/*
 * Copyright 2026 Misha Brukman
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *      http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

@import url('https://fonts.googleapis.com/css2?family=Inter:wght@300;400;500;600;700&display=swap');

:root {
  --bg-color: #0f172a;
  --panel-bg: #1e293b;
  --text-primary: #f8fafc;
  --text-secondary: #94a3b8;
  --accent-color: #3b82f6;
  --accent-hover: #2563eb;
  --border-color: #334155;
  
  --diff-add-bg: rgba(34, 197, 94, 0.2);
  --diff-add-text: #4ade80;
  --diff-del-bg: rgba(239, 68, 68, 0.2);
  --diff-del-text: #f87171;
  --diff-unchanged: #cbd5e1;

  --shadow-sm: 0 1px 2px 0 rgba(0, 0, 0, 0.05);
  --shadow-md: 0 4px 6px -1px rgba(0, 0, 0, 0.1), 0 2px 4px -1px rgba(0, 0, 0, 0.06);
  --shadow-lg: 0 10px 15px -3px rgba(0, 0, 0, 0.1), 0 4px 6px -2px rgba(0, 0, 0, 0.05);
  
  --border-radius-md: 0.5rem;
  --border-radius-lg: 0.75rem;
}

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

body {
  font-family: 'Inter', sans-serif;
  background-color: var(--bg-color);
  color: var(--text-primary);
  line-height: 1.5;
  min-height: 100vh;
}

#app {
  max-width: 1400px;
  margin: 0 auto;
  padding: 2rem;
  display: flex;
  flex-direction: column;
  gap: 2rem;
  height: 100vh;
}

header {
  text-align: center;
  padding: 1rem 0;
}

.header-content h1 {
  font-size: 2.5rem;
  font-weight: 700;
  background: linear-gradient(to right, #60a5fa, #a78bfa);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  margin-bottom: 0.5rem;
}

.header-content p {
  color: var(--text-secondary);
  font-size: 1.1rem;
}

/* Controls Container (Upload & Action) */
.controls-container {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 1.5rem;
  background: var(--panel-bg);
  padding: 1.5rem;
  border-radius: var(--border-radius-lg);
  box-shadow: var(--shadow-md);
  border: 1px solid var(--border-color);
}

.file-upload {
  flex: 1;
}

.upload-label {
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  padding: 1.5rem;
  border: 2px dashed var(--border-color);
  border-radius: var(--border-radius-md);
  cursor: pointer;
  transition: all 0.2s ease-in-out;
  background-color: rgba(15, 23, 42, 0.5);
}

.upload-label:hover {
  border-color: var(--accent-color);
  background-color: rgba(59, 130, 246, 0.05);
}

.upload-label input[type="file"] {
  display: none;
}

.upload-title {
  font-weight: 600;
  margin-bottom: 0.5rem;
}

.filename-display {
  font-size: 0.875rem;
  color: var(--text-secondary);
  word-break: break-all;
  text-align: center;
}

.action-area {
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
}

.primary-btn {
  background-color: var(--accent-color);
  color: white;
  border: none;
  padding: 0.75rem 2rem;
  font-size: 1rem;
  font-weight: 600;
  border-radius: var(--border-radius-md);
  cursor: pointer;
  transition: background-color 0.2s;
  box-shadow: var(--shadow-sm);
}

.primary-btn:hover:not(:disabled) {
  background-color: var(--accent-hover);
}

.primary-btn:disabled {
  background-color: var(--border-color);
  color: var(--text-secondary);
  cursor: not-allowed;
  opacity: 0.7;
}

/* Loading Overlay */
.loading-overlay {
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  padding: 2rem;
}

.spinner {
  width: 40px;
  height: 40px;
  border: 4px solid var(--border-color);
  border-top: 4px solid var(--accent-color);
  border-radius: 50%;
  animation: spin 1s linear infinite;
  margin-bottom: 1rem;
}

@keyframes spin {
  0% { transform: rotate(0deg); }
  100% { transform: rotate(360deg); }
}

/* Error Banner */
.error-banner {
  background-color: rgba(239, 68, 68, 0.1);
  border: 1px solid rgba(239, 68, 68, 0.5);
  color: #fca5a5;
  padding: 1rem;
  border-radius: var(--border-radius-md);
  text-align: center;
}

.hidden {
  display: none !important;
}

/* Diff Container */
.diff-container {
  display: flex;
  flex: 1;
  background: var(--panel-bg);
  border-radius: var(--border-radius-lg);
  box-shadow: var(--shadow-lg);
  border: 1px solid var(--border-color);
  overflow: hidden;
  height: 100%;
  min-height: 500px;
}

.diff-pane {
  flex: 1;
  display: flex;
  flex-direction: column;
  min-width: 0;
}

.pane-title {
  padding: 1rem;
  font-size: 1rem;
  font-weight: 600;
  text-align: center;
  background-color: rgba(15, 23, 42, 0.5);
  border-bottom: 1px solid var(--border-color);
  color: var(--text-secondary);
  text-transform: uppercase;
  letter-spacing: 0.05em;
}

.diff-content {
  flex: 1;
  padding: 1.5rem;
  overflow-y: auto;
  font-family: ui-monospace, SFMono-Regular, Menlo, Monaco, Consolas, "Liberation Mono", "Courier New", monospace;
  font-size: 0.9rem;
  white-space: pre-wrap;
  color: var(--diff-unchanged);
  line-height: 1.6;
}

.diff-divider {
  width: 1px;
  background-color: var(--border-color);
}

/* Diff Token Styling */
ins {
  text-decoration: none;
  background-color: var(--diff-add-bg);
  color: var(--diff-add-text);
  border-radius: 2px;
  padding: 0.1rem 0;
}

del {
  text-decoration: line-through;
  background-color: var(--diff-del-bg);
  color: var(--diff-del-text);
  border-radius: 2px;
  padding: 0.1rem 0;
}

/* New Contextual Diff Styles */
.context-text {
  opacity: 0.7;
  transition: opacity 0.2s;
}

.diff-content:hover .context-text {
  opacity: 1;
}

.diff-hunk-separator {
  display: block;
  text-align: center;
  color: var(--text-secondary);
  font-weight: bold;
  padding: 1rem 0;
  letter-spacing: 0.5rem;
  border-top: 1px dashed var(--border-color);
  border-bottom: 1px dashed var(--border-color);
  margin: 1.5rem 0;
  background: rgba(15, 23, 42, 0.3);
}

.diff-section-header {
  font-family: 'Inter', sans-serif;
  font-weight: 700;
  font-size: 1.1rem;
  color: var(--accent-color);
  margin-top: 1.5rem;
  margin-bottom: 0.5rem;
  padding-bottom: 0.25rem;
  border-bottom: 2px solid var(--border-color);
  text-transform: uppercase;
  letter-spacing: 0.02em;
}

.identical-message {
  display: flex;
  align-items: center;
  justify-content: center;
  height: 100%;
  padding: 3rem;
  text-align: center;
  color: var(--text-secondary);
  font-style: italic;
  font-size: 1.2rem;
}

/* Custom Scrollbar for diff panes */
::-webkit-scrollbar {
  width: 8px;
  height: 8px;
}

::-webkit-scrollbar-track {
  background: var(--bg-color);
}

::-webkit-scrollbar-thumb {
  background: var(--border-color);
  border-radius: 4px;
}

::-webkit-scrollbar-thumb:hover {
  background: var(--text-secondary);
}