/* ---- Design tokens (loosely matching strategyscience2026.org) ---- */
:root {
  --paper: #F8F5EE;
  --paper-soft: #FBF9F2;
  --ink: #1B1A18;
  --ink-soft: #4A463F;
  --ink-mute: #7A746A;
  --gold: #CFB87C;
  --gold-deep: #A8915A;
  --rule: #E5DFD2;
  --rule-soft: #EFEBDF;
  --ok: #3B7A4A;
  --warn: #B6701A;
  --err: #A03A2C;
  --shadow: 0 1px 0 rgba(27, 26, 24, 0.04), 0 6px 24px -12px rgba(27, 26, 24, 0.18);

  --display: "Source Serif 4", "Source Serif Pro", Georgia, serif;
  --body: "Source Sans 3", "Source Sans Pro", -apple-system, "Segoe UI", sans-serif;
  --mono: "JetBrains Mono", ui-monospace, "SF Mono", Menlo, monospace;
}

/* ---- Reset + base ---- */
*, *::before, *::after { box-sizing: border-box; }
html { -webkit-text-size-adjust: 100%; }
body {
  margin: 0;
  background: var(--paper);
  color: var(--ink);
  font-family: var(--body);
  font-size: 16px;
  line-height: 1.5;
  font-feature-settings: "ss01", "ss02";
  -webkit-font-smoothing: antialiased;
  text-rendering: optimizeLegibility;
}
img, svg { display: block; max-width: 100%; }
button, input, select { font: inherit; color: inherit; }
a { color: var(--ink); text-decoration: underline; text-underline-offset: 2px; text-decoration-thickness: 1px; }
a:hover { text-decoration-thickness: 2px; }

/* ---- Layout ---- */
.wrap { max-width: 1080px; margin: 0 auto; padding: 32px 24px 96px; }
@media (max-width: 640px) {
  .wrap { padding: 20px 16px 80px; }
}

/* ---- Header ---- */
.site-header {
  border-bottom: 1px solid var(--rule);
  padding-bottom: 24px;
  margin-bottom: 32px;
}
.eyebrow {
  font-family: var(--mono);
  font-size: 12px;
  letter-spacing: 0.12em;
  text-transform: uppercase;
  color: var(--ink-mute);
  margin: 0 0 8px;
}
.site-header h1 {
  font-family: var(--display);
  font-weight: 600;
  font-size: clamp(28px, 4vw, 38px);
  line-height: 1.15;
  margin: 0 0 12px;
  letter-spacing: -0.01em;
}
.site-header .lead {
  font-size: 17px;
  color: var(--ink-soft);
  margin: 0;
  max-width: 62ch;
}
.site-header .meta {
  font-family: var(--mono);
  font-size: 12px;
  color: var(--ink-mute);
  margin-top: 12px;
}

/* ---- Jump grid ---- */
.jump {
  margin: 24px 0 40px;
}
.jump h2 {
  font-family: var(--display);
  font-weight: 600;
  font-size: 20px;
  margin: 24px 0 12px;
  letter-spacing: -0.005em;
}
.jump-grid {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 8px;
}
@media (max-width: 640px) {
  .jump-grid { grid-template-columns: repeat(2, 1fr); }
}
.jump-cell {
  display: block;
  padding: 10px 12px;
  background: var(--paper-soft);
  border: 1px solid var(--rule);
  border-radius: 6px;
  text-decoration: none;
  transition: border-color 120ms, background 120ms;
}
.jump-cell:hover {
  border-color: var(--gold);
  background: #fff;
}
.jump-cell .code {
  font-family: var(--mono);
  font-size: 13px;
  font-weight: 600;
  color: var(--ink);
}
.jump-cell .theme {
  display: block;
  font-size: 12px;
  color: var(--ink-mute);
  margin-top: 2px;
  line-height: 1.3;
}

/* ---- Session block ---- */
.session {
  margin: 48px 0 0;
  scroll-margin-top: 24px;
}
.session-head {
  border-top: 2px solid var(--ink);
  padding-top: 14px;
  margin-bottom: 16px;
}
.session-code {
  font-family: var(--mono);
  font-size: 12px;
  letter-spacing: 0.06em;
  color: var(--ink-mute);
  text-transform: uppercase;
  margin-bottom: 4px;
}
.session-theme {
  font-family: var(--display);
  font-weight: 600;
  font-size: 22px;
  margin: 0;
  letter-spacing: -0.005em;
}
.session-desc {
  margin: 6px 0 0;
  color: var(--ink-soft);
  font-size: 14px;
  max-width: 70ch;
}

/* ---- Paper card ---- */
.papers {
  display: flex;
  flex-direction: column;
  gap: 10px;
  margin-top: 12px;
}
.paper {
  background: #fff;
  border: 1px solid var(--rule);
  border-radius: 8px;
  padding: 14px 16px;
  box-shadow: var(--shadow);
  display: grid;
  grid-template-columns: 1fr auto;
  gap: 12px 16px;
  align-items: start;
}
@media (max-width: 640px) {
  .paper { grid-template-columns: 1fr; }
}
.paper.is-uploaded {
  border-left: 3px solid var(--ok);
}
.paper-meta {
  font-family: var(--mono);
  font-size: 11px;
  color: var(--ink-mute);
  letter-spacing: 0.04em;
  text-transform: uppercase;
  margin-bottom: 4px;
}
.paper-title {
  font-family: var(--display);
  font-weight: 600;
  font-size: 16px;
  line-height: 1.3;
  margin: 0 0 4px;
}
.paper-authors {
  font-size: 14px;
  color: var(--ink-soft);
  margin: 0;
}
.paper-inst {
  font-size: 13px;
  color: var(--ink-mute);
  margin: 2px 0 0;
  font-style: italic;
}
.paper-actions {
  display: flex;
  flex-direction: column;
  align-items: flex-end;
  gap: 6px;
  min-width: 0;
}
@media (max-width: 640px) {
  .paper-actions { align-items: stretch; }
}
.upload-state {
  font-family: var(--mono);
  font-size: 11px;
  color: var(--ok);
  text-align: right;
  line-height: 1.4;
  word-break: break-all;
}
.upload-state .filename {
  display: block;
  color: var(--ink);
  font-weight: 600;
  margin-bottom: 2px;
}
@media (max-width: 640px) {
  .upload-state { text-align: left; }
}

/* ---- Buttons ---- */
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 6px;
  padding: 8px 16px;
  font-family: var(--body);
  font-size: 14px;
  font-weight: 600;
  background: var(--ink);
  color: var(--paper);
  border: 1px solid var(--ink);
  border-radius: 6px;
  cursor: pointer;
  text-decoration: none;
  transition: opacity 120ms, transform 60ms;
  white-space: nowrap;
}
.btn:hover { opacity: 0.92; }
.btn:active { transform: translateY(1px); }
.btn:disabled { opacity: 0.5; cursor: not-allowed; }
.btn.btn-secondary {
  background: transparent;
  color: var(--ink);
}
.btn.btn-secondary:hover {
  background: var(--ink);
  color: var(--paper);
}
.btn .file-input {
  position: absolute;
  width: 1px; height: 1px;
  opacity: 0;
  pointer-events: none;
}

/* ---- Progress + status ---- */
.progress {
  width: 100%;
  height: 4px;
  background: var(--rule);
  border-radius: 2px;
  overflow: hidden;
  margin-top: 8px;
}
.progress-bar {
  height: 100%;
  width: 0%;
  background: var(--gold-deep);
  transition: width 200ms ease-out;
}
.error {
  color: var(--err);
  font-size: 12px;
  font-family: var(--mono);
  margin-top: 6px;
}

/* ---- Toast ---- */
.toast-host {
  position: fixed;
  bottom: 16px;
  left: 50%;
  transform: translateX(-50%);
  z-index: 1000;
  display: flex;
  flex-direction: column;
  gap: 8px;
  pointer-events: none;
}
.toast {
  background: var(--ink);
  color: var(--paper);
  padding: 10px 16px;
  border-radius: 6px;
  font-size: 14px;
  box-shadow: 0 8px 24px -8px rgba(0,0,0,0.4);
  animation: toast-in 200ms ease-out;
  pointer-events: auto;
  max-width: 90vw;
}
.toast.err { background: var(--err); }
.toast.ok::before { content: "✓ "; }
@keyframes toast-in {
  from { transform: translateY(8px); opacity: 0; }
  to { transform: translateY(0); opacity: 1; }
}

/* ---- Skeleton ---- */
.skeleton {
  padding: 40px 0;
  text-align: center;
  color: var(--ink-mute);
  font-family: var(--mono);
  font-size: 13px;
}

/* ---- Room view ---- */
.room-header { margin-bottom: 24px; }
.room-header .room-tag {
  display: inline-flex;
  align-items: baseline;
  gap: 12px;
  font-family: var(--mono);
  color: var(--ink-mute);
  font-size: 13px;
  margin-bottom: 8px;
}
.room-header .room-tag .big {
  font-family: var(--display);
  font-weight: 600;
  font-size: 32px;
  color: var(--ink);
  letter-spacing: -0.01em;
}
.room-header h1 {
  font-family: var(--display);
  font-weight: 600;
  font-size: clamp(22px, 3vw, 28px);
  margin: 0;
  letter-spacing: -0.005em;
}
.room-header .room-date {
  font-family: var(--mono);
  font-size: 13px;
  color: var(--ink-mute);
  margin-top: 4px;
}
.room-nav {
  display: flex;
  gap: 6px;
  margin-top: 16px;
  flex-wrap: wrap;
}
.room-nav a {
  padding: 4px 10px;
  font-family: var(--mono);
  font-size: 12px;
  text-decoration: none;
  border: 1px solid var(--rule);
  border-radius: 4px;
  color: var(--ink-soft);
}
.room-nav a.active {
  background: var(--ink);
  color: var(--paper);
  border-color: var(--ink);
}
.room-empty {
  padding: 48px 16px;
  text-align: center;
  color: var(--ink-mute);
  font-family: var(--display);
  font-size: 18px;
  border: 1px dashed var(--rule);
  border-radius: 8px;
}

.session-card {
  background: #fff;
  border: 1px solid var(--rule);
  border-radius: 10px;
  padding: 20px 22px;
  margin-top: 16px;
  box-shadow: var(--shadow);
}
.session-card.is-now {
  border-color: var(--gold);
  background: #FFFCF3;
  position: relative;
}
.session-card.is-now::before {
  content: "NOW";
  position: absolute;
  top: 16px; right: 18px;
  font-family: var(--mono);
  font-size: 11px;
  font-weight: 700;
  letter-spacing: 0.1em;
  color: var(--gold-deep);
  padding: 2px 8px;
  border: 1px solid var(--gold);
  border-radius: 4px;
  background: var(--paper);
}
.session-card.is-past { opacity: 0.55; }
.session-card .when {
  font-family: var(--mono);
  font-size: 12px;
  color: var(--ink-mute);
  letter-spacing: 0.04em;
  text-transform: uppercase;
  margin-bottom: 6px;
}
.session-card h2 {
  font-family: var(--display);
  font-weight: 600;
  font-size: 22px;
  margin: 0 0 4px;
  letter-spacing: -0.005em;
  padding-right: 60px;
}
.session-card .desc {
  font-size: 14px;
  color: var(--ink-soft);
  margin: 0 0 12px;
}
.paper-list {
  list-style: none;
  padding: 0;
  margin: 12px 0 0;
  display: flex;
  flex-direction: column;
}
.paper-list li {
  border-top: 1px solid var(--rule-soft);
}
.paper-list li:first-child { border-top: none; }
.paper-link {
  display: grid;
  grid-template-columns: 28px 1fr auto;
  gap: 12px;
  padding: 12px 4px;
  align-items: baseline;
  text-decoration: none;
  color: var(--ink);
  border-radius: 6px;
  transition: background 120ms;
}
.paper-link:hover { background: var(--rule-soft); }
.paper-link .num {
  font-family: var(--mono);
  font-size: 13px;
  color: var(--ink-mute);
  text-align: right;
}
.paper-link .info {
  display: flex;
  flex-direction: column;
  gap: 2px;
  min-width: 0;
}
.paper-link .title {
  font-family: var(--display);
  font-weight: 600;
  font-size: 16px;
  line-height: 1.3;
  text-decoration: underline;
  text-decoration-color: transparent;
  text-underline-offset: 3px;
  transition: text-decoration-color 120ms;
}
.paper-link:hover .title { text-decoration-color: var(--gold); }
.paper-link .who {
  font-size: 13px;
  color: var(--ink-mute);
}
.paper-link .tag {
  font-family: var(--mono);
  font-size: 11px;
  color: var(--ok);
  letter-spacing: 0.04em;
  text-transform: uppercase;
  white-space: nowrap;
}
.paper-link .tag.missing { color: var(--ink-mute); }
.paper-link.no-slides {
  pointer-events: none;
  opacity: 0.7;
}

/* ---- Footer ---- */
.site-footer {
  margin-top: 64px;
  padding-top: 16px;
  border-top: 1px solid var(--rule);
  font-family: var(--mono);
  font-size: 11px;
  color: var(--ink-mute);
  letter-spacing: 0.04em;
  text-transform: uppercase;
}
.site-footer a { color: var(--ink-mute); }