:root {
  --bg: #f4f7f7;
  --panel: #ffffff;
  --ink: #12232f;
  --muted: #5f6f79;
  --soft: #e9eff2;
  --soft-2: #f7faf9;
  --accent: #1f8a70;
  --accent-dark: #14624f;
  --blue: #2e5f9f;
  --warn: #ad7b13;
  --bad: #b94a48;
  --shadow: 0 22px 60px rgba(25, 45, 58, 0.11);
}

* {
  box-sizing: border-box;
}

body {
  margin: 0;
  min-height: 100vh;
  font-family: Inter, -apple-system, BlinkMacSystemFont, "Segoe UI", "Microsoft YaHei", Arial, sans-serif;
  color: var(--ink);
  background:
    radial-gradient(circle at top left, rgba(31, 138, 112, 0.12), transparent 32rem),
    linear-gradient(135deg, #f7fafc 0%, var(--bg) 100%);
}

button,
input,
textarea,
select {
  font: inherit;
}

button {
  cursor: pointer;
}

.app-shell {
  width: min(1440px, 100%);
  margin: 0 auto;
  padding: 32px;
}

.topbar {
  display: flex;
  align-items: flex-end;
  justify-content: space-between;
  gap: 24px;
  margin-bottom: 28px;
}

.eyebrow {
  margin: 0 0 8px;
  color: var(--accent);
  font-size: 13px;
  font-weight: 800;
  letter-spacing: 0.08em;
  text-transform: uppercase;
}

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

h1 {
  max-width: 820px;
  margin-bottom: 12px;
  font-size: clamp(34px, 5vw, 58px);
  line-height: 1.04;
  letter-spacing: 0;
}

.subtitle {
  max-width: 780px;
  margin-bottom: 0;
  color: var(--muted);
  font-size: 20px;
  line-height: 1.6;
}

.source-pill {
  flex: 0 0 auto;
  border: 1px solid rgba(31, 138, 112, 0.28);
  border-radius: 999px;
  padding: 10px 14px;
  color: var(--accent-dark);
  background: rgba(255, 255, 255, 0.78);
  font-size: 14px;
  font-weight: 700;
}

.workspace {
  display: grid;
  grid-template-columns: minmax(360px, 0.9fr) minmax(460px, 1.1fr);
  gap: 22px;
  align-items: start;
}

.panel {
  border: 1px solid rgba(198, 211, 218, 0.8);
  border-radius: 18px;
  background: rgba(255, 255, 255, 0.94);
  box-shadow: var(--shadow);
}

.input-panel,
.result-panel {
  min-height: 720px;
  padding: 24px;
}

.panel-heading,
.section-title,
.rewrite-head {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 16px;
}

.panel-heading h2,
.result-state h2,
.explain-panel h2 {
  margin-bottom: 6px;
  font-size: 25px;
  letter-spacing: 0;
}

.panel-heading p,
.section-title span,
.basis-grid p {
  margin: 0;
  color: var(--muted);
}

.field {
  margin-top: 22px;
}

label {
  display: block;
  margin-bottom: 8px;
  color: #334652;
  font-size: 14px;
  font-weight: 800;
}

.segmented {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 6px;
  border: 1px solid var(--soft);
  border-radius: 14px;
  padding: 5px;
  background: #f7faf9;
}

.segment {
  border: 0;
  border-radius: 10px;
  padding: 11px 10px;
  color: var(--muted);
  background: transparent;
  font-weight: 800;
}

.segment.active {
  color: #fff;
  background: var(--accent);
}

.segment:disabled {
  cursor: not-allowed;
  opacity: 0.42;
}

.grid-fields {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 14px;
}

.url-row {
  display: grid;
  grid-template-columns: 1fr auto;
  gap: 10px;
}

input,
textarea,
select {
  width: 100%;
  border: 1px solid #d7e1e6;
  border-radius: 14px;
  padding: 13px 14px;
  color: var(--ink);
  background: #fff;
  outline: none;
  transition: border-color 0.18s ease, box-shadow 0.18s ease;
}

.advanced-panel {
  border: 1px solid #dfe7ec;
  border-radius: 14px;
  margin-top: 22px;
  padding: 13px 14px;
  background: #fbfdfc;
}

.advanced-panel summary {
  cursor: pointer;
  color: #314753;
  font-weight: 900;
}

.advanced-panel p {
  margin: 10px 0 0;
  color: var(--muted);
  font-size: 13px;
  line-height: 1.55;
}

.performance-grid {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 10px;
  margin-top: 12px;
}

.performance-grid label {
  margin: 0;
}

.performance-grid input {
  margin-top: 6px;
  padding: 10px;
}

.compact-field {
  margin-top: 12px;
}

textarea {
  min-height: 320px;
  resize: vertical;
  line-height: 1.7;
}

input:focus,
textarea:focus {
  border-color: rgba(31, 138, 112, 0.7);
  box-shadow: 0 0 0 4px rgba(31, 138, 112, 0.12);
}

.textarea-meta {
  display: flex;
  justify-content: space-between;
  margin-top: 8px;
  color: var(--muted);
  font-size: 13px;
}

.input-error {
  margin: 10px 0 0;
  color: var(--bad);
  font-size: 14px;
  font-weight: 800;
}

.example-row {
  display: flex;
  flex-wrap: wrap;
  gap: 10px;
  margin-top: 18px;
}

.sample-button,
.ghost-button,
.copy-button,
.secondary-button {
  border: 1px solid #d7e1e6;
  border-radius: 999px;
  padding: 9px 12px;
  color: #314753;
  background: #fff;
  font-size: 14px;
  font-weight: 800;
}

.secondary-button {
  border-radius: 14px;
  padding-inline: 16px;
  color: #fff;
  background: var(--ink);
}

.helper-text {
  margin: 8px 0 0;
  color: var(--muted);
  font-size: 13px;
  line-height: 1.55;
}

.helper-text.loading {
  color: var(--blue);
  font-weight: 800;
}

.helper-text.error {
  color: var(--bad);
  font-weight: 800;
}

.helper-text.success {
  color: var(--accent-dark);
  font-weight: 800;
}

.ghost-button:hover,
.sample-button:hover,
.copy-button:hover,
.secondary-button:hover {
  border-color: rgba(31, 138, 112, 0.5);
  color: var(--accent-dark);
}

.secondary-button:hover {
  color: #fff;
  background: var(--accent-dark);
}

.primary-button {
  width: 100%;
  border: 0;
  border-radius: 14px;
  margin-top: 22px;
  padding: 15px 18px;
  color: #fff;
  background: linear-gradient(135deg, var(--accent) 0%, #2473a6 100%);
  font-weight: 900;
  box-shadow: 0 12px 30px rgba(31, 138, 112, 0.25);
}

.empty-state {
  display: grid;
  place-items: center;
  min-height: 660px;
  text-align: center;
  color: var(--muted);
}

.empty-state h2 {
  margin: 18px 0 8px;
  color: var(--ink);
}

.empty-state p {
  max-width: 420px;
}

.empty-icon {
  display: grid;
  place-items: center;
  width: 74px;
  height: 74px;
  border-radius: 24px;
  color: #fff;
  background: var(--ink);
  font-size: 34px;
}

.hidden {
  display: none;
}

.score-header {
  display: grid;
  grid-template-columns: auto 1fr;
  gap: 20px;
  align-items: center;
}

.score-ring {
  --score: 0deg;
  display: grid;
  place-items: center;
  width: 138px;
  height: 138px;
  border-radius: 50%;
  background: conic-gradient(var(--accent) var(--score), #e3ebef 0deg);
  position: relative;
}

.score-ring::after {
  content: "";
  position: absolute;
  inset: 12px;
  border-radius: 50%;
  background: #fff;
}

.score-ring span,
.score-ring small {
  position: relative;
  z-index: 1;
}

.score-ring span {
  font-size: 42px;
  font-weight: 900;
  line-height: 1;
}

.score-ring small {
  color: var(--muted);
  font-weight: 800;
}

.rating-label {
  display: inline-flex;
  border-radius: 999px;
  margin-bottom: 10px;
  padding: 6px 10px;
  color: var(--accent-dark);
  background: #e8f6f1;
  font-size: 13px;
  font-weight: 900;
}

.rating-copy {
  margin-bottom: 0;
  color: var(--muted);
  font-size: 16px;
  line-height: 1.7;
}

.priority-box {
  display: grid;
  grid-template-columns: 210px 1fr;
  gap: 20px;
  border: 1px solid rgba(31, 138, 112, 0.24);
  border-radius: 16px;
  margin: 24px 0;
  padding: 18px;
  background: linear-gradient(135deg, #f0faf6 0%, #f8fbfd 100%);
}

.context-box {
  border: 1px solid rgba(46, 95, 159, 0.22);
  border-radius: 16px;
  margin: 20px 0 0;
  padding: 16px;
  background: #f2f7fc;
}

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

.context-box p {
  margin: 0;
  color: #39515c;
}

.box-kicker {
  color: var(--accent);
  font-size: 12px;
  font-weight: 900;
  letter-spacing: 0.06em;
}

.priority-box h3,
.priority-box p,
.section-block h3 {
  margin-bottom: 0;
}

.priority-box p {
  color: #39515c;
}

.section-block {
  border-top: 1px solid var(--soft);
  padding-top: 22px;
  margin-top: 22px;
}

.metric-list {
  display: grid;
  gap: 14px;
  margin-top: 16px;
}

.metric-row {
  display: grid;
  grid-template-columns: 190px 1fr 46px;
  gap: 12px;
  align-items: center;
}

.metric-name {
  color: #2e4653;
  font-weight: 800;
}

.bar {
  height: 12px;
  overflow: hidden;
  border-radius: 999px;
  background: #e6edf1;
}

.bar span {
  display: block;
  height: 100%;
  border-radius: inherit;
  background: linear-gradient(90deg, var(--accent), var(--blue));
}

.metric-score {
  text-align: right;
  color: var(--muted);
  font-weight: 900;
}

.two-col,
.rewrite-grid,
.basis-grid {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 16px;
}

.plain-list {
  margin: 14px 0 0;
  padding-left: 20px;
}

.plain-list li {
  margin: 8px 0;
  color: #40545f;
}

.rewrite-card {
  border: 1px solid var(--soft);
  border-radius: 14px;
  padding: 16px;
  background: var(--soft-2);
}

.rewrite-card p {
  min-height: 150px;
  margin: 14px 0 0;
  white-space: pre-wrap;
  color: #304753;
}

.copy-button {
  padding: 7px 10px;
  font-size: 13px;
}

.explain-panel {
  margin-top: 22px;
  padding: 24px;
}

.brand-watermark {
  display: flex;
  align-items: center;
  justify-content: center;
  gap: 9px;
  margin: 18px auto 0;
  color: rgba(18, 35, 47, 0.66);
  font-size: 13px;
  font-weight: 900;
}

.brand-watermark img {
  width: 28px;
  height: 28px;
  border: 1px solid rgba(18, 35, 47, 0.12);
  border-radius: 50%;
  object-fit: cover;
}

.basis-grid {
  margin-top: 18px;
}

.basis-grid div {
  border: 1px solid var(--soft);
  border-radius: 14px;
  padding: 16px;
  background: var(--soft-2);
}

.basis-grid strong {
  display: block;
  margin-bottom: 8px;
}

.toast {
  position: fixed;
  right: 24px;
  bottom: 24px;
  transform: translateY(18px);
  opacity: 0;
  pointer-events: none;
  border-radius: 999px;
  padding: 12px 16px;
  color: #fff;
  background: var(--ink);
  font-weight: 800;
  transition: opacity 0.18s ease, transform 0.18s ease;
}

.toast.show {
  transform: translateY(0);
  opacity: 1;
}

.visually-hidden {
  position: absolute;
  width: 1px;
  height: 1px;
  overflow: hidden;
  clip: rect(0, 0, 0, 0);
}

@media (max-width: 980px) {
  .app-shell {
    padding: 22px;
  }

  .topbar {
    align-items: flex-start;
    flex-direction: column;
  }

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

  .input-panel,
  .result-panel {
    min-height: auto;
  }

  .empty-state {
    min-height: 360px;
  }
}

@media (max-width: 680px) {
  .app-shell {
    padding: 14px;
  }

  .panel {
    border-radius: 14px;
  }

  .input-panel,
  .result-panel,
  .explain-panel {
    padding: 16px;
  }

  .grid-fields,
  .url-row,
  .performance-grid,
  .two-col,
  .rewrite-grid,
  .basis-grid,
  .priority-box {
    grid-template-columns: 1fr;
  }

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

  .score-header {
    grid-template-columns: 1fr;
  }

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

  .bar {
    grid-column: 1 / -1;
    grid-row: 2;
  }
}