:root {
  --ink: #1a1a1a;
  --paper: #faf9f7;
  --accent: #c45a3b;
  --accent-light: #e8d5cf;
  --muted: #6b6b6b;
  --border: #e0ddd8;
  --success: #2d6a4f;
  --warning: #b86e00;
}

* {
  margin: 0;
  padding: 0;
  box-sizing: border-box;
}

body {
  font-family: 'Noto Sans KR', sans-serif;
  background: var(--paper);
  color: var(--ink);
  min-height: 100vh;
  line-height: 1.7;
}

/* Header */
header {
  border-bottom: 1px solid var(--border);
  padding: 2rem 0;
  background: linear-gradient(180deg, #fff 0%, var(--paper) 100%);
}

.header-content {
  max-width: 1200px;
  margin: 0 auto;
  padding: 0 2rem;
  display: flex;
  justify-content: space-between;
  align-items: center;
}

.logo {
  font-family: 'Cormorant Garamond', serif;
  font-size: 1.8rem;
  font-weight: 700;
  color: var(--ink);
  letter-spacing: -0.02em;
}

.logo span {
  color: var(--accent);
}

.tagline {
  font-size: 0.85rem;
  color: var(--muted);
  font-weight: 300;
}

/* Main Layout */
main {
  max-width: 1200px;
  margin: 0 auto;
  padding: 3rem 2rem;
  display: grid;
  grid-template-columns: 380px 1fr;
  gap: 3rem;
  min-height: calc(100vh - 200px);
}

@media (max-width: 900px) {
  main {
    grid-template-columns: 1fr;
  }
}

/* Sidebar */
.sidebar {
  position: sticky;
  top: 2rem;
  height: fit-content;
}

.card {
  background: #fff;
  border: 1px solid var(--border);
  padding: 2rem;
  margin-bottom: 1.5rem;
}

.card-title {
  font-family: 'Cormorant Garamond', serif;
  font-size: 1.3rem;
  font-weight: 600;
  margin-bottom: 1.5rem;
  padding-bottom: 0.75rem;
  border-bottom: 2px solid var(--accent);
  display: inline-block;
}

/* API Key Input */
.api-section {
  margin-bottom: 1.5rem;
}

.api-section:last-child {
  margin-bottom: 0;
}

label {
  display: block;
  font-size: 0.8rem;
  font-weight: 500;
  text-transform: uppercase;
  letter-spacing: 0.05em;
  color: var(--muted);
  margin-bottom: 0.5rem;
}

input[type="password"],
input[type="text"] {
  width: 100%;
  padding: 0.875rem 1rem;
  border: 1px solid var(--border);
  background: var(--paper);
  font-family: 'JetBrains Mono', monospace;
  font-size: 0.85rem;
  transition: all 0.2s ease;
}

input:focus {
  outline: none;
  border-color: var(--accent);
  background: #fff;
}

.api-status {
  display: flex;
  align-items: center;
  gap: 0.5rem;
  margin-top: 0.5rem;
  font-size: 0.75rem;
}

.status-dot {
  width: 6px;
  height: 6px;
  border-radius: 50%;
  background: var(--border);
}

.status-dot.active {
  background: var(--success);
}

/* File Upload */
.upload-zone {
  border: 2px dashed var(--border);
  padding: 2.5rem 1.5rem;
  text-align: center;
  cursor: pointer;
  transition: all 0.3s ease;
  background: var(--paper);
}

.upload-zone:hover {
  border-color: var(--accent);
  background: var(--accent-light);
}

.upload-zone.dragover {
  border-color: var(--accent);
  background: var(--accent-light);
  transform: scale(1.01);
}

.upload-zone.has-file {
  border-style: solid;
  border-color: var(--success);
  background: #f0f7f4;
}

.upload-icon {
  font-size: 2.5rem;
  margin-bottom: 1rem;
  opacity: 0.6;
}

.upload-text {
  font-size: 0.9rem;
  color: var(--muted);
}

.upload-text strong {
  color: var(--ink);
  display: block;
  margin-bottom: 0.25rem;
}

.file-info {
  font-family: 'JetBrains Mono', monospace;
  font-size: 0.8rem;
  color: var(--success);
  margin-top: 0.5rem;
}

#file-input {
  display: none;
}

/* Analyze Button */
.analyze-btn {
  width: 100%;
  padding: 1.125rem 2rem;
  background: var(--ink);
  color: #fff;
  border: none;
  font-family: 'Noto Sans KR', sans-serif;
  font-size: 0.95rem;
  font-weight: 500;
  cursor: pointer;
  transition: all 0.3s ease;
  letter-spacing: 0.02em;
}

.analyze-btn:hover:not(:disabled) {
  background: var(--accent);
  transform: translateY(-1px);
}

.analyze-btn:disabled {
  background: var(--border);
  cursor: not-allowed;
}

.analyze-btn.loading {
  position: relative;
  color: transparent;
}

.analyze-btn.loading::after {
  content: "";
  position: absolute;
  width: 20px;
  height: 20px;
  top: 50%;
  left: 50%;
  margin-left: -10px;
  margin-top: -10px;
  border: 2px solid #fff;
  border-top-color: transparent;
  border-radius: 50%;
  animation: spin 0.8s linear infinite;
}

@keyframes spin {
  to {
    transform: rotate(360deg);
  }
}

/* Results Section */
.results-section {
  min-height: 400px;
}

.results-header {
  display: flex;
  justify-content: space-between;
  align-items: center;
  margin-bottom: 2rem;
  padding-bottom: 1rem;
  border-bottom: 1px solid var(--border);
}

.results-title {
  font-family: 'Cormorant Garamond', serif;
  font-size: 2rem;
  font-weight: 700;
}

.export-buttons {
  display: flex;
  gap: 0.75rem;
}

.export-btn {
  padding: 0.625rem 1.25rem;
  background: transparent;
  border: 1px solid var(--border);
  font-family: 'Noto Sans KR', sans-serif;
  font-size: 0.8rem;
  cursor: pointer;
  transition: all 0.2s ease;
}

.export-btn:hover {
  border-color: var(--ink);
  background: var(--ink);
  color: #fff;
}

/* Empty State */
.empty-state {
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  height: 400px;
  text-align: center;
  color: var(--muted);
}

.empty-state-icon {
  font-size: 4rem;
  margin-bottom: 1.5rem;
  opacity: 0.3;
}

.empty-state h3 {
  font-family: 'Cormorant Garamond', serif;
  font-size: 1.5rem;
  font-weight: 400;
  color: var(--ink);
  margin-bottom: 0.5rem;
}

/* Tabs */
.tabs {
  display: flex;
  gap: 0;
  border-bottom: 1px solid var(--border);
  margin-bottom: 2rem;
}

.tab {
  padding: 1rem 1.5rem;
  background: none;
  border: none;
  font-family: 'Noto Sans KR', sans-serif;
  font-size: 0.9rem;
  color: var(--muted);
  cursor: pointer;
  position: relative;
  transition: color 0.2s ease;
}

.tab:hover {
  color: var(--ink);
}

.tab.active {
  color: var(--ink);
  font-weight: 500;
}

.tab.active::after {
  content: "";
  position: absolute;
  bottom: -1px;
  left: 0;
  right: 0;
  height: 2px;
  background: var(--accent);
}

/* Category Section */
.category {
  margin-bottom: 3rem;
  animation: fadeIn 0.5s ease;
}

@keyframes fadeIn {
  from {
    opacity: 0;
    transform: translateY(10px);
  }
  to {
    opacity: 1;
    transform: translateY(0);
  }
}

.category-header {
  display: flex;
  align-items: baseline;
  gap: 1rem;
  margin-bottom: 1.5rem;
  padding-bottom: 0.75rem;
  border-bottom: 1px solid var(--border);
}

.category-name {
  font-family: 'Cormorant Garamond', serif;
  font-size: 1.4rem;
  font-weight: 600;
}

.category-name-en {
  font-size: 0.85rem;
  color: var(--muted);
  font-style: italic;
}

/* Expression Card */
.expression {
  background: #fff;
  border-left: 3px solid var(--border);
  padding: 1.5rem;
  margin-bottom: 1rem;
  transition: all 0.2s ease;
}

.expression:hover {
  border-left-color: var(--accent);
  box-shadow: 0 2px 12px rgba(0, 0, 0, 0.06);
}

.expression-header {
  display: flex;
  align-items: flex-start;
  gap: 0.75rem;
  margin-bottom: 1rem;
}

a {
  color: var(--accent);
  text-decoration: none;
}

.difficulty {
  padding: 0.25rem 0.5rem;
  font-size: 0.65rem;
  font-weight: 500;
  text-transform: uppercase;
  letter-spacing: 0.05em;
  border-radius: 2px;
  flex-shrink: 0;
}

.difficulty.basic {
  background: #e8f5e9;
  color: #2d6a4f;
}

.difficulty.intermediate {
  background: #fff3e0;
  color: #b86e00;
}

.difficulty.advanced {
  background: #fce4ec;
  color: #c45a3b;
}

.expression-text {
  font-family: 'Cormorant Garamond', serif;
  font-size: 1.2rem;
  font-weight: 600;
  line-height: 1.4;
  color: var(--ink);
}

.expression-meta {
  font-size: 0.875rem;
}

.expression-meta dt {
  font-weight: 500;
  color: var(--muted);
  font-size: 0.75rem;
  text-transform: uppercase;
  letter-spacing: 0.03em;
  margin-bottom: 0.25rem;
  margin-top: 0.75rem;
}

.expression-meta dd {
  color: var(--ink);
}

.expression-meta dd em {
  font-style: italic;
  color: var(--muted);
}

/* Verbs & Transitions Table */
.data-table {
  width: 100%;
  border-collapse: collapse;
  font-size: 0.9rem;
}

.data-table th {
  text-align: left;
  padding: 1rem;
  background: var(--paper);
  font-weight: 500;
  font-size: 0.75rem;
  text-transform: uppercase;
  letter-spacing: 0.05em;
  color: var(--muted);
  border-bottom: 2px solid var(--border);
}

.data-table td {
  padding: 1rem;
  border-bottom: 1px solid var(--border);
  vertical-align: top;
}

.data-table tr:hover td {
  background: #fff;
}

.verb-name {
  font-family: 'Cormorant Garamond', serif;
  font-size: 1.1rem;
  font-weight: 600;
}

/* Progress Indicator */
.progress-container {
  margin-top: 1.5rem;
  display: none;
}

.progress-container.show {
  display: block;
}

.progress-step {
  display: flex;
  align-items: center;
  gap: 0.75rem;
  padding: 0.75rem 0;
  font-size: 0.85rem;
  color: var(--muted);
}

.progress-step.active {
  color: var(--ink);
}

.progress-step.done {
  color: var(--success);
}

.step-indicator {
  width: 24px;
  height: 24px;
  border: 2px solid var(--border);
  border-radius: 50%;
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 0.7rem;
  font-weight: 600;
}

.progress-step.active .step-indicator {
  border-color: var(--accent);
  color: var(--accent);
}

.progress-step.done .step-indicator {
  border-color: var(--success);
  background: var(--success);
  color: #fff;
}

/* Error State */
.error-message {
  background: #fef2f2;
  border: 1px solid #fecaca;
  color: #991b1b;
  padding: 1rem 1.5rem;
  margin-top: 1rem;
  font-size: 0.875rem;
}

/* Footer */
footer {
  text-align: center;
  padding: 2rem;
  color: var(--muted);
  font-size: 0.8rem;
  border-top: 1px solid var(--border);
  margin-top: 4rem;
}

footer a {
  color: var(--accent);
  text-decoration: none;
}

/* Responsive */
@media (max-width: 600px) {
  .header-content {
    flex-direction: column;
    gap: 0.5rem;
    text-align: center;
  }

  main {
    padding: 1.5rem 1rem;
  }

  .card {
    padding: 1.5rem;
  }

  .results-header {
    flex-direction: column;
    gap: 1rem;
    align-items: flex-start;
  }
}