/*!
 * 无障碍吐槽平台 - 基础样式
 * 遵循 WCAG 2.1 AA 无障碍标准
 */

/* ==================== 变量定义 ==================== */
:root {
  /* 主色调 */
  --color-primary: #4A90D9;
  --color-primary-dark: #2D5A87;
  --color-primary-light: #E8F4FD;

  /* 功能色 */
  --color-success: #52C41A;
  --color-warning: #FAAD14;
  --color-error: #FF4D4F;
  --color-info: #1890ff;

  /* 中性色 */
  --color-text-primary: #333333;
  --color-text-secondary: #666666;
  --color-text-tertiary: #999999;
  --color-border: #E8E8E8;
  --color-bg: #F8F9FA;
  --color-white: #FFFFFF;

  /* 状态色 */
  --color-pending: #FAAD14;
  --color-processing: #4A90D9;
  --color-resolved: #52C41A;
  --color-verified: #52C41A;

  /* 字体 */
  --font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, 'Helvetica Neue', Arial, sans-serif;
  --font-size-xs: 12px;
  --font-size-sm: 14px;
  --font-size-base: 16px;
  --font-size-lg: 18px;
  --font-size-xl: 20px;
  --font-size-2xl: 24px;

  /* 间距 */
  --spacing-xs: 4px;
  --spacing-sm: 8px;
  --spacing-md: 16px;
  --spacing-lg: 24px;
  --spacing-xl: 32px;
  --spacing-2xl: 48px;

  /* 圆角 */
  --radius-sm: 4px;
  --radius-md: 8px;
  --radius-lg: 12px;
  --radius-full: 50%;

  /* 阴影 */
  --shadow-sm: 0 2px 8px rgba(0, 0, 0, 0.08);
  --shadow-md: 0 4px 16px rgba(0, 0, 0, 0.12);
  --shadow-lg: 0 8px 24px rgba(0, 0, 0, 0.16);

  /* 过渡 */
  --transition-fast: 150ms ease-out;
  --transition-normal: 300ms ease-out;

  /* 容器宽度 */
  --container-max: 1200px;
  --container-padding: 16px;
}

/* ==================== 基础重置 ==================== */
*,
*::before,
*::after {
  box-sizing: border-box;
  margin: 0;
  padding: 0;
}

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

body {
  font-family: var(--font-family);
  font-size: var(--font-size-base);
  line-height: 1.6;
  color: var(--color-text-primary);
  background-color: var(--color-bg);
  min-height: 100vh;
}

/* ==================== 无障碍相关 ==================== */
/* 屏幕阅读器专用 - 可见但不可见 */
.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;
}

/* 跳过链接 */
.skip-link {
  position: absolute;
  top: -100%;
  left: 50%;
  transform: translateX(-50%);
  background: var(--color-primary);
  color: var(--color-white);
  padding: var(--spacing-sm) var(--spacing-md);
  border-radius: var(--radius-md);
  z-index: 10000;
  text-decoration: none;
}

.skip-link:focus {
  top: var(--spacing-md);
}

/* 焦点样式 */
*:focus {
  outline: 2px solid var(--color-primary);
  outline-offset: 2px;
}

*:focus:not(:focus-visible) {
  outline: none;
}

*:focus-visible {
  outline: 2px solid var(--color-primary);
  outline-offset: 2px;
}

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

a:hover {
  color: var(--color-primary-dark);
  text-decoration: underline;
}

a:focus {
  outline: 2px solid var(--color-primary);
  outline-offset: 2px;
}

.link {
  color: var(--color-primary);
  text-decoration: underline;
}

/* ==================== 容器 ==================== */
.container {
  width: 100%;
  max-width: var(--container-max);
  margin: 0 auto;
  padding: 0 var(--container-padding);
}

/* ==================== 头部 ==================== */
.header {
  background: var(--color-white);
  box-shadow: var(--shadow-sm);
  position: sticky;
  top: 0;
  z-index: 100;
}

.nav {
  display: flex;
  align-items: center;
  justify-content: space-between;
  height: 64px;
}

.nav-brand {
  display: flex;
  align-items: center;
}

.logo,
.logo-link {
  font-size: var(--font-size-lg);
  font-weight: 700;
  color: var(--color-primary);
  text-decoration: none;
}

.nav-menu {
  display: flex;
  list-style: none;
  gap: var(--spacing-lg);
}

.nav-link {
  display: block;
  padding: var(--spacing-sm) var(--spacing-md);
  color: var(--color-text-secondary);
  font-weight: 500;
  border-radius: var(--radius-md);
  transition: all var(--transition-fast);
}

.nav-link:hover {
  color: var(--color-primary);
  text-decoration: none;
  background: var(--color-primary-light);
}

.nav-link.active {
  color: var(--color-primary);
  background: var(--color-primary-light);
}

.nav-toggle {
  display: none;
  background: none;
  border: none;
  cursor: pointer;
  padding: var(--spacing-sm);
}

/* ==================== 主内容区 ==================== */
.main {
  min-height: calc(100vh - 64px - 200px);
  padding: var(--spacing-xl) 0;
}

/* ==================== 页面头部 ==================== */
.page-header {
  text-align: center;
  margin-bottom: var(--spacing-xl);
}

.page-title {
  font-size: var(--font-size-2xl);
  font-weight: 700;
  color: var(--color-text-primary);
  margin-bottom: var(--spacing-sm);
}

.page-desc {
  font-size: var(--font-size-base);
  color: var(--color-text-secondary);
}

/* ==================== 按钮 ==================== */
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: var(--spacing-sm);
  padding: var(--spacing-sm) var(--spacing-lg);
  font-size: var(--font-size-base);
  font-weight: 500;
  line-height: 1.5;
  border: 2px solid transparent;
  border-radius: var(--radius-md);
  cursor: pointer;
  transition: all var(--transition-fast);
  text-decoration: none;
  min-height: 44px;
  min-width: 44px;
}

.btn:hover {
  text-decoration: none;
}

.btn:disabled {
  opacity: 0.5;
  cursor: not-allowed;
}

.btn-primary {
  background: var(--color-primary);
  color: var(--color-white);
  border-color: var(--color-primary);
}

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

.btn-secondary {
  background: var(--color-white);
  color: var(--color-primary);
  border-color: var(--color-primary);
}

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

.btn-outline {
  background: transparent;
  color: var(--color-primary);
  border-color: var(--color-primary);
}

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

.btn-text {
  background: transparent;
  color: var(--color-primary);
  border: none;
}

.btn-text:hover:not(:disabled) {
  text-decoration: underline;
}

.btn-large {
  padding: var(--spacing-md) var(--spacing-xl);
  font-size: var(--font-size-lg);
  min-height: 52px;
}

.btn-success {
  background: var(--color-success);
  color: var(--color-white);
  border-color: var(--color-success);
}

.btn-success:hover:not(:disabled) {
  background: #3da815;
}

.btn-danger {
  background: var(--color-error);
  color: var(--color-white);
  border-color: var(--color-error);
}

.btn-danger:hover:not(:disabled) {
  background: #e64444;
}

.btn-icon {
  font-size: 1.2em;
}

.btn[aria-disabled="true"] {
  pointer-events: none;
}

/* ==================== 表单元素 ==================== */
.form-group {
  margin-bottom: var(--spacing-lg);
}

.form-label {
  display: block;
  margin-bottom: var(--spacing-sm);
  font-weight: 500;
  color: var(--color-text-primary);
}

.form-label .required {
  color: var(--color-error);
}

.form-input,
.form-select,
.form-textarea {
  width: 100%;
  padding: var(--spacing-sm) var(--spacing-md);
  font-size: var(--font-size-base);
  font-family: inherit;
  line-height: 1.5;
  color: var(--color-text-primary);
  background: var(--color-white);
  border: 1.5px solid var(--color-border);
  border-radius: var(--radius-md);
  transition: border-color var(--transition-fast), box-shadow var(--transition-fast);
  min-height: 44px;
}

.form-input:focus,
.form-select:focus,
.form-textarea:focus {
  border-color: var(--color-primary);
  box-shadow: 0 0 0 3px rgba(74, 144, 217, 0.15);
  outline: none;
}

.form-input::placeholder,
.form-textarea::placeholder {
  color: var(--color-text-tertiary);
}

.form-input[aria-required="true"]::after {
  content: ' *';
  color: var(--color-error);
}

.form-textarea {
  resize: vertical;
  min-height: 100px;
}

.form-select {
  appearance: none;
  background-image: url("data:image/svg+xml,%3Csvg xmlns='http://www.w3.org/2000/svg' width='12' height='12' viewBox='0 0 12 12'%3E%3Cpath fill='%23666' d='M6 8L1 3h10z'/%3E%3C/svg%3E");
  background-repeat: no-repeat;
  background-position: right 12px center;
  padding-right: 36px;
}

.form-hint {
  margin-top: var(--spacing-xs);
  font-size: var(--font-size-sm);
  color: var(--color-text-tertiary);
}

.form-error {
  margin-top: var(--spacing-xs);
  font-size: var(--font-size-sm);
  color: var(--color-error);
}

.form-input.error,
.form-textarea.error {
  border-color: var(--color-error);
}

/* ==================== 卡片 ==================== */
.card {
  background: var(--color-white);
  border-radius: var(--radius-lg);
  padding: var(--spacing-lg);
  box-shadow: var(--shadow-sm);
}

/* ==================== 标签 ==================== */
.tag {
  display: inline-flex;
  align-items: center;
  padding: var(--spacing-xs) var(--spacing-sm);
  font-size: var(--font-size-xs);
  font-weight: 500;
  border-radius: var(--radius-sm);
  background: var(--color-primary-light);
  color: var(--color-primary);
}

.tag-pending {
  background: #FFF9E6;
  color: var(--color-warning);
}

.tag-processing {
  background: var(--color-primary-light);
  color: var(--color-primary);
}

.tag-resolved,
.tag-verified {
  background: #E8F8E8;
  color: var(--color-success);
}

/* ==================== 加载状态 ==================== */
.loading {
  position: fixed;
  top: 0;
  left: 0;
  right: 0;
  bottom: 0;
  background: rgba(0, 0, 0, 0.5);
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  z-index: 9999;
}

.loading-spinner {
  width: 40px;
  height: 40px;
  border: 3px solid var(--color-border);
  border-top-color: var(--color-primary);
  border-radius: 50%;
  animation: spin 1s linear infinite;
}

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

.loading-text {
  margin-top: var(--spacing-md);
  color: var(--color-white);
  font-size: var(--font-size-base);
}

.loading-state {
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  padding: var(--spacing-2xl);
  color: var(--color-text-tertiary);
}

.loading-state .loading-spinner {
  border-top-color: var(--color-primary);
}

.loading-state .loading-text {
  color: var(--color-text-tertiary);
  margin-top: var(--spacing-md);
}

/* ==================== 空状态 ==================== */
.empty-state {
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  padding: var(--spacing-2xl);
  text-align: center;
}

.empty-icon {
  font-size: 64px;
  margin-bottom: var(--spacing-lg);
  opacity: 0.5;
}

.empty-title {
  font-size: var(--font-size-xl);
  font-weight: 600;
  color: var(--color-text-primary);
  margin-bottom: var(--spacing-sm);
}

.empty-desc {
  color: var(--color-text-secondary);
  margin-bottom: var(--spacing-lg);
}

/* ==================== 错误状态 ==================== */
.error-state {
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  padding: var(--spacing-2xl);
  text-align: center;
}

.error-icon {
  font-size: 64px;
  margin-bottom: var(--spacing-lg);
}

.error-title {
  font-size: var(--font-size-xl);
  font-weight: 600;
  color: var(--color-error);
  margin-bottom: var(--spacing-sm);
}

.error-desc {
  color: var(--color-text-secondary);
  margin-bottom: var(--spacing-lg);
}

/* ==================== 弹窗 ==================== */
.modal {
  position: fixed;
  top: 0;
  left: 0;
  right: 0;
  bottom: 0;
  z-index: 1000;
  display: flex;
  align-items: center;
  justify-content: center;
  padding: var(--spacing-md);
}

.modal[hidden] {
  display: none;
}

.modal-overlay {
  position: absolute;
  top: 0;
  left: 0;
  right: 0;
  bottom: 0;
  background: rgba(0, 0, 0, 0.5);
}

.modal-content {
  position: relative;
  background: var(--color-white);
  border-radius: var(--radius-lg);
  padding: var(--spacing-xl);
  max-width: 400px;
  width: 100%;
  text-align: center;
  animation: modalIn var(--transition-normal);
}

@keyframes modalIn {
  from {
    opacity: 0;
    transform: scale(0.95);
  }
  to {
    opacity: 1;
    transform: scale(1);
  }
}

.modal-icon {
  font-size: 64px;
  margin-bottom: var(--spacing-lg);
}

.modal-title {
  font-size: var(--font-size-xl);
  font-weight: 600;
  margin-bottom: var(--spacing-sm);
}

.modal-desc {
  color: var(--color-text-secondary);
  margin-bottom: var(--spacing-md);
}

.modal-info {
  font-size: var(--font-size-sm);
  color: var(--color-text-tertiary);
  margin-bottom: var(--spacing-lg);
}

.modal-actions {
  display: flex;
  flex-direction: column;
  gap: var(--spacing-sm);
}

/* ==================== 页脚 ==================== */
.footer {
  background: var(--color-white);
  border-top: 1px solid var(--color-border);
  padding: var(--spacing-xl) 0;
  margin-top: var(--spacing-2xl);
}

.footer-content {
  display: grid;
  grid-template-columns: 2fr 1fr 1fr;
  gap: var(--spacing-xl);
  margin-bottom: var(--spacing-xl);
}

.footer-brand {
  max-width: 300px;
}

.footer-title {
  font-size: var(--font-size-lg);
  font-weight: 600;
  color: var(--color-primary);
  margin-bottom: var(--spacing-sm);
}

.footer-desc {
  font-size: var(--font-size-sm);
  color: var(--color-text-secondary);
}

.footer-heading {
  font-size: var(--font-size-base);
  font-weight: 600;
  margin-bottom: var(--spacing-md);
}

.footer-list {
  list-style: none;
}

.footer-list li {
  margin-bottom: var(--spacing-sm);
}

.footer-list a {
  color: var(--color-text-secondary);
  font-size: var(--font-size-sm);
}

.footer-bottom {
  padding-top: var(--spacing-lg);
  border-top: 1px solid var(--color-border);
  text-align: center;
}

.copyright {
  font-size: var(--font-size-sm);
  color: var(--color-text-tertiary);
}

/* ==================== 面包屑 ==================== */
.breadcrumb {
  margin-bottom: var(--spacing-lg);
}

.back-link {
  display: inline-flex;
  align-items: center;
  gap: var(--spacing-xs);
  color: var(--color-primary);
  font-weight: 500;
}

.back-link:hover {
  text-decoration: underline;
}

/* ==================== 响应式 ==================== */
@media (max-width: 768px) {
  :root {
    --container-padding: 12px;
  }

  .nav-menu {
    display: none;
    position: absolute;
    top: 64px;
    left: 0;
    right: 0;
    background: var(--color-white);
    flex-direction: column;
    padding: var(--spacing-md);
    box-shadow: var(--shadow-md);
  }

  .nav-menu.active {
    display: flex;
  }

  .nav-toggle {
    display: block;
  }

  .footer-content {
    grid-template-columns: 1fr;
    text-align: center;
  }

  .footer-brand {
    max-width: 100%;
  }
}

/* ==================== 打印样式 ==================== */
@media print {
  .header,
  .footer,
  .nav,
  .btn {
    display: none;
  }

  body {
    background: white;
    color: black;
  }
}