:root {
  --bg-base: #0F0F12;
  --bg-card: #1A1A1F;
  --accent: #E10600;
  --text-main: #F5F5F7;
  --text-sub: #9A9AA0;
  --divider: #2A2A30;
  --radius: 10px;
  --max-width: 880px;
  --font-system: -apple-system, BlinkMacSystemFont, "Hiragino Kaku Gothic ProN", "Yu Gothic", "Meiryo", sans-serif;
}

* {
  box-sizing: border-box;
}

html, body {
  margin: 0;
  padding: 0;
  background-color: var(--bg-base);
  color: var(--text-main);
  font-family: var(--font-system);
  font-size: 16px;
  line-height: 1.6;
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
}

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

a:hover {
  color: var(--accent);
}

.container {
  max-width: var(--max-width);
  margin: 0 auto;
  padding: 24px 20px 80px;
}

/* ===== Header ===== */
.site-header {
  display: flex;
  align-items: baseline;
  justify-content: space-between;
  gap: 16px;
  padding-bottom: 20px;
  border-bottom: 1px solid var(--divider);
  margin-bottom: 28px;
}

.site-title {
  font-size: 24px;
  font-weight: 700;
  letter-spacing: 0.02em;
  margin: 0;
}

.site-title .accent {
  color: var(--accent);
}

.last-updated {
  font-size: 12px;
  color: var(--text-sub);
}

/* ===== GP Tabs (Phase 1.1) ===== */
.gp-tabs {
  margin: 0 -20px 20px;
  border-bottom: 1px solid var(--divider);
  position: relative;
}

.gp-tabs__scroller {
  display: flex;
  gap: 4px;
  overflow-x: auto;
  overflow-y: hidden;
  padding: 0 20px 2px;
  scroll-behavior: smooth;
  -webkit-overflow-scrolling: touch;
  scroll-snap-type: x mandatory;
  scrollbar-width: none;
  -ms-overflow-style: none;
}

.gp-tabs__scroller::-webkit-scrollbar {
  display: none;
}

.gp-tab {
  flex: 0 0 auto;
  scroll-snap-align: center;
  display: flex;
  flex-direction: column;
  align-items: flex-start;
  justify-content: center;
  gap: 2px;
  min-width: 88px;
  height: 50px;
  padding: 6px 12px;
  background: transparent;
  border: 0;
  border-bottom: 2px solid transparent;
  color: var(--text-main);
  font-family: var(--font-system);
  cursor: pointer;
  position: relative;
  transition: opacity 0.15s ease, color 0.15s ease, border-color 0.15s ease;
}

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

.gp-tab__round {
  font-size: 10px;
  font-weight: 600;
  letter-spacing: 0.05em;
  color: var(--text-sub);
  text-transform: uppercase;
}

.gp-tab__name {
  font-size: 13px;
  font-weight: 600;
  white-space: nowrap;
}

.gp-tab--past {
  opacity: 0.4;
}

.gp-tab--past:hover {
  opacity: 0.7;
}

.gp-tab--current::after {
  content: "";
  position: absolute;
  top: 8px;
  right: 10px;
  width: 6px;
  height: 6px;
  background: var(--accent);
  border-radius: 50%;
  box-shadow: 0 0 0 2px var(--bg-base);
  animation: pulse-dot 1.6s ease-in-out infinite;
}

@keyframes pulse-dot {
  0%, 100% { transform: scale(1); opacity: 1; }
  50% { transform: scale(1.4); opacity: 0.7; }
}

.gp-tab--active {
  border-bottom-color: var(--accent);
  color: var(--text-main);
  opacity: 1;
}

.gp-tab--active .gp-tab__round {
  color: var(--accent);
}

/* current かつ active の組合せ: アンダーライン + 赤ドット両方を維持 */
.gp-tab--current.gp-tab--active {
  opacity: 1;
}

/* past かつ active の組合せ: グレーアウトを少し戻し、アンダーラインを優先 */
.gp-tab--past.gp-tab--active {
  opacity: 0.85;
}

/* ===== Session Table (Phase 1.1) ===== */
.session-table {
  margin-top: 20px;
  padding-top: 16px;
  border-top: 1px solid var(--divider);
  display: flex;
  flex-direction: column;
  gap: 4px;
}

.session-table--empty {
  font-size: 13px;
  color: var(--text-sub);
  font-style: italic;
  border-top: 1px solid var(--divider);
  padding: 14px 0 4px;
}

.session-row {
  display: grid;
  grid-template-columns: 110px 1fr auto;
  align-items: baseline;
  gap: 12px;
  padding: 8px 10px;
  border-radius: 6px;
  font-size: 14px;
  transition: background 0.15s ease;
}

.session-row:hover {
  background: rgba(255, 255, 255, 0.03);
}

.session-row__label {
  color: var(--text-sub);
  font-size: 12px;
  font-weight: 600;
  letter-spacing: 0.05em;
  text-transform: uppercase;
}

.session-row__day {
  color: var(--text-main);
}

.session-row__time {
  color: var(--text-main);
  font-variant-numeric: tabular-nums;
  font-weight: 600;
  letter-spacing: 0.02em;
}

.session-row--gp {
  background: rgba(225, 6, 0, 0.08);
  border-left: 3px solid var(--accent);
  padding-left: 10px;
}

.session-row--gp .session-row__label {
  color: var(--accent);
}

.session-row--gp .session-row__time {
  color: #fff;
  font-weight: 700;
}

.race-cards {
  margin-bottom: 32px;
}

.next-race__days--small {
  font-size: 32px;
  letter-spacing: 0;
}

/* ===== Next Race Hero ===== */
.next-race {
  background: linear-gradient(135deg, #1A1A1F 0%, #20141B 100%);
  border: 1px solid var(--divider);
  border-radius: var(--radius);
  padding: 24px 24px 28px;
  margin-bottom: 32px;
  position: relative;
  overflow: hidden;
}

.next-race__label {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  font-size: 12px;
  font-weight: 600;
  color: var(--accent);
  letter-spacing: 0.1em;
  text-transform: uppercase;
  margin-bottom: 12px;
}

.next-race__round {
  font-size: 13px;
  color: var(--text-sub);
  margin-right: 8px;
}

.next-race__title {
  font-size: 28px;
  font-weight: 700;
  margin: 0 0 6px;
  line-height: 1.3;
}

.next-race__circuit {
  font-size: 14px;
  color: var(--text-sub);
  margin-bottom: 18px;
}

.next-race__countdown {
  display: flex;
  align-items: baseline;
  gap: 12px;
  margin-top: 12px;
}

.next-race__days {
  font-size: 56px;
  font-weight: 800;
  color: var(--accent);
  line-height: 1;
  letter-spacing: -0.02em;
}

.next-race__days-unit {
  font-size: 18px;
  color: var(--text-sub);
}

.next-race__date {
  font-size: 14px;
  color: var(--text-sub);
  margin-top: 4px;
}

.sprint-badge {
  display: inline-block;
  background: var(--accent);
  color: #fff;
  font-size: 11px;
  font-weight: 700;
  letter-spacing: 0.08em;
  padding: 3px 8px;
  border-radius: 4px;
  margin-left: 10px;
  vertical-align: middle;
}

.next-race--empty {
  text-align: center;
  color: var(--text-sub);
  padding: 32px 24px;
}

/* ===== Filters ===== */
.filters {
  display: flex;
  flex-wrap: wrap;
  gap: 12px;
  margin-bottom: 24px;
  padding: 16px;
  background: var(--bg-card);
  border: 1px solid var(--divider);
  border-radius: var(--radius);
}

.filter-group {
  display: flex;
  flex-direction: column;
  gap: 6px;
  flex: 1 1 200px;
}

.filter-group__label {
  font-size: 11px;
  color: var(--text-sub);
  letter-spacing: 0.05em;
  text-transform: uppercase;
}

.filter-group select {
  background: var(--bg-base);
  color: var(--text-main);
  border: 1px solid var(--divider);
  border-radius: 6px;
  padding: 8px 10px;
  font-size: 14px;
  font-family: var(--font-system);
  cursor: pointer;
}

.filter-group select:focus {
  outline: 2px solid var(--accent);
  outline-offset: 1px;
}

.filter-reset {
  align-self: flex-end;
  background: transparent;
  color: var(--text-sub);
  border: 1px solid var(--divider);
  border-radius: 6px;
  padding: 8px 14px;
  font-size: 13px;
  cursor: pointer;
  font-family: var(--font-system);
}

.filter-reset:hover {
  color: var(--text-main);
  border-color: var(--text-sub);
}

/* ===== GP Article Filter Header (Phase 1.2) ===== */
.gp-filter-header {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 12px;
  background: var(--bg-card);
  border: 1px solid var(--divider);
  border-left: 3px solid var(--accent);
  border-radius: var(--radius);
  padding: 12px 16px;
  margin-bottom: 14px;
}

.gp-filter-header__label {
  font-size: 14px;
  color: var(--text-main);
  line-height: 1.4;
}

.gp-filter-header__label strong {
  font-weight: 700;
  color: var(--text-main);
}

#gp-filter-count {
  color: var(--accent);
  font-weight: 700;
  font-variant-numeric: tabular-nums;
}

.gp-filter-header__clear {
  flex-shrink: 0;
  background: transparent;
  color: var(--text-sub);
  border: 1px solid var(--divider);
  border-radius: 6px;
  padding: 6px 12px;
  font-size: 12px;
  font-family: var(--font-system);
  cursor: pointer;
  white-space: nowrap;
  transition: color 0.15s ease, border-color 0.15s ease;
}

.gp-filter-header__clear:hover {
  color: var(--accent);
  border-color: var(--accent);
}

.empty-state__link {
  display: inline-block;
  margin-top: 10px;
  color: var(--accent);
  font-weight: 600;
  text-decoration: underline;
  text-underline-offset: 3px;
}

.empty-state__link:hover {
  color: var(--accent);
  opacity: 0.8;
}

/* ===== Article List ===== */
.article-count {
  font-size: 13px;
  color: var(--text-sub);
  margin-bottom: 12px;
}

.article-count strong {
  color: var(--text-main);
  font-weight: 700;
  font-variant-numeric: tabular-nums;
}

.articles {
  display: flex;
  flex-direction: column;
  gap: 14px;
}

.article-card {
  background: var(--bg-card);
  border: 1px solid var(--divider);
  border-radius: var(--radius);
  padding: 18px 20px;
  transition: transform 0.15s ease, border-color 0.15s ease;
}

.article-card:hover {
  transform: translateY(-2px);
  border-color: #3a3a44;
}

.article-card__title {
  font-size: 17px;
  font-weight: 600;
  line-height: 1.45;
  margin: 0 0 10px;
}

.article-card__title a {
  color: var(--text-main);
}

.article-card__title a:hover {
  color: var(--accent);
}

.article-card__meta {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 10px;
  font-size: 12px;
  color: var(--text-sub);
}

.article-card__date-relative {
  color: var(--text-main);
  font-weight: 500;
}

.article-card__date-absolute::before {
  content: "・";
  margin: 0 2px;
  color: var(--divider);
}

.source-badge {
  display: inline-block;
  background: var(--bg-base);
  color: var(--text-main);
  border: 1px solid var(--divider);
  border-radius: 4px;
  padding: 2px 8px;
  font-size: 11px;
  font-weight: 500;
}

.team-tags {
  display: inline-flex;
  flex-wrap: wrap;
  gap: 6px;
  margin-left: 4px;
}

.team-tag {
  display: inline-block;
  color: #fff;
  font-size: 11px;
  font-weight: 600;
  padding: 2px 8px;
  border-radius: 4px;
  letter-spacing: 0.02em;
  text-shadow: 0 1px 1px rgba(0, 0, 0, 0.25);
}

.empty-state {
  text-align: center;
  padding: 60px 20px;
  color: var(--text-sub);
  background: var(--bg-card);
  border: 1px solid var(--divider);
  border-radius: var(--radius);
}

/* ===== Footer ===== */
.site-footer {
  margin-top: 48px;
  padding-top: 20px;
  border-top: 1px solid var(--divider);
  font-size: 12px;
  color: var(--text-sub);
  text-align: center;
}

/* ===== Mobile (≤480px) ===== */
@media (max-width: 480px) {
  .container {
    padding: 16px 14px 60px;
  }
  .site-header {
    flex-direction: column;
    align-items: flex-start;
    gap: 4px;
  }
  .site-title {
    font-size: 20px;
  }
  .gp-tabs {
    margin: 0 -14px 16px;
  }
  .gp-tabs__scroller {
    padding: 0 14px 2px;
  }
  .gp-tab {
    min-width: 76px;
    padding: 6px 10px;
  }
  .gp-tab__name {
    font-size: 12px;
  }
  .next-race {
    padding: 20px 18px;
  }
  .next-race__title {
    font-size: 22px;
  }
  .next-race__days {
    font-size: 44px;
  }
  .session-row {
    grid-template-columns: 90px 1fr auto;
    gap: 8px;
    font-size: 13px;
    padding: 7px 8px;
  }
  .session-row__label {
    font-size: 11px;
  }
  .article-card {
    padding: 14px 16px;
  }
  .article-card__title {
    font-size: 16px;
  }
  .filters {
    flex-direction: column;
    gap: 10px;
  }
  .gp-filter-header {
    flex-direction: column;
    align-items: flex-start;
    gap: 8px;
    padding: 12px 14px;
  }
  .gp-filter-header__clear {
    align-self: flex-end;
  }
}