:root {
  --sky-primary: #3B82F6;
  --sky-primary-bright: #60A5FA;
  --sky-primary-deep: #1D4ED8;
  --sky-primary-soft: #DBEAFE;
  --sky-sun: #FBBF24;
  --sky-sun-soft: #FEF3C7;
  --sky-sun-deep: #D97706;
  --sky-leaf: #22C55E;
  --sky-leaf-soft: #DCFCE7;
  --sky-leaf-deep: #16A34A;
  --sky-coral: #F87171;
  --sky-coral-soft: #FEE2E2;
  --sky-coral-deep: #B91C1C;
  --sky-berry: #A855F7;
  --sky-bg: #F8FAFC;
  --sky-surface: #FFFFFF;
  --sky-surface-sunken: #F1F5F9;
  --sky-ink: #0F172A;
  --sky-ink-muted: #475569;
  --sky-ink-subtle: #94A3B8;
  --sky-outline: #E2E8F0;
  --sky-font-display: 'Nunito', 'Noto Sans KR', sans-serif;
  --sky-font-body: 'Atkinson Hyperlegible', 'Noto Sans KR', sans-serif;
  --sky-font-mono: 'JetBrains Mono', monospace;
}

.sky-page {
  height: 100vh;
  min-width: 1280px;
  display: flex;
  flex-direction: column;
  overflow: hidden;
  background: var(--sky-bg);
  font-family: var(--sky-font-body);
  color: var(--sky-ink);
  letter-spacing: 0.01em;
}

.sky-card {
  background: var(--sky-surface);
  border: 1px solid var(--sky-outline);
  border-radius: 20px;
  padding: 18px;
}

.sky-stack > .sky-card {
  margin-bottom: 2rem;
}

.sky-btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 8px;
  height: 48px;
  padding: 0 22px;
  border-radius: 16px;
  border: none;
  cursor: pointer;
  font-family: inherit;
  font-size: 16px;
  font-weight: 700;
  background: var(--sky-primary);
  color: #fff;
  text-decoration: none;
}
.sky-btn:hover { background: var(--sky-primary-deep); }
.sky-btn:disabled { background: #CBD5E1; cursor: default; }

.sky-btn-secondary {
  background: var(--sky-surface-sunken);
  color: var(--sky-ink-muted);
}
.sky-btn-secondary:hover { background: var(--sky-outline); }

.sky-pill {
  display: inline-flex;
  align-items: center;
  border-radius: 999px;
  padding: 4px 12px;
  font-size: 13px;
  font-weight: 700;
  white-space: nowrap;
}
.sky-pill-blue { background: var(--sky-primary-soft); color: var(--sky-primary-deep); }
.sky-pill-green { background: var(--sky-leaf-soft); color: var(--sky-leaf-deep); }
.sky-pill-amber { background: var(--sky-sun-soft); color: var(--sky-sun-deep); }
.sky-pill-red { background: var(--sky-coral-soft); color: var(--sky-coral-deep); }
.sky-pill-gray { background: var(--sky-surface-sunken); color: var(--sky-ink-subtle); }

.sky-avatar {
  flex: none;
  border-radius: 999px;
  background: var(--sky-primary-soft);
  color: var(--sky-primary-deep);
  display: flex;
  align-items: center;
  justify-content: center;
  font-weight: 700;
}

.sky-textarea, .sky-input {
  font-family: inherit;
  border: 1px solid var(--sky-outline);
  border-radius: 12px;
  background: var(--sky-surface);
  padding: 12px 14px;
  font-size: 16px;
  line-height: 1.55;
}
.sky-textarea:focus, .sky-input:focus {
  outline: none;
  border-color: var(--sky-primary);
  box-shadow: 0 0 0 4px var(--sky-primary-soft);
}

.sky-hidden { display: none !important; }

@keyframes sky-livepulse {
  0% { box-shadow: 0 0 0 0 rgba(34,197,94,.45); }
  70% { box-shadow: 0 0 0 10px rgba(34,197,94,0); }
  100% { box-shadow: 0 0 0 0 rgba(34,197,94,0); }
}
@keyframes sky-caret {
  0%, 45% { opacity: 1; }
  50%, 100% { opacity: 0; }
}

/* --- Page Header --- */
.sky-header {
  background: var(--sky-surface);
  border-bottom: 1px solid var(--sky-outline);
  padding: 20px 32px;
  display: flex;
  align-items: center;
  justify-content: space-between;
  flex-wrap: wrap;
  gap: 12px;
}
.sky-header h1 {
  font-family: var(--sky-font-display);
  font-size: 28px;
  font-weight: 800;
  color: var(--sky-ink);
  margin: 0;
}
.sky-header p {
  font-size: 14px;
  color: var(--sky-ink-muted);
  margin: 4px 0 0;
}
.sky-header-actions {
  display: flex;
  gap: 8px;
  flex-wrap: wrap;
}

/* --- Card text defaults (so pages don't need per-h2/p inline overrides) --- */
.sky-card h2 {
  font-family: var(--sky-font-display);
  color: var(--sky-ink);
  font-weight: 800;
  font-size: 1.25rem;
  display: flex;
  align-items: center;
  gap: 8px;
  margin: 0 0 0.75rem;
}
.sky-card > h3 {
  font-family: var(--sky-font-display);
  color: var(--sky-ink);
  font-weight: 700;
  font-size: 1.1rem;
  display: flex;
  align-items: center;
  gap: 8px;
  margin: 0 0 0.75rem;
}
.sky-card p {
  color: var(--sky-ink-muted);
}

/* --- Button variants (danger / success) --- */
.sky-btn-danger {
  background: var(--sky-coral);
  color: #fff;
}
.sky-btn-danger:hover { background: var(--sky-coral-deep); }
.sky-btn-success {
  background: var(--sky-leaf);
  color: #fff;
}
.sky-btn-success:hover { background: var(--sky-leaf-deep); }

/* --- Modal --- */
.sky-modal {
  position: fixed;
  z-index: 1000;
  left: 0;
  top: 0;
  width: 100%;
  height: 100%;
  overflow: auto;
  background-color: rgba(15, 23, 42, 0.5);
  display: flex;
  justify-content: center;
  align-items: center;
}
.sky-modal-content {
  background: var(--sky-surface);
  padding: 28px;
  border-radius: 20px;
  border: 1px solid var(--sky-outline);
  width: 90%;
  max-width: 800px;
  max-height: 85vh;
  overflow-y: auto;
  box-shadow: 0 20px 40px rgba(15, 23, 42, 0.2);
  position: relative;
}
.sky-modal-content h2 {
  font-family: var(--sky-font-display);
  color: var(--sky-ink);
  font-weight: 800;
  margin: 0 0 0.5rem;
}
.sky-modal-content p {
  color: var(--sky-ink-muted);
}
.sky-close-button {
  color: var(--sky-ink-subtle);
  position: absolute;
  top: 16px;
  right: 20px;
  font-size: 28px;
  font-weight: bold;
  cursor: pointer;
  line-height: 1;
}
.sky-close-button:hover { color: var(--sky-ink); }

/* --- List row (class list / student list / experiment list) --- */
.sky-list-item {
  display: flex;
  justify-content: space-between;
  align-items: center;
  padding: 14px 18px;
  background: var(--sky-surface);
  border: 1px solid var(--sky-outline);
  border-radius: 14px;
  margin-bottom: 10px;
  transition: box-shadow 0.2s, background 0.2s;
}
.sky-list-item:hover {
  background: var(--sky-surface-sunken);
  box-shadow: 0 4px 12px rgba(15, 23, 42, 0.06);
}
.sky-list-item-link {
  text-decoration: none;
  color: inherit;
  flex-grow: 1;
  display: flex;
  align-items: center;
  gap: 10px;
}
.sky-list-item-actions {
  display: flex;
  gap: 6px;
  align-items: center;
}
.sky-icon-btn {
  background: none;
  border: none;
  cursor: pointer;
  color: var(--sky-ink-subtle);
  font-size: 1.1rem;
  padding: 8px;
  border-radius: 999px;
  width: 36px;
  height: 36px;
  display: flex;
  align-items: center;
  justify-content: center;
  transition: color 0.2s, background-color 0.2s;
}
.sky-icon-btn:hover {
  color: var(--sky-primary);
  background: var(--sky-primary-soft);
}
.sky-icon-btn.sky-icon-btn-danger:hover {
  color: var(--sky-coral-deep);
  background: var(--sky-coral-soft);
}

/* --- Empty state --- */
.sky-empty-state {
  text-align: center;
  padding: 48px 24px;
  border: 2px dashed var(--sky-outline);
  border-radius: 20px;
}
.sky-empty-state-icon {
  font-size: 3rem;
  color: var(--sky-ink-subtle);
  margin-bottom: 1rem;
}
.sky-empty-state p {
  font-size: 1.05rem;
  color: var(--sky-ink-muted);
}

/* --- Form group (label + input stacked) --- */
.sky-form-group {
  display: flex;
  flex-direction: column;
  gap: 6px;
}
.sky-form-group label {
  font-size: 0.85rem;
  font-weight: 700;
  color: var(--sky-ink-muted);
}

/* --- Filter tags --- */
.sky-filter-tags {
  display: flex;
  flex-wrap: wrap;
  gap: 8px;
  margin-bottom: 16px;
  padding-bottom: 16px;
  border-bottom: 1px solid var(--sky-outline);
}
.sky-filter-tag {
  background: var(--sky-surface-sunken);
  color: var(--sky-ink-muted);
  border: none;
  border-radius: 999px;
  padding: 8px 16px;
  font-size: 0.85rem;
  font-weight: 600;
  cursor: pointer;
  transition: all 0.2s ease;
}
.sky-filter-tag.active,
.sky-filter-tag:hover {
  background: var(--sky-primary-soft);
  color: var(--sky-primary-deep);
}

/* --- Radio card group (개인/그룹 보고서 선택) --- */
.sky-radio-card-group {
  display: flex;
  gap: 12px;
  margin-bottom: 8px;
}
.sky-radio-card-group input[type="radio"] {
  display: none;
}
.sky-radio-card-group label {
  flex: 1;
  padding: 14px;
  border: 2px solid var(--sky-outline);
  border-radius: 14px;
  text-align: center;
  cursor: pointer;
  font-weight: 700;
  color: var(--sky-ink-muted);
  transition: all 0.2s ease;
}
.sky-radio-card-group input[type="radio"]:checked + label {
  background: var(--sky-primary);
  color: #fff;
  border-color: var(--sky-primary);
}

/* --- Group editor (drag & drop) --- */
.sky-group-editor {
  display: grid;
  grid-template-columns: 1fr 2fr;
  gap: 16px;
  margin-top: 20px;
  min-height: 300px;
}
.sky-student-pool,
.sky-groups-area {
  border: 2px dashed var(--sky-outline);
  border-radius: 16px;
  padding: 16px;
  background: var(--sky-surface-sunken);
  min-height: 300px;
}
.sky-groups-area {
  border-style: solid;
  background: var(--sky-surface);
  max-height: 550px;
  overflow-y: auto;
}
.sky-student-pool h3,
.sky-groups-area h3 {
  color: var(--sky-primary-deep);
  font-size: 1.05rem;
  margin-bottom: 12px;
}
.sky-students-pool-list {
  display: flex;
  flex-wrap: wrap;
  gap: 6px;
  align-content: flex-start;
}
.sky-groups-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(180px, 1fr));
  gap: 12px;
}
.sky-group-box {
  background: linear-gradient(135deg, var(--sky-primary) 0%, var(--sky-primary-deep) 100%);
  border-radius: 14px;
  padding: 12px;
  min-height: 80px;
  max-height: 200px;
  overflow: hidden;
  display: flex;
  flex-direction: column;
}
.sky-group-box h4 {
  color: #fff;
  font-size: 0.95rem;
  margin-bottom: 8px;
  flex-shrink: 0;
}
.sky-group-box-members {
  display: flex;
  flex-wrap: wrap;
  gap: 4px;
  flex: 1;
  overflow-y: auto;
}
.sky-draggable {
  background: var(--sky-surface);
  border: 1px solid var(--sky-outline);
  border-radius: 999px;
  padding: 4px 10px;
  margin: 3px;
  cursor: grab;
  font-size: 0.8rem;
  font-weight: 600;
  display: inline-block;
  color: var(--sky-ink);
}

/* --- Page canvas override (neutralizes style.css's purple body background/blobs/font) --- */
.sky-body {
  background-color: var(--sky-bg);
  background-image: none;
  color: var(--sky-ink);
  font-family: var(--sky-font-body);
}
.sky-body::before,
.sky-body::after {
  content: none;
}

/* --- experiment-details.html: page header card --- */
.sky-header-card {
  background: var(--sky-surface);
  border: 1px solid var(--sky-outline);
  border-radius: 20px;
  padding: 24px 28px;
  margin-bottom: 1.5rem;
}
.sky-header-card h1 {
  font-family: var(--sky-font-display);
  font-size: 1.75rem;
  font-weight: 800;
  color: var(--sky-ink);
  margin: 0 0 0.4rem;
  line-height: 1.2;
}
.sky-header-card p {
  color: var(--sky-ink-muted);
  margin: 0;
  max-width: 800px;
}

/* --- Card header row (title + action buttons) --- */
.sky-card-header {
  display: flex;
  justify-content: space-between;
  align-items: center;
  flex-wrap: wrap;
  gap: 8px;
  margin-bottom: 1rem;
}
.sky-card-header h2 {
  margin: 0;
}
.sky-card-header h4 {
  margin: 0;
  color: var(--sky-ink);
  font-size: 1.1rem;
  display: flex;
  align-items: center;
  gap: 8px;
}

.sky-btn-small {
  height: 36px;
  padding: 0 14px;
  font-size: 0.85rem;
}

.sky-attachment-actions {
  display: flex;
  justify-content: center;
  gap: 0.5rem;
  margin-top: 0.5rem;
}

/* --- Individual student status cards --- */
.sky-status-grid {
  display: flex;
  flex-wrap: wrap;
  gap: 12px;
}
.sky-status-card {
  position: relative;
  display: flex;
  flex-direction: column;
  justify-content: center;
  align-items: center;
  width: 96px;
  height: 96px;
  border-radius: 16px;
  text-align: center;
  padding: 8px;
  flex-shrink: 0;
  transition: transform 0.2s ease;
}
.sky-status-card-grade-btn {
  position: absolute;
  top: 4px;
  right: 4px;
  width: 24px;
  height: 24px;
  border-radius: 50%;
  background: var(--sky-surface);
  color: var(--sky-leaf-deep);
  border: 1px solid var(--sky-leaf);
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 0.7rem;
  text-decoration: none;
  transition: transform 0.15s ease;
}
.sky-status-card-grade-btn:hover {
  transform: scale(1.15);
  background: var(--sky-leaf);
  color: #fff;
}
.sky-status-card .sky-student-number {
  font-size: 0.75rem;
  font-weight: 600;
}
.sky-status-card .sky-student-name {
  font-size: 0.95rem;
  font-weight: 700;
  margin-top: 4px;
}
.sky-status-card.submitted {
  background: var(--sky-leaf-soft);
  border: 2px solid var(--sky-leaf);
  color: var(--sky-leaf-deep);
  cursor: pointer;
}
.sky-status-card.submitted:hover {
  transform: scale(1.05);
}
.sky-status-card.not-submitted {
  background: var(--sky-surface-sunken);
  border: 2px dashed var(--sky-outline);
  color: var(--sky-ink-subtle);
}
.sky-attachment-loading {
  min-height: 20px;
  display: flex;
  align-items: center;
  justify-content: center;
}
.sky-attachment-indicator {
  display: inline-flex;
  align-items: center;
  gap: 4px;
  color: var(--sky-primary);
  font-size: 0.85rem;
  margin-left: 6px;
}
.sky-attachment-count {
  background: var(--sky-primary);
  color: #fff;
  border-radius: 999px;
  width: 18px;
  height: 18px;
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 0.65rem;
  font-weight: 700;
}

/* --- Group report status cards --- */
.sky-group-status-card {
  background: var(--sky-surface);
  border: 1px solid var(--sky-outline);
  border-radius: 16px;
  padding: 18px;
  flex: 1 1 280px;
  max-width: 360px;
  display: flex;
  flex-direction: column;
  transition: transform 0.2s ease;
}
.sky-group-status-card:hover {
  transform: translateY(-2px);
}
.sky-group-status-card h4 {
  color: var(--sky-primary-deep);
  margin: 0;
  font-size: 1.05rem;
}
.sky-group-status-header {
  display: flex;
  justify-content: space-between;
  align-items: center;
  margin-bottom: 10px;
  border-bottom: 1px solid var(--sky-outline);
  padding-bottom: 10px;
}
.sky-group-submission-status {
  display: flex;
  align-items: center;
  gap: 6px;
  padding: 4px 10px;
  border-radius: 999px;
  font-weight: 600;
  font-size: 0.8rem;
}
.sky-group-submission-status.submitted {
  background: var(--sky-leaf-soft);
  color: var(--sky-leaf-deep);
}
.sky-group-submission-status.pending {
  background: var(--sky-sun-soft);
  color: var(--sky-sun-deep);
}
.sky-group-members {
  display: flex;
  flex-wrap: wrap;
  gap: 6px;
  flex-grow: 1;
  align-content: flex-start;
}
.sky-member-tag {
  background: var(--sky-primary-soft);
  color: var(--sky-primary-deep);
  border-radius: 999px;
  padding: 4px 10px;
  font-size: 0.8rem;
  font-weight: 600;
}

/* --- Selected report detail card --- */
.sky-report-card {
  background: var(--sky-surface);
  border: 1px solid var(--sky-outline);
  border-radius: 16px;
  padding: 20px;
  margin-bottom: 1rem;
}
.sky-report-card h4 {
  color: var(--sky-ink);
  margin: 0 0 1rem;
  display: flex;
  align-items: center;
  gap: 8px;
}
.sky-report-section {
  margin-bottom: 1rem;
  padding: 14px;
  background: var(--sky-surface-sunken);
  border-radius: 12px;
  border-left: 4px solid var(--sky-primary);
}
.sky-report-section:last-child {
  margin-bottom: 0;
}
.sky-report-section strong {
  color: var(--sky-primary-deep);
  display: block;
  margin-bottom: 4px;
}
.sky-report-section h4 {
  color: var(--sky-primary-deep);
  margin: 0 0 0.5rem;
  font-size: 1.05rem;
  display: flex;
  align-items: center;
  gap: 8px;
}
.sky-report-section p {
  margin: 0;
  color: var(--sky-ink);
  line-height: 1.6;
}

/* --- AI feedback card (+ inline edit mode) --- */
.sky-feedback-card {
  background: var(--sky-surface);
  border: 1px solid var(--sky-outline);
  border-radius: 16px;
  padding: 20px;
  margin-bottom: 1rem;
}
.sky-feedback-card.pending {
  border-style: dashed;
}
.sky-feedback-header {
  display: flex;
  justify-content: space-between;
  align-items: center;
  margin-bottom: 12px;
}
.sky-feedback-header h4 {
  margin: 0;
  color: var(--sky-primary-deep);
  display: flex;
  align-items: center;
  gap: 8px;
}
.sky-feedback-content {
  line-height: 1.7;
  color: var(--sky-ink);
}
.sky-feedback-content p {
  color: var(--sky-ink);
}
.sky-feedback-editor {
  display: flex;
  flex-direction: column;
  gap: 10px;
}
.sky-feedback-textarea {
  width: 100%;
  min-height: 150px;
  font-family: inherit;
  border: 1px solid var(--sky-outline);
  border-radius: 12px;
  background: var(--sky-surface);
  padding: 12px 14px;
  font-size: 1rem;
  line-height: 1.55;
}
.sky-feedback-editor-actions {
  display: flex;
  gap: 8px;
}
.sky-loading-feedback {
  color: var(--sky-ink-muted);
  display: flex;
  align-items: center;
  gap: 8px;
}

/* --- Peer feedback card --- */
.sky-peer-feedback-card {
  background: var(--sky-surface);
  border: 1px solid var(--sky-outline);
  border-radius: 16px;
  padding: 20px;
}
.sky-peer-feedback-card-header {
  margin-bottom: 12px;
}
.sky-peer-feedback-card-header h4 {
  margin: 0;
  color: var(--sky-primary-deep);
  display: flex;
  align-items: center;
  gap: 8px;
}
.sky-peer-feedback-list {
  display: flex;
  flex-direction: column;
  gap: 12px;
}
.sky-peer-feedback-item {
  background: var(--sky-surface-sunken);
  border-radius: 12px;
  padding: 14px;
}
.sky-peer-feedback-header {
  display: flex;
  justify-content: space-between;
  align-items: center;
  margin-bottom: 8px;
  font-size: 0.85rem;
}
.sky-reviewer-name {
  font-weight: 700;
  color: var(--sky-ink);
}
.sky-peer-feedback-header .sky-feedback-date {
  color: var(--sky-ink-subtle);
}
.sky-peer-feedback-content .sky-feedback-section {
  margin-bottom: 8px;
}
.sky-peer-feedback-content .sky-feedback-section:last-child {
  margin-bottom: 0;
}
.sky-peer-feedback-content strong {
  color: var(--sky-primary-deep);
  display: block;
  margin-bottom: 2px;
}
.sky-peer-feedback-content p {
  margin: 0;
  color: var(--sky-ink);
}
.sky-no-peer-feedback {
  color: var(--sky-ink-subtle);
  text-align: center;
  padding: 1rem;
}

/* --- Attachment gallery modal --- */
.sky-attachment-gallery {
  max-width: 700px;
}
.sky-gallery-header {
  display: flex;
  justify-content: space-between;
  align-items: center;
  margin-bottom: 1rem;
}
.sky-gallery-header h3 {
  margin: 0;
  color: var(--sky-ink);
}
.sky-gallery-content {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(180px, 1fr));
  gap: 12px;
}
.sky-attachment-item {
  border: 1px solid var(--sky-outline);
  border-radius: 12px;
  overflow: hidden;
  background: var(--sky-surface);
}
.sky-attachment-preview {
  width: 100%;
  height: 120px;
  object-fit: cover;
  display: block;
  cursor: pointer;
}
.sky-attachment-info {
  padding: 10px;
}
.sky-attachment-filename {
  font-size: 0.85rem;
  font-weight: 600;
  color: var(--sky-ink);
  overflow: hidden;
  text-overflow: ellipsis;
  white-space: nowrap;
}
.sky-attachment-type {
  font-size: 0.75rem;
  color: var(--sky-ink-subtle);
  margin: 4px 0 8px;
}
.sky-no-attachments {
  color: var(--sky-ink-subtle);
  text-align: center;
  padding: 2rem;
  font-style: italic;
  grid-column: 1 / -1;
}

/* --- report.html: file upload cards --- */
.sky-upload-section {
  margin-top: 2rem;
  padding: 1.5rem;
  border: 2px dashed var(--sky-outline);
  border-radius: 16px;
  background: var(--sky-surface-sunken);
  transition: border-color 0.2s ease, background 0.2s ease;
}
.sky-upload-section:hover {
  border-color: var(--sky-primary);
  background: var(--sky-primary-soft);
}
.sky-upload-section h4 {
  color: var(--sky-primary-deep);
  margin-bottom: 0.5rem;
  font-size: 1.1rem;
}
.sky-upload-help {
  color: var(--sky-ink-subtle);
  font-size: 0.9rem;
  margin-bottom: 1rem;
  font-style: italic;
}
.sky-upload-area {
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 0.5rem;
  margin-bottom: 1.5rem;
}
.sky-upload-hint {
  font-size: 0.85rem;
  color: var(--sky-ink-subtle);
  text-align: center;
}
.sky-uploads-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(150px, 1fr));
  gap: 1rem;
  margin-top: 1rem;
}
.sky-upload-item {
  position: relative;
  border: 1px solid var(--sky-outline);
  border-radius: 12px;
  padding: 1rem;
  background: var(--sky-surface);
  text-align: center;
  transition: transform 0.2s ease, box-shadow 0.2s ease;
}
.sky-upload-item:hover {
  transform: translateY(-2px);
  box-shadow: 0 4px 16px rgba(15, 23, 42, 0.1);
}
.sky-upload-item.uploading {
  opacity: 0.7;
  pointer-events: none;
}
.sky-upload-icon {
  font-size: 2rem;
  margin-bottom: 0.5rem;
  color: var(--sky-ink-subtle);
}
.sky-upload-icon.image { color: var(--sky-coral); }
.sky-upload-icon.video { color: var(--sky-leaf); }
.sky-upload-icon.pdf { color: var(--sky-coral-deep); }
.sky-upload-icon.word { color: var(--sky-primary); }
.sky-upload-icon.handwriting { color: var(--sky-berry); }
.sky-upload-info {
  margin-bottom: 0.5rem;
}
.sky-upload-name {
  font-size: 0.8rem;
  font-weight: 600;
  color: var(--sky-ink);
  word-break: break-word;
  margin-bottom: 0.25rem;
}
.sky-upload-size {
  font-size: 0.7rem;
  color: var(--sky-ink-subtle);
}
.sky-upload-actions {
  display: flex;
  justify-content: center;
  gap: 0.5rem;
  margin-top: 0.5rem;
}
.sky-upload-btn {
  padding: 0.25rem 0.5rem;
  border: none;
  border-radius: 8px;
  background: var(--sky-primary);
  color: #fff;
  font-size: 0.7rem;
  cursor: pointer;
  transition: background 0.15s ease;
}
.sky-upload-btn:hover {
  background: var(--sky-primary-deep);
}
.sky-upload-btn.delete {
  background: var(--sky-coral);
}
.sky-upload-btn.delete:hover {
  background: var(--sky-coral-deep);
}
.sky-upload-progress {
  width: 100%;
  height: 4px;
  background: var(--sky-outline);
  border-radius: 2px;
  overflow: hidden;
  margin-top: 0.5rem;
}
.sky-upload-progress-bar {
  height: 100%;
  background: var(--sky-primary);
  border-radius: 2px;
  transition: width 0.3s ease;
  width: 0%;
}
.sky-upload-error {
  color: var(--sky-coral-deep);
  font-size: 0.8rem;
  margin-top: 0.5rem;
  padding: 0.5rem;
  background: var(--sky-coral-soft);
  border: 1px solid var(--sky-coral);
  border-radius: 8px;
}

/* --- peer-feedback.html: nested page header --- */
.sky-header-content {
  display: flex;
  justify-content: space-between;
  align-items: center;
  flex-wrap: wrap;
  gap: 12px;
  flex: 1;
}
.sky-header-left {
  display: flex;
  align-items: center;
  gap: 12px;
}
.sky-header-icon {
  font-size: 1.5rem;
  color: var(--sky-primary);
}

/* --- Info card grid (탐구 정보) --- */
.sky-info-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(200px, 1fr));
  gap: 1rem;
}
.sky-info-item {
  display: flex;
  flex-direction: column;
  gap: 0.25rem;
}
.sky-info-label {
  font-weight: 600;
  color: var(--sky-ink-muted);
  font-size: 0.9rem;
}
.sky-info-item span:last-child {
  color: var(--sky-ink);
  font-weight: 500;
}

/* --- Centered section header (제출된 보고서) --- */
.sky-section-header {
  margin-bottom: 1.5rem;
  text-align: center;
}
.sky-section-header h2 {
  color: var(--sky-ink);
  font-family: var(--sky-font-display);
  margin-bottom: 0.5rem;
}
.sky-section-header p {
  color: var(--sky-ink-muted);
}
.sky-section-header h2 {
  justify-content: center;
}

/* --- Submission card grid --- */
.sky-submissions-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(280px, 1fr));
  gap: 1.5rem;
  margin-top: 1rem;
}
.sky-submission-card {
  background: var(--sky-surface);
  border: 1px solid var(--sky-outline);
  border-radius: 16px;
  padding: 18px;
  display: flex;
  flex-direction: column;
  gap: 12px;
  transition: transform 0.2s ease, box-shadow 0.2s ease;
}
.sky-submission-card:hover {
  transform: translateY(-2px);
  box-shadow: 0 8px 20px rgba(15, 23, 42, 0.1);
}
.sky-submission-header {
  display: flex;
  justify-content: space-between;
  align-items: center;
  padding-bottom: 10px;
  border-bottom: 1px solid var(--sky-outline);
}
.sky-submission-type {
  display: flex;
  align-items: center;
  gap: 6px;
}
.sky-submission-type-badge {
  background: var(--sky-primary);
  color: #fff;
  padding: 3px 10px;
  border-radius: 999px;
  font-size: 0.8rem;
  font-weight: 600;
}
.sky-submission-date {
  color: var(--sky-ink-subtle);
  font-size: 0.85rem;
}
.sky-submission-author {
  color: var(--sky-primary-deep);
  margin: 0;
  font-size: 1.05rem;
  font-weight: 700;
}
.sky-submission-preview {
  color: var(--sky-ink-muted);
  line-height: 1.5;
  margin: 0;
  display: -webkit-box;
  -webkit-line-clamp: 3;
  -webkit-box-orient: vertical;
  overflow: hidden;
}
.sky-submission-actions {
  display: flex;
  justify-content: flex-end;
  padding-top: 10px;
  border-top: 1px solid var(--sky-outline);
}

/* --- Page-level loading state --- */
.sky-loading-state {
  text-align: center;
  padding: 3rem;
  color: var(--sky-ink-muted);
}
.sky-loading-state i {
  font-size: 2rem;
  margin-bottom: 1rem;
  color: var(--sky-primary);
}

/* --- Wide modal modifier + header/body/actions structure --- */
.sky-large-modal {
  max-width: 800px;
  width: 90vw;
}
.sky-modal-header {
  padding: 24px 24px 16px;
  border-bottom: 1px solid var(--sky-outline);
  display: flex;
  justify-content: space-between;
  align-items: center;
  position: sticky;
  top: 0;
  background: var(--sky-surface);
  z-index: 1;
}
.sky-modal-header h3 {
  margin: 0;
  color: var(--sky-ink);
  font-size: 1.3rem;
  font-family: var(--sky-font-display);
}
.sky-modal-body {
  padding: 24px;
}
.sky-modal-actions {
  display: flex;
  justify-content: flex-end;
  gap: 10px;
  margin-top: 1.5rem;
  padding-top: 1rem;
  border-top: 1px solid var(--sky-outline);
}

/* --- Strengths/improvements color variants for existing .sky-feedback-section --- */
.sky-feedback-section h5 {
  color: var(--sky-primary-deep);
  margin: 0 0 0.5rem;
  font-size: 1rem;
  font-weight: 600;
}
.sky-feedback-section.strengths {
  background: var(--sky-leaf-soft);
  border-left-color: var(--sky-leaf);
}
.sky-feedback-section.improvements {
  background: var(--sky-primary-soft);
  border-left-color: var(--sky-primary);
}
.sky-feedback-section {
  padding: 0.75rem;
  border-radius: 12px;
  border-left: 4px solid var(--sky-outline);
}

/* --- student-portfolio.html: summary stat cards --- */
.sky-summary-cards {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(220px, 1fr));
  gap: 1.5rem;
  margin: 1.5rem 0;
}
.sky-summary-card {
  background: var(--sky-surface);
  border: 1px solid var(--sky-outline);
  border-radius: 20px;
  padding: 20px;
  display: flex;
  align-items: center;
  gap: 16px;
  transition: transform 0.2s ease, box-shadow 0.2s ease;
}
.sky-summary-card:hover {
  transform: translateY(-4px);
  box-shadow: 0 12px 24px rgba(15, 23, 42, 0.08);
}
.sky-summary-card-icon {
  background: var(--sky-primary);
  color: #fff;
  width: 52px;
  height: 52px;
  border-radius: 16px;
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 1.3rem;
  flex-shrink: 0;
}
.sky-summary-card-content h3 {
  font-size: 1.8rem;
  font-weight: 800;
  color: var(--sky-ink);
  margin: 0;
  line-height: 1.2;
}
.sky-summary-card-content p {
  color: var(--sky-ink-muted);
  margin: 2px 0 0;
  font-size: 0.9rem;
  font-weight: 600;
}

/* --- Peer activity cards --- */
.sky-peer-activities-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(280px, 1fr));
  gap: 1.5rem;
  margin-bottom: 1rem;
}
.sky-peer-activity-card {
  background: var(--sky-surface);
  border: 1px solid var(--sky-outline);
  border-radius: 16px;
  padding: 18px;
  transition: transform 0.2s ease, box-shadow 0.2s ease;
}
.sky-peer-activity-card:hover {
  transform: translateY(-2px);
  box-shadow: 0 8px 20px rgba(15, 23, 42, 0.1);
}
.sky-activity-header {
  display: flex;
  justify-content: space-between;
  align-items: center;
  margin-bottom: 10px;
}
.sky-activity-subject {
  background: var(--sky-primary);
  color: #fff;
  padding: 3px 10px;
  border-radius: 999px;
  font-size: 0.8rem;
  font-weight: 600;
}
.sky-activity-date {
  color: var(--sky-ink-subtle);
  font-size: 0.85rem;
}
.sky-activity-title {
  color: var(--sky-ink);
  margin: 0 0 8px;
  font-size: 1.1rem;
  font-weight: 700;
}
.sky-activity-goal {
  color: var(--sky-ink-muted);
  margin: 0 0 16px;
  line-height: 1.5;
  font-size: 0.9rem;
}
.sky-activity-footer {
  display: flex;
  justify-content: space-between;
  align-items: center;
}
.sky-activity-type {
  display: flex;
  align-items: center;
  gap: 6px;
  color: var(--sky-ink-muted);
  font-size: 0.85rem;
}
.sky-activity-type i {
  color: var(--sky-primary);
}

/* --- Search/filter bar --- */
.sky-portfolio-filters {
  background: var(--sky-surface);
  border: 1px solid var(--sky-outline);
  border-radius: 20px;
  padding: 20px;
  margin-bottom: 1.5rem;
}
.sky-filter-bar {
  display: flex;
  gap: 1rem;
  align-items: center;
  flex-wrap: wrap;
}
.sky-search-box {
  position: relative;
  flex: 1;
  min-width: 220px;
}
.sky-search-box i {
  position: absolute;
  left: 14px;
  top: 50%;
  transform: translateY(-50%);
  color: var(--sky-ink-subtle);
}
.sky-search-box input {
  width: 100%;
  padding: 12px 16px 12px 40px;
  border: 1px solid var(--sky-outline);
  border-radius: 999px;
  background: var(--sky-surface-sunken);
  font-size: 0.9rem;
  font-family: inherit;
}
.sky-search-box input:focus {
  outline: none;
  border-color: var(--sky-primary);
  box-shadow: 0 0 0 4px var(--sky-primary-soft);
  background: var(--sky-surface);
}
.sky-filter-options {
  display: flex;
  gap: 0.5rem;
  flex-wrap: wrap;
}
.sky-select {
  padding: 12px 14px;
  border: 1px solid var(--sky-outline);
  border-radius: 12px;
  background: var(--sky-surface);
  font-size: 0.9rem;
  font-family: inherit;
  cursor: pointer;
}

/* --- Timeline header + results badge --- */
.sky-timeline-header {
  display: flex;
  justify-content: space-between;
  align-items: center;
  margin-bottom: 1.5rem;
  padding-bottom: 1rem;
  border-bottom: 2px solid var(--sky-outline);
}
.sky-timeline-header h2 {
  color: var(--sky-ink);
  margin: 0;
  font-size: 1.3rem;
  font-family: var(--sky-font-display);
}
.sky-results-count {
  background: var(--sky-primary);
  color: #fff;
  padding: 6px 14px;
  border-radius: 999px;
  font-weight: 600;
  font-size: 0.85rem;
}

/* --- Subsection header (unsubmitted/submitted groups) --- */
.sky-subsection-header {
  margin-bottom: 1.25rem;
  padding-bottom: 0.75rem;
  border-bottom: 2px solid var(--sky-outline);
}
.sky-subsection-header h3 {
  font-size: 1.2rem;
  font-weight: 700;
  color: var(--sky-ink);
  margin: 0 0 4px;
  display: flex;
  align-items: center;
  gap: 8px;
}
.sky-subsection-header p {
  color: var(--sky-ink-muted);
  margin: 0;
  font-size: 0.9rem;
}

/* --- Unsubmitted assignment cards --- */
.sky-unsubmitted-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(260px, 1fr));
  gap: 1rem;
}
.sky-unsubmitted-card {
  background: var(--sky-sun-soft);
  border: 1px solid var(--sky-sun);
  border-radius: 16px;
  padding: 18px;
  transition: transform 0.2s ease, box-shadow 0.2s ease;
}
.sky-unsubmitted-card:hover {
  transform: translateY(-3px);
  box-shadow: 0 8px 20px rgba(217, 119, 6, 0.15);
}
.sky-unsubmitted-card-header {
  display: flex;
  justify-content: space-between;
  align-items: center;
  margin-bottom: 10px;
}
.sky-unsubmitted-card-subject {
  background: var(--sky-sun-deep);
  color: #fff;
  font-size: 0.75rem;
  font-weight: 600;
  padding: 3px 10px;
  border-radius: 999px;
}
.sky-unsubmitted-card-title {
  font-size: 1.05rem;
  font-weight: 700;
  color: var(--sky-ink);
  margin: 0 0 16px;
  line-height: 1.4;
}
.sky-start-btn {
  background: var(--sky-sun-deep);
  color: #fff;
  border: none;
  padding: 10px 20px;
  border-radius: 12px;
  font-weight: 700;
  cursor: pointer;
  display: flex;
  align-items: center;
  justify-content: center;
  gap: 8px;
  font-size: 0.9rem;
  width: 100%;
}
.sky-start-btn:hover {
  background: var(--sky-sun);
}

/* --- Submitted report list items --- */
.sky-submitted-list {
  display: flex;
  flex-direction: column;
  gap: 10px;
}
.sky-submitted-item {
  background: var(--sky-surface);
  border: 1px solid var(--sky-outline);
  border-radius: 14px;
  padding: 16px 18px;
  display: flex;
  justify-content: space-between;
  align-items: center;
  transition: transform 0.2s ease, box-shadow 0.2s ease;
}
.sky-submitted-item:hover {
  transform: translateY(-2px);
  box-shadow: 0 4px 12px rgba(15, 23, 42, 0.08);
}
.sky-submitted-item-header {
  display: flex;
  align-items: center;
  gap: 10px;
  margin-bottom: 6px;
}
.sky-report-type-badge {
  font-size: 0.75rem;
  padding: 3px 10px;
  border-radius: 999px;
  font-weight: 600;
}
.sky-report-type-badge.individual {
  background: var(--sky-berry);
  color: #fff;
}
.sky-report-type-badge.group {
  background: var(--sky-primary);
  color: #fff;
}
.sky-submit-date {
  color: var(--sky-ink-subtle);
  font-size: 0.85rem;
  font-weight: 500;
}
.sky-submitted-item-title {
  font-size: 1.05rem;
  font-weight: 700;
  color: var(--sky-ink);
  margin: 0;
  line-height: 1.3;
}
.sky-view-btn {
  background: var(--sky-primary);
  color: #fff;
  border: none;
  padding: 10px 18px;
  border-radius: 10px;
  font-weight: 600;
  cursor: pointer;
  display: flex;
  align-items: center;
  gap: 6px;
  font-size: 0.9rem;
}
.sky-view-btn:hover {
  background: var(--sky-primary-deep);
}

/* --- Report detail modal badges/sections --- */
.sky-modal-report-header {
  margin-bottom: 1.5rem;
  padding-bottom: 1rem;
  border-bottom: 1px solid var(--sky-outline);
}
.sky-modal-date {
  color: var(--sky-ink-muted);
  margin-bottom: 8px;
}
.sky-modal-report-type {
  padding: 6px 14px;
  border-radius: 999px;
  font-weight: 600;
  display: inline-block;
  font-size: 0.9rem;
}
.sky-modal-report-type.individual {
  background: var(--sky-berry);
  color: #fff;
}
.sky-modal-report-type.group {
  background: var(--sky-primary);
  color: #fff;
}
.sky-modal-section {
  margin-bottom: 1.5rem;
}
.sky-modal-section h4 {
  color: var(--sky-primary-deep);
  margin-bottom: 8px;
  font-size: 1.05rem;
  display: flex;
  align-items: center;
  gap: 8px;
}
.sky-modal-section p {
  line-height: 1.7;
  color: var(--sky-ink);
  margin: 0;
}

/* --- Landing page (public/landing.html) --- */
.sky-landing-header {
  position: fixed;
  top: 0;
  left: 0;
  width: 100%;
  padding: 1rem 2rem;
  z-index: 1000;
  display: flex;
  justify-content: space-between;
  align-items: center;
  background: rgba(255, 255, 255, 0.6);
  backdrop-filter: blur(10px);
  -webkit-backdrop-filter: blur(10px);
  border-bottom: 1px solid var(--sky-outline);
  transition: all 0.3s ease;
}
.sky-landing-header.scrolled {
  background: rgba(255, 255, 255, 0.95);
  box-shadow: 0 4px 20px rgba(15, 23, 42, 0.06);
}
.sky-landing-logo {
  font-family: var(--sky-font-display);
  font-weight: 800;
  font-size: 1.5rem;
  color: var(--sky-ink);
  display: flex;
  align-items: center;
  gap: 0.5rem;
  text-decoration: none;
}
.sky-landing-logo i {
  color: var(--sky-primary);
}

.sky-hero {
  padding: 8rem 2rem 4rem;
  text-align: center;
  min-height: 80vh;
  display: flex;
  flex-direction: column;
  justify-content: center;
  align-items: center;
}
.sky-hero-badge {
  display: inline-block;
  padding: 0.5rem 1rem;
  background: var(--sky-primary-soft);
  border: 1px solid var(--sky-primary);
  border-radius: 50px;
  color: var(--sky-primary-deep);
  font-weight: 700;
  margin-bottom: 1.5rem;
  font-size: 0.9rem;
  animation: fadeDown 0.8s ease-out;
}
.sky-hero-title {
  font-family: var(--sky-font-display);
  font-size: 4rem;
  font-weight: 800;
  line-height: 1.1;
  margin-bottom: 1.5rem;
  max-width: 900px;
  color: var(--sky-ink);
  animation: fadeUp 0.8s ease-out 0.1s backwards;
}
.sky-hero-title span {
  color: var(--sky-primary);
  position: relative;
}
.sky-hero-title span::after {
  content: '';
  position: absolute;
  bottom: 5px;
  left: 0;
  width: 100%;
  height: 15px;
  background: var(--sky-primary);
  opacity: 0.2;
  z-index: -1;
  transform: skewX(-15deg);
}
.sky-hero-subtitle {
  font-size: 1.25rem;
  color: var(--sky-ink-muted);
  max-width: 600px;
  margin-bottom: 3rem;
  line-height: 1.6;
  animation: fadeUp 0.8s ease-out 0.2s backwards;
}
.sky-hero-cta-group {
  display: flex;
  gap: 1rem;
  animation: fadeUp 0.8s ease-out 0.3s backwards;
}

.sky-features {
  padding: 5rem 2rem;
}
.sky-features-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
  gap: 2rem;
  max-width: 1200px;
  margin: 0 auto;
}
.sky-feature-card {
  background: var(--sky-surface);
  border: 1px solid var(--sky-outline);
  border-radius: 20px;
  padding: 2.5rem;
  transition: all 0.3s ease;
}
.sky-feature-card:hover {
  transform: translateY(-10px);
  box-shadow: 0 20px 40px rgba(15, 23, 42, 0.08);
}
.sky-feature-icon {
  width: 60px;
  height: 60px;
  border-radius: 16px;
  background: linear-gradient(135deg, var(--sky-primary), var(--sky-primary-bright));
  color: #fff;
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 1.5rem;
  margin-bottom: 1.5rem;
}
.sky-feature-title {
  font-family: var(--sky-font-display);
  font-size: 1.5rem;
  margin-bottom: 1rem;
  color: var(--sky-ink);
}
.sky-feature-text {
  color: var(--sky-ink-muted);
  line-height: 1.6;
}

.sky-cta-section {
  padding: 8rem 2rem;
  text-align: center;
}
.sky-cta-card {
  background: linear-gradient(135deg, #1F2937 0%, #111827 100%);
  color: #fff;
  max-width: 900px;
  margin: 0 auto;
  border-radius: 40px;
  padding: 5rem 3rem;
  position: relative;
  overflow: hidden;
  box-shadow: 0 25px 50px -12px rgba(0, 0, 0, 0.5);
}
.sky-cta-card::before {
  content: '';
  position: absolute;
  top: 0;
  right: 0;
  width: 400px;
  height: 400px;
  background: radial-gradient(circle, var(--sky-primary) 0%, transparent 70%);
  opacity: 0.2;
  filter: blur(50px);
}
.sky-cta-title {
  font-family: var(--sky-font-display);
  font-size: 3rem;
  margin-bottom: 1.5rem;
  position: relative;
  z-index: 1;
}
.sky-cta-text {
  color: #9CA3AF;
  font-size: 1.2rem;
  margin-bottom: 3rem;
  max-width: 600px;
  margin-left: auto;
  margin-right: auto;
  position: relative;
  z-index: 1;
}

.sky-landing-footer {
  padding: 3rem 2rem;
  text-align: center;
  color: var(--sky-ink-muted);
  font-size: 0.9rem;
}
.sky-landing-footer-social {
  display: flex;
  gap: 1.5rem;
  justify-content: center;
}
.sky-landing-footer-social a {
  color: var(--sky-ink-muted);
}

@media (max-width: 768px) {
  .sky-hero-title {
    font-size: 2.5rem;
  }
  .sky-cta-title {
    font-size: 2rem;
    padding: 0 1rem;
  }
  .sky-landing-header {
    padding: 1rem;
  }
}

/* --- Mobile refinements (phone-width screens, e.g. student-portfolio.html) --- */
@media (max-width: 480px) {
  .sky-header {
    padding: 14px 16px;
  }
  .sky-header h1 {
    font-size: 1.3rem;
  }
  .sky-header-content {
    flex-direction: column;
    align-items: flex-start;
  }
  .sky-header-actions {
    width: 100%;
  }
  .sky-header-card {
    padding: 18px 16px;
  }
  .sky-header-card h1 {
    font-size: 1.4rem;
  }
  .sky-header-actions .sky-btn {
    flex: 1 1 100%;
    justify-content: center;
  }
  .sky-card-header {
    align-items: flex-start;
  }
  .sky-summary-card {
    padding: 14px;
    gap: 12px;
  }
  .sky-summary-card-icon {
    width: 40px;
    height: 40px;
    font-size: 1.1rem;
  }
  .sky-summary-card-content h3 {
    font-size: 1.4rem;
  }
  .sky-filter-bar {
    flex-direction: column;
    align-items: stretch;
  }
  .sky-filter-options {
    flex-direction: column;
  }
  .sky-select {
    width: 100%;
  }
  .sky-modal-content {
    width: 94%;
    padding: 18px;
  }
  .sky-modal-header {
    padding: 16px 16px 12px;
  }
  .sky-modal-body {
    padding: 16px;
  }
}