:root {
  --bg: #f6f8fb;
  --surface: #ffffff;
  --surface-soft: #f9fbfd;
  --text: #142033;
  --muted: #5f6f86;
  --line: #d9e1ec;
  --primary: #0b4f8a;
  --primary-strong: #073d6e;
  --primary-soft: #e9f2fb;
  --success: #157347;
  --danger: #a61b2b;
  --warning: #b45309;
  --gold: #946200;
  --blue: #1d5fbf;
  --shadow: 0 14px 34px rgba(20, 32, 51, 0.08);
  --radius: 8px;
}

* {
  box-sizing: border-box;
}

html {
  scroll-behavior: smooth;
}

body {
  margin: 0;
  color: var(--text);
  background: var(--bg);
  font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei", sans-serif;
  line-height: 1.65;
}

button,
input,
select {
  font: inherit;
}

button {
  cursor: pointer;
}

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

.site-header {
  position: sticky;
  top: 0;
  z-index: 20;
  background: rgba(255, 255, 255, 0.92);
  border-bottom: 1px solid var(--line);
  backdrop-filter: blur(14px);
}

.top-nav {
  width: min(1160px, calc(100% - 32px));
  min-height: 64px;
  margin: 0 auto;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 20px;
}

.brand {
  display: inline-flex;
  align-items: center;
  gap: 10px;
  font-weight: 700;
  color: #10243f;
  white-space: nowrap;
}

.brand img {
  display: block;
}

.nav-links {
  display: flex;
  align-items: center;
  gap: 18px;
  color: var(--muted);
  font-size: 14px;
}

.nav-links a:hover {
  color: var(--primary);
}

.section-band {
  border-bottom: 1px solid var(--line);
  background: linear-gradient(180deg, #ffffff 0%, #f7faff 100%);
}

.hero-grid,
.content-section {
  width: min(1160px, calc(100% - 32px));
  margin: 0 auto;
}

.hero-grid {
  min-height: 560px;
  display: grid;
  grid-template-columns: minmax(0, 1.12fr) minmax(360px, 0.88fr);
  gap: 44px;
  align-items: center;
  padding: 72px 0;
}

.eyebrow,
.section-kicker {
  margin: 0 0 10px;
  color: var(--primary);
  font-size: 12px;
  font-weight: 700;
  letter-spacing: 0.08em;
  text-transform: uppercase;
}

h1,
h2,
h3,
p {
  margin-top: 0;
}

h1 {
  margin-bottom: 18px;
  font-size: clamp(34px, 5vw, 56px);
  line-height: 1.12;
  letter-spacing: 0;
}

h2 {
  margin-bottom: 10px;
  font-size: clamp(24px, 3vw, 34px);
  line-height: 1.25;
  letter-spacing: 0;
}

h3 {
  margin-bottom: 8px;
  font-size: 18px;
  line-height: 1.42;
}

.hero-subtitle {
  max-width: 680px;
  color: #415269;
  font-size: 18px;
}

.hero-note {
  max-width: 720px;
  margin: 18px 0 0;
  padding: 14px 16px;
  color: #4c5c70;
  background: #f8fafc;
  border: 1px solid var(--line);
  border-radius: var(--radius);
  font-size: 14px;
}

.hero-actions {
  display: flex;
  flex-wrap: wrap;
  gap: 12px;
  margin-top: 28px;
}

.btn {
  min-height: 46px;
  padding: 10px 18px;
  border-radius: var(--radius);
  border: 1px solid transparent;
  display: inline-flex;
  align-items: center;
  justify-content: center;
  font-weight: 700;
  transition: transform 0.18s ease, box-shadow 0.18s ease, background 0.18s ease, border-color 0.18s ease;
}

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

.btn-primary {
  color: #ffffff;
  background: var(--primary);
  box-shadow: 0 10px 22px rgba(11, 79, 138, 0.22);
}

.btn-primary:hover {
  background: var(--primary-strong);
}

.btn-secondary {
  color: var(--primary);
  background: #ffffff;
  border-color: #b7cde4;
}

.btn-secondary:hover {
  background: #f3f8fd;
  border-color: #8fb3d6;
}

.preview-panel {
  background: var(--surface);
  border: 1px solid var(--line);
  border-radius: var(--radius);
  padding: 22px;
  box-shadow: var(--shadow);
}

.preview-header {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 14px;
  margin-bottom: 18px;
  color: var(--muted);
}

.preview-header strong {
  padding: 6px 10px;
  color: var(--warning);
  background: #fff5e6;
  border: 1px solid #f3d2a3;
  border-radius: 999px;
  font-size: 14px;
}

.preview-metrics {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 10px;
  margin-bottom: 18px;
}

.preview-metrics div {
  padding: 12px;
  background: var(--surface-soft);
  border: 1px solid var(--line);
  border-radius: var(--radius);
}

.preview-metrics span {
  display: block;
  color: var(--muted);
  font-size: 12px;
}

.preview-metrics strong {
  display: block;
  margin-top: 4px;
  color: #17253a;
  font-size: 26px;
  line-height: 1;
}

.preview-bars {
  display: grid;
  gap: 10px;
  margin: 16px 0 18px;
}

.preview-bars span {
  display: block;
  height: 10px;
  border-radius: 999px;
  background: linear-gradient(90deg, var(--primary), #4e8bc1);
}

.preview-panel p {
  margin-bottom: 0;
  color: #405168;
  font-size: 14px;
}

.content-section {
  padding: 72px 0;
}

.section-heading {
  max-width: 820px;
  margin-bottom: 26px;
}

.section-heading p:not(.section-kicker) {
  color: var(--muted);
}

.scenario-grid {
  display: grid;
  grid-template-columns: repeat(3, minmax(0, 1fr));
  gap: 16px;
}

.scenario-card,
.upload-card,
.context-form,
.progress-card,
.empty-report,
.report-block,
.boundary-grid article {
  background: var(--surface);
  border: 1px solid var(--line);
  border-radius: var(--radius);
  box-shadow: 0 10px 24px rgba(20, 32, 51, 0.05);
}

.scenario-card {
  padding: 22px;
}

.scenario-card span {
  display: inline-flex;
  margin-bottom: 12px;
  padding: 5px 9px;
  color: var(--primary);
  background: var(--primary-soft);
  border-radius: 999px;
  font-size: 12px;
  font-weight: 700;
}

.scenario-card p {
  margin-bottom: 0;
  color: var(--muted);
  font-size: 14px;
}

.demo-layout {
  display: grid;
  grid-template-columns: minmax(0, 0.95fr) minmax(0, 1.05fr);
  gap: 20px;
  align-items: start;
}

.upload-card,
.context-form {
  padding: 22px;
}

.drop-zone {
  min-height: 190px;
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  gap: 8px;
  margin-top: 16px;
  padding: 24px;
  color: #30445f;
  background: #f8fbff;
  border: 1px dashed #94b6d8;
  border-radius: var(--radius);
  text-align: center;
  transition: background 0.18s ease, border-color 0.18s ease;
}

.drop-zone.is-dragging {
  background: #edf6ff;
  border-color: var(--primary);
}

.drop-title {
  font-size: 17px;
  font-weight: 700;
}

.drop-subtitle {
  color: var(--muted);
  font-size: 14px;
}

.file-status,
.demo-notice {
  margin-top: 14px;
  padding: 12px 14px;
  border-radius: var(--radius);
  font-size: 14px;
}

.file-status {
  color: #46596f;
  background: #f8fafc;
  border: 1px solid var(--line);
}

.demo-notice {
  color: #704d10;
  background: #fff8e8;
  border: 1px solid #f1d8a5;
}

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

.field-group {
  display: grid;
  gap: 6px;
}

.field-group label,
.focus-fieldset legend {
  color: #25384f;
  font-size: 14px;
  font-weight: 700;
}

.field-group input,
.field-group select {
  width: 100%;
  min-height: 42px;
  padding: 9px 11px;
  color: var(--text);
  background: #ffffff;
  border: 1px solid #cdd7e4;
  border-radius: var(--radius);
}

.field-group input:focus,
.field-group select:focus {
  outline: 2px solid rgba(11, 79, 138, 0.18);
  border-color: var(--primary);
}

.focus-fieldset {
  grid-column: 1 / -1;
  margin: 0;
  padding: 14px;
  border: 1px solid var(--line);
  border-radius: var(--radius);
  display: flex;
  flex-wrap: wrap;
  gap: 10px 14px;
}

.focus-fieldset legend {
  padding: 0 6px;
}

.focus-fieldset label {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  color: #33465f;
  font-size: 14px;
}

.form-submit {
  grid-column: 1 / -1;
}

.progress-section {
  padding-top: 28px;
}

.progress-card {
  padding: 22px;
}

.progress-bar {
  height: 12px;
  background: #e5ebf3;
  border-radius: 999px;
  overflow: hidden;
}

.progress-bar span {
  display: block;
  width: 0;
  height: 100%;
  background: linear-gradient(90deg, var(--primary), #2f7fbd);
  border-radius: inherit;
  transition: width 0.3s ease;
}

.progress-meta {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 14px;
  margin-top: 12px;
  color: var(--muted);
}

.progress-meta strong {
  color: var(--text);
}

.stage-list {
  display: grid;
  grid-template-columns: repeat(3, minmax(0, 1fr));
  gap: 10px;
  margin: 22px 0 0;
  padding: 0;
  list-style: none;
}

.stage-list li {
  padding: 11px 12px;
  color: var(--muted);
  background: #f8fafc;
  border: 1px solid var(--line);
  border-radius: var(--radius);
  font-size: 14px;
}

.stage-list li.is-active {
  color: var(--primary);
  background: #eef7ff;
  border-color: #afd0ee;
  font-weight: 700;
}

.stage-list li.is-done {
  color: var(--success);
  background: #effaf4;
  border-color: #bfe3cf;
}

.empty-report {
  padding: 28px;
  display: grid;
  gap: 6px;
  color: var(--muted);
}

.empty-report strong {
  color: var(--text);
  font-size: 18px;
}

.report-output {
  display: grid;
  gap: 18px;
}

.report-block {
  overflow: hidden;
}

.report-block-header {
  padding: 16px 18px;
  background: #f9fbfe;
  border-bottom: 1px solid var(--line);
}

.report-block-header h3 {
  margin-bottom: 4px;
}

.report-block-header p {
  margin-bottom: 0;
  color: var(--muted);
  font-size: 14px;
}

.report-block-body {
  padding: 18px;
}

.metric-grid {
  display: grid;
  grid-template-columns: repeat(6, minmax(0, 1fr));
  gap: 12px;
}

.metric-card {
  padding: 14px;
  background: #ffffff;
  border: 1px solid var(--line);
  border-radius: var(--radius);
}

.metric-card span {
  display: block;
  color: var(--muted);
  font-size: 13px;
}

.metric-card strong {
  display: block;
  margin-top: 4px;
  color: var(--text);
  font-size: 24px;
  line-height: 1.1;
}

.decision-box {
  margin-bottom: 16px;
  padding: 16px;
  color: #24384f;
  background: #f7faff;
  border: 1px solid #cfdded;
  border-radius: var(--radius);
}

.distribution-grid {
  display: grid;
  grid-template-columns: minmax(0, 1fr) minmax(260px, 0.75fr);
  gap: 18px;
}

.bar-list {
  display: grid;
  gap: 12px;
}

.bar-row {
  display: grid;
  grid-template-columns: 92px minmax(0, 1fr) 32px;
  gap: 10px;
  align-items: center;
  color: #33465f;
  font-size: 14px;
}

.bar-track {
  height: 10px;
  overflow: hidden;
  background: #e7edf5;
  border-radius: 999px;
}

.bar-fill {
  height: 100%;
  min-width: 8%;
  border-radius: inherit;
}

.profile-list {
  display: grid;
  gap: 10px;
}

.profile-item {
  padding: 12px;
  background: #f8fafc;
  border: 1px solid var(--line);
  border-radius: var(--radius);
}

.profile-item strong {
  display: block;
  margin-bottom: 4px;
}

.profile-item span {
  color: var(--muted);
  font-size: 14px;
}

.risk-list,
.revision-list,
.checklist-list,
.summary-grid {
  display: grid;
  gap: 14px;
}

.risk-card {
  border: 1px solid var(--line);
  border-radius: var(--radius);
  overflow: hidden;
  background: #ffffff;
}

.risk-card-header {
  width: 100%;
  padding: 16px;
  display: grid;
  grid-template-columns: minmax(0, 1fr) auto;
  gap: 14px;
  align-items: start;
  color: inherit;
  background: transparent;
  border: 0;
  text-align: left;
}

.risk-card-title {
  display: flex;
  align-items: center;
  gap: 10px;
  flex-wrap: wrap;
}

.risk-card-title strong {
  font-size: 17px;
}

.risk-card-subtitle {
  display: block;
  margin-top: 6px;
  color: var(--muted);
  font-size: 14px;
}

.expand-hint {
  color: var(--primary);
  font-size: 14px;
  white-space: nowrap;
}

.risk-card-details {
  padding: 0 16px 16px;
  display: grid;
  gap: 12px;
}

.detail-grid {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 12px;
}

.detail-item {
  padding: 12px;
  background: #f8fafc;
  border: 1px solid var(--line);
  border-radius: var(--radius);
}

.detail-item strong {
  display: block;
  margin-bottom: 4px;
}

.detail-item p,
.detail-item ul {
  margin: 0;
  color: var(--muted);
  font-size: 14px;
}

.detail-item ul {
  padding-left: 18px;
}

.level-badge {
  display: inline-flex;
  align-items: center;
  min-height: 26px;
  padding: 4px 9px;
  border-radius: 999px;
  font-size: 12px;
  font-weight: 700;
  border: 1px solid transparent;
}

.level-high {
  color: var(--danger);
  background: #fff0f1;
  border-color: #f4b9c1;
}

.level-medium-high {
  color: var(--warning);
  background: #fff4e8;
  border-color: #f2cda4;
}

.level-general {
  color: var(--gold);
  background: #fff9dc;
  border-color: #eadc9e;
}

.level-optimize {
  color: var(--blue);
  background: #edf5ff;
  border-color: #bdd5f5;
}

.level-default {
  color: #4b5f78;
  background: #f2f5f8;
  border-color: #d6dee7;
}

.revision-card,
.checklist-card,
.summary-card {
  padding: 16px;
  background: #ffffff;
  border: 1px solid var(--line);
  border-radius: var(--radius);
}

.revision-head,
.checklist-head {
  display: flex;
  align-items: flex-start;
  justify-content: space-between;
  gap: 12px;
  margin-bottom: 12px;
}

.revision-head h4,
.checklist-head h4,
.summary-card h4 {
  margin: 0;
  font-size: 16px;
}

.clause-compare {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 12px;
  margin-top: 12px;
}

.clause-box {
  padding: 12px;
  border: 1px solid var(--line);
  border-radius: var(--radius);
  background: #f8fafc;
}

.clause-box strong {
  display: block;
  margin-bottom: 6px;
}

.clause-box p {
  margin-bottom: 0;
  color: var(--muted);
  font-size: 14px;
}

.revision-meta,
.checklist-meta {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 10px;
  margin-top: 12px;
  color: var(--muted);
  font-size: 14px;
}

.checklist-card {
  display: grid;
  grid-template-columns: auto minmax(0, 1fr);
  gap: 12px;
}

.checklist-card input {
  width: 18px;
  height: 18px;
  margin-top: 4px;
}

.checklist-card.is-complete {
  background: #f5fbf7;
  border-color: #bde1ca;
}

.checklist-card.is-complete h4 {
  color: var(--success);
}

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

.summary-card p,
.summary-card ul {
  margin-bottom: 0;
  color: var(--muted);
}

.summary-card ul {
  padding-left: 18px;
}

.empty-state {
  padding: 18px;
  color: var(--muted);
  background: #f8fafc;
  border: 1px dashed var(--line);
  border-radius: var(--radius);
}

.boundary-grid {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 16px;
}

.boundary-grid article {
  padding: 22px;
}

.boundary-grid p {
  margin-bottom: 0;
  color: var(--muted);
}

.back-to-top {
  position: fixed;
  right: 18px;
  bottom: 18px;
  width: 42px;
  height: 42px;
  border: 1px solid #bfd2e5;
  border-radius: 999px;
  color: var(--primary);
  background: #ffffff;
  box-shadow: var(--shadow);
  opacity: 0;
  pointer-events: none;
  transition: opacity 0.18s ease, transform 0.18s ease;
}

.back-to-top.is-visible {
  opacity: 1;
  pointer-events: auto;
}

.back-to-top:hover {
  transform: translateY(-2px);
}

@media (max-width: 960px) {
  .hero-grid,
  .demo-layout,
  .distribution-grid,
  .boundary-grid {
    grid-template-columns: 1fr;
  }

  .hero-grid {
    min-height: auto;
    padding: 48px 0;
  }

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

  .metric-grid {
    grid-template-columns: repeat(3, minmax(0, 1fr));
  }
}

@media (max-width: 720px) {
  .top-nav {
    align-items: flex-start;
    flex-direction: column;
    padding: 12px 0;
    gap: 10px;
  }

  .nav-links {
    width: 100%;
    overflow-x: auto;
    padding-bottom: 2px;
    gap: 14px;
  }

  .content-section {
    padding: 48px 0;
  }

  .preview-metrics,
  .context-form,
  .stage-list,
  .metric-grid,
  .detail-grid,
  .clause-compare,
  .revision-meta,
  .checklist-meta,
  .summary-grid {
    grid-template-columns: 1fr;
  }

  .hero-actions {
    flex-direction: column;
    align-items: stretch;
  }

  .risk-card-header,
  .revision-head,
  .checklist-head {
    grid-template-columns: 1fr;
    flex-direction: column;
  }

  .bar-row {
    grid-template-columns: 86px minmax(0, 1fr) 28px;
  }
}