:root {
  --bg: #0e1528;
  --bg-deep: #080d18;
  --paper: #f5eddc;
  --paper-strong: #fcf7ee;
  --paper-soft: rgba(245, 237, 220, 0.9);
  --paper-muted: rgba(234, 224, 203, 0.82);
  --line: rgba(74, 55, 36, 0.16);
  --line-strong: rgba(74, 55, 36, 0.28);
  --ink: #1f1a17;
  --ink-soft: #5f5245;
  --ink-faint: #857767;
  --accent: #f26a3d;
  --accent-strong: #d94f24;
  --accent-cool: #3ea892;
  --accent-cool-strong: #288977;
  --accent-gold: #f0c96a;
  --danger: #b04433;
  --shadow-xl: 0 30px 80px rgba(5, 9, 20, 0.36);
  --shadow-lg: 0 22px 52px rgba(5, 9, 20, 0.22);
  --shadow-sm: 0 12px 22px rgba(5, 9, 20, 0.12);
  --radius-xl: 34px;
  --radius-lg: 26px;
  --radius-md: 18px;
  --font-body: "Instrument Sans", sans-serif;
  --font-display: "Fraunces", serif;
}

* {
  box-sizing: border-box;
}

html {
  scroll-behavior: smooth;
}

body {
  position: relative;
  margin: 0;
  min-height: 100vh;
  font-family: var(--font-body);
  color: var(--ink);
  background:
    radial-gradient(circle at 12% 18%, rgba(62, 168, 146, 0.24), transparent 18%),
    radial-gradient(circle at 82% 6%, rgba(240, 201, 106, 0.18), transparent 18%),
    radial-gradient(circle at 88% 82%, rgba(242, 106, 61, 0.16), transparent 22%),
    linear-gradient(135deg, #0b1121 0%, #141f36 42%, #130f24 100%);
}

body::before,
body::after {
  content: "";
  position: fixed;
  inset: 0;
  pointer-events: none;
}

body::before {
  background:
    linear-gradient(rgba(255, 255, 255, 0.018) 1px, transparent 1px),
    linear-gradient(90deg, rgba(255, 255, 255, 0.018) 1px, transparent 1px);
  background-size: 56px 56px;
  opacity: 0.42;
}

body::after {
  opacity: 0.12;
  background:
    radial-gradient(circle, rgba(255, 255, 255, 0.18) 0.7px, transparent 0.8px) 0 0 / 9px
      9px,
    radial-gradient(circle at top left, rgba(255, 255, 255, 0.12), transparent 60%);
  mix-blend-mode: soft-light;
}

button,
input,
select {
  font: inherit;
}

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

.hidden {
  display: none !important;
}

.page-shell {
  position: relative;
  width: min(1380px, calc(100% - 28px));
  margin: 0 auto;
  padding: 24px 0 48px;
}

.atmosphere {
  position: absolute;
  inset: auto;
  border-radius: 999px;
  filter: blur(14px);
  pointer-events: none;
}

.atmosphere-a {
  top: 92px;
  right: 12px;
  width: 220px;
  height: 220px;
  background: radial-gradient(circle, rgba(240, 201, 106, 0.22), transparent 70%);
}

.atmosphere-b {
  left: -28px;
  bottom: 180px;
  width: 260px;
  height: 260px;
  background: radial-gradient(circle, rgba(62, 168, 146, 0.16), transparent 72%);
}

.hero,
.panel {
  animation: lift-in 700ms cubic-bezier(0.2, 0.85, 0.25, 1) both;
}

.hero {
  position: relative;
  overflow: hidden;
  padding: 24px clamp(22px, 4vw, 42px) 38px;
  border: 1px solid rgba(255, 255, 255, 0.12);
  border-radius: 40px;
  color: #f7f2e7;
  background:
    radial-gradient(circle at top right, rgba(242, 106, 61, 0.24), transparent 28%),
    radial-gradient(circle at left center, rgba(62, 168, 146, 0.16), transparent 32%),
    linear-gradient(145deg, rgba(18, 24, 42, 0.92), rgba(11, 17, 32, 0.88));
  box-shadow: var(--shadow-xl);
}

.hero::before,
.hero::after {
  content: "";
  position: absolute;
  pointer-events: none;
}

.hero::before {
  inset: 0;
  background:
    linear-gradient(115deg, rgba(255, 255, 255, 0.08), transparent 34%),
    linear-gradient(180deg, rgba(255, 255, 255, 0.05), transparent 44%);
}

.hero::after {
  top: 44px;
  right: -54px;
  width: 200px;
  height: 200px;
  border-radius: 26px;
  border: 1px solid rgba(255, 255, 255, 0.08);
  transform: rotate(18deg);
  background: linear-gradient(145deg, rgba(255, 255, 255, 0.04), transparent);
}

.hero-badge-row,
.hero-layout {
  position: relative;
  z-index: 1;
}

.hero-badge-row {
  display: flex;
  align-items: flex-start;
  justify-content: space-between;
  gap: 16px;
}

.brand-mark {
  margin: 0;
  font-size: 0.78rem;
  font-weight: 700;
  letter-spacing: 0.24em;
  text-transform: uppercase;
  color: rgba(247, 242, 231, 0.72);
}

.hero-mini-metrics {
  display: flex;
  gap: 12px;
  flex-wrap: wrap;
  justify-content: flex-end;
}

.mini-metric {
  min-width: 144px;
  padding: 13px 14px;
  border: 1px solid rgba(255, 255, 255, 0.1);
  border-radius: 18px;
  background: rgba(255, 255, 255, 0.06);
  backdrop-filter: blur(14px);
}

.mini-metric span,
.board-stat span,
.fact-card span,
.meta-badge,
.section-tag,
.history-stamp,
.history-meta-chip,
.pill,
.flashcard-badge,
.board-note-kicker,
.board-label,
.summary-label {
  letter-spacing: 0.09em;
  text-transform: uppercase;
}

.mini-metric span {
  display: block;
  margin-bottom: 6px;
  font-size: 0.72rem;
  color: rgba(247, 242, 231, 0.62);
}

.mini-metric strong {
  display: block;
  font-size: 0.98rem;
  font-weight: 700;
  color: #fff8ef;
}

.hero-layout {
  display: grid;
  grid-template-columns: minmax(0, 1.15fr) minmax(320px, 0.85fr);
  gap: 34px;
  margin-top: 34px;
  align-items: center;
}

.eyebrow,
.section-tag {
  margin: 0 0 12px;
  font-size: 0.75rem;
  font-weight: 700;
}

.eyebrow {
  color: var(--accent-gold);
}

.eyebrow.small {
  margin-bottom: 8px;
  color: var(--accent);
}

.hero-copy h1 {
  margin: 0;
  max-width: 11ch;
  font-family: var(--font-display);
  font-size: clamp(3rem, 7vw, 5.8rem);
  line-height: 0.95;
  letter-spacing: -0.05em;
}

.hero-text {
  max-width: 60ch;
  margin: 18px 0 0;
  color: rgba(247, 242, 231, 0.76);
  font-size: 1.02rem;
  line-height: 1.8;
}

.hero-ribbon {
  display: flex;
  flex-wrap: wrap;
  gap: 10px;
  margin-top: 24px;
}

.hero-ribbon span {
  display: inline-flex;
  align-items: center;
  padding: 10px 14px;
  border: 1px solid rgba(255, 255, 255, 0.1);
  border-radius: 999px;
  background: rgba(255, 255, 255, 0.06);
  color: rgba(247, 242, 231, 0.84);
  font-size: 0.86rem;
  backdrop-filter: blur(10px);
}

.hero-board {
  position: relative;
  min-height: 100%;
  padding: 20px 12px 0;
}

.board-sheet,
.board-note {
  position: relative;
  border-radius: 28px;
  box-shadow: var(--shadow-lg);
}

.board-sheet {
  padding: 22px 22px 24px;
  color: var(--ink);
  background:
    linear-gradient(180deg, rgba(255, 255, 255, 0.64), transparent 26%),
    linear-gradient(145deg, rgba(252, 247, 238, 0.98), rgba(241, 231, 210, 0.94));
}

.board-sheet::before,
.panel::before,
.card::before,
.flashcard-face::before,
.info-modal-card::before {
  content: "";
  position: absolute;
  inset: 0;
  border-radius: inherit;
  pointer-events: none;
  background:
    linear-gradient(180deg, rgba(255, 255, 255, 0.42), transparent 30%),
    repeating-linear-gradient(
      180deg,
      rgba(255, 255, 255, 0) 0,
      rgba(255, 255, 255, 0) 28px,
      rgba(74, 55, 36, 0.03) 29px
    );
}

.board-sheet-main {
  z-index: 2;
  transform: rotate(-2deg);
}

.board-sheet-main strong {
  display: block;
  margin-top: 8px;
  font-family: var(--font-display);
  font-size: 2rem;
  line-height: 1.05;
  letter-spacing: -0.04em;
}

.board-sheet-main p,
.board-note p,
.generator-callout p,
.summary-box p,
.empty-stage p {
  margin: 12px 0 0;
  line-height: 1.72;
}

.board-label {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  font-size: 0.72rem;
  font-weight: 700;
  color: var(--accent-strong);
}

.board-label::before,
.board-note-kicker::before,
.summary-label::before,
.section-tag::before {
  content: "";
  width: 10px;
  height: 10px;
  border-radius: 999px;
  display: inline-block;
}

.board-label::before {
  background: var(--accent);
  box-shadow: 18px 0 0 var(--accent-cool);
  margin-right: 16px;
}

.board-sheet-stats {
  z-index: 1;
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 14px;
  margin: -10px 0 0 56px;
  transform: rotate(3deg);
}

.board-stat {
  padding: 18px 16px;
  border: 1px solid var(--line);
  border-radius: 20px;
  background: rgba(255, 255, 255, 0.5);
}

.board-stat span {
  display: block;
  margin-bottom: 8px;
  font-size: 0.72rem;
  font-weight: 700;
  color: var(--ink-faint);
}

.board-stat strong {
  display: block;
  font-family: var(--font-display);
  font-size: 1.65rem;
  line-height: 1.05;
}

.board-note {
  max-width: 84%;
  margin: 18px auto 0 0;
  padding: 18px 20px;
  border: 1px solid rgba(255, 255, 255, 0.1);
  color: rgba(247, 242, 231, 0.88);
  background: rgba(255, 255, 255, 0.08);
  backdrop-filter: blur(14px);
}

.board-note-kicker,
.section-tag,
.summary-label {
  display: inline-flex;
  align-items: center;
  gap: 10px;
  font-size: 0.72rem;
  font-weight: 700;
}

.board-note-kicker::before {
  background: var(--accent-gold);
}

.summary-label::before {
  background: var(--accent-cool);
}

.section-tag {
  color: var(--accent-strong);
}

.section-tag::before {
  background: var(--accent);
}

.dashboard {
  display: grid;
  grid-template-columns: 340px minmax(0, 1fr);
  gap: 24px;
  margin-top: 24px;
}

.sidebar,
.workspace {
  display: grid;
  gap: 24px;
  align-content: start;
}

.panel {
  position: relative;
  overflow: hidden;
  border: 1px solid rgba(255, 249, 240, 0.14);
  border-radius: 34px 16px 34px 16px;
  background:
    linear-gradient(180deg, rgba(255, 255, 255, 0.46), transparent 20%),
    linear-gradient(145deg, rgba(249, 243, 232, 0.96), rgba(238, 227, 205, 0.92));
  box-shadow: var(--shadow-lg);
}

.panel-heading h2,
.info-modal-card h2,
.viewer-topbar h2,
.file-picker-copy strong {
  margin: 0;
  font-family: var(--font-display);
  letter-spacing: -0.03em;
}

.panel-heading h2,
.info-modal-card h2 {
  font-size: 1.5rem;
}

.panel-heading p,
.helper-copy,
.muted-copy,
.history-source,
.status,
.history-caption {
  margin: 8px 0 0;
  color: var(--ink-soft);
  line-height: 1.68;
}

.auth-panel,
.history-panel,
.generator-panel,
.viewer-panel,
.info-modal-card {
  padding: 26px;
}

.panel-frame {
  display: grid;
  grid-template-columns: minmax(0, 1fr) minmax(220px, 0.5fr);
  gap: 18px;
  align-items: start;
}

.generator-callout {
  padding: 18px;
  border: 1px dashed var(--line-strong);
  border-radius: 22px;
  background:
    radial-gradient(circle at top right, rgba(62, 168, 146, 0.12), transparent 44%),
    rgba(255, 255, 255, 0.34);
}

.generator-callout span {
  display: inline-flex;
  align-items: center;
  padding: 8px 12px;
  border-radius: 999px;
  font-size: 0.76rem;
  font-weight: 700;
  letter-spacing: 0.08em;
  text-transform: uppercase;
  color: var(--accent-cool-strong);
  background: rgba(62, 168, 146, 0.12);
}

.panel-heading-split {
  display: flex;
  align-items: flex-start;
  justify-content: space-between;
  gap: 18px;
}

.section-counter {
  min-width: 52px;
  padding: 12px 14px;
  border-radius: 20px;
  text-align: center;
  font-family: var(--font-display);
  font-size: 1.6rem;
  line-height: 1;
  color: var(--accent-strong);
  background: rgba(242, 106, 61, 0.1);
}

.title-row {
  display: flex;
  align-items: flex-start;
  justify-content: space-between;
  gap: 16px;
}

.stack-form {
  display: grid;
  gap: 16px;
  margin-top: 20px;
}

.field,
.upload-field {
  display: grid;
  gap: 8px;
}

.field span {
  font-size: 0.92rem;
  font-weight: 700;
}

.field-grid {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 14px;
}

input,
select {
  width: 100%;
  padding: 15px 16px;
  border: 1px solid rgba(74, 55, 36, 0.14);
  border-radius: 18px;
  color: var(--ink);
  background: rgba(252, 247, 238, 0.86);
  box-shadow: inset 0 1px 0 rgba(255, 255, 255, 0.8);
  transition:
    border-color 160ms ease,
    transform 160ms ease,
    background 160ms ease,
    box-shadow 160ms ease;
}

input:hover,
select:hover {
  border-color: rgba(74, 55, 36, 0.22);
}

button,
.file-picker-btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 8px;
  padding: 14px 18px;
  border: 1px solid transparent;
  border-radius: 18px;
  cursor: pointer;
  font-weight: 700;
  text-decoration: none;
  transition:
    transform 160ms ease,
    opacity 160ms ease,
    background 160ms ease,
    border-color 160ms ease,
    box-shadow 160ms ease;
}

button:hover,
.file-picker-btn:hover {
  transform: translateY(-1px);
}

button:disabled {
  cursor: not-allowed;
  opacity: 0.6;
  transform: none;
}

button {
  color: #fff8f0;
  background: linear-gradient(135deg, var(--accent), #ff8a58);
  box-shadow: 0 16px 28px rgba(242, 106, 61, 0.26);
}

.secondary-btn,
.file-picker-btn {
  color: var(--ink);
  border-color: rgba(74, 55, 36, 0.14);
  background:
    linear-gradient(180deg, rgba(255, 255, 255, 0.48), transparent 100%),
    linear-gradient(145deg, rgba(252, 247, 238, 0.98), rgba(240, 229, 205, 0.94));
  box-shadow: none;
}

.ghost-btn,
.icon-btn {
  color: var(--ink);
  border-color: rgba(74, 55, 36, 0.12);
  background: rgba(255, 255, 255, 0.24);
  box-shadow: none;
}

.danger-btn {
  background: linear-gradient(135deg, var(--danger), #d1654e);
  box-shadow: 0 16px 28px rgba(176, 68, 51, 0.2);
}

.icon-btn {
  width: 44px;
  height: 44px;
  min-width: 44px;
  padding: 0;
  border-radius: 999px;
  font-size: 1.08rem;
}

#api-key-info-btn {
  color: #fff9ef;
  border-color: transparent;
  background: linear-gradient(135deg, var(--accent-cool), #62ceb6);
}

#close-api-key-info-btn,
#close-missing-key-btn {
  font-size: 1.3rem;
}

.button-row {
  display: flex;
  gap: 10px;
  flex-wrap: wrap;
}

.button-row button {
  flex: 1 1 0;
}

.button-row.compact {
  justify-content: flex-end;
}

.button-row.compact button {
  flex: 0 0 auto;
}

input:focus-visible,
select:focus-visible,
button:focus-visible,
.file-picker-btn:focus-visible,
.flashcard:focus-visible {
  outline: 3px solid rgba(62, 168, 146, 0.32);
  outline-offset: 2px;
}

#api-key-status,
#status {
  min-height: 24px;
  margin-top: 8px;
  padding-left: 2px;
  font-size: 0.94rem;
}

#api-key-status:empty,
#status:empty {
  min-height: 0;
  margin-top: 0;
}

#api-key-status[data-state="success"],
#status[data-state="success"] {
  color: var(--accent-cool-strong);
}

#api-key-status[data-state="error"],
#status[data-state="error"] {
  color: var(--danger);
}

#status[data-state="working"] {
  color: var(--accent-strong);
}

.history-list {
  display: grid;
  gap: 14px;
  margin-top: 18px;
}

.history-card {
  overflow: hidden;
  border: 1px solid rgba(74, 55, 36, 0.1);
  border-radius: 24px;
  background:
    linear-gradient(180deg, rgba(255, 255, 255, 0.55), transparent 100%),
    rgba(255, 252, 246, 0.88);
  transition:
    transform 160ms ease,
    border-color 160ms ease,
    box-shadow 160ms ease;
}

.history-card:hover {
  transform: translateY(-2px);
}

.history-card.active {
  border-color: rgba(242, 106, 61, 0.34);
  box-shadow:
    inset 0 0 0 1px rgba(242, 106, 61, 0.18),
    0 12px 24px rgba(242, 106, 61, 0.08);
}

.history-open {
  display: grid;
  gap: 12px;
  width: 100%;
  padding: 18px;
  border: 0;
  color: var(--ink);
  text-align: left;
  background: transparent;
  box-shadow: none;
}

.history-row {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 12px;
  flex-wrap: wrap;
}

.history-stamp,
.history-meta-chip {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  padding: 6px 10px;
  border-radius: 999px;
  font-size: 0.72rem;
  font-weight: 700;
}

.history-stamp {
  color: var(--accent-strong);
  background: rgba(242, 106, 61, 0.1);
}

.history-meta-chip {
  color: var(--ink-faint);
  background: rgba(74, 55, 36, 0.07);
}

.history-meta-chip-accent {
  color: var(--accent-cool-strong);
  background: rgba(62, 168, 146, 0.12);
}

.history-title {
  display: block;
  font-family: var(--font-display);
  font-size: 1.22rem;
  line-height: 1.18;
  letter-spacing: -0.03em;
}

.history-source {
  display: -webkit-box;
  overflow: hidden;
  margin: 0;
  -webkit-box-orient: vertical;
  -webkit-line-clamp: 2;
}

.history-divider {
  display: block;
  width: 100%;
  height: 1px;
  background: linear-gradient(90deg, rgba(74, 55, 36, 0.16), transparent);
}

.history-meta-row {
  display: flex;
  flex-wrap: wrap;
  gap: 8px;
}

.viewer-topbar {
  display: flex;
  align-items: flex-start;
  justify-content: space-between;
  gap: 20px;
}

.viewer-topbar h2 {
  font-size: clamp(2rem, 3vw, 2.75rem);
  line-height: 0.96;
}

.viewer-title-block {
  min-width: 0;
}

.muted-copy {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 8px;
  max-width: 72ch;
}

.meta-badge {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  padding: 8px 12px;
  border-radius: 999px;
  font-size: 0.72rem;
  font-weight: 700;
  color: var(--ink-soft);
  background: rgba(74, 55, 36, 0.07);
}

.meta-badge::before {
  content: "";
  width: 7px;
  height: 7px;
  border-radius: 999px;
  background: var(--accent-cool);
}

.active-brief {
  display: grid;
  grid-template-columns: minmax(0, 1fr) 220px;
  gap: 18px;
  margin-top: 22px;
}

.summary-box {
  position: relative;
  overflow: hidden;
  padding: 22px 22px 24px;
  border: 1px solid rgba(255, 255, 255, 0.08);
  border-radius: 28px;
  color: #f7f2e7;
  background:
    radial-gradient(circle at top right, rgba(242, 106, 61, 0.22), transparent 24%),
    linear-gradient(145deg, rgba(20, 28, 46, 0.96), rgba(13, 19, 33, 0.94));
  box-shadow: var(--shadow-sm);
}

.summary-box p {
  color: rgba(247, 242, 231, 0.74);
}

.summary-box > :first-child {
  margin-top: 0;
}

.summary-box > :last-child {
  margin-bottom: 0;
}

.fact-stack {
  display: grid;
  gap: 12px;
}

.fact-card {
  padding: 16px 18px;
  border: 1px solid rgba(74, 55, 36, 0.1);
  border-radius: 24px;
  background:
    linear-gradient(180deg, rgba(255, 255, 255, 0.52), transparent 100%),
    rgba(255, 252, 246, 0.84);
}

.fact-card span {
  display: block;
  margin-bottom: 8px;
  font-size: 0.72rem;
  font-weight: 700;
  color: var(--ink-faint);
}

.fact-card strong {
  display: block;
  font-family: var(--font-display);
  font-size: 1.45rem;
  line-height: 1.04;
}

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

.tab-row {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  padding: 7px;
  border: 1px solid rgba(74, 55, 36, 0.12);
  border-radius: 999px;
  background: rgba(255, 255, 255, 0.44);
}

.tab-btn {
  min-width: 116px;
  color: var(--ink-soft);
  background: transparent;
  box-shadow: none;
}

.tab-btn.active {
  color: #fff8f0;
  background: linear-gradient(135deg, var(--accent-cool), #65d4bb);
}

.quiz-summary {
  display: grid;
  grid-template-columns: repeat(3, minmax(0, 1fr));
  gap: 12px;
  margin-top: 16px;
}

.quiz-summary-item {
  padding: 14px 16px;
  border: 1px solid rgba(74, 55, 36, 0.1);
  border-radius: 20px;
  background: rgba(255, 252, 246, 0.78);
}

.quiz-summary-item span {
  display: block;
  margin-bottom: 6px;
  font-size: 0.72rem;
  font-weight: 700;
  letter-spacing: 0.08em;
  text-transform: uppercase;
  color: var(--ink-faint);
}

.quiz-summary-item strong {
  display: block;
  font-family: var(--font-display);
  font-size: 1.55rem;
  line-height: 1;
}

.content-grid {
  display: grid;
  gap: 18px;
  margin-top: 18px;
}

.content-grid[data-view="study"] {
  grid-template-columns: repeat(2, minmax(0, 1fr));
}

.content-grid[data-view="quiz"] {
  grid-template-columns: 1fr;
}

.card,
.empty-stage,
.info-modal-card {
  position: relative;
  overflow: hidden;
}

.card {
  padding: 20px;
  border: 1px solid rgba(74, 55, 36, 0.1);
  border-radius: 28px;
  background:
    linear-gradient(180deg, rgba(255, 255, 255, 0.58), transparent 100%),
    rgba(255, 252, 246, 0.94);
  box-shadow: var(--shadow-sm);
}

.study-card,
.quiz-card {
  display: grid;
  grid-template-columns: 54px minmax(0, 1fr);
  gap: 16px;
}

.card-side-number {
  display: flex;
  align-items: flex-start;
  justify-content: center;
  padding-top: 6px;
  font-family: var(--font-display);
  font-size: 2rem;
  line-height: 1;
  color: rgba(31, 26, 23, 0.32);
}

.card-body {
  min-width: 0;
}

.card-head {
  display: flex;
  gap: 8px;
  flex-wrap: wrap;
  margin-bottom: 14px;
}

.pill {
  display: inline-flex;
  align-items: center;
  padding: 6px 11px;
  border-radius: 999px;
  font-size: 0.72rem;
  font-weight: 700;
  color: var(--accent-strong);
  background: rgba(242, 106, 61, 0.1);
}

.pill:nth-child(2n) {
  color: var(--accent-cool-strong);
  background: rgba(62, 168, 146, 0.1);
}

.pill:nth-child(3n) {
  color: #8b6515;
  background: rgba(240, 201, 106, 0.18);
}

.card h3,
.flashcard-face p {
  margin: 0;
  font-family: var(--font-display);
  letter-spacing: -0.03em;
}

.card h3 {
  font-size: 1.38rem;
  line-height: 1.24;
}

.answer {
  margin: 14px 0 0;
  line-height: 1.72;
}

.answer strong {
  color: var(--accent-strong);
}

.option-list {
  margin: 14px 0 0;
  padding-left: 18px;
  line-height: 1.84;
}

.correct-option {
  color: var(--accent-cool-strong);
  font-weight: 700;
}

.upload-field input[type="file"] {
  position: absolute;
  width: 1px;
  height: 1px;
  opacity: 0;
  pointer-events: none;
}

.file-picker {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 16px;
  padding: 20px;
  border: 1px dashed rgba(74, 55, 36, 0.26);
  border-radius: 24px;
  background:
    radial-gradient(circle at top left, rgba(242, 106, 61, 0.1), transparent 40%),
    linear-gradient(145deg, rgba(252, 247, 238, 0.96), rgba(244, 233, 213, 0.92));
}

.file-picker.has-file {
  border-style: solid;
  border-color: rgba(62, 168, 146, 0.34);
  background:
    radial-gradient(circle at top left, rgba(62, 168, 146, 0.12), transparent 40%),
    linear-gradient(145deg, rgba(246, 253, 250, 0.96), rgba(231, 244, 239, 0.92));
}

.file-picker-copy {
  display: grid;
  gap: 4px;
  min-width: 0;
}

.file-picker-copy strong {
  font-size: 1.24rem;
}

.file-picker-copy span {
  color: var(--ink-soft);
  line-height: 1.56;
  word-break: break-word;
}

.flashcard-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(240px, 1fr));
  gap: 20px;
}

.flashcard-shell {
  display: grid;
  gap: 12px;
}

.flashcard {
  position: relative;
  width: 100%;
  min-height: 316px;
  padding: 0;
  cursor: pointer;
  perspective: 1200px;
  border: 0;
  background: transparent;
  box-shadow: none;
}

.flashcard-stage,
.flashcard-surface {
  position: relative;
  min-height: 316px;
  border-radius: 28px;
  transform-style: preserve-3d;
}

.flashcard-surface {
  transition: transform 480ms cubic-bezier(0.2, 0.82, 0.2, 1);
}

.flashcard.flipped .flashcard-surface {
  transform: rotateY(180deg);
}

.flashcard-face {
  position: absolute;
  inset: 0;
  display: flex;
  flex-direction: column;
  justify-content: space-between;
  gap: 16px;
  padding: 22px;
  border: 1px solid rgba(74, 55, 36, 0.1);
  border-radius: 28px;
  backface-visibility: hidden;
  box-shadow: var(--shadow-sm);
}

.flashcard-front {
  background:
    linear-gradient(160deg, rgba(255, 249, 241, 0.98), rgba(245, 236, 219, 0.94)),
    repeating-linear-gradient(
      180deg,
      transparent,
      transparent 28px,
      rgba(74, 55, 36, 0.04) 29px
    );
}

.flashcard-back {
  transform: rotateY(180deg);
  background:
    linear-gradient(160deg, rgba(239, 251, 247, 0.98), rgba(225, 245, 238, 0.94)),
    repeating-linear-gradient(
      180deg,
      transparent,
      transparent 28px,
      rgba(62, 168, 146, 0.06) 29px
    );
}

.flashcard-edge {
  position: absolute;
  top: 12px;
  left: 16px;
  right: 16px;
  height: 10px;
  border-radius: 999px;
  background: rgba(255, 255, 255, 0.54);
  z-index: 2;
}

.flashcard-badge {
  display: inline-flex;
  width: fit-content;
  padding: 7px 12px;
  border-radius: 999px;
  font-size: 0.72rem;
  font-weight: 700;
  color: var(--ink-faint);
  background: rgba(255, 255, 255, 0.72);
}

.flashcard-face p {
  font-size: 1.48rem;
  line-height: 1.24;
}

.flashcard-toolbar {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 12px;
}

.flashcard-meta {
  color: var(--ink-soft);
  font-size: 0.88rem;
  font-weight: 600;
}

.quiz-card .quiz-option-list {
  display: grid;
  gap: 10px;
  margin-top: 16px;
}

.quiz-option {
  width: 100%;
  display: flex;
  align-items: flex-start;
  gap: 12px;
  padding: 14px 16px;
  color: var(--ink);
  text-align: left;
  border-color: rgba(74, 55, 36, 0.12);
  background: rgba(255, 249, 241, 0.96);
  box-shadow: none;
}

.quiz-option-marker {
  flex: 0 0 32px;
  display: inline-flex;
  align-items: center;
  justify-content: center;
  width: 32px;
  height: 32px;
  border-radius: 999px;
  font-size: 0.82rem;
  font-weight: 700;
  color: var(--accent-strong);
  background: rgba(242, 106, 61, 0.1);
}

.quiz-option.selected.correct {
  color: #ffffff;
  background: linear-gradient(135deg, var(--accent-cool), #5dcab2);
}

.quiz-option.selected.correct .quiz-option-marker,
.quiz-option.selected.wrong .quiz-option-marker {
  color: inherit;
  background: rgba(255, 255, 255, 0.16);
}

.quiz-option.selected.wrong {
  color: #ffffff;
  background: linear-gradient(135deg, var(--danger), #d86e56);
}

.quiz-option.correct-answer {
  border-color: rgba(62, 168, 146, 0.38);
  box-shadow: inset 0 0 0 1px rgba(62, 168, 146, 0.18);
}

.quiz-check-row {
  margin-top: 16px;
}

.quiz-check-row button {
  min-width: 0;
}

.empty-state {
  margin: 0;
  color: var(--ink-soft);
  line-height: 1.7;
}

.empty-stage {
  padding: 28px;
  border: 1px dashed rgba(74, 55, 36, 0.18);
  border-radius: 28px;
  background:
    radial-gradient(circle at top right, rgba(62, 168, 146, 0.08), transparent 30%),
    rgba(255, 252, 246, 0.84);
}

.empty-stage strong {
  display: block;
  font-family: var(--font-display);
  font-size: 1.7rem;
  letter-spacing: -0.03em;
}

.info-modal {
  width: min(560px, calc(100% - 24px));
  padding: 0;
  border: 0;
  border-radius: 30px;
  background: transparent;
}

.info-modal::backdrop {
  background: rgba(5, 9, 20, 0.5);
  backdrop-filter: blur(8px);
}

.info-modal-card {
  border: 1px solid rgba(255, 255, 255, 0.08);
  border-radius: 30px;
  background:
    linear-gradient(180deg, rgba(255, 255, 255, 0.56), transparent 18%),
    linear-gradient(145deg, rgba(249, 243, 232, 0.98), rgba(239, 228, 205, 0.96));
  box-shadow: var(--shadow-xl);
}

.info-list {
  margin: 18px 0 0;
  padding-left: 20px;
  line-height: 1.86;
}

.modal-actions {
  margin-top: 18px;
}

.modal-actions button {
  flex: 0 0 auto;
  min-width: 160px;
}

@keyframes lift-in {
  from {
    opacity: 0;
    transform: translateY(18px);
  }

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

@media (max-width: 1180px) {
  .dashboard,
  .hero-layout,
  .panel-frame,
  .active-brief {
    grid-template-columns: 1fr;
  }

  .board-note {
    max-width: 100%;
  }

  .content-grid[data-view="study"] {
    grid-template-columns: 1fr;
  }
}

@media (max-width: 940px) {
  .dashboard {
    grid-template-columns: 1fr;
  }

  .sidebar {
    grid-template-columns: repeat(2, minmax(0, 1fr));
  }

  .viewer-topbar,
  .hero-badge-row {
    flex-direction: column;
  }

  .button-row.compact {
    justify-content: stretch;
  }
}

@media (max-width: 720px) {
  .page-shell {
    width: min(100% - 18px, 1380px);
    padding-top: 14px;
  }

  .hero,
  .auth-panel,
  .history-panel,
  .generator-panel,
  .viewer-panel,
  .info-modal-card {
    padding: 20px;
  }

  .sidebar {
    grid-template-columns: 1fr;
  }

  .hero-copy h1 {
    max-width: none;
    font-size: clamp(2.5rem, 12vw, 4.2rem);
  }

  .hero-mini-metrics,
  .panel-heading-split,
  .button-row,
  .button-row.compact,
  .viewer-controls,
  .flashcard-toolbar,
  .file-picker {
    flex-direction: column;
    align-items: stretch;
  }

  .field-grid,
  .quiz-summary {
    grid-template-columns: 1fr;
  }

  .tab-row {
    width: 100%;
    display: grid;
    grid-template-columns: repeat(3, minmax(0, 1fr));
  }

  .tab-btn,
  .button-row button,
  .button-row.compact button,
  .file-picker-btn,
  .flashcard-toolbar button {
    width: 100%;
  }

  .board-sheet-stats {
    margin-left: 18px;
  }

  .study-card,
  .quiz-card {
    grid-template-columns: 1fr;
  }

  .card-side-number {
    justify-content: flex-start;
    padding-top: 0;
  }

  .flashcard,
  .flashcard-stage,
  .flashcard-surface {
    min-height: 270px;
  }
}

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

  *,
  *::before,
  *::after {
    animation: none !important;
    transition: none !important;
  }
}