/* Bootstrap 5.3.0 核心样式 */
:root {
  --bs-blue: #0d6efd;
  --bs-indigo: #6610f2;
  --bs-purple: #6f42c1;
  --bs-pink: #d63384;
  --bs-red: #dc3545;
  --bs-orange: #fd7e14;
  --bs-yellow: #ffc107;
  --bs-green: #198754;
  --bs-teal: #20c997;
  --bs-cyan: #0dcaf0;
  --bs-white: #fff;
  --bs-gray: #6c757d;
  --bs-gray-dark: #343a40;
  --bs-primary: #0d6efd;
  --bs-secondary: #6c757d;
  --bs-success: #198754;
  --bs-info: #0dcaf0;
  --bs-warning: #ffc107;
  --bs-danger: #dc3545;
  --bs-light: #f8f9fa;
  --bs-dark: #212529;
  --bs-font-sans-serif: system-ui, -apple-system, "Segoe UI", Roboto, "Helvetica Neue", Arial, "Noto Sans", "Liberation Sans", sans-serif, "Apple Color Emoji", "Segoe UI Emoji", "Segoe UI Symbol", "Noto Color Emoji";
  --bs-font-monospace: SFMono-Regular, Menlo, Monaco, Consolas, "Liberation Mono", "Courier New", monospace;
  --bs-gradient: linear-gradient(180deg, rgba(255, 255, 255, 0.15), rgba(255, 255, 255, 0));
}

*,
*::before,
*::after {
  box-sizing: border-box;
}

@media (prefers-reduced-motion: no-preference) {
  :root {
    scroll-behavior: smooth;
  }
}

body {
  margin: 0;
  font-family: var(--bs-font-sans-serif);
  font-size: 1rem;
  font-weight: 400;
  line-height: 1.5;
  color: #212529;
  background-color: #fff;
  -webkit-text-size-adjust: 100%;
  -webkit-tap-highlight-color: rgba(0, 0, 0, 0);
}

/* 容器 */
.container,
.container-fluid {
  width: 100%;
  padding-right: 0.75rem;
  padding-left: 0.75rem;
  margin-right: auto;
  margin-left: auto;
}

@media (min-width: 576px) {
  .container {
    max-width: 540px;
  }
}

@media (min-width: 768px) {
  .container {
    max-width: 720px;
  }
}

@media (min-width: 992px) {
  .container {
    max-width: 960px;
  }
}

@media (min-width: 1200px) {
  .container {
    max-width: 1140px;
  }
}

@media (min-width: 1400px) {
  .container {
    max-width: 1320px;
  }
}

/* 网格系统 */
.row {
  --bs-gutter-x: 1.5rem;
  --bs-gutter-y: 0;
  display: flex;
  flex-wrap: wrap;
  margin-top: calc(-1 * var(--bs-gutter-y));
  margin-right: calc(-0.5 * var(--bs-gutter-x));
  margin-left: calc(-0.5 * var(--bs-gutter-x));
}

.row > * {
  flex-shrink: 0;
  width: 100%;
  max-width: 100%;
  padding-right: calc(var(--bs-gutter-x) * 0.5);
  padding-left: calc(var(--bs-gutter-x) * 0.5);
  margin-top: var(--bs-gutter-y);
}

.col {
  flex: 1 0 0%;
}

.col-auto {
  flex: 0 0 auto;
  width: auto;
}

.col-1 { flex: 0 0 auto; width: 8.33333333%; }
.col-2 { flex: 0 0 auto; width: 16.66666667%; }
.col-3 { flex: 0 0 auto; width: 25%; }
.col-4 { flex: 0 0 auto; width: 33.33333333%; }
.col-5 { flex: 0 0 auto; width: 41.66666667%; }
.col-6 { flex: 0 0 auto; width: 50%; }
.col-7 { flex: 0 0 auto; width: 58.33333333%; }
.col-8 { flex: 0 0 auto; width: 66.66666667%; }
.col-9 { flex: 0 0 auto; width: 75%; }
.col-10 { flex: 0 0 auto; width: 83.33333333%; }
.col-11 { flex: 0 0 auto; width: 91.66666667%; }
.col-12 { flex: 0 0 auto; width: 100%; }

@media (min-width: 576px) {
  .col-sm { flex: 1 0 0%; }
  .col-sm-auto { flex: 0 0 auto; width: auto; }
  .col-sm-1 { flex: 0 0 auto; width: 8.33333333%; }
  .col-sm-2 { flex: 0 0 auto; width: 16.66666667%; }
  .col-sm-3 { flex: 0 0 auto; width: 25%; }
  .col-sm-4 { flex: 0 0 auto; width: 33.33333333%; }
  .col-sm-5 { flex: 0 0 auto; width: 41.66666667%; }
  .col-sm-6 { flex: 0 0 auto; width: 50%; }
  .col-sm-7 { flex: 0 0 auto; width: 58.33333333%; }
  .col-sm-8 { flex: 0 0 auto; width: 66.66666667%; }
  .col-sm-9 { flex: 0 0 auto; width: 75%; }
  .col-sm-10 { flex: 0 0 auto; width: 83.33333333%; }
  .col-sm-11 { flex: 0 0 auto; width: 91.66666667%; }
  .col-sm-12 { flex: 0 0 auto; width: 100%; }
}

@media (min-width: 768px) {
  .col-md { flex: 1 0 0%; }
  .col-md-auto { flex: 0 0 auto; width: auto; }
  .col-md-1 { flex: 0 0 auto; width: 8.33333333%; }
  .col-md-2 { flex: 0 0 auto; width: 16.66666667%; }
  .col-md-3 { flex: 0 0 auto; width: 25%; }
  .col-md-4 { flex: 0 0 auto; width: 33.33333333%; }
  .col-md-5 { flex: 0 0 auto; width: 41.66666667%; }
  .col-md-6 { flex: 0 0 auto; width: 50%; }
  .col-md-7 { flex: 0 0 auto; width: 58.33333333%; }
  .col-md-8 { flex: 0 0 auto; width: 66.66666667%; }
  .col-md-9 { flex: 0 0 auto; width: 75%; }
  .col-md-10 { flex: 0 0 auto; width: 83.33333333%; }
  .col-md-11 { flex: 0 0 auto; width: 91.66666667%; }
  .col-md-12 { flex: 0 0 auto; width: 100%; }
}

@media (min-width: 992px) {
  .col-lg { flex: 1 0 0%; }
  .col-lg-auto { flex: 0 0 auto; width: auto; }
  .col-lg-1 { flex: 0 0 auto; width: 8.33333333%; }
  .col-lg-2 { flex: 0 0 auto; width: 16.66666667%; }
  .col-lg-3 { flex: 0 0 auto; width: 25%; }
  .col-lg-4 { flex: 0 0 auto; width: 33.33333333%; }
  .col-lg-5 { flex: 0 0 auto; width: 41.66666667%; }
  .col-lg-6 { flex: 0 0 auto; width: 50%; }
  .col-lg-7 { flex: 0 0 auto; width: 58.33333333%; }
  .col-lg-8 { flex: 0 0 auto; width: 66.66666667%; }
  .col-lg-9 { flex: 0 0 auto; width: 75%; }
  .col-lg-10 { flex: 0 0 auto; width: 83.33333333%; }
  .col-lg-11 { flex: 0 0 auto; width: 91.66666667%; }
  .col-lg-12 { flex: 0 0 auto; width: 100%; }
}

@media (min-width: 1200px) {
  .col-xl { flex: 1 0 0%; }
  .col-xl-auto { flex: 0 0 auto; width: auto; }
  .col-xl-1 { flex: 0 0 auto; width: 8.33333333%; }
  .col-xl-2 { flex: 0 0 auto; width: 16.66666667%; }
  .col-xl-3 { flex: 0 0 auto; width: 25%; }
  .col-xl-4 { flex: 0 0 auto; width: 33.33333333%; }
  .col-xl-5 { flex: 0 0 auto; width: 41.66666667%; }
  .col-xl-6 { flex: 0 0 auto; width: 50%; }
  .col-xl-7 { flex: 0 0 auto; width: 58.33333333%; }
  .col-xl-8 { flex: 0 0 auto; width: 66.66666667%; }
  .col-xl-9 { flex: 0 0 auto; width: 75%; }
  .col-xl-10 { flex: 0 0 auto; width: 83.33333333%; }
  .col-xl-11 { flex: 0 0 auto; width: 91.66666667%; }
  .col-xl-12 { flex: 0 0 auto; width: 100%; }
}

/* 间距 */
.m-0 { margin: 0 !important; }
.m-1 { margin: 0.25rem !important; }
.m-2 { margin: 0.5rem !important; }
.m-3 { margin: 1rem !important; }
.m-4 { margin: 1.5rem !important; }
.m-5 { margin: 3rem !important; }

.mt-0 { margin-top: 0 !important; }
.mt-1 { margin-top: 0.25rem !important; }
.mt-2 { margin-top: 0.5rem !important; }
.mt-3 { margin-top: 1rem !important; }
.mt-4 { margin-top: 1.5rem !important; }
.mt-5 { margin-top: 3rem !important; }

.mb-0 { margin-bottom: 0 !important; }
.mb-1 { margin-bottom: 0.25rem !important; }
.mb-2 { margin-bottom: 0.5rem !important; }
.mb-3 { margin-bottom: 1rem !important; }
.mb-4 { margin-bottom: 1.5rem !important; }
.mb-5 { margin-bottom: 3rem !important; }

.p-0 { padding: 0 !important; }
.p-1 { padding: 0.25rem !important; }
.p-2 { padding: 0.5rem !important; }
.p-3 { padding: 1rem !important; }
.p-4 { padding: 1.5rem !important; }
.p-5 { padding: 3rem !important; }

/* 卡片组件 */
.card {
  position: relative;
  display: flex;
  flex-direction: column;
  min-width: 0;
  word-wrap: break-word;
  background-color: #fff;
  background-clip: border-box;
  border: 1px solid rgba(0, 0, 0, 0.125);
  border-radius: 0.375rem;
}

.card-body {
  flex: 1 1 auto;
  padding: 1rem;
}

.card-img-top {
  width: 100%;
  border-top-left-radius: calc(0.375rem - 1px);
  border-top-right-radius: calc(0.375rem - 1px);
}

.card-title {
  margin-bottom: 0.5rem;
}

/* 轮播组件 */
.carousel {
  position: relative;
}

.carousel-inner {
  position: relative;
  width: 100%;
  overflow: hidden;
}

.carousel-item {
  position: relative;
  display: none;
  float: left;
  width: 100%;
  margin-right: -100%;
  backface-visibility: hidden;
  transition: transform 0.6s ease-in-out;
}

.carousel-item.active {
  display: block;
}

/* 工具类 */
.d-flex { display: flex !important; }
.d-block { display: block !important; }
.d-none { display: none !important; }

.justify-content-between { justify-content: space-between !important; }
.justify-content-center { justify-content: center !important; }
.align-items-center { align-items: center !important; }

.flex-column { flex-direction: column !important; }
.flex-wrap { flex-wrap: wrap !important; }
.flex-grow-1 { flex-grow: 1 !important; }

.text-center { text-align: center !important; }
.text-start { text-align: left !important; }
.text-end { text-align: right !important; }

.text-decoration-none { text-decoration: none !important; }
.text-dark { color: #212529 !important; }
.text-muted { color: #6c757d !important; }

.h-100 { height: 100% !important; }
.w-100 { width: 100% !important; }

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

.ratio {
  position: relative;
  width: 100%;
}

.ratio-16x9 {
  --bs-aspect-ratio: 56.25%;
}

.ratio::before {
  display: block;
  padding-top: var(--bs-aspect-ratio);
  content: "";
}

.ratio > * {
  position: absolute;
  top: 0;
  left: 0;
  width: 100%;
  height: 100%;
}

/* 按钮 */
.btn {
  display: inline-block;
  font-weight: 400;
  line-height: 1.5;
  color: #212529;
  text-align: center;
  text-decoration: none;
  vertical-align: middle;
  cursor: pointer;
  user-select: none;
  background-color: transparent;
  border: 1px solid transparent;
  padding: 0.375rem 0.75rem;
  font-size: 1rem;
  border-radius: 0.375rem;
  transition: color 0.15s ease-in-out, background-color 0.15s ease-in-out, border-color 0.15s ease-in-out, box-shadow 0.15s ease-in-out;
}

.btn-primary {
  color: #fff;
  background-color: #0d6efd;
  border-color: #0d6efd;
}

.btn-close {
  box-sizing: content-box;
  width: 1em;
  height: 1em;
  padding: 0.25em 0.25em;
  color: #000;
  background: transparent url("data:image/svg+xml,%3csvg xmlns='http://www.w3.org/2000/svg' viewBox='0 0 16 16' fill='%23000'%3e%3cpath d='M.293.293a1 1 0 011.414 0L8 6.586 14.293.293a1 1 0 111.414 1.414L9.414 8l6.293 6.293a1 1 0 01-1.414 1.414L8 9.414l-6.293 6.293a1 1 0 01-1.414-1.414L6.586 8 .293 1.707a1 1 0 010-1.414z'/%3e%3c/svg%3e") center/1em auto no-repeat;
  border: 0;
  border-radius: 0.375rem;
  opacity: 0.5;
}

/* 警告框 */
.alert {
  position: relative;
  padding: 0.75rem 1.25rem;
  margin-bottom: 1rem;
  border: 1px solid transparent;
  border-radius: 0.375rem;
}

.alert-success {
  color: #155724;
  background-color: #d4edda;
  border-color: #c3e6cb;
}

.alert-danger {
  color: #721c24;
  background-color: #f8d7da;
  border-color: #f5c6cb;
}

.alert-warning {
  color: #856404;
  background-color: #fff3cd;
  border-color: #ffeaa7;
}

.alert-info {
  color: #0c5460;
  background-color: #d1ecf1;
  border-color: #bee5eb;
}

.alert-dismissible {
  padding-right: 4rem;
}

/* 过渡效果 */
.fade {
  transition: opacity 0.15s linear;
}

.show {
  opacity: 1;
}

/* 响应式工具类 */
@media (max-width: 575.98px) {
  .d-sm-none { display: none !important; }
  .d-sm-block { display: block !important; }
}

@media (min-width: 576px) and (max-width: 767.98px) {
  .d-md-none { display: none !important; }
  .d-md-block { display: block !important; }
}

@media (min-width: 768px) and (max-width: 991.98px) {
  .d-lg-none { display: none !important; }
  .d-lg-block { display: block !important; }
}

@media (min-width: 992px) {
  .d-xl-none { display: none !important; }
  .d-xl-block { display: block !important; }
}