:root {
  --ink: #14212b;
  --muted: #5f6f7a;
  --line: #d7e0e6;
  --bg: #f3f7f8;
  --card: #ffffff;
  --accent: #0d7377;
  --accent-deep: #095456;
  --heart: #d9486f;
  --shadow: 0 10px 30px rgba(20, 33, 43, 0.06);
  --radius: 16px;
  --font: "Hiragino Sans", "Hiragino Kaku Gothic ProN", "Segoe UI", sans-serif;
}

* { box-sizing: border-box; }
html, body { margin: 0; padding: 0; }
body {
  font-family: var(--font);
  color: var(--ink);
  background:
    radial-gradient(1200px 500px at 10% -10%, #d7f3f1 0%, transparent 55%),
    radial-gradient(900px 400px at 100% 0%, #e8eef2 0%, transparent 50%),
    var(--bg);
  min-height: 100vh;
}

a { color: var(--accent); text-decoration: none; }
.muted { color: var(--muted); }
.hint { color: var(--muted); font-size: .88rem; margin: 0; }
.error { color: #b42318; font-size: .9rem; margin: 0; }

.topbar {
  position: sticky;
  top: 0;
  z-index: 20;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 1rem;
  padding: .85rem 1.25rem;
  background: rgba(255,255,255,.86);
  backdrop-filter: blur(10px);
  border-bottom: 1px solid rgba(215,224,230,.8);
}

.brand {
  font-weight: 800;
  letter-spacing: .04em;
  color: var(--ink);
  font-size: 1.1rem;
}

.topbar-actions {
  display: flex;
  align-items: center;
  gap: .6rem;
}

.user-label { font-size: .88rem; }

.btn {
  border: 1px solid var(--line);
  background: #fff;
  color: var(--ink);
  border-radius: 999px;
  padding: .45rem .95rem;
  font: inherit;
  font-size: .9rem;
  cursor: pointer;
}
.btn.primary {
  background: var(--accent);
  border-color: var(--accent);
  color: #fff;
}
.btn.primary:hover { background: var(--accent-deep); }
.btn.ghost:hover { background: #f4f8f9; }
.btn.liked {
  color: var(--heart);
  border-color: #f2c4d0;
  background: #fff5f8;
}

main {
  width: min(1120px, calc(100% - 2rem));
  margin: 0 auto;
  padding: 1.5rem 0 3rem;
}

.hero {
  margin-bottom: 1.25rem;
}
.eyebrow {
  margin: 0 0 .35rem;
  font-size: .78rem;
  font-weight: 700;
  letter-spacing: .14em;
  text-transform: uppercase;
  color: var(--accent);
}
.hero h1 {
  margin: 0;
  font-size: clamp(1.9rem, 4.5vw, 2.6rem);
  letter-spacing: .04em;
}
.hero > p:last-child {
  margin: .65rem 0 0;
  color: var(--muted);
  max-width: 38rem;
  line-height: 1.7;
}

.filters {
  display: flex;
  flex-wrap: wrap;
  gap: .5rem;
  margin-bottom: 1.15rem;
}
.chip {
  border: 1px solid var(--line);
  background: rgba(255,255,255,.8);
  color: var(--muted);
  border-radius: 999px;
  padding: .4rem .9rem;
  font: inherit;
  font-size: .88rem;
  cursor: pointer;
}
.chip:hover { background: #fff; color: var(--ink); }
.chip.is-active {
  background: var(--ink);
  border-color: var(--ink);
  color: #fff;
}

.badge {
  display: inline-block;
  margin: 0 0 .35rem;
  padding: .15rem .55rem;
  border-radius: 999px;
  font-size: .72rem;
  font-weight: 700;
  letter-spacing: .04em;
}
.badge-knowledge {
  background: #e7f4f4;
  color: var(--accent-deep);
}
.badge-game {
  background: #fff0e8;
  color: #b85a2a;
}
.badge-on-thumb {
  position: absolute;
  left: .65rem;
  top: .65rem;
  z-index: 2;
  margin: 0;
  box-shadow: 0 4px 12px rgba(0,0,0,.08);
}

.category-pick {
  border: 1px solid var(--line);
  border-radius: 12px;
  padding: .75rem .9rem;
  margin: 0;
}
.category-pick legend {
  padding: 0 .35rem;
  font-size: .82rem;
  color: var(--muted);
}
.category-pick {
  display: flex;
  flex-wrap: wrap;
  gap: .85rem 1.2rem;
  align-items: center;
}
.dropzone {
  position: relative;
  border: 1.5px dashed var(--line);
  border-radius: 14px;
  padding: 1.25rem 1rem;
  text-align: center;
  background: #f7fbfb;
  transition: border-color .15s ease, background .15s ease, transform .15s ease;
  cursor: pointer;
}
.dropzone:hover,
.dropzone.is-dragover {
  border-color: var(--accent);
  background: #eaf6f6;
}
.dropzone.is-dragover {
  transform: scale(1.01);
}
.dropzone.has-file {
  border-style: solid;
  border-color: #b7d8d9;
}
.dropzone input[type="file"] {
  position: absolute;
  inset: 0;
  opacity: 0;
  cursor: pointer;
  width: 100%;
  height: 100%;
}
.dropzone-title {
  margin: 0;
  font-weight: 700;
  color: var(--ink);
}
.dropzone-sub {
  margin: .25rem 0 0;
  font-size: .88rem;
  color: var(--muted);
}
.dropzone-file {
  margin: .65rem 0 0;
  font-size: .85rem;
  word-break: break-all;
}

.feed {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(240px, 1fr));
  gap: 1rem;
}

.card {
  background: var(--card);
  border: 1px solid var(--line);
  border-radius: var(--radius);
  overflow: hidden;
  box-shadow: var(--shadow);
  display: flex;
  flex-direction: column;
  cursor: pointer;
  transition: transform .18s ease, box-shadow .18s ease;
}
.card:hover {
  transform: translateY(-2px);
  box-shadow: 0 14px 34px rgba(20, 33, 43, 0.09);
}

.thumb {
  position: relative;
  aspect-ratio: 16 / 10;
  background: linear-gradient(160deg, #eef5f6, #dfe9ec);
  overflow: hidden;
  border-bottom: 1px solid var(--line);
}
.thumb iframe {
  position: absolute;
  inset: 0;
  width: 200%;
  height: 200%;
  transform: scale(.5);
  transform-origin: top left;
  border: 0;
  pointer-events: none;
  background: #fff;
}
.thumb-fallback {
  position: absolute;
  inset: 0;
  display: grid;
  place-items: center;
  color: var(--muted);
  font-size: .85rem;
  padding: 1rem;
  text-align: center;
}

.card-body {
  padding: .9rem 1rem 1rem;
  display: flex;
  flex-direction: column;
  gap: .55rem;
  flex: 1;
}
.card-title {
  margin: 0;
  font-size: 1rem;
  line-height: 1.45;
  display: -webkit-box;
  -webkit-line-clamp: 2;
  -webkit-box-orient: vertical;
  overflow: hidden;
}
.card-meta {
  margin: 0;
  font-size: .82rem;
  color: var(--muted);
}
.card-foot {
  margin-top: auto;
  display: flex;
  align-items: center;
  gap: .75rem;
  font-size: .85rem;
  color: var(--muted);
}

.empty-state {
  grid-column: 1 / -1;
  padding: 2.5rem 1rem;
  text-align: center;
  color: var(--muted);
  border: 1px dashed var(--line);
  border-radius: var(--radius);
  background: rgba(255,255,255,.6);
}

.site-footer {
  display: flex;
  flex-wrap: wrap;
  gap: 1rem;
  justify-content: center;
  padding: 1.5rem 1rem 2.5rem;
  font-size: .82rem;
  color: var(--muted);
}
.site-footer a { color: var(--muted); }

.modal {
  border: 0;
  padding: 0;
  background: transparent;
  max-width: calc(100vw - 2rem);
}
.modal::backdrop {
  background: rgba(15, 28, 36, .45);
}
.modal-card {
  width: min(420px, 100%);
  background: #fff;
  border-radius: 18px;
  padding: 1.25rem;
  box-shadow: var(--shadow);
  display: grid;
  gap: .85rem;
}
.modal.wide .modal-card,
.detail-card {
  width: min(920px, 100%);
}
.modal-card h2 { margin: 0; font-size: 1.15rem; }
.modal-card label {
  display: grid;
  gap: .35rem;
  font-size: .88rem;
  color: var(--muted);
}
.modal-card label[hidden] {
  display: none !important;
}
.modal-card input[type="text"],
.modal-card input[type="password"],
.modal-card input:not([type]),
.comment-form input {
  width: 100%;
  border: 1px solid var(--line);
  border-radius: 10px;
  padding: .65rem .75rem;
  font: inherit;
  color: var(--ink);
  background: #fff;
}
.modal-actions {
  display: flex;
  justify-content: flex-end;
  gap: .5rem;
}

.detail-head {
  display: flex;
  justify-content: space-between;
  gap: 1rem;
  align-items: flex-start;
}
.detail-frame-wrap {
  border: 1px solid var(--line);
  border-radius: 12px;
  overflow: hidden;
  background: #fff;
  height: min(55vh, 480px);
}
.detail-frame-wrap.is-game {
  height: min(68vh, 560px);
  background: #0b1216;
}
.detail-frame-wrap iframe {
  width: 100%;
  height: 100%;
  border: 0;
  background: #fff;
}
.detail-actions {
  display: flex;
  gap: .5rem;
  flex-wrap: wrap;
}
.comments h3 {
  margin: 0 0 .75rem;
  font-size: 1rem;
}
#comment-list {
  display: grid;
  gap: .65rem;
  margin-bottom: .85rem;
  max-height: 180px;
  overflow: auto;
}
.comment {
  padding: .7rem .8rem;
  border-radius: 10px;
  background: #f6fafb;
  border: 1px solid var(--line);
}
.comment strong { display: block; font-size: .86rem; }
.comment p { margin: .25rem 0 0; font-size: .92rem; }
.comment-form {
  display: grid;
  grid-template-columns: 1fr auto;
  gap: .5rem;
}

@media (max-width: 640px) {
  .topbar { padding: .75rem 1rem; }
  .user-label { display: none; }
  .hero { margin-bottom: 1rem; }
  .detail-frame-wrap { height: 42vh; }
}