:root {
  color-scheme: light;
  --ink: #18221e;
  --muted: #66716b;
  --paper: #fbfcfb;
  --surface: #f1f4f2;
  --line: #d7ded9;
  --accent: #355e4b;
  --accent-soft: #e2ece6;
  --focus: #1769aa;
  font-family: ui-sans-serif, system-ui, -apple-system, BlinkMacSystemFont, "Segoe UI", "Noto Sans TC", sans-serif;
  font-size: 16px;
}

* { box-sizing: border-box; }

body {
  background: var(--paper);
  color: var(--ink);
  margin: 0;
  min-height: 100vh;
  padding: 0 24px 64px;
}

a { color: var(--accent); text-underline-offset: .2em; }
button, input, textarea { font: inherit; }
button, a { -webkit-tap-highlight-color: transparent; }
button:focus-visible, a:focus-visible, input:focus-visible, textarea:focus-visible, summary:focus-visible {
  outline: 3px solid color-mix(in srgb, var(--focus), transparent 45%);
  outline-offset: 3px;
}

.site-header,
body > main {
  margin-left: auto;
  margin-right: auto;
  max-width: 860px;
}

.site-header {
  align-items: center;
  display: flex;
  justify-content: space-between;
  padding: 32px 0 24px;
}

.site-header h1 {
  font-size: clamp(1.45rem, 4vw, 1.85rem);
  font-weight: 650;
  letter-spacing: .01em;
  line-height: 1.25;
  margin: 0;
}

.site-header p {
  color: var(--muted);
  margin: 6px 0 0;
}

.language-toggle,
.secondary-action,
.primary-action,
.talk-actions button {
  align-items: center;
  border-radius: 8px;
  display: inline-flex;
  justify-content: center;
  min-height: 42px;
  padding: 8px 13px;
}

.language-toggle {
  background: transparent;
  border: 1px solid var(--line);
  color: var(--ink);
  cursor: pointer;
  flex: 0 0 auto;
}

.subscription-panel {
  align-items: center;
  background: var(--surface);
  border-radius: 12px;
  display: grid;
  gap: 12px 20px;
  grid-template-columns: minmax(220px, 1fr) minmax(290px, .9fr);
  margin-bottom: 24px;
  padding: 18px 20px;
}

.subscription-panel h2 {
  font-size: 1rem;
  font-weight: 650;
  margin: 0 0 4px;
}

.subscription-panel p {
  color: var(--muted);
  line-height: 1.55;
  margin: 0;
}

.subscription-actions { display: flex; flex-wrap: wrap; gap: 8px; }

.primary-action,
.talk-actions .primary-action {
  background: var(--accent);
  border: 1px solid var(--accent);
  color: #fff;
  cursor: pointer;
  text-decoration: none;
}

.semester-note {
  border-left: 3px solid var(--line);
  color: var(--muted);
  line-height: 1.65;
  margin: 22px 0 28px;
  padding-left: 16px;
}

.semester-note p { margin: 0 0 8px; }
.semester-note p:last-child { margin-bottom: 0; }

.talk-tabs {
  border-bottom: 1px solid var(--line);
  display: flex;
  gap: 28px;
}

.talk-tabs button {
  background: transparent;
  border: 0;
  border-bottom: 3px solid transparent;
  color: var(--muted);
  cursor: pointer;
  min-height: 48px;
  padding: 10px 2px 8px;
}

.talk-tabs button.active {
  border-bottom-color: var(--accent);
  color: var(--ink);
  font-weight: 650;
}

.talk-tabs span { color: var(--muted); font-variant-numeric: tabular-nums; }

.talk-card {
  align-items: flex-start;
  border-bottom: 1px solid var(--line);
  display: flex;
  gap: 20px;
  padding: 26px 4px;
  scroll-margin-top: 16px;
}

.talk-card-target {
  background: linear-gradient(90deg, var(--accent-soft), transparent 46%);
  border-radius: 10px 10px 0 0;
  padding-left: 12px;
}

.date-stack {
  display: flex;
  flex: 0 0 66px;
  flex-direction: column;
  gap: 7px;
}

.date-tile {
  background: var(--accent-soft);
  border-radius: 10px;
  color: var(--accent);
  padding: 9px 6px;
  text-align: center;
  width: 66px;
}

.date-stack-multiple .date-tile:not(.date-tile-next) { background: var(--surface); color: var(--muted); }
.date-tile-next { box-shadow: inset 0 0 0 1px color-mix(in srgb, var(--accent), transparent 68%); }

.date-tile span,
.date-tile strong { display: block; }
.date-tile span { font-size: .78rem; }
.date-tile strong { font-size: 1.75rem; font-variant-numeric: tabular-nums; line-height: 1.08; }

.talk-content { flex: 1; min-width: 0; }
.talk-heading {
  align-items: flex-start;
  display: flex;
  gap: 18px;
  justify-content: space-between;
}

.talk-heading h2 {
  font-size: 1.1rem;
  font-weight: 650;
  line-height: 1.45;
  margin: 0;
  overflow-wrap: anywhere;
}

.talk-heading time,
.series-heading {
  color: var(--accent);
  flex: 0 0 auto;
  font-size: .95rem;
  font-variant-numeric: tabular-nums;
  font-weight: 650;
  padding-top: 2px;
}

.next-label {
  color: var(--accent);
  display: inline-block;
  font-size: .8rem;
  font-weight: 650;
  margin-bottom: 5px;
}

.talk-facts { display: grid; gap: 7px; margin: 14px 0 0; }
.talk-facts div { display: grid; grid-template-columns: 3.2rem 1fr; line-height: 1.55; }
.talk-facts dt { color: var(--muted); }
.talk-facts dd { margin: 0; min-width: 0; overflow-wrap: anywhere; }
html[data-language="en"] .talk-facts > div { grid-template-columns: 6.5rem minmax(0, 1fr); }
.lang-en { display: none !important; }
html[data-language="en"] .lang-zh { display: none !important; }
html[data-language="en"] .lang-en { display: revert !important; }
html[data-language="en"] .date-tile .lang-en { display: block !important; }
.series-schedule { display: grid; gap: 4px; list-style: none; margin: 0; padding: 0; }
.series-schedule li { align-items: baseline; display: flex; flex-wrap: wrap; gap: 5px 12px; justify-content: space-between; }
.series-schedule strong { color: var(--accent); font-variant-numeric: tabular-nums; font-weight: 650; white-space: nowrap; }

.external-link { font-size: .92rem; margin: 12px 0 0; }

details {
  border-top: 1px solid var(--line);
  margin-top: 17px;
  padding-top: 13px;
}

summary { color: var(--accent); cursor: pointer; font-weight: 600; }
.abstract { color: #39443f; line-height: 1.72; margin-top: 14px; }
.abstract p { margin: 0 0 1em; }
.abstract mjx-container[display="true"] { overflow-x: auto; overflow-y: hidden; padding: .25rem 0; }
.abstract mjx-container:not([display="true"]) { margin: 0 .08em; }

.talk-actions {
  align-items: center;
  display: flex;
  flex-wrap: wrap;
  gap: 8px;
  margin-top: 17px;
}

.secondary-action {
  background: transparent;
  border: 1px solid var(--line);
  color: var(--ink);
  cursor: pointer;
  text-decoration: none;
}

.past-semester-selector {
  display: flex;
  flex-wrap: wrap;
  gap: 7px;
  padding: 20px 4px 2px;
}
#panel-past[aria-busy="true"] .semester-choice { cursor: progress; }
.semester-choice {
  align-items: center;
  border: 1px solid var(--line);
  border-radius: 999px;
  color: var(--muted);
  display: inline-flex;
  font-size: .86rem;
  justify-content: center;
  min-height: 38px;
  padding: 6px 12px;
  text-decoration: none;
}
.semester-choice.active {
  background: var(--accent-soft);
  border-color: color-mix(in srgb, var(--accent), transparent 60%);
  color: var(--accent);
  font-weight: 650;
}
.past-semester { margin-top: 18px; }
.past-semester-title {
  border-bottom: 1px solid var(--line);
  color: var(--ink);
  font-size: 1rem;
  font-weight: 650;
  margin: 0;
  padding: 18px 4px 12px;
}
.past-semester-title small {
  color: var(--muted);
  font-size: .82rem;
  font-weight: 450;
  margin-left: 8px;
}

.empty-state { color: var(--muted); padding: 42px 4px; }
.empty-state h2 { color: var(--ink); font-size: 1.08rem; margin: 0 0 6px; }
.empty-state p { margin: 0; }

.toast {
  background: var(--ink);
  border-radius: 8px;
  bottom: 20px;
  color: var(--paper);
  left: 50%;
  padding: 10px 14px;
  position: fixed;
  transform: translateX(-50%);
  z-index: 10;
}

.visually-hidden {
  border: 0 !important;
  clip: rect(0 0 0 0) !important;
  height: 1px !important;
  margin: -1px !important;
  overflow: hidden !important;
  padding: 0 !important;
  position: absolute !important;
  white-space: nowrap !important;
  width: 1px !important;
}

.message-page {
  align-items: center;
  display: flex;
  justify-content: center;
  padding: 24px;
}

.message-card {
  background: var(--surface);
  border-radius: 14px;
  max-width: 520px;
  padding: 30px;
  text-align: center;
}

.message-card h1 { font-size: 1.35rem; margin: 8px 0; }
.message-card p { color: var(--muted); line-height: 1.6; }
.message-symbol { color: var(--accent) !important; font-size: 2rem; margin: 0 !important; }
.message-card .primary-action { margin-top: 10px; }

.admin-page { padding-bottom: 72px; }
.admin-header { max-width: 960px; }
.admin-header > div { min-width: 0; }
.admin-header-actions { align-items: center; display: flex; flex: 0 0 auto; flex-wrap: wrap; gap: 8px; justify-content: flex-end; }
.admin-header-actions form { margin: 0; }
.admin-user { color: var(--muted); font-size: .9rem; max-width: 180px; overflow-wrap: anywhere; }
.admin-header h1 { margin-bottom: 5px; }
.admin-header p { overflow-wrap: anywhere; }
.admin-eyebrow {
  color: var(--accent) !important;
  font-size: .78rem;
  font-weight: 700;
  letter-spacing: .08em;
  text-transform: uppercase;
}
.admin-shell { max-width: 960px; }
.admin-note {
  background: var(--accent-soft);
  border-radius: 10px;
  line-height: 1.6;
  margin: 0 0 20px;
  padding: 13px 16px;
}
.admin-list {
  border-bottom: 1px solid var(--line);
  padding: 22px 0 26px;
}
.admin-list-heading {
  align-items: center;
  display: flex;
  gap: 20px;
  justify-content: space-between;
  margin-bottom: 12px;
}
.admin-list h2 { font-size: 1.08rem; margin: 0; }
.admin-list-heading p { color: var(--muted); margin: 3px 0 0; }
.admin-list textarea {
  background: var(--surface);
  border: 1px solid var(--line);
  border-radius: 10px;
  color: var(--ink);
  line-height: 1.55;
  min-height: 116px;
  padding: 12px;
  resize: vertical;
  width: 100%;
}
.admin-error {
  background: #fff2f0;
  border-radius: 8px;
  color: #8a2f25;
  margin: 0;
  padding: 11px 13px;
}

.admin-flash {
  border-radius: 10px;
  line-height: 1.6;
  margin: 0 0 20px;
  padding: 13px 16px;
}
.admin-flash-success { background: #e5f2e8; color: #225f37; }
.admin-flash-error { background: #fff2f0; color: #8a2f25; }
.admin-warning { color: #8a5a12; }
.admin-section-heading { margin: 28px 0 12px; }
.admin-section-heading h2 { font-size: 1.15rem; margin: 0; }
.admin-section-heading p { color: var(--muted); margin: 4px 0 0; }
.admin-recipient-grid {
  display: grid;
  gap: 14px;
  grid-template-columns: repeat(auto-fit, minmax(min(100%, 280px), 1fr));
}
.admin-recipient-card {
  background: var(--surface);
  border-radius: 10px;
  min-width: 0;
  padding: 15px;
}
.admin-recipient-card .admin-list-heading { margin-bottom: 10px; }
.admin-recipient-card h3 { font-size: 1rem; margin: 0; overflow-wrap: anywhere; }
.admin-recipient-card .admin-list-heading p { font-size: .88rem; }
.admin-recipient-rows {
  border: 1px solid var(--line);
  border-radius: 8px;
  list-style: none;
  margin: 0;
  max-height: 280px;
  overflow-y: auto;
  padding: 2px 10px;
}
.admin-recipient-rows li {
  border-bottom: 1px solid var(--line);
  display: grid;
  gap: 8px;
  grid-template-columns: minmax(0, .8fr) minmax(0, 1.2fr);
  padding: 8px 0;
}
.admin-recipient-rows li:last-child { border-bottom: 0; }
.admin-recipient-name,
.admin-recipient-email { min-width: 0; overflow: hidden; text-overflow: ellipsis; white-space: nowrap; }
.admin-recipient-name { font-weight: 600; }
.admin-recipient-email { color: var(--muted); font-size: .86rem; }
.admin-list-empty { color: var(--muted); margin: 0; }
.mail-preview {
  background: var(--paper);
  border: 1px solid var(--line);
  border-radius: 8px;
  color: var(--ink);
  line-height: 1.55;
  padding: 10px;
  resize: vertical;
  width: 100%;
}
.admin-announcements { margin-top: 30px; }
.mail-event {
  border-bottom: 1px solid var(--line);
  display: grid;
  gap: 18px;
  grid-template-columns: minmax(0, 1fr);
  padding: 25px 4px;
}
.mail-event-main { min-width: 0; }
.mail-event-date {
  color: var(--accent);
  font-size: .9rem;
  font-variant-numeric: tabular-nums;
  font-weight: 650;
  margin: 0 0 6px;
}
.mail-event h3 { font-size: 1.1rem; line-height: 1.45; margin: 0; overflow-wrap: anywhere; }
.mail-event-facts { display: grid; gap: 7px; margin: 14px 0 0; }
.mail-event-facts > div { display: grid; gap: 12px; grid-template-columns: 3.2rem minmax(0, 1fr); line-height: 1.55; }
.mail-event-facts dt { color: var(--muted); }
.mail-event-facts dd { margin: 0; min-width: 0; overflow-wrap: anywhere; }
.mail-event-schedule { display: grid; gap: 3px; list-style: none; margin: 0; padding: 0; }
.mail-preview { display: block; font-family: ui-monospace, SFMono-Regular, Menlo, monospace; font-size: .84rem; min-height: 240px; }
.mail-event-action {
  background: var(--surface);
  border-radius: 10px;
  display: grid;
  gap: 9px;
  min-width: 0;
  padding: 15px;
}
.mail-event-fields { display: grid; gap: 16px; grid-template-columns: minmax(0, 2fr) minmax(0, 1fr); margin-bottom: 5px; }
.mail-event-field { display: grid; gap: 6px; min-width: 0; }
.mail-event-action label { color: var(--muted); font-size: .88rem; }
.mail-event-action select,
.mail-event-action input[type="text"] {
  background: var(--paper);
  border: 1px solid var(--line);
  border-radius: 8px;
  color: var(--ink);
  font: inherit;
  min-height: 42px;
  min-width: 0;
  padding: 7px 9px;
  width: 100%;
}
.mail-event-submit { display: flex; justify-content: flex-end; margin-top: 4px; }
.primary-action:disabled,
.mail-event-action select:disabled { cursor: not-allowed; opacity: .55; }
.admin-login-card { width: min(100%, 430px); }
.admin-login-card .admin-eyebrow { margin: 0 0 8px; }
.admin-login-card > p:not(.admin-eyebrow) { margin-bottom: 20px; }
.admin-login-form { display: grid; gap: 8px; margin: 0 0 16px; text-align: left; }
.admin-login-form label { color: var(--muted); font-size: .9rem; }
.admin-login-form input {
  background: var(--paper);
  border: 1px solid var(--line);
  border-radius: 8px;
  color: var(--ink);
  min-height: 44px;
  padding: 8px 10px;
  width: 100%;
}
.admin-login-form button { margin-top: 8px; width: 100%; }
.admin-login-card > .secondary-action { display: inline-flex; }
.admin-log { margin-top: 30px; }
.admin-log-empty { color: var(--muted); padding: 8px 4px 28px; }
.admin-log-table-wrap { overflow-x: auto; }
.admin-log-table { border-collapse: collapse; min-width: 720px; width: 100%; }
.admin-log-table th,
.admin-log-table td { border-bottom: 1px solid var(--line); padding: 11px 8px; text-align: left; vertical-align: top; }
.admin-log-table th { color: var(--muted); font-size: .82rem; font-weight: 650; white-space: nowrap; }
.admin-log-record-row td { border-bottom: 0; padding-bottom: 8px; }
.admin-log-detail-row td { padding-top: 0; padding-bottom: 14px; }
.admin-log-details { min-width: 0; width: 100%; }
.admin-log-details summary { width: fit-content; }
.admin-log-details p { margin: 10px 0 4px; }
.admin-log-details ul { margin: 4px 0 10px; max-height: 240px; overflow-y: auto; padding-left: 20px; }
.admin-log-details li { overflow-wrap: anywhere; }
.admin-log-details code { font-size: .85em; }
.admin-log-details pre { background: var(--paper); border: 1px solid var(--line); border-radius: 8px; font-family: ui-monospace, SFMono-Regular, Menlo, monospace; font-size: .82rem; margin: 4px 0 12px; max-height: 360px; overflow: auto; padding: 10px; white-space: pre-wrap; overflow-wrap: anywhere; }
.admin-log-no-details { color: var(--muted); font-size: .85rem; white-space: nowrap; }
.admin-log-table td { font-size: .9rem; line-height: 1.45; }
.admin-log-table small { color: var(--muted); display: block; font-size: .78rem; margin-top: 3px; max-width: 260px; overflow-wrap: anywhere; }
.admin-log-title { display: block; max-width: 270px; overflow-wrap: anywhere; }
.admin-log-status { border-radius: 999px; display: inline-block; font-size: .78rem; font-weight: 650; padding: 3px 8px; white-space: nowrap; }
.admin-log-status-sent { background: #e5f2e8; color: #225f37; }
.admin-log-status-sending { background: #fff7df; color: #8a5a12; }
.admin-log-status-failed { background: #fff2f0; color: #8a2f25; }

@media (max-width: 700px) {
  body { padding-left: 16px; padding-right: 16px; }
  .site-header { align-items: flex-start; padding-top: 24px; }
  .subscription-panel { grid-template-columns: 1fr; }
  .talk-card { flex-direction: column; }
  .date-stack { flex: 0 1 auto; flex-direction: row; flex-wrap: wrap; width: 100%; }
  .date-tile { flex: 1 1 80px; min-width: 80px; width: auto; }
  .date-stack:not(.date-stack-multiple) .date-tile { align-items: center; display: flex; gap: 10px; justify-content: center; }
  .date-stack:not(.date-stack-multiple) .date-tile span,
  .date-stack:not(.date-stack-multiple) .date-tile strong { font-size: .9rem; font-weight: 400; line-height: 1.5; }
  .talk-content { width: 100%; }
  .talk-heading { flex-direction: column; gap: 7px; }
  .mail-event-fields { grid-template-columns: minmax(0, 1fr); }
}

@media (max-width: 480px) {
  .site-header { gap: 12px; }
  .site-header p { font-size: .88rem; }
  .language-toggle { padding-left: 10px; padding-right: 10px; }
  .subscription-panel { padding: 16px; }
  .subscription-actions > * { flex: 1; }
  .talk-tabs { gap: 20px; }
  .talk-card { gap: 12px; padding-bottom: 22px; padding-top: 22px; }
  .date-stack { gap: 6px; }
  .date-tile strong { font-size: 1.45rem; }
  .talk-facts div { grid-template-columns: 2.8rem 1fr; }
  html[data-language="en"] .talk-facts > div { grid-template-columns: 5.8rem minmax(0, 1fr); }
  .talk-actions { align-items: stretch; flex-direction: column; }
  .talk-actions > * { width: 100%; }
  .admin-header { align-items: stretch; flex-direction: column; }
  .admin-header > .secondary-action { margin-top: 12px; }
  .admin-header-actions { align-items: stretch; justify-content: flex-start; }
  .admin-header-actions .secondary-action { flex: 1; }
  .admin-user { align-self: center; flex: 0 1 auto; }
  .admin-list-heading { align-items: stretch; flex-direction: column; gap: 10px; }
  .past-semester-title small { display: block; margin: 3px 0 0; }
  .mail-event-facts > div { gap: 8px; grid-template-columns: 2.8rem minmax(0, 1fr); }
}

@media (max-width: 370px) {
  html[data-language="en"] .talk-facts > div { gap: 1px; grid-template-columns: 1fr; }
}

@media (prefers-reduced-motion: reduce) {
  * { scroll-behavior: auto !important; }
}