:root {
  --primary-color: #4a90e2;
  --primary-color-dark: #357abd;
  --background-gradient-start: #f4f6f9;
  --background-gradient-end: #e9edf2;
  --card-background: #ffffff;
  --text-color: #333;
  --text-color-light: #666;
  --border-color: #e0e6ed;
  --success-color: #52c41a;
  --error-color: #ff4d4f;
  --font-family: 'Noto Sans SC', -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, Helvetica, Arial, sans-serif;
  --card-shadow: 0 8px 32px rgba(0, 30, 80, 0.08);
  --card-shadow-hover: 0 12px 40px rgba(0, 30, 80, 0.12);
  --border-radius: 16px;
  --transition-speed: 0.3s;
}

body {
  font-family: var(--font-family);
  background-image: linear-gradient(to top, var(--background-gradient-start), var(--background-gradient-end));
  color: var(--text-color);
  margin: 0;
  display: flex;
  justify-content: center;
  align-items: flex-start;
  min-height: 100vh;
  padding: 40px 20px;
  box-sizing: border-box;
}

.container {
  width: 100%;
  max-width: 560px;
  text-align: center;
}

.app-header {
  margin-bottom: 40px;
}

.app-header h1 {
  font-size: 2.8rem;
  font-weight: 700;
  margin: 0;
  color: #1a2a4d;
}

.app-header p {
  font-size: 1.1rem;
  color: var(--text-color-light);
  margin-top: 8px;
}

.main-content {
  display: flex;
  flex-direction: column;
  gap: 30px;
}

.panel {
  background: var(--card-background);
  padding: 30px;
  border-radius: var(--border-radius);
  box-shadow: var(--card-shadow);
  transition: box-shadow var(--transition-speed) ease;
  display: flex;
  flex-direction: column;
  text-align: left;
}

.panel:hover {
  box-shadow: var(--card-shadow-hover);
}

.panel h3 {
  font-size: 1.6rem;
  margin: 0 0 25px;
  text-align: center;
  color: #1a2a4d;
}

/* Upload Area */
#upload-area-wrapper {
  width: 100%;
}

.upload-area {
  border: 2px dashed var(--border-color);
  border-radius: var(--border-radius);
  padding: 50px 30px;
  text-align: center;
  cursor: pointer;
  transition: all var(--transition-speed) ease;
  background-color: #fcfdff;
}

.upload-area.dragover {
  border-color: var(--primary-color);
  background-color: #f0f8ff;
  transform: translateY(-5px);
}

.upload-icon svg {
  color: var(--primary-color);
  margin-bottom: 20px;
  transition: transform var(--transition-speed) ease;
}

.upload-area.dragover .upload-icon svg {
  transform: scale(1.1) rotate(-5deg);
}

.upload-area p {
  margin: 0;
  font-size: 1.1rem;
  color: var(--text-color);
}

.upload-area p strong {
  color: var(--primary-color);
}

.upload-area .upload-hint {
  font-size: 0.9rem;
  color: var(--text-color-light);
  margin-top: 10px;
}

/* Progress View */
#progress-view {
  display: flex;
  flex-direction: column;
  gap: 15px;
  width: 100%;
}

.progress-bar {
  width: 100%;
}

.progress-bar-info {
  display: flex;
  justify-content: space-between;
  font-size: 0.9rem;
  margin-bottom: 8px;
  color: var(--text-color-light);
}

.file-name {
  white-space: nowrap;
  overflow: hidden;
  text-overflow: ellipsis;
  max-width: 80%;
}

.percent {
  color: var(--primary-color);
  font-weight: 700;
}

.progress-bar-track {
  height: 10px;
  background-color: #e9ecef;
  border-radius: 5px;
  overflow: hidden;
}

.progress-bar-fill {
  width: 0;
  height: 100%;
  background-color: var(--primary-color);
  transition: width 0.4s ease;
  border-radius: 5px;
}

/* Result View */
#result-view h2 {
  font-size: 1.5rem;
  margin: 0 0 20px;
  text-align: center;
}

.pickup-code-wrapper {
  display: flex;
  gap: 10px;
  margin-bottom: 20px;
}

.button-group {
  display: flex;
  gap: 10px;
}

#pickup-code-input-display {
  font-family: var(--font-family);
  font-size: 1.2rem;
  font-weight: 700;
  letter-spacing: 3px;
  color: var(--primary-color);
  background-color: #f8f9fa;
  border: 1px solid var(--border-color);
  border-radius: 8px;
  padding: 12px;
  text-align: center;
  flex-grow: 1;
  box-sizing: border-box;
}

#qrcode-container {
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 15px;
  margin-top: 15px;
}

#qrcode {
  width: 140px;
  height: 140px;
  padding: 10px;
  border: 1px solid var(--border-color);
  border-radius: 8px;
  background-color: white;
}

#save-qr-btn {
  color: var(--primary-color);
  text-decoration: none;
  font-weight: 500;
  font-size: 0.9rem;
}

/* Download View */
.download-form {
  display: flex;
  gap: 10px;
}

#pickup-code-input {
  flex-grow: 1;
  padding: 12px 15px;
  font-size: 1rem;
  border: 1px solid var(--border-color);
  border-radius: 8px;
  text-align: center;
  letter-spacing: 2px;
  transition: all var(--transition-speed) ease;
}

#pickup-code-input:focus {
  outline: none;
  border-color: var(--primary-color);
  box-shadow: 0 0 0 3px rgba(74, 144, 226, 0.2);
}

#download-result {
  margin-top: 25px;
  text-align: center;
}

.download-info {
  padding: 25px;
  background-color: #f8f9fa;
  border-radius: 8px;
  border: 1px solid var(--border-color);
}

.download-info p {
  margin: 0 0 15px;
  font-size: 1.1rem;
}

.download-info .file-name {
  font-weight: 700;
  color: var(--primary-color);
}

.error-message {
  color: var(--error-color);
  font-weight: 500;
}

/* General Buttons */
.button-primary,
.button-secondary {
  background-color: var(--primary-color);
  color: white;
  border: none;
  padding: 12px 25px;
  border-radius: 8px;
  font-size: 1rem;
  font-weight: 500;
  cursor: pointer;
  transition: all var(--transition-speed) ease;
  box-shadow: 0 4px 12px rgba(74, 144, 226, 0.2);
}

.button-secondary {
  background-color: #869ab8;
  box-shadow: 0 4px 12px rgba(134, 154, 184, 0.2);
}

.button-primary:hover {
  background-color: var(--primary-color-dark);
  transform: translateY(-2px);
  box-shadow: 0 6px 16px rgba(74, 144, 226, 0.3);
}

.button-secondary:hover {
  background-color: #6c7a92;
  transform: translateY(-2px);
  box-shadow: 0 6px 16px rgba(134, 154, 184, 0.3);
}

/* Modal Styles */
.modal {
  position: fixed;
  z-index: 1000;
  left: 0;
  top: 0;
  width: 100%;
  height: 100%;
  overflow: auto;
  background-color: rgba(30, 40, 60, 0.8);
  display: flex;
  align-items: center;
  justify-content: center;
  backdrop-filter: blur(5px);
}

.modal-content {
  position: relative;
  background-color: #fff;
  padding: 20px;
  border-radius: var(--border-radius);
  max-width: 90%;
  max-height: 90%;
  box-shadow: 0 10px 40px rgba(0, 0, 0, 0.2);
}

.close-modal-btn {
  position: absolute;
  top: 15px;
  right: 20px;
  color: #aaa;
  font-size: 32px;
  font-weight: bold;
  cursor: pointer;
  transition: color var(--transition-speed) ease;
}

.close-modal-btn:hover {
  color: #333;
}

#modal-media-container {
  max-height: 80vh;
  max-width: 80vw;
}

#modal-media-container img,
#modal-media-container video {
  max-width: 100%;
  max-height: 80vh;
  display: block;
  margin: auto;
  border-radius: 8px;
}

footer {
  margin-top: 50px;
  color: #99aabc;
  font-size: 0.9rem;
}

.hidden {
  display: none !important;
}

/* Download Page Specific */
.download-page-body .container {
  max-width: 560px;
}

.download-page-body .main-content-single {
  background: var(--card-background);
  padding: 30px;
  border-radius: var(--border-radius);
  box-shadow: var(--card-shadow);
}

@media (max-width: 600px) {
  body {
    padding: 20px 15px;
  }

  .app-header h1 {
    font-size: 2.2rem;
  }

  .app-header p {
    font-size: 1rem;
  }

  .panel {
    padding: 25px 20px;
  }

  .download-page-body .main-content-single {
    padding: 25px 20px;
  }

  .panel h3 {
    font-size: 1.4rem;
  }

  .upload-area {
    padding: 30px 20px;
  }

  .upload-area p {
    font-size: 1rem;
  }

  .pickup-code-wrapper {
    flex-direction: column;
    align-items: stretch;
  }

  .download-form {
    flex-direction: column;
    gap: 15px;
  }

  .download-form {
    flex-direction: column;
    gap: 15px;
  }

  #pickup-code-input-display {
    font-size: 1.1rem;
    padding: 10px;
  }

  .button-group {
    width: 100%;
  }

  .button-group>.button-primary,
  .button-group>.button-secondary {
    flex-grow: 1;
  }

  .button-primary,
  .button-secondary {
    width: 100%;
    padding: 12px;
    font-size: 1rem;
  }

  .modal-content {
    width: 95%;
    padding: 15px;
  }
}

/* Result Tabs */
.result-tabs {
  display: flex;
  justify-content: center;
  margin-top: 20px;
  border-top: 1px solid var(--border-color);
  padding-top: 15px;
}

.tab-link {
  padding: 8px 16px;
  cursor: pointer;
  border: none;
  background: none;
  font-size: 1rem;
  color: var(--text-color-light);
  position: relative;
  transition: color var(--transition-speed) ease;
}

.tab-link.active {
  color: var(--primary-color);
  font-weight: 700;
}

.tab-link:not(.active):hover {
  color: var(--text-color);
}

.tab-link.active::after {
  content: '';
  position: absolute;
  bottom: -2px;
  left: 50%;
  transform: translateX(-50%);
  width: 50%;
  height: 2px;
  background-color: var(--primary-color);
}

.result-tab-content {
  display: none;
}

.result-tab-content.active {
  display: block;
  animation: fadeIn var(--transition-speed) ease;
}

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

  to {
    opacity: 1;
    transform: translateY(0);
  }
}