:root {
  --bg: #eef2f6;
  --panel: rgba(255, 255, 255, 0.92);
  --panel-strong: #ffffff;
  --line: rgba(25, 37, 52, 0.1);
  --text: #18212d;
  --muted: #5f6c7b;
  --accent: #0f766e;
  --accent-soft: rgba(15, 118, 110, 0.1);
  --warn: #b45309;
  --shadow: 0 22px 60px rgba(18, 34, 54, 0.08);
  --radius: 24px;
}

* {
  box-sizing: border-box;
}

body {
  margin: 0;
  min-height: 100vh;
  font-family: "Segoe UI", "PingFang SC", "Microsoft YaHei", sans-serif;
  color: var(--text);
  background:
    radial-gradient(circle at top left, rgba(15, 118, 110, 0.13), transparent 28%),
    radial-gradient(circle at bottom right, rgba(217, 119, 6, 0.08), transparent 26%),
    linear-gradient(180deg, #f8fafc 0%, var(--bg) 100%);
}

.page-shell {
  width: min(1200px, calc(100vw - 40px));
  margin: 0 auto;
  padding: 42px 0 64px;
}

.hero {
  display: grid;
  grid-template-columns: 1.4fr 0.8fr;
  gap: 24px;
  align-items: end;
  margin-bottom: 26px;
}

.eyebrow {
  margin: 0 0 10px;
  font-size: 12px;
  letter-spacing: 0.18em;
  text-transform: uppercase;
  color: var(--accent);
}

.hero h1 {
  margin: 0;
  font-size: clamp(32px, 4vw, 52px);
  line-height: 1.05;
}

.lead {
  margin: 14px 0 0;
  max-width: 62ch;
  color: var(--muted);
  font-size: 16px;
  line-height: 1.7;
}

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

.ghost-button,
.copy-button {
  border: 1px solid var(--line);
  border-radius: 999px;
  padding: 12px 18px;
  font-size: 14px;
  font-weight: 600;
  cursor: pointer;
  transition: transform 140ms ease, border-color 140ms ease, background 140ms ease;
}

.ghost-button {
  background: rgba(255, 255, 255, 0.78);
  color: var(--text);
}

.ghost-button:hover,
.copy-button:hover:not(:disabled) {
  transform: translateY(-1px);
  border-color: rgba(15, 118, 110, 0.35);
}

.file-button {
  display: inline-flex;
  align-items: center;
}

.workspace {
  display: grid;
  gap: 18px;
}

.dropzone,
.status-panel,
.summary-card,
.section-card {
  background: var(--panel);
  backdrop-filter: blur(18px);
  border: 1px solid rgba(255, 255, 255, 0.6);
  box-shadow: var(--shadow);
}

.dropzone {
  border-radius: 32px;
  min-height: 220px;
  display: grid;
  place-items: center;
  padding: 20px;
  position: relative;
  overflow: hidden;
}

.dropzone::before {
  content: "";
  position: absolute;
  inset: 16px;
  border: 2px dashed rgba(15, 118, 110, 0.22);
  border-radius: 24px;
}

.dropzone.is-active::before {
  border-color: rgba(15, 118, 110, 0.72);
  background: rgba(15, 118, 110, 0.04);
}

.dropzone-inner {
  text-align: center;
  z-index: 1;
}

.dropzone-title {
  margin: 0;
  font-size: 28px;
  font-weight: 700;
}

.dropzone-subtitle {
  margin: 12px 0 0;
  color: var(--muted);
  font-size: 15px;
}

.status-panel {
  border-radius: 24px;
  padding: 18px 22px;
  display: flex;
  justify-content: space-between;
  gap: 16px;
  align-items: center;
}

.status-label,
.summary-label,
.section-kicker,
.meta-label,
.question-label,
.list-label {
  margin: 0;
  font-size: 12px;
  letter-spacing: 0.12em;
  text-transform: uppercase;
  color: var(--muted);
}

.status-text {
  margin: 6px 0 0;
  font-size: 18px;
  font-weight: 600;
}

.copy-button {
  background: linear-gradient(135deg, #115e59, #0f766e);
  color: white;
}

.copy-button:disabled {
  cursor: not-allowed;
  opacity: 0.45;
}

.summary-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(180px, 1fr));
  gap: 14px;
}

.summary-card {
  border-radius: 20px;
  padding: 18px 20px;
}

.summary-value {
  margin: 8px 0 0;
  font-size: 30px;
  font-weight: 700;
}

.results {
  display: grid;
  gap: 18px;
}

.homework-list {
  display: grid;
  gap: 16px;
  margin-top: 22px;
}

.homework-actions {
  display: flex;
  justify-content: flex-end;
  margin-top: 16px;
}

.score-list {
  display: grid;
  gap: 8px;
  margin-top: 14px;
}

.score-row {
  display: grid;
  grid-template-columns: 70px minmax(0, 1fr) 80px;
  gap: 12px;
  align-items: center;
  padding: 10px 12px;
  border-radius: 14px;
  background: rgba(255, 255, 255, 0.72);
  border: 1px solid var(--line);
}

.score-rank,
.score-value {
  font-weight: 700;
  color: var(--accent);
}

.score-name {
  min-width: 0;
  overflow: hidden;
  text-overflow: ellipsis;
  white-space: nowrap;
}

.section-card {
  border-radius: var(--radius);
  padding: 24px;
}

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

.section-title {
  margin: 8px 0 0;
  font-size: 28px;
  line-height: 1.15;
}

.section-badge {
  white-space: nowrap;
  border-radius: 999px;
  background: var(--accent-soft);
  color: var(--accent);
  padding: 8px 12px;
  font-size: 13px;
  font-weight: 700;
}

.section-meta {
  display: flex;
  flex-wrap: wrap;
  gap: 10px;
  margin-top: 16px;
}

.meta-pill {
  border-radius: 999px;
  border: 1px solid var(--line);
  padding: 8px 12px;
  color: var(--muted);
  font-size: 13px;
}

.section-body {
  display: grid;
  gap: 18px;
  margin-top: 22px;
}

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

.panel {
  background: rgba(248, 250, 252, 0.92);
  border: 1px solid var(--line);
  border-radius: 20px;
  padding: 18px;
}

.panel p,
.panel li {
  line-height: 1.7;
}

.rich-text {
  margin: 10px 0 0;
  white-space: pre-wrap;
}

.question-list {
  display: grid;
  gap: 16px;
}

.question-card {
  border: 1px solid var(--line);
  border-radius: 20px;
  padding: 18px;
  background: linear-gradient(180deg, rgba(255, 255, 255, 0.9), rgba(248, 250, 252, 0.95));
}

.question-card h3 {
  margin: 8px 0 0;
  font-size: 22px;
}

.question-prompt {
  margin: 14px 0;
  line-height: 1.7;
}

.answer-row {
  display: grid;
  gap: 12px;
}

.answer-chip {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  padding: 10px 14px;
  border-radius: 14px;
  background: rgba(15, 118, 110, 0.08);
  color: #0b5d57;
  font-weight: 600;
}

.variants {
  margin-top: 14px;
}

.variants summary {
  cursor: pointer;
  color: var(--warn);
  font-weight: 600;
}

.variants-list,
.keypoint-list {
  margin: 12px 0 0;
  padding-left: 20px;
}

.image-preview {
  width: 100%;
  border-radius: 18px;
  border: 1px solid var(--line);
  object-fit: cover;
  max-height: 340px;
}

.empty-state {
  padding: 32px 24px;
  text-align: center;
  color: var(--muted);
}

@media (max-width: 900px) {
  .page-shell {
    width: min(100vw - 20px, 1200px);
    padding-top: 22px;
  }

  .hero,
  .split-panel {
    grid-template-columns: 1fr;
  }

  .hero-actions,
  .status-panel {
    justify-content: flex-start;
  }

  .section-head {
    flex-direction: column;
  }
}