:root {
    --primary: #3b82f6;
    --primary-hover: #2563eb;
    --success: #22c55e;
    --bg-glass: rgba(255, 255, 255, 0.75);
    --border-glass: rgba(255, 255, 255, 0.25);
    --shadow: 0 8px 25px rgba(0, 0, 0, 0.1);
    --text-main: #1e293b;
    --text-sub: #64748b;
    --radius: 14px;
    --transition: all 0.3s ease;
}

@media (prefers-color-scheme: dark) {
  :root {
    --bg-glass: rgba(30, 41, 59, 0.55);
    --border-glass: rgba(255, 255, 255, 0.08);
    --text-main: #f1f5f9;
    --text-sub: #94a3b8;
    --shadow: 0 8px 25px rgba(0,0,0,0.3);
  }
}

* {
  margin: 0;
  padding: 0;
  box-sizing: border-box;
  font-family: "Inter", "Segoe UI", "PingFang SC", sans-serif;
}

body {
  background: linear-gradient(135deg, #e0e7ff 0%, #f0f9ff 100%);
  min-height: 100vh;
  display: flex;
  align-items: flex-start;
  justify-content: center;
  padding: 40px 20px;
  transition: var(--transition);
}

@media (prefers-color-scheme: dark) {
  body {
    background: linear-gradient(135deg, #1e293b 0%, #0f172a 100%);
  }
}

.container {
  max-width: 1100px;
  width: 100%;
  backdrop-filter: blur(12px);
  background: var(--bg-glass);
  border: 1px solid var(--border-glass);
  box-shadow: var(--shadow);
  border-radius: var(--radius);
  padding: 40px;
}

header {
  text-align: center;
  margin-bottom: 40px;
}

h1 {
  font-size: 2.2rem;
  background: linear-gradient(135deg, #3b82f6, #22d3ee);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  margin-bottom: 8px;
}

.subtitle {
  font-size: 1.1rem;
  color: var(--text-sub);
}

/* Upload Area */
.upload-area {
  border: 2px dashed var(--primary);
  border-radius: var(--radius);
  text-align: center;
  padding: 50px 20px;
  cursor: pointer;
  transition: var(--transition);
  background: rgba(255, 255, 255, 0.4);
}
.upload-area:hover {
  background: rgba(59,130,246,0.05);
}
.upload-icon {
  font-size: 64px;
  color: var(--primary);
}
.upload-text {
  font-size: 1.1rem;
  margin-top: 10px;
  font-weight: 500;
}

/* Buttons */
.btn {
  background: var(--primary);
  color: white;
  border: none;
  padding: 14px 30px;
  border-radius: var(--radius);
  cursor: pointer;
  font-weight: 600;
  font-size: 1rem;
  transition: var(--transition);
  box-shadow: 0 4px 15px rgba(59,130,246,0.3);
  text-decoration: none;
  display: inline-block;
}
.btn:hover {
  background: var(--primary-hover);
}
.btn:disabled {
  background: #94a3b8;
  box-shadow: none;
  cursor: not-allowed;
}
.btn-compress {
  width: 100%;
  background: var(--success);
  box-shadow: 0 4px 15px rgba(34,197,94,0.3);
}
.btn-compress:hover {
  background: #16a34a;
}

/* Controls */
.controls {
  margin: 30px 0;
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
  gap: 24px;
}
.control-group {
  background: var(--bg-glass);
  border: 1px solid var(--border-glass);
  border-radius: var(--radius);
  padding: 20px;
  box-shadow: var(--shadow);
}
.control-title {
  font-size: 1rem;
  font-weight: 600;
  color: var(--text-main);
  margin-bottom: 15px;
}
label {
  font-size: 0.9rem;
  color: var(--text-sub);
  display: block;
  margin-bottom: 8px;
}
input[type="number"], input[type="text"], input[type="range"] {
  width: 100%;
  border-radius: 8px;
  border: 1px solid #cbd5e1;
  padding: 10px;
  transition: var(--transition);
  font-size: 1rem;
}
input[type="number"]:focus, input[type="text"]:focus {
  border-color: var(--primary);
  outline: none;
  box-shadow: 0 0 0 2px rgba(59,130,246,0.2);
}

.radio-group {
  margin-bottom: 15px;
}
.radio-group label {
  display: flex;
  align-items: center;
  margin-bottom: 8px;
  cursor: pointer;
}
.radio-group input[type="radio"] {
  width: auto;
  margin-right: 8px;
}

.input-group {
  margin-top: 15px;
}
.range-value {
  text-align: center;
  font-weight: 600;
  color: var(--primary);
  margin-top: 5px;
}

/* Preview */
.preview-container {
  display: flex;
  flex-wrap: wrap;
  gap: 20px;
  margin-top: 20px;
}
.preview-item {
  flex: 1;
  min-width: 280px;
  text-align: center;
}
.preview-img {
  display: block;
  max-width: 320px;
  max-height: 220px;
  width: auto;
  height: auto;
  margin: 0 auto;
  object-fit: contain;
  border-radius: var(--radius);
  box-shadow: var(--shadow);
  background: rgba(0,0,0,0.02);
  padding: 4px;
}

.preview-info {
  margin-top: 10px;
  color: var(--text-sub);
  font-size: 0.9rem;
}

/* Result Section */
.result {
  margin-top: 30px;
  background: var(--bg-glass);
  border: 1px solid var(--border-glass);
  border-radius: var(--radius);
  padding: 20px;
  box-shadow: var(--shadow);
  display: none;
}
.result-info {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(180px, 1fr));
  gap: 15px;
  margin-bottom: 20px;
}
.info-item {
  background: rgba(255, 255, 255, 0.5);
  border-radius: var(--radius);
  padding: 15px;
  text-align: center;
  border: 1px solid var(--border-glass);
  box-shadow: inset 0 0 10px rgba(255,255,255,0.2);
}
.info-label {
  color: var(--text-sub);
  font-size: 0.85rem;
}
.info-value {
  font-size: 1.1rem;
  font-weight: 600;
  color: var(--text-main);
}

/* Loading Spinner */
.loading {
  display: none;
  text-align: center;
  margin: 20px 0;
}
.spinner {
  width: 48px;
  height: 48px;
  border: 4px solid rgba(0,0,0,0.1);
  border-top-color: var(--primary);
  border-radius: 50%;
  animation: spin 1s linear infinite;
  margin: 0 auto 10px;
}
@keyframes spin {
  to { transform: rotate(360deg); }
}

@media (max-width: 600px) {
  .container { padding: 25px; }
  .upload-area { padding: 35px 15px; }
}