:root {
  --bg: #f2ede4;
  --surface: #fffdf7;
  --surface-strong: #fff7ea;
  --text: #1f2518;
  --muted: #5f6756;
  --line: #d8d0c1;
  --shadow: 0 10px 28px rgba(43, 41, 28, 0.08);
  --success: #2a7c43;
  --failure: #8f2e2e;
  --warning: #9a6715;
}

* {
  box-sizing: border-box;
}

html,
body {
  margin: 0;
  min-height: 100%;
}

body {
  color: var(--text);
  font-family: "Noto Sans SC", "Source Han Sans SC", "PingFang SC", "Microsoft YaHei", sans-serif;
  line-height: 1.55;
  background:
    radial-gradient(circle at 5% 5%, rgba(31, 111, 74, 0.14), transparent 35%),
    radial-gradient(circle at 95% 0%, rgba(160, 91, 17, 0.15), transparent 25%),
    linear-gradient(180deg, #f7f2e9 0%, var(--bg) 60%);
}

body.modal-open {
  overflow: hidden;
}

a {
  color: inherit;
  text-decoration: none;
}

.shell {
  width: min(1120px, 94vw);
  margin: 0 auto;
  padding: 1rem 0 3rem;
}

.panel {
  border: 1px solid var(--line);
  border-radius: 18px;
  background: var(--surface);
  box-shadow: var(--shadow);
}

.main-nav {
  margin-bottom: 0.9rem;
  padding: 0.35rem;
  display: grid;
  grid-template-columns: repeat(3, minmax(0, 1fr));
  gap: 0.35rem;
}

.nav-link {
  border-radius: 12px;
  padding: 0.56rem 0.65rem;
  text-align: center;
  font-weight: 700;
  color: var(--muted);
  transition: background-color 120ms ease, color 120ms ease;
}

.nav-link:hover {
  background: #f6f2e8;
}

.nav-link.active {
  background: #ece6d8;
  color: var(--text);
}

.hero {
  border: 1px solid var(--line);
  border-radius: 24px;
  padding: clamp(1.1rem, 2.8vw, 2rem);
  background: linear-gradient(145deg, var(--surface) 0%, var(--surface-strong) 100%);
  box-shadow: var(--shadow);
  animation: rise 360ms ease-out;
}

.eyebrow {
  margin: 0 0 0.2rem;
  font-size: 0.78rem;
  letter-spacing: 0.08em;
  text-transform: uppercase;
  color: var(--muted);
}

.hero h1 {
  margin: 0;
  font-family: "Noto Serif SC", "Source Han Serif SC", "Songti SC", serif;
  font-size: clamp(1.5rem, 4.8vw, 2.2rem);
  line-height: 1.2;
}

.lead {
  margin: 0.7rem 0 0;
  color: var(--muted);
}

.stats-grid {
  margin-top: 1rem;
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 0.7rem;
}

.stat-card {
  border-radius: 14px;
  border: 1px solid var(--line);
  background: #fffcf6;
  padding: 0.8rem 0.9rem;
}

.stat-card.success {
  border-color: #b7d5c1;
  background: linear-gradient(155deg, rgba(42, 124, 67, 0.14) 0%, #fffdf8 70%);
}

.stat-card.failure {
  border-color: #dab8ba;
  background: linear-gradient(155deg, rgba(143, 46, 46, 0.14) 0%, #fffdf8 70%);
}

.stat-card.warning {
  border-color: #e0cca9;
  background: linear-gradient(155deg, rgba(154, 103, 21, 0.15) 0%, #fffdf8 70%);
}

.stat-card p {
  margin: 0;
  font-size: 0.86rem;
  color: var(--muted);
}

.stat-card strong {
  display: block;
  margin-top: 0.2rem;
  font-size: 1.22rem;
}

.stat-card.success strong {
  color: var(--success);
}

.stat-card.failure strong {
  color: var(--failure);
}

.stat-card.warning strong {
  color: var(--warning);
}

.controls {
  margin-top: 1rem;
  padding: 1rem;
}

.study-shell .hero {
  margin-bottom: 1rem;
}

.study-auth-panel,
.study-profile,
.study-toolbar,
.study-case {
  margin-top: 1rem;
  padding: 1rem;
}

.study-auth-panel h2 {
  margin: 0 0 0.8rem;
}

.study-auth-form {
  display: grid;
  gap: 0.5rem;
}

.study-auth-form label {
  font-weight: 700;
}

.study-auth-form input {
  width: 100%;
  border: 1px solid #c8c0b2;
  border-radius: 12px;
  padding: 0.7rem 0.75rem;
  font: inherit;
  background: #fff;
  color: var(--text);
}

.study-auth-actions {
  margin-top: 0.4rem;
  display: flex;
  flex-wrap: wrap;
  gap: 0.55rem;
}

.study-primary-button,
.study-secondary-button {
  border-radius: 12px;
  padding: 0.55rem 0.9rem;
  font: inherit;
  cursor: pointer;
}

.study-primary-button {
  border: 1px solid #2b6f57;
  background: #2f725a;
  color: #f9fffc;
}

.study-primary-button:hover {
  background: #255f4c;
}

.study-primary-button:disabled,
.study-secondary-button:disabled {
  opacity: 0.55;
  cursor: not-allowed;
}

.study-secondary-button {
  border: 1px solid #c8c0b2;
  background: #fffaf0;
  color: #4d5147;
}

.study-secondary-button:hover {
  background: #f6f0e2;
}

.study-status {
  margin: 0.8rem 0 0;
  font-size: 0.9rem;
}

.study-status.info {
  color: #2e6250;
}

.study-status.error {
  color: #8f2e2e;
}

.study-profile {
  display: grid;
  gap: 0.8rem;
}

.study-profile strong {
  font-size: 1.02rem;
}

.study-label {
  margin: 0 0 0.25rem;
  color: var(--muted);
  font-size: 0.84rem;
}

.study-toolbar {
  display: grid;
  gap: 0.7rem;
}

.study-mode-switch {
  display: flex;
  flex-wrap: wrap;
  gap: 0.5rem;
}

.study-case {
  --study-case-line: #5f6756;
  position: relative;
  overflow: hidden;
}

.study-case::before {
  content: "";
  position: absolute;
  inset: 0 auto 0 0;
  width: 6px;
  background: var(--study-case-line);
}

.study-case.success {
  --study-case-line: #2a7c43;
  background: linear-gradient(180deg, rgba(42, 124, 67, 0.08) 0%, #fffefb 20%, #fffefb 100%);
}

.study-case.failure {
  --study-case-line: #8f2e2e;
  background: linear-gradient(180deg, rgba(143, 46, 46, 0.08) 0%, #fffefb 20%, #fffefb 100%);
}

.study-case.warning {
  --study-case-line: #9a6715;
  background: linear-gradient(180deg, rgba(154, 103, 21, 0.09) 0%, #fffefb 20%, #fffefb 100%);
}

.study-case-header h2 {
  margin: 0.6rem 0 0;
  font-family: "Noto Serif SC", "Source Han Serif SC", "Songti SC", serif;
  line-height: 1.3;
}

.study-actions {
  margin-top: 1rem;
  display: flex;
  flex-wrap: wrap;
  gap: 0.6rem;
}

.study-favorite-cards {
  margin-top: 1rem;
}

.study-favorite-actions {
  margin-top: 0.85rem;
  display: flex;
  flex-wrap: wrap;
  gap: 0.5rem;
}

.study-favorite-actions .detail-button {
  margin-top: 0;
}

.search-form {
  margin-bottom: 0.95rem;
}

.search-form label {
  display: inline-block;
  margin-bottom: 0.5rem;
  font-weight: 700;
}

.search-row {
  display: grid;
  grid-template-columns: 1fr;
  gap: 0.45rem;
}

.search-row input {
  width: 100%;
  border: 1px solid #c8c0b2;
  border-radius: 12px;
  padding: 0.7rem 0.75rem;
  font: inherit;
  background: #fff;
  color: var(--text);
}

.search-button,
.search-clear {
  border: 1px solid #c8c0b2;
  border-radius: 12px;
  padding: 0.55rem 0.85rem;
  font: inherit;
  cursor: pointer;
}

.search-button {
  color: #1e5e48;
  background: #eaf3ef;
}

.search-button:hover {
  background: #dcece4;
}

.search-clear {
  background: #fffdf8;
  color: #5d6358;
}

.search-clear:hover {
  background: #f6f0e4;
}

.field label {
  display: inline-block;
  margin-bottom: 0.5rem;
  font-weight: 700;
}

.field select {
  width: 100%;
  border: 1px solid #c8c0b2;
  border-radius: 12px;
  padding: 0.7rem 0.75rem;
  font: inherit;
  background: #fff;
  color: var(--text);
}

.chip-row {
  margin-top: 0.9rem;
  display: flex;
  flex-wrap: wrap;
  gap: 0.6rem;
}

.chip {
  border: 1px solid #c7c0b0;
  border-radius: 999px;
  padding: 0.4rem 0.8rem;
  background: #fff;
  color: var(--text);
  font: inherit;
  cursor: pointer;
  transition: transform 120ms ease, border-color 120ms ease, color 120ms ease;
}

.chip:hover {
  transform: translateY(-1px);
}

.chip.active {
  border-width: 2px;
}

.chip.success.active {
  border-color: var(--success);
  color: var(--success);
}

.chip.failure.active {
  border-color: var(--failure);
  color: var(--failure);
}

.chip.warning.active {
  border-color: var(--warning);
  color: var(--warning);
}

.chip.all.active {
  border-color: #5f6756;
}

.hint {
  margin: 0.8rem 0 0;
  color: var(--muted);
}

.cards {
  margin-top: 1rem;
  display: grid;
  gap: 0.9rem;
}

.card {
  --card-line: #c9c0b2;
  border: 1px solid rgba(201, 192, 178, 0.62);
  border-radius: 16px;
  background: #fffefb;
  padding: 0.95rem;
  box-shadow: 0 4px 12px rgba(43, 41, 28, 0.06);
  animation: rise 380ms ease-out;
  position: relative;
  overflow: hidden;
  transition: transform 140ms ease, box-shadow 140ms ease, border-color 140ms ease;
}

.card::before {
  content: "";
  position: absolute;
  inset: 0 auto 0 0;
  width: 6px;
  background: var(--card-line);
}

.card:hover {
  transform: translateY(-1px);
  border-color: rgba(191, 182, 166, 0.78);
  box-shadow: 0 7px 16px rgba(43, 41, 28, 0.08);
}

.card.success {
  --card-line: #2a7c43;
  background:
    radial-gradient(circle at 86% 8%, rgba(42, 124, 67, 0.22), transparent 34%),
    linear-gradient(165deg, #f4fcf7 0%, #fdfefc 58%, #fffefb 100%);
}

.card.failure {
  --card-line: #8f2e2e;
  background:
    radial-gradient(circle at 86% 8%, rgba(143, 46, 46, 0.22), transparent 34%),
    linear-gradient(165deg, #fff6f5 0%, #fffdfd 58%, #fffefb 100%);
}

.card.warning {
  --card-line: #9a6715;
  background:
    radial-gradient(circle at 86% 8%, rgba(154, 103, 21, 0.22), transparent 34%),
    linear-gradient(165deg, #fff9ef 0%, #fffefb 58%, #fffefb 100%);
}

.card-header h2 {
  margin: 0.45rem 0 0;
  font-size: 1.06rem;
  line-height: 1.35;
}

.result-badge {
  display: inline-flex;
  align-items: center;
  border-radius: 999px;
  padding: 0.2rem 0.58rem;
  font-size: 0.78rem;
  font-weight: 700;
}

.result-badge.success {
  background: rgba(42, 124, 67, 0.14);
  color: var(--success);
}

.result-badge.failure {
  background: rgba(143, 46, 46, 0.14);
  color: var(--failure);
}

.result-badge.warning {
  background: rgba(154, 103, 21, 0.15);
  color: var(--warning);
}

.meta-line {
  margin: 0.6rem 0 0;
  display: flex;
  flex-wrap: wrap;
  gap: 0.55rem;
  color: var(--muted);
  font-size: 0.88rem;
}

.summary {
  margin: 0.6rem 0 0;
}

.points {
  margin: 0.7rem 0 0;
  padding-left: 1.1rem;
}

.points li + li {
  margin-top: 0.4rem;
}

.tag-row {
  margin-top: 0.8rem;
  display: flex;
  flex-wrap: wrap;
  gap: 0.4rem;
}

.meta-tag {
  border: 1px solid #cdc6b8;
  border-radius: 999px;
  padding: 0.2rem 0.55rem;
  font-size: 0.78rem;
  color: #4d5147;
  background: #fdfaf3;
}

.detail-button {
  margin-top: 0.9rem;
  display: inline-flex;
  align-items: center;
  border: 0;
  border-radius: 999px;
  padding: 0.42rem 0.86rem;
  font: inherit;
  color: #1e5846;
  background: rgba(44, 98, 80, 0.13);
  cursor: pointer;
}

.detail-button:hover {
  background: rgba(44, 98, 80, 0.2);
}

.detail-button:disabled {
  opacity: 0.62;
  cursor: not-allowed;
}

.detail-modal-actions {
  margin-top: 1rem;
}

.detail-modal-actions .detail-button {
  margin-top: 0;
}

.detail-favorite-button.is-favorited {
  color: #7f2222;
  background: rgba(143, 46, 46, 0.14);
}

.detail-favorite-button.is-favorited:hover {
  background: rgba(143, 46, 46, 0.22);
}

.card.success .detail-button {
  color: #1a5f3a;
  background: rgba(42, 124, 67, 0.17);
}

.card.success .detail-button:hover {
  background: rgba(42, 124, 67, 0.24);
}

.card.failure .detail-button {
  color: #7f2222;
  background: rgba(143, 46, 46, 0.15);
}

.card.failure .detail-button:hover {
  background: rgba(143, 46, 46, 0.22);
}

.card.warning .detail-button {
  color: #855510;
  background: rgba(154, 103, 21, 0.18);
}

.card.warning .detail-button:hover {
  background: rgba(154, 103, 21, 0.26);
}

.inline-link {
  margin-top: 0.9rem;
  display: inline-flex;
  color: #2c6250;
  text-decoration: underline;
  text-underline-offset: 0.2rem;
}

.empty-panel,
.error-panel,
.loading-panel {
  padding: 1rem;
}

.empty-panel h2,
.error-panel h1 {
  margin: 0 0 0.5rem;
}

.modal-overlay {
  position: fixed;
  inset: 0;
  z-index: 100;
  background: rgba(18, 20, 16, 0.56);
  padding: 0.8rem;
  display: flex;
  justify-content: center;
  align-items: center;
  animation: fadeIn 160ms ease-out;
}

.modal-dialog {
  --modal-line: #c9c0b2;
  --modal-soft-bg: #fffefb;
  --modal-spot: rgba(95, 103, 86, 0.15);
  width: min(920px, 100%);
  max-height: calc(100vh - 1.6rem);
  overflow: auto;
  padding: 1rem;
  position: relative;
  border-color: #d6ccbe;
  background:
    radial-gradient(circle at 90% 8%, var(--modal-spot), transparent 34%),
    linear-gradient(165deg, var(--modal-soft-bg) 0%, #fffefb 62%, #fffefb 100%);
}

.modal-dialog::before {
  content: "";
  position: absolute;
  inset: 0 auto 0 0;
  width: 5px;
  background: var(--modal-line);
}

.modal-dialog.success {
  --modal-line: #2a7c43;
  --modal-soft-bg: #f4fcf7;
  --modal-spot: rgba(42, 124, 67, 0.22);
  border-color: #b8d6c2;
}

.modal-dialog.failure {
  --modal-line: #8f2e2e;
  --modal-soft-bg: #fff6f5;
  --modal-spot: rgba(143, 46, 46, 0.22);
  border-color: #ddb9bb;
}

.modal-dialog.warning {
  --modal-line: #9a6715;
  --modal-soft-bg: #fff9ef;
  --modal-spot: rgba(154, 103, 21, 0.22);
  border-color: #dfcca7;
}

.modal-close {
  position: sticky;
  top: 0;
  margin-left: auto;
  border: 0;
  border-radius: 10px;
  width: 2rem;
  height: 2rem;
  font-size: 1.4rem;
  line-height: 1;
  cursor: pointer;
  color: #5e635a;
  background: #efe8d9;
  z-index: 1;
}

.modal-close:hover {
  background: #e2daca;
}

.modal-dialog.success .modal-close {
  color: #1e5f3b;
  background: rgba(42, 124, 67, 0.18);
}

.modal-dialog.success .modal-close:hover {
  background: rgba(42, 124, 67, 0.28);
}

.modal-dialog.failure .modal-close {
  color: #7f2222;
  background: rgba(143, 46, 46, 0.18);
}

.modal-dialog.failure .modal-close:hover {
  background: rgba(143, 46, 46, 0.28);
}

.modal-dialog.warning .modal-close {
  color: #855510;
  background: rgba(154, 103, 21, 0.2);
}

.modal-dialog.warning .modal-close:hover {
  background: rgba(154, 103, 21, 0.3);
}

.detail-header h2 {
  margin: 0.6rem 0 0;
  font-family: "Noto Serif SC", "Source Han Serif SC", "Songti SC", serif;
  line-height: 1.3;
}

.detail-section + .detail-section {
  margin-top: 1rem;
}

.detail-section h3 {
  margin: 0 0 0.45rem;
  font-size: 1.03rem;
}

.detail-section p {
  margin: 0;
}

.detail-grid {
  margin-top: 1rem;
  display: grid;
  gap: 0.6rem;
  grid-template-columns: repeat(2, minmax(0, 1fr));
}

.detail-metric {
  border: 1px solid #d8d1c3;
  border-radius: 12px;
  background: #fffcf6;
  padding: 0.65rem 0.7rem;
}

.modal-dialog.success .detail-metric {
  border-color: #b8d6c2;
  background: rgba(42, 124, 67, 0.09);
}

.modal-dialog.failure .detail-metric {
  border-color: #ddb9bb;
  background: rgba(143, 46, 46, 0.09);
}

.modal-dialog.warning .detail-metric {
  border-color: #dfcca7;
  background: rgba(154, 103, 21, 0.1);
}

.detail-metric p {
  margin: 0;
  font-size: 0.84rem;
  color: var(--muted);
}

.detail-metric strong {
  display: block;
  margin-top: 0.2rem;
}

.summary-shell .hero {
  margin-bottom: 1rem;
}

.core-summary {
  padding: 1rem;
}

.core-summary h2 {
  margin: 0 0 0.5rem;
}

.core-quote {
  margin: 0;
  font-size: 1.02rem;
  font-weight: 700;
}

.formula {
  margin-top: 0.75rem;
  border: 1px dashed #cfc7b7;
  border-radius: 12px;
  background: #fffaf0;
  padding: 0.8rem;
}

.formula p {
  margin: 0;
}

.formula p + p {
  margin-top: 0.35rem;
}

.knowledge-section {
  margin-top: 1rem;
  padding: 1rem;
}

.section-header {
  display: flex;
  align-items: center;
  gap: 0.65rem;
}

.section-header h2 {
  margin: 0;
  font-size: 1.16rem;
}

.section-number {
  width: 2rem;
  height: 2rem;
  border-radius: 999px;
  display: inline-flex;
  align-items: center;
  justify-content: center;
  color: #fff;
  font-weight: 700;
  background: #5f6756;
}

.section-number.danger {
  background: var(--failure);
}

.section-number.success {
  background: var(--success);
}

.knowledge-cards {
  margin-top: 0.9rem;
  display: grid;
  gap: 0.75rem;
}

.knowledge-card {
  border: 1px solid #d9d2c4;
  border-radius: 14px;
  background: #fffefb;
  padding: 0.8rem;
}

.knowledge-card h3 {
  margin: 0;
  font-size: 1rem;
}

.knowledge-card p {
  margin: 0.5rem 0 0;
  color: #43473d;
}

.danger-section {
  border-color: #d6b6b8;
  background: linear-gradient(180deg, rgba(143, 46, 46, 0.08) 0%, #fffdf9 18%);
}

.success-section {
  border-color: #b7d0bf;
  background: linear-gradient(180deg, rgba(42, 124, 67, 0.08) 0%, #fffdf9 18%);
}

.knowledge-card.danger {
  border-color: #dab8b9;
  background: rgba(143, 46, 46, 0.08);
}

.knowledge-card.success {
  border-color: #bcd6c4;
  background: rgba(42, 124, 67, 0.08);
}

.summary-footer {
  margin-top: 1rem;
  padding: 0.8rem 1rem;
  text-align: center;
  color: var(--muted);
}

@media (min-width: 760px) {
  .shell {
    padding-top: 1.2rem;
  }

  .study-profile {
    grid-template-columns: repeat(4, minmax(0, 1fr));
    align-items: end;
  }

  .study-profile .study-secondary-button {
    justify-self: end;
  }

  .search-row {
    grid-template-columns: 1fr auto auto;
  }

  .stats-grid {
    grid-template-columns: repeat(4, minmax(0, 1fr));
  }

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

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

@media (min-width: 1080px) {
  .cards {
    grid-template-columns: repeat(3, minmax(0, 1fr));
  }

  /* Desktop view can show many cards at once.
     Tone down large gradients and keep only subtle status cues. */
  .card {
    transition: box-shadow 140ms ease;
  }

  .card:hover {
    transform: none;
    box-shadow: 0 6px 14px rgba(43, 41, 28, 0.07);
  }

  .card::before {
    width: 5px;
  }

  .card.success {
    background: linear-gradient(180deg, rgba(42, 124, 67, 0.07) 0%, #fffefb 24%, #fffefb 100%);
  }

  .card.failure {
    background: linear-gradient(180deg, rgba(143, 46, 46, 0.07) 0%, #fffefb 24%, #fffefb 100%);
  }

  .card.warning {
    background: linear-gradient(180deg, rgba(154, 103, 21, 0.08) 0%, #fffefb 24%, #fffefb 100%);
  }
}

@media (prefers-reduced-motion: reduce) {
  * {
    animation: none !important;
    transition: none !important;
  }
}

@keyframes rise {
  from {
    opacity: 0;
    transform: translateY(8px);
  }
  to {
    opacity: 1;
    transform: translateY(0);
  }
}

@keyframes fadeIn {
  from {
    opacity: 0;
  }
  to {
    opacity: 1;
  }
}