@keyframes spin { to { transform: rotate(360deg); } }