:root {
  color: #111827;
  font-family: -apple-system, BlinkMacSystemFont, "PingFang SC", "Microsoft YaHei", sans-serif;
  background: #f5f7fb;
}

body {
  margin: 0;
}

a {
  color: #2563eb;
  text-decoration: none;
}

a:hover {
  text-decoration: underline;
}

.site-header {
  align-items: center;
  background: #111827;
  color: #fff;
  display: flex;
  justify-content: space-between;
  padding: 24px 40px;
}

.site-header h1 {
  font-size: 24px;
  margin: 4px 0 0;
}

.site-header nav {
  display: flex;
  gap: 16px;
}

.site-header a {
  color: #dbeafe;
}

main {
  margin: 0 auto;
  max-width: 1180px;
  padding: 28px 24px 48px;
}

.eyebrow {
  color: #6b7280;
  font-size: 12px;
  font-weight: 700;
  letter-spacing: 0.12em;
  margin: 0;
  text-transform: uppercase;
}

.site-header .eyebrow {
  color: #93c5fd;
}

.panel {
  background: #fff;
  border: 1px solid #e5e7eb;
  border-radius: 16px;
  box-shadow: 0 12px 30px rgba(15, 23, 42, 0.06);
  padding: 22px;
}

.panel + .panel,
.grid {
  margin-top: 22px;
}

.grid.two-columns {
  display: grid;
  gap: 22px;
  grid-template-columns: minmax(0, 1fr) minmax(0, 1fr);
}

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

.card {
  border: 1px solid #e5e7eb;
  border-radius: 12px;
  padding: 14px;
}

.card h3 {
  margin: 0 0 6px;
}

.card p {
  margin: 0 0 8px;
}

.card small,
.worksheet-list span {
  color: #6b7280;
}

.worksheet-list {
  list-style: none;
  margin: 0;
  padding: 0;
}

.worksheet-list li {
  border-bottom: 1px solid #e5e7eb;
  display: grid;
  gap: 4px;
  padding: 12px 0;
}

.worksheet-form {
  display: grid;
  gap: 18px;
}

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

.worksheet-form label {
  color: #374151;
  display: grid;
  font-size: 14px;
  font-weight: 700;
  gap: 8px;
}

.worksheet-form input,
.worksheet-form textarea {
  border: 1px solid #d1d5db;
  border-radius: 10px;
  box-sizing: border-box;
  font: inherit;
  font-weight: 400;
  padding: 10px 12px;
  width: 100%;
}

.worksheet-form textarea {
  resize: vertical;
}

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

.field-label {
  color: #374151;
  font-size: 14px;
  font-weight: 700;
}

.drop-zone {
  align-items: center;
  border: 2px dashed #93c5fd;
  border-radius: 14px;
  cursor: pointer;
  display: grid;
  gap: 6px;
  justify-items: center;
  padding: 28px;
  text-align: center;
  transition: background 0.15s ease, border-color 0.15s ease;
}

.drop-zone input {
  height: 1px;
  opacity: 0;
  overflow: hidden;
  padding: 0;
  position: absolute;
  width: 1px;
}

.drop-zone.is-dragover {
  background: #eff6ff;
  border-color: #2563eb;
}

.drop-zone-title {
  color: #111827;
  font-size: 16px;
  font-weight: 800;
}

.drop-zone-hint {
  color: #6b7280;
  font-size: 13px;
  font-weight: 400;
}

.file-list {
  color: #4b5563;
  font-size: 13px;
  margin: 0;
  padding-left: 20px;
}

.checkbox-label {
  align-items: center;
  display: flex !important;
  gap: 8px;
}

.checkbox-label input {
  width: auto;
}

.worksheet-form button {
  background: #111827;
  border: 0;
  border-radius: 10px;
  color: #fff;
  cursor: pointer;
  font: inherit;
  font-weight: 700;
  padding: 12px 16px;
  width: fit-content;
}

.error {
  background: #fef2f2;
  border: 1px solid #fecaca;
  border-radius: 10px;
  color: #991b1b;
  padding: 10px 12px;
}

@media (max-width: 860px) {
  .site-header,
  .grid.two-columns,
  .form-grid {
    display: block;
  }

  .site-header nav {
    margin-top: 16px;
  }
}