/* =====================================================
   CSS Variables - Design System
   ===================================================== */
:root {
  --bg-primary: #0a0a0f;
  --bg-secondary: #12121a;
  --bg-card: rgba(25, 25, 35, 0.7);
  --bg-card-hover: rgba(35, 35, 50, 0.8);
  --text-primary: #ffffff;
  --text-secondary: #a0a0b0;
  --text-muted: #6b6b80;
  --accent-primary: #667eea;
  --accent-secondary: #764ba2;
  --accent-gradient: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
  --accent-glow: rgba(102, 126, 234, 0.4);
  --success: #10b981;
  --error: #ef4444;
  --warning: #f59e0b;
  --border-color: rgba(255, 255, 255, 0.08);
  --border-light: rgba(255, 255, 255, 0.15);
  --spacing-xs: 4px;
  --spacing-sm: 8px;
  --spacing-md: 16px;
  --spacing-lg: 24px;
  --spacing-xl: 32px;
  --spacing-2xl: 48px;
  --radius-sm: 8px;
  --radius-md: 12px;
  --radius-lg: 20px;
  --radius-full: 9999px;
  --shadow-sm: 0 2px 4px rgba(0, 0, 0, 0.3);
  --shadow-md: 0 4px 12px rgba(0, 0, 0, 0.4);
  --shadow-lg: 0 8px 24px rgba(0, 0, 0, 0.5);
  --shadow-glow: 0 0 40px var(--accent-glow);
  --transition-fast: 0.15s ease;
  --transition-normal: 0.3s ease;
  --transition-slow: 0.5s ease;
}

/* =====================================================
   Reset & Base
   ===================================================== */
*, *::before, *::after { box-sizing: border-box; margin: 0; padding: 0; }
html { font-size: 16px; scroll-behavior: smooth; }
body {
  font-family: 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, sans-serif;
  background: var(--bg-primary);
  color: var(--text-primary);
  min-height: 100vh;
  line-height: 1.6;
  overflow-x: hidden;
}

/* =====================================================
   Background Effects
   ===================================================== */
.background-effects {
  position: fixed; top: 0; left: 0; width: 100%; height: 100%;
  pointer-events: none; z-index: 0; overflow: hidden;
}
.gradient-orb {
  position: absolute; border-radius: 50%; filter: blur(80px);
  opacity: 0.5; animation: float 20s infinite ease-in-out;
}
.orb-1 { width: 600px; height: 600px; background: radial-gradient(circle, rgba(102, 126, 234, 0.3) 0%, transparent 70%); top: -200px; left: -100px; }
.orb-2 { width: 500px; height: 500px; background: radial-gradient(circle, rgba(118, 75, 162, 0.3) 0%, transparent 70%); bottom: -150px; right: -100px; animation-delay: -7s; }
.orb-3 { width: 400px; height: 400px; background: radial-gradient(circle, rgba(16, 185, 129, 0.2) 0%, transparent 70%); top: 50%; left: 50%; transform: translate(-50%, -50%); animation-delay: -14s; }

@keyframes float {
  0%, 100% { transform: translate(0, 0) scale(1); }
  25% { transform: translate(30px, -30px) scale(1.05); }
  50% { transform: translate(-20px, 20px) scale(0.95); }
  75% { transform: translate(-30px, -20px) scale(1.02); }
}

/* =====================================================
   Container
   ===================================================== */
.container {
  position: relative; z-index: 1; max-width: 720px;
  margin: 0 auto; padding: var(--spacing-xl); min-height: 100vh;
  display: flex; flex-direction: column;
}

/* =====================================================
   Header
   ===================================================== */
.header { text-align: center; margin-bottom: var(--spacing-xl); padding-top: var(--spacing-xl); }
.logo { display: inline-flex; align-items: center; gap: var(--spacing-sm); margin-bottom: var(--spacing-md); }
.logo-icon { font-size: 2.5rem; animation: bounce 2s infinite; }
@keyframes bounce { 0%, 100% { transform: translateY(0); } 50% { transform: translateY(-5px); } }
.logo-text { font-size: 2rem; font-weight: 800; letter-spacing: -0.02em; }
.accent { background: var(--accent-gradient); -webkit-background-clip: text; -webkit-text-fill-color: transparent; background-clip: text; }
.tagline { color: var(--text-secondary); font-size: 1rem; margin-bottom: var(--spacing-md); }

.header-nav { display: flex; justify-content: center; gap: var(--spacing-md); }
.nav-link {
  color: var(--text-secondary); text-decoration: none; font-weight: 500;
  padding: var(--spacing-xs) var(--spacing-md);
  border-radius: var(--radius-sm); transition: all var(--transition-fast);
}
.nav-link:hover { color: var(--text-primary); background: rgba(255,255,255,0.05); }
.nav-link.active { color: var(--accent-primary); background: rgba(102, 126, 234, 0.1); }

/* =====================================================
   Main Card
   ===================================================== */
.main-card {
  background: var(--bg-card); backdrop-filter: blur(20px); -webkit-backdrop-filter: blur(20px);
  border: 1px solid var(--border-color); border-radius: var(--radius-lg);
  padding: var(--spacing-xl); box-shadow: var(--shadow-lg);
}

/* =====================================================
   Tabs
   ===================================================== */
.tabs { display: grid; grid-template-columns: 1fr 1fr; gap: var(--spacing-sm); margin-bottom: var(--spacing-lg); }
.tab {
  display: flex; align-items: center; justify-content: center; gap: var(--spacing-sm);
  padding: var(--spacing-md) var(--spacing-lg); background: var(--bg-secondary);
  border: 1px solid var(--border-color); border-radius: var(--radius-md);
  color: var(--text-secondary); font-size: 0.95rem; font-weight: 500;
  cursor: pointer; transition: all var(--transition-normal);
}
.tab:hover { background: var(--bg-card-hover); color: var(--text-primary); border-color: var(--border-light); }
.tab.active { background: var(--accent-gradient); border-color: transparent; color: white; box-shadow: var(--shadow-glow); }
.tab-icon { font-size: 1.2rem; }

/* =====================================================
   Option Info
   ===================================================== */
.option-info { margin-bottom: var(--spacing-lg); }
.info-text {
  background: rgba(102, 126, 234, 0.1); border: 1px solid rgba(102, 126, 234, 0.2);
  border-radius: var(--radius-sm); padding: var(--spacing-md);
  color: var(--text-secondary); font-size: 0.9rem;
}
.info-text strong { color: var(--accent-primary); }

/* =====================================================
   Forms
   ===================================================== */
.link-form { display: flex; flex-direction: column; gap: var(--spacing-lg); }
.form-group { display: flex; flex-direction: column; gap: var(--spacing-sm); }
.form-group label { font-size: 0.9rem; font-weight: 500; color: var(--text-secondary); }
.optional { font-weight: 400; color: var(--text-muted); font-size: 0.8rem; }

.form-row { display: grid; grid-template-columns: 1fr 1fr; gap: var(--spacing-md); }
.form-group-half { min-width: 0; }

.form-group input[type="url"],
.form-group input[type="text"],
.form-group input[type="datetime-local"],
.form-group textarea {
  background: var(--bg-secondary); border: 1px solid var(--border-color);
  border-radius: var(--radius-sm); padding: var(--spacing-md);
  color: var(--text-primary); font-size: 1rem; font-family: inherit;
  transition: all var(--transition-fast); resize: vertical;
}
.form-group input[type="datetime-local"] { color-scheme: dark; }
.form-group input:focus, .form-group textarea:focus {
  outline: none; border-color: var(--accent-primary);
  box-shadow: 0 0 0 3px rgba(102, 126, 234, 0.2);
}
.form-group input::placeholder, .form-group textarea::placeholder { color: var(--text-muted); }
.input-hint { font-size: 0.8rem; color: var(--text-muted); }

/* =====================================================
   Image Upload
   ===================================================== */
.image-upload {
  position: relative; border: 2px dashed var(--border-light);
  border-radius: var(--radius-md); padding: var(--spacing-xl);
  text-align: center; cursor: pointer; transition: all var(--transition-normal);
  overflow: hidden;
}
.image-upload:hover { border-color: var(--accent-primary); background: rgba(102, 126, 234, 0.05); }
.image-upload input[type="file"] {
  position: absolute; top: 0; left: 0; width: 100%; height: 100%;
  opacity: 0; cursor: pointer;
}
.upload-content { display: flex; flex-direction: column; align-items: center; gap: var(--spacing-sm); pointer-events: none; }
.upload-icon { font-size: 2.5rem; opacity: 0.7; }
.upload-text { font-weight: 500; color: var(--text-secondary); }
.upload-hint { font-size: 0.8rem; color: var(--text-muted); }
.image-preview { position: relative; }
.image-preview img { max-width: 100%; max-height: 200px; border-radius: var(--radius-sm); object-fit: cover; }
.remove-image {
  position: absolute; top: -10px; right: -10px; width: 28px; height: 28px;
  background: var(--error); border: none; border-radius: 50%;
  color: white; font-size: 0.9rem; cursor: pointer;
  display: flex; align-items: center; justify-content: center;
  transition: transform var(--transition-fast);
}
.remove-image:hover { transform: scale(1.1); }

/* =====================================================
   Submit Button
   ===================================================== */
.submit-btn {
  display: flex; align-items: center; justify-content: center; gap: var(--spacing-sm);
  padding: var(--spacing-md) var(--spacing-xl);
  background: var(--accent-gradient); border: none; border-radius: var(--radius-md);
  color: white; font-size: 1rem; font-weight: 600;
  cursor: pointer; transition: all var(--transition-normal); box-shadow: var(--shadow-md);
  position: relative;
}
.submit-btn:hover:not(:disabled) { transform: translateY(-2px); box-shadow: var(--shadow-glow); }
.submit-btn:active:not(:disabled) { transform: translateY(0); }
.submit-btn:disabled { opacity: 0.7; cursor: not-allowed; }
.btn-icon { font-size: 1.2rem; transition: transform var(--transition-fast); }
.submit-btn:hover:not(:disabled) .btn-icon { transform: translateX(4px); }

.btn-loader {
  width: 20px; height: 20px;
  border: 2px solid rgba(255,255,255,0.3); border-top-color: white;
  border-radius: 50%; animation: spin 0.6s linear infinite;
}

/* =====================================================
   Result Section
   ===================================================== */
.result {
  margin-top: var(--spacing-xl); padding: var(--spacing-lg);
  background: rgba(16, 185, 129, 0.1); border: 1px solid rgba(16, 185, 129, 0.2);
  border-radius: var(--radius-md); animation: slideIn 0.3s ease;
}
@keyframes slideIn { from { opacity: 0; transform: translateY(10px); } to { opacity: 1; transform: translateY(0); } }
.result-header { display: flex; align-items: center; gap: var(--spacing-sm); margin-bottom: var(--spacing-md); }
.result-icon { font-size: 1.5rem; }
.result-title { font-size: 1.1rem; font-weight: 600; color: var(--success); }
.result-link-container { display: flex; gap: var(--spacing-sm); margin-bottom: var(--spacing-md); }
.result-link {
  flex: 1; background: var(--bg-secondary); border: 1px solid var(--border-light);
  border-radius: var(--radius-sm); padding: var(--spacing-md);
  color: var(--text-primary); font-size: 0.95rem; font-family: 'Courier New', monospace;
}
.copy-btn {
  display: flex; align-items: center; gap: var(--spacing-xs);
  padding: var(--spacing-md) var(--spacing-lg);
  background: var(--accent-gradient); border: none; border-radius: var(--radius-sm);
  color: white; font-weight: 500; cursor: pointer;
  transition: all var(--transition-fast);
}
.copy-btn:hover { transform: scale(1.02); }
.copy-btn.copied { background: var(--success); }
.result-info { font-size: 0.85rem; color: var(--text-secondary); }
.url-count {
  margin-top: var(--spacing-md); padding: var(--spacing-sm) var(--spacing-md);
  background: rgba(102, 126, 234, 0.1); border-radius: var(--radius-sm);
  font-size: 0.9rem; color: var(--accent-primary);
}
.result-expiry {
  margin-top: var(--spacing-sm); padding: var(--spacing-sm) var(--spacing-md);
  background: rgba(245, 158, 11, 0.1); border-radius: var(--radius-sm);
  font-size: 0.9rem; color: var(--warning);
}

/* QR Code */
.qr-section {
  margin-top: var(--spacing-lg); text-align: center;
  padding-top: var(--spacing-lg); border-top: 1px solid var(--border-color);
}
.qr-label { font-size: 0.85rem; color: var(--text-secondary); margin-bottom: var(--spacing-sm); }
.qr-image { width: 180px; height: 180px; border-radius: var(--radius-sm); background: white; padding: 8px; }
.download-qr-btn {
  display: inline-block; margin-top: var(--spacing-sm);
  padding: var(--spacing-xs) var(--spacing-md);
  background: var(--bg-secondary); border: 1px solid var(--border-light);
  border-radius: var(--radius-sm); color: var(--text-secondary);
  font-size: 0.85rem; cursor: pointer; transition: all var(--transition-fast);
}
.download-qr-btn:hover { color: var(--text-primary); border-color: var(--accent-primary); }

/* =====================================================
   Loading & Error
   ===================================================== */
.loading {
  display: flex; flex-direction: column; align-items: center;
  gap: var(--spacing-md); padding: var(--spacing-xl); margin-top: var(--spacing-lg);
}
.spinner {
  width: 40px; height: 40px; border: 3px solid var(--border-light);
  border-top-color: var(--accent-primary); border-radius: 50%;
  animation: spin 1s linear infinite;
}
@keyframes spin { to { transform: rotate(360deg); } }
.loading p { color: var(--text-secondary); }
.error {
  display: flex; align-items: center; gap: var(--spacing-sm);
  margin-top: var(--spacing-lg); padding: var(--spacing-md);
  background: rgba(239, 68, 68, 0.1); border: 1px solid rgba(239, 68, 68, 0.2);
  border-radius: var(--radius-sm); color: var(--error);
  animation: shake 0.4s ease;
}
@keyframes shake { 0%, 100% { transform: translateX(0); } 25% { transform: translateX(-5px); } 75% { transform: translateX(5px); } }

/* =====================================================
   Link History
   ===================================================== */
.history-section {
  margin-top: var(--spacing-2xl); padding: var(--spacing-lg);
  background: var(--bg-card); backdrop-filter: blur(20px);
  border: 1px solid var(--border-color); border-radius: var(--radius-lg);
}
.section-title {
  font-size: 1.1rem; font-weight: 600; margin-bottom: var(--spacing-lg);
  color: var(--text-primary);
}
.history-list { display: flex; flex-direction: column; gap: var(--spacing-sm); }
.history-item {
  display: flex; justify-content: space-between; align-items: center;
  padding: var(--spacing-md); background: var(--bg-secondary);
  border: 1px solid var(--border-color); border-radius: var(--radius-sm);
  transition: all var(--transition-fast);
}
.history-item:hover { border-color: var(--border-light); }
.history-info { display: flex; flex-direction: column; gap: 2px; min-width: 0; flex: 1; }
.history-url {
  color: var(--accent-primary); text-decoration: none; font-size: 0.9rem;
  font-family: 'Courier New', monospace; white-space: nowrap;
  overflow: hidden; text-overflow: ellipsis;
}
.history-url:hover { text-decoration: underline; }
.history-title { font-size: 0.8rem; color: var(--text-muted); }
.history-date { font-size: 0.75rem; color: var(--text-muted); }
.history-copy-btn {
  padding: var(--spacing-xs) var(--spacing-md);
  background: var(--bg-card); border: 1px solid var(--border-light);
  border-radius: var(--radius-sm); color: var(--text-secondary);
  font-size: 0.8rem; cursor: pointer; white-space: nowrap;
  transition: all var(--transition-fast);
}
.history-copy-btn:hover { color: var(--accent-primary); border-color: var(--accent-primary); }
.clear-history-btn {
  margin-top: var(--spacing-md); padding: var(--spacing-xs) var(--spacing-md);
  background: none; border: 1px solid rgba(239, 68, 68, 0.3);
  border-radius: var(--radius-sm); color: var(--error);
  font-size: 0.8rem; cursor: pointer; transition: all var(--transition-fast);
}
.clear-history-btn:hover { background: rgba(239, 68, 68, 0.1); }

/* =====================================================
   Features
   ===================================================== */
.features {
  display: grid; grid-template-columns: repeat(3, 1fr);
  gap: var(--spacing-lg); margin-top: var(--spacing-2xl);
}
.feature { text-align: center; padding: var(--spacing-lg); }
.feature-icon { font-size: 2rem; margin-bottom: var(--spacing-sm); display: block; }
.feature h3 { font-size: 1rem; font-weight: 600; margin-bottom: var(--spacing-xs); }
.feature p { font-size: 0.85rem; color: var(--text-muted); }

/* =====================================================
   Footer
   ===================================================== */
.footer { margin-top: auto; padding-top: var(--spacing-2xl); text-align: center; }
.footer p { color: var(--text-muted); font-size: 0.85rem; }

/* =====================================================
   Utilities
   ===================================================== */
.hidden { display: none !important; }

/* =====================================================
   Responsive
   ===================================================== */
@media (max-width: 768px) {
  .container { padding: var(--spacing-md); }
  .main-card { padding: var(--spacing-lg); }
  .logo-text { font-size: 1.5rem; }
  .logo-icon { font-size: 2rem; }
  .tabs { grid-template-columns: 1fr; }
  .form-row { grid-template-columns: 1fr; }
  .features { grid-template-columns: 1fr 1fr; gap: var(--spacing-md); }
  .result-link-container { flex-direction: column; }
  .copy-btn { justify-content: center; }
}

@media (max-width: 480px) {
  .tab { padding: var(--spacing-sm) var(--spacing-md); font-size: 0.85rem; }
  .tab-text { display: none; }
  .tab-icon { font-size: 1.5rem; }
  .features { grid-template-columns: 1fr; }
}

@media (prefers-reduced-motion: reduce) {
  *, *::before, *::after { animation-duration: 0.01ms !important; transition-duration: 0.01ms !important; }
}