:root {
  --bg: #f6f7fb;
  --surface: rgba(255,255,255,.82);
  --surface-solid: #ffffff;
  --text: #171923;
  --muted: #677084;
  --line: rgba(23,25,35,.09);
  --accent: #6558e8;
  --accent-2: #23a6d5;
  --accent-soft: rgba(101,88,232,.11);
  --shadow: 0 18px 45px rgba(32, 39, 71, .10);
  --radius: 24px;
  --max: 1180px;
}

@media (prefers-color-scheme: dark) {
  :root {
    --bg: #0d1018;
    --surface: rgba(24,28,40,.78);
    --surface-solid: #181c28;
    --text: #f3f5fb;
    --muted: #aeb7ca;
    --line: rgba(255,255,255,.10);
    --accent: #9c8cff;
    --accent-2: #56c7eb;
    --accent-soft: rgba(156,140,255,.15);
    --shadow: 0 20px 50px rgba(0,0,0,.28);
  }
}

* { box-sizing: border-box; }
html { scroll-behavior: smooth; }
body {
  margin: 0;
  min-height: 100vh;
  color: var(--text);
  background:
    radial-gradient(circle at 12% 0%, rgba(101,88,232,.17), transparent 32rem),
    radial-gradient(circle at 88% 10%, rgba(35,166,213,.14), transparent 28rem),
    var(--bg);
  font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", "Noto Sans JP", "Hiragino Kaku Gothic ProN", Meiryo, sans-serif;
  line-height: 1.7;
  -webkit-font-smoothing: antialiased;
}

a { color: inherit; }
button, input { font: inherit; }

.site-header {
  width: min(var(--max), calc(100% - 36px));
  margin: 0 auto;
  padding: 28px 0 0;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 20px;
}

.brand {
  display: inline-flex;
  align-items: center;
  gap: 11px;
  font-weight: 800;
  letter-spacing: -.02em;
}

.brand-mark {
  width: 34px;
  height: 34px;
  display: grid;
  place-items: center;
  border-radius: 11px;
  color: white;
  background: linear-gradient(135deg, var(--accent), var(--accent-2));
  box-shadow: 0 8px 20px rgba(101,88,232,.25);
}

.brand-mark svg { width: 19px; }

.status-pill {
  border: 1px solid var(--line);
  background: var(--surface);
  backdrop-filter: blur(14px);
  padding: 7px 12px;
  border-radius: 999px;
  font-size: .78rem;
  color: var(--muted);
}

.hero {
  width: min(var(--max), calc(100% - 36px));
  margin: 0 auto;
  padding: clamp(76px, 11vw, 138px) 0 60px;
  text-align: center;
}

.eyebrow {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  margin-bottom: 22px;
  padding: 7px 12px;
  border: 1px solid var(--line);
  border-radius: 999px;
  background: var(--surface);
  color: var(--muted);
  font-size: .82rem;
  font-weight: 700;
  backdrop-filter: blur(14px);
}

.eyebrow::before {
  content: "";
  width: 8px;
  height: 8px;
  border-radius: 50%;
  background: linear-gradient(135deg, var(--accent), var(--accent-2));
  box-shadow: 0 0 0 5px var(--accent-soft);
}

h1 {
  max-width: 840px;
  margin: 0 auto;
  font-size: clamp(2.45rem, 7vw, 5.7rem);
  line-height: 1.04;
  letter-spacing: -.065em;
}

.gradient-text {
  background: linear-gradient(110deg, var(--accent), var(--accent-2));
  -webkit-background-clip: text;
  background-clip: text;
  color: transparent;
}

.lead {
  max-width: 700px;
  margin: 27px auto 0;
  color: var(--muted);
  font-size: clamp(1rem, 2vw, 1.16rem);
}

.notice {
  max-width: 790px;
  margin: 32px auto 0;
  padding: 16px 19px;
  display: flex;
  align-items: flex-start;
  gap: 12px;
  text-align: left;
  border: 1px solid var(--line);
  border-radius: 17px;
  background: var(--surface);
  color: var(--muted);
  font-size: .88rem;
  backdrop-filter: blur(14px);
}

.notice svg {
  flex: 0 0 auto;
  width: 20px;
  margin-top: 2px;
  color: var(--accent);
}

.toolbar-wrap {
  position: sticky;
  top: 0;
  z-index: 20;
  border-top: 1px solid transparent;
  border-bottom: 1px solid var(--line);
  background: color-mix(in srgb, var(--bg) 83%, transparent);
  backdrop-filter: blur(18px);
}

.toolbar {
  width: min(var(--max), calc(100% - 36px));
  margin: 0 auto;
  padding: 16px 0;
  display: grid;
  grid-template-columns: minmax(230px, 330px) 1fr auto;
  align-items: center;
  gap: 14px;
}

.search {
  position: relative;
}

.search svg {
  position: absolute;
  top: 50%;
  left: 15px;
  width: 18px;
  transform: translateY(-50%);
  color: var(--muted);
  pointer-events: none;
}

.search input {
  width: 100%;
  min-height: 44px;
  padding: 10px 14px 10px 43px;
  color: var(--text);
  border: 1px solid var(--line);
  border-radius: 14px;
  outline: none;
  background: var(--surface);
}

.search input:focus {
  border-color: color-mix(in srgb, var(--accent) 65%, var(--line));
  box-shadow: 0 0 0 4px var(--accent-soft);
}

.filters {
  display: flex;
  gap: 8px;
  overflow-x: auto;
  scrollbar-width: none;
  padding: 2px;
}

.filters::-webkit-scrollbar { display: none; }

.filter-chip {
  flex: 0 0 auto;
  min-height: 39px;
  padding: 8px 13px;
  border: 1px solid var(--line);
  border-radius: 999px;
  color: var(--muted);
  background: transparent;
  cursor: pointer;
  transition: .2s ease;
}

.filter-chip:hover {
  color: var(--text);
  border-color: color-mix(in srgb, var(--accent) 35%, var(--line));
  transform: translateY(-1px);
}

.filter-chip.is-active {
  color: white;
  border-color: transparent;
  background: linear-gradient(135deg, var(--accent), var(--accent-2));
  box-shadow: 0 8px 18px rgba(101,88,232,.2);
}

.result-count {
  white-space: nowrap;
  color: var(--muted);
  font-size: .86rem;
}

main {
  width: min(var(--max), calc(100% - 36px));
  margin: 0 auto;
  padding: 46px 0 90px;
}

.grid {
  display: grid;
  grid-template-columns: repeat(3, minmax(0, 1fr));
  gap: 20px;
}

.gpt-card {
  min-height: 390px;
  display: flex;
  flex-direction: column;
  padding: 23px;
  border: 1px solid var(--line);
  border-radius: var(--radius);
  background: var(--surface);
  box-shadow: var(--shadow);
  backdrop-filter: blur(18px);
  transition: transform .25s ease, border-color .25s ease, box-shadow .25s ease;
}

.gpt-card:hover {
  transform: translateY(-6px);
  border-color: color-mix(in srgb, var(--accent) 30%, var(--line));
  box-shadow: 0 24px 55px rgba(32,39,71,.15);
}

.gpt-card[hidden] { display: none; }

.card-top {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 16px;
  margin-bottom: 24px;
}

.icon-wrap {
  width: 50px;
  height: 50px;
  display: grid;
  place-items: center;
  border-radius: 16px;
  color: var(--accent);
  background: linear-gradient(135deg, var(--accent-soft), rgba(35,166,213,.09));
  border: 1px solid color-mix(in srgb, var(--accent) 14%, var(--line));
}

.icon-wrap svg { width: 26px; }

.category-badge {
  padding: 6px 10px;
  border-radius: 999px;
  color: var(--muted);
  background: color-mix(in srgb, var(--surface-solid) 75%, transparent);
  border: 1px solid var(--line);
  font-size: .76rem;
  font-weight: 700;
}

.card-copy { flex: 1; }

.card-copy h2 {
  margin: 0;
  font-size: 1.26rem;
  line-height: 1.4;
  letter-spacing: -.02em;
}

.card-summary {
  margin: 13px 0 0;
  color: var(--muted);
  font-size: .94rem;
}

details {
  margin-top: 18px;
  padding-top: 15px;
  border-top: 1px solid var(--line);
}

summary {
  width: max-content;
  color: var(--accent);
  font-size: .86rem;
  font-weight: 750;
  cursor: pointer;
  user-select: none;
}

details p {
  margin: 12px 0 0;
  color: var(--muted);
  font-size: .86rem;
  line-height: 1.75;
}

.open-button {
  min-height: 46px;
  margin-top: 24px;
  padding: 11px 15px;
  display: flex;
  align-items: center;
  justify-content: center;
  gap: 8px;
  color: var(--text);
  border: 1px solid var(--line);
  border-radius: 14px;
  text-decoration: none;
  font-size: .91rem;
  font-weight: 750;
  background: color-mix(in srgb, var(--surface-solid) 82%, transparent);
  transition: .2s ease;
}

.open-button svg {
  width: 17px;
  fill: none;
  stroke: currentColor;
  stroke-width: 1.9;
  stroke-linecap: round;
  stroke-linejoin: round;
}

.open-button:hover {
  color: white;
  border-color: transparent;
  background: linear-gradient(135deg, var(--accent), var(--accent-2));
  transform: translateY(-1px);
}

.empty {
  display: none;
  padding: 64px 20px;
  text-align: center;
  color: var(--muted);
  border: 1px dashed var(--line);
  border-radius: var(--radius);
}

.empty.is-visible { display: block; }

footer {
  border-top: 1px solid var(--line);
}

.footer-inner {
  width: min(var(--max), calc(100% - 36px));
  margin: 0 auto;
  padding: 27px 0 38px;
  display: flex;
  justify-content: space-between;
  gap: 22px;
  color: var(--muted);
  font-size: .79rem;
}

.reveal {
  opacity: 0;
  transform: translateY(14px);
  animation: reveal .55s ease forwards;
  animation-delay: var(--delay);
}

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

@media (max-width: 980px) {
  .grid { grid-template-columns: repeat(2, minmax(0, 1fr)); }
  .toolbar { grid-template-columns: 1fr auto; }
  .filters { grid-column: 1 / -1; grid-row: 2; }
}

@media (max-width: 640px) {
  .site-header { width: min(100% - 28px, var(--max)); padding-top: 18px; }
  .status-pill { display: none; }
  .hero { width: min(100% - 28px, var(--max)); padding-top: 72px; }
  h1 { letter-spacing: -.052em; }
  .notice { padding: 14px 15px; }
  .toolbar { width: min(100% - 28px, var(--max)); grid-template-columns: 1fr auto; }
  .result-count { font-size: .78rem; }
  main { width: min(100% - 28px, var(--max)); padding-top: 30px; }
  .grid { grid-template-columns: 1fr; gap: 16px; }
  .gpt-card { min-height: auto; padding: 20px; }
  .footer-inner { width: min(100% - 28px, var(--max)); flex-direction: column; }
}

@media (prefers-reduced-motion: reduce) {
  *, *::before, *::after {
    scroll-behavior: auto !important;
    animation-duration: .01ms !important;
    animation-iteration-count: 1 !important;
    transition-duration: .01ms !important;
  }
}