:root {
  --color-primary: #0071e3;
  --color-primary-hover: #0077ed;
  --color-success: #34c759;
  --color-warning: #ff9500;
  --color-danger: #ff3b30;
  --color-info: #5ac8fa;
  --color-bg: #fbfbfd;
  --color-white: #ffffff;
  --color-gray-1: #f5f5f7;
  --color-gray-2: #e8e8ed;
  --color-gray-3: #d1d1d6;
  --color-gray-4: #86868b;
  --color-gray-5: #515154;
  --color-gray-6: #1d1d1f;
  --border-color: rgba(0, 0, 0, 0.1);
  --border-radius-sm: 8px;
  --border-radius-md: 12px;
  --border-radius-lg: 16px;
  --border-radius-xl: 20px;
  --shadow-sm: 0 1px 3px rgba(0, 0, 0, 0.05);
  --shadow-md: 0 4px 12px rgba(0, 0, 0, 0.08);
  --shadow-lg: 0 10px 40px rgba(0, 0, 0, 0.15);
  --font-family:
    -apple-system, BlinkMacSystemFont, 'SF Pro Text', 'PingFang SC',
    'Helvetica Neue', sans-serif;
  --font-size-xs: 11px;
  --font-size-sm: 12px;
  --font-size-md: 14px;
  --font-size-lg: 16px;
  --font-size-xl: 18px;
  --font-size-2xl: 20px;
  --font-size-3xl: 24px;
  --spacing-xs: 4px;
  --spacing-sm: 8px;
  --spacing-md: 12px;
  --spacing-lg: 16px;
  --spacing-xl: 20px;
  --spacing-2xl: 24px;
  --spacing-3xl: 32px;
  --transition-fast: 0.15s ease;
  --transition-normal: 0.3s ease;
  --transition-slow: 0.5s ease;
}

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

html {
  font-size: 16px;
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
}

body {
  font-family: var(--font-family);
  font-size: var(--font-size-md);
  line-height: 1.5;
  color: var(--color-gray-6);
  background-color: var(--color-bg);
  min-height: 100vh;
}

a {
  color: var(--color-primary);
  text-decoration: none;
  transition: color var(--transition-fast);
}

a:hover {
  color: var(--color-primary-hover);
}

button {
  font-family: inherit;
  cursor: pointer;
  border: none;
  outline: none;
  transition: all var(--transition-fast);
}

button:disabled {
  cursor: not-allowed;
  opacity: 0.6;
}

input,
textarea,
select {
  font-family: inherit;
  font-size: inherit;
  outline: none;
  border: 1px solid var(--color-gray-3);
  border-radius: var(--border-radius-md);
  padding: var(--spacing-md) var(--spacing-lg);
  transition:
    border-color var(--transition-fast),
    box-shadow var(--transition-fast);
}

input:focus,
textarea:focus,
select:focus {
  border-color: var(--color-primary);
  box-shadow: 0 0 0 3px rgba(0, 113, 227, 0.1);
}

input::placeholder,
textarea::placeholder {
  color: var(--color-gray-4);
}

img {
  max-width: 100%;
  height: auto;
}

ul,
ol {
  list-style: none;
}

table {
  width: 100%;
  border-collapse: collapse;
}

::-webkit-scrollbar {
  width: 8px;
  height: 8px;
}

::-webkit-scrollbar-track {
  background: var(--color-gray-1);
  border-radius: 4px;
}

::-webkit-scrollbar-thumb {
  background: var(--color-gray-3);
  border-radius: 4px;
}

::-webkit-scrollbar-thumb:hover {
  background: var(--color-gray-4);
}

::selection {
  background-color: var(--color-primary);
  color: var(--color-white);
}

.loading {
  position: relative;
  pointer-events: none;
}

.loading::after {
  content: '';
  position: absolute;
  top: 50%;
  left: 50%;
  width: 20px;
  height: 20px;
  margin: -10px 0 0 -10px;
  border: 2px solid var(--color-gray-3);
  border-top-color: var(--color-primary);
  border-radius: 50%;
  animation: spin 0.8s linear infinite;
}

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

.error-message {
  color: var(--color-danger);
  background-color: rgba(255, 59, 48, 0.1);
  padding: var(--spacing-md) var(--spacing-lg);
  border-radius: var(--border-radius-md);
  font-size: var(--font-size-sm);
}

.success-message {
  color: var(--color-success);
  background-color: rgba(52, 199, 89, 0.1);
  padding: var(--spacing-md) var(--spacing-lg);
  border-radius: var(--border-radius-md);
  font-size: var(--font-size-sm);
}

.text-center {
  text-align: center;
}

.text-left {
  text-align: left;
}

.text-right {
  text-align: right;
}

.hidden {
  display: none !important;
}

.invisible {
  visibility: hidden;
}

.sr-only {
  position: absolute;
  width: 1px;
  height: 1px;
  padding: 0;
  margin: -1px;
  overflow: hidden;
  clip: rect(0, 0, 0, 0);
  white-space: nowrap;
  border: 0;
}

.feedback-float-btn {
  position: fixed;
  bottom: 30px;
  right: 30px;
  width: 56px;
  height: 56px;
  border-radius: 50%;
  background: linear-gradient(135deg, #0071e3 0%, #0077ed 100%);
  color: white;
  border: none;
  cursor: pointer;
  box-shadow: 0 4px 12px rgba(0, 113, 227, 0.4);
  transition: all 0.3s ease;
  z-index: 9999;
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 24px;
}

.feedback-float-btn:hover {
  transform: translateY(-4px) scale(1.05);
  box-shadow: 0 8px 24px rgba(0, 113, 227, 0.5);
}

.feedback-float-btn:active {
  transform: translateY(-2px) scale(1.02);
}

@media (max-width: 768px) {
  .feedback-float-btn {
    width: 48px;
    height: 48px;
    bottom: 20px;
    right: 20px;
    font-size: 20px;
  }
}