/* ============================================================
   三九健康网 - 样式表
   纯CSS实现，无需构建工具
   ============================================================ */

/* Reset & Base */
*, *::before, *::after { box-sizing: border-box; margin: 0; padding: 0; }
html { font-size: 16px; scroll-behavior: smooth; -webkit-text-size-adjust: 100%; }
body { font-family: 'Noto Sans SC', -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, sans-serif; line-height: 1.6; color: #1f2937; background: #f9fafb; }
img { max-width: 100%; height: auto; display: block; }
a { color: inherit; text-decoration: none; }
ul, ol { list-style: none; }
button, input, select, textarea { font: inherit; }

/* Typography */
h1 { font-size: 2rem; font-weight: 700; line-height: 1.3; }
h2 { font-size: 1.5rem; font-weight: 600; line-height: 1.4; }
h3 { font-size: 1.25rem; font-weight: 600; line-height: 1.4; }
h4 { font-size: 1.125rem; font-weight: 600; }
p { margin-bottom: 1rem; }

/* Layout */
.max-w-7xl { max-width: 80rem; margin: 0 auto; }
.max-w-4xl { max-width: 56rem; margin: 0 auto; }
.container { max-width: 1200px; margin: 0 auto; padding: 0 1rem; }

/* Flexbox */
.flex { display: flex; }
.flex-col { flex-direction: column; }
.flex-wrap { flex-wrap: wrap; }
.items-center { align-items: center; }
.items-start { align-items: flex-start; }
.items-stretch { align-items: stretch; }
.justify-center { justify-content: center; }
.justify-between { justify-content: space-between; }
.justify-around { justify-content: space-around; }
.flex-1 { flex: 1 1 0%; }
.flex-shrink-0 { flex-shrink: 0; }
.gap-2 { gap: 0.5rem; }
.gap-3 { gap: 0.75rem; }
.gap-4 { gap: 1rem; }
.gap-6 { gap: 1.5rem; }
.gap-8 { gap: 2rem; }

/* Grid */
.grid { display: grid; }
.grid-cols-1 { grid-template-columns: repeat(1, minmax(0, 1fr)); }
.grid-cols-2 { grid-template-columns: repeat(2, minmax(0, 1fr)); }
.grid-cols-3 { grid-template-columns: repeat(3, minmax(0, 1fr)); }
.grid-cols-4 { grid-template-columns: repeat(4, minmax(0, 1fr)); }

/* Spacing */
.p-2 { padding: 0.5rem; }
.p-3 { padding: 0.75rem; }
.p-4 { padding: 1rem; }
.p-6 { padding: 1.5rem; }
.px-2 { padding-left: 0.5rem; padding-right: 0.5rem; }
.px-3 { padding-left: 0.75rem; padding-right: 0.75rem; }
.px-4 { padding-left: 1rem; padding-right: 1rem; }
.px-6 { padding-left: 1.5rem; padding-right: 1.5rem; }
.py-1 { padding-top: 0.25rem; padding-bottom: 0.25rem; }
.py-2 { padding-top: 0.5rem; padding-bottom: 0.5rem; }
.py-3 { padding-top: 0.75rem; padding-bottom: 0.75rem; }
.py-4 { padding-top: 1rem; padding-bottom: 1rem; }
.py-6 { padding-top: 1.5rem; padding-bottom: 1.5rem; }
.py-8 { padding-top: 2rem; padding-bottom: 2rem; }
.py-12 { padding-top: 3rem; padding-bottom: 3rem; }
.m-0 { margin: 0; }
.mt-1 { margin-top: 0.25rem; }
.mt-2 { margin-top: 0.5rem; }
.mt-3 { margin-top: 0.75rem; }
.mt-4 { margin-top: 1rem; }
.mt-6 { margin-top: 1.5rem; }
.mt-8 { margin-top: 2rem; }
.mt-12 { margin-top: 3rem; }
.mb-1 { margin-bottom: 0.25rem; }
.mb-2 { margin-bottom: 0.5rem; }
.mb-3 { margin-bottom: 0.75rem; }
.mb-4 { margin-bottom: 1rem; }
.mb-6 { margin-bottom: 1.5rem; }
.mb-8 { margin-bottom: 2rem; }
.ml-2 { margin-left: 0.5rem; }
.ml-3 { margin-left: 0.75rem; }
.mr-2 { margin-right: 0.5rem; }
.mr-3 { margin-right: 0.75rem; }
.mx-auto { margin-left: auto; margin-right: auto; }
.space-x-1 > * + * { margin-left: 0.25rem; }
.space-x-2 > * + * { margin-left: 0.5rem; }
.space-x-3 > * + * { margin-left: 0.75rem; }
.space-x-4 > * + * { margin-left: 1rem; }
.space-y-1 > * + * { margin-top: 0.25rem; }
.space-y-2 > * + * { margin-top: 0.5rem; }
.space-y-3 > * + * { margin-top: 0.75rem; }
.space-y-4 > * + * { margin-top: 1rem; }

/* Sizing */
.w-4 { width: 1rem; }
.w-5 { width: 1.25rem; }
.w-6 { width: 1.5rem; }
.w-8 { width: 2rem; }
.w-10 { width: 2.5rem; }
.w-12 { width: 3rem; }
.w-16 { width: 4rem; }
.w-20 { width: 5rem; }
.w-24 { width: 6rem; }
.w-32 { width: 8rem; }
.w-48 { width: 12rem; }
.w-full { width: 100%; }
.h-4 { height: 1rem; }
.h-5 { height: 1.25rem; }
.h-6 { height: 1.5rem; }
.h-8 { height: 2rem; }
.h-10 { height: 2.5rem; }
.h-12 { height: 3rem; }
.h-16 { height: 4rem; }
.h-20 { height: 5rem; }
.h-24 { height: 6rem; }
.h-32 { height: 8rem; }
.h-48 { height: 12rem; }
.h-64 { height: 16rem; }
.h-full { height: 100%; }
.min-h-screen { min-height: 100vh; }

/* Colors */
.text-white { color: #ffffff; }
.text-gray-300 { color: #d1d5db; }
.text-gray-400 { color: #9ca3af; }
.text-gray-500 { color: #6b7280; }
.text-gray-600 { color: #4b5563; }
.text-gray-700 { color: #374151; }
.text-gray-800 { color: #1f2937; }
.text-gray-900 { color: #111827; }
.text-emerald-500 { color: #10b981; }
.text-emerald-600 { color: #059669; }
.text-emerald-700 { color: #047857; }
.text-red-500 { color: #ef4444; }
.text-blue-500 { color: #3b82f6; }
.text-yellow-500 { color: #f59e0b; }

.bg-white { background-color: #ffffff; }
.bg-gray-50 { background-color: #f9fafb; }
.bg-gray-100 { background-color: #f3f4f6; }
.bg-gray-200 { background-color: #e5e7eb; }
.bg-gray-700 { background-color: #374151; }
.bg-gray-800 { background-color: #1f2937; }
.bg-gray-900 { background-color: #111827; }
.bg-emerald-50 { background-color: #ecfdf5; }
.bg-emerald-100 { background-color: #d1fae5; }
.bg-emerald-500 { background-color: #10b981; }
.bg-emerald-600 { background-color: #059669; }
.bg-emerald-700 { background-color: #047857; }
.bg-red-50 { background-color: #fef2f2; }
.bg-red-500 { background-color: #ef4444; }
.bg-blue-50 { background-color: #eff6ff; }
.bg-blue-500 { background-color: #3b82f6; }
.bg-yellow-50 { background-color: #fffbeb; }

/* Borders */
.border { border: 1px solid #e5e7eb; }
.border-t { border-top: 1px solid #e5e7eb; }
.border-b { border-bottom: 1px solid #e5e7eb; }
.border-l { border-left: 1px solid #e5e7eb; }
.border-r { border-right: 1px solid #e5e7eb; }
.border-gray-100 { border-color: #f3f4f6; }
.border-gray-200 { border-color: #e5e7eb; }
.border-gray-300 { border-color: #d1d5db; }
.border-gray-700 { border-color: #374151; }
.border-emerald-500 { border-color: #10b981; }
.border-transparent { border-color: transparent; }

/* Border Radius */
.rounded { border-radius: 0.25rem; }
.rounded-md { border-radius: 0.375rem; }
.rounded-lg { border-radius: 0.5rem; }
.rounded-xl { border-radius: 0.75rem; }
.rounded-2xl { border-radius: 1rem; }
.rounded-full { border-radius: 9999px; }

/* Shadows */
.shadow { box-shadow: 0 1px 3px rgba(0,0,0,.1), 0 1px 2px rgba(0,0,0,.06); }
.shadow-md { box-shadow: 0 4px 6px -1px rgba(0,0,0,.1), 0 2px 4px -1px rgba(0,0,0,.06); }
.shadow-lg { box-shadow: 0 10px 15px -3px rgba(0,0,0,.1), 0 4px 6px -2px rgba(0,0,0,.05); }
.shadow-sm { box-shadow: 0 1px 2px 0 rgba(0,0,0,.05); }

/* Position */
.relative { position: relative; }
.absolute { position: absolute; }
.fixed { position: fixed; }
.sticky { position: sticky; }
.top-0 { top: 0; }
.bottom-0 { bottom: 0; }
.left-0 { left: 0; }
.right-0 { right: 0; }
.bottom-6 { bottom: 1.5rem; }
.right-6 { right: 1.5rem; }
.left-3 { left: 0.75rem; }
.top-2 { top: 0.5rem; }
.top-2\.5 { top: 0.625rem; }

/* Z-index */
.z-10 { z-index: 10; }
.z-50 { z-index: 50; }

/* Display */
.block { display: block; }
.inline-block { display: inline-block; }
.inline { display: inline; }
.hidden { display: none; }

/* Overflow */
.overflow-hidden { overflow: hidden; }
.overflow-x-auto { overflow-x: auto; }
.overflow-y-auto { overflow-y: auto; }

/* Text */
.text-xs { font-size: 0.75rem; line-height: 1rem; }
.text-sm { font-size: 0.875rem; line-height: 1.25rem; }
.text-base { font-size: 1rem; line-height: 1.5rem; }
.text-lg { font-size: 1.125rem; line-height: 1.75rem; }
.text-xl { font-size: 1.25rem; line-height: 1.75rem; }
.text-2xl { font-size: 1.5rem; line-height: 2rem; }
.text-3xl { font-size: 1.875rem; line-height: 2.25rem; }
.text-4xl { font-size: 2.25rem; line-height: 2.5rem; }
.font-normal { font-weight: 400; }
.font-medium { font-weight: 500; }
.font-semibold { font-weight: 600; }
.font-bold { font-weight: 700; }
.text-center { text-align: center; }
.text-left { text-align: left; }
.text-right { text-align: right; }
.leading-tight { line-height: 1.25; }
.leading-relaxed { line-height: 1.625; }
.truncate { overflow: hidden; text-overflow: ellipsis; white-space: nowrap; }
.whitespace-nowrap { white-space: nowrap; }
.line-clamp-2 { display: -webkit-box; -webkit-line-clamp: 2; -webkit-box-orient: vertical; overflow: hidden; }
.line-clamp-3 { display: -webkit-box; -webkit-line-clamp: 3; -webkit-box-orient: vertical; overflow: hidden; }

/* Transitions */
.transition { transition: all 0.3s ease; }
.transition-all { transition: all 0.3s ease; }
.transition-colors { transition: color 0.3s ease, background-color 0.3s ease, border-color 0.3s ease; }
.transition-transform { transition: transform 0.3s ease; }
.duration-200 { transition-duration: 200ms; }
.duration-300 { transition-duration: 300ms; }

/* Opacity */
.opacity-0 { opacity: 0; }
.opacity-100 { opacity: 1; }
.invisible { visibility: hidden; }
.visible { visibility: visible; }

/* Hover States */
.hover\:bg-gray-100:hover { background-color: #f3f4f6; }
.hover\:bg-gray-200:hover { background-color: #e5e7eb; }
.hover\:bg-emerald-600:hover { background-color: #059669; }
.hover\:bg-emerald-700:hover { background-color: #047857; }
.hover\:text-emerald-500:hover { color: #10b981; }
.hover\:text-emerald-600:hover { color: #059669; }
.hover\:text-emerald-700:hover { color: #047857; }
.hover\:text-white:hover { color: #ffffff; }
.hover\:shadow-lg:hover { box-shadow: 0 10px 15px -3px rgba(0,0,0,.1), 0 4px 6px -2px rgba(0,0,0,.05); }
.hover\:-translate-y-1:hover { transform: translateY(-4px); }

/* Focus */
.focus\:outline-none:focus { outline: none; }
.focus\:ring-2:focus { box-shadow: 0 0 0 2px rgba(16, 185, 129, 0.5); }
.focus\:ring-emerald-500:focus { --tw-ring-color: #10b981; }
.focus\:border-transparent:focus { border-color: transparent; }

/* Responsive */
@media (min-width: 640px) {
    .sm\:grid-cols-2 { grid-template-columns: repeat(2, minmax(0, 1fr)); }
    .sm\:grid-cols-3 { grid-template-columns: repeat(3, minmax(0, 1fr)); }
    .sm\:flex { display: flex; }
    .sm\:hidden { display: none; }
    .sm\:text-2xl { font-size: 1.5rem; }
    .sm\:text-3xl { font-size: 1.875rem; }
}

@media (min-width: 768px) {
    .md\:flex { display: flex; }
    .md\:hidden { display: none; }
    .md\:grid-cols-2 { grid-template-columns: repeat(2, minmax(0, 1fr)); }
    .md\:grid-cols-3 { grid-template-columns: repeat(3, minmax(0, 1fr)); }
    .md\:grid-cols-4 { grid-template-columns: repeat(4, minmax(0, 1fr)); }
    .md\:col-span-1 { grid-column: span 1 / span 1; }
    .md\:col-span-2 { grid-column: span 2 / span 2; }
    .md\:text-3xl { font-size: 1.875rem; }
    .md\:text-4xl { font-size: 2.25rem; }
    .md\:flex-row { flex-direction: row; }
    .md\:items-center { align-items: center; }
    .md\:justify-between { justify-content: space-between; }
    .md\:space-x-4 > * + * { margin-left: 1rem; }
    .md\:space-y-0 > * + * { margin-top: 0; }
    .md\:w-1\/2 { width: 50%; }
    .md\:w-1\/3 { width: 33.333%; }
    .md\:w-2\/3 { width: 66.666%; }
}

@media (min-width: 1024px) {
    .lg\:flex { display: flex; }
    .lg\:hidden { display: none; }
    .lg\:grid-cols-3 { grid-template-columns: repeat(3, minmax(0, 1fr)); }
    .lg\:grid-cols-4 { grid-template-columns: repeat(4, minmax(0, 1fr)); }
    .lg\:grid-cols-5 { grid-template-columns: repeat(5, minmax(0, 1fr)); }
    .lg\:col-span-2 { grid-column: span 2 / span 2; }
    .lg\:col-span-3 { grid-column: span 3 / span 3; }
    .lg\:flex-row { flex-direction: row; }
    .lg\:w-1\/2 { width: 50%; }
    .lg\:w-1\/3 { width: 33.333%; }
    .lg\:w-2\/3 { width: 66.666%; }
    .lg\:w-3\/4 { width: 75%; }
}

/* Component Styles */

/* Card */
.card {
    background: white;
    border-radius: 0.75rem;
    box-shadow: 0 1px 3px rgba(0,0,0,.1);
    overflow: hidden;
    transition: transform 0.3s ease, box-shadow 0.3s ease;
}
.card:hover {
    transform: translateY(-4px);
    box-shadow: 0 10px 15px -3px rgba(0,0,0,.1);
}
.card-body { padding: 1.25rem; }
.card-img { width: 100%; height: 200px; object-fit: cover; }

/* Button */
.btn {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    padding: 0.5rem 1rem;
    font-size: 0.875rem;
    font-weight: 500;
    border-radius: 0.5rem;
    cursor: pointer;
    transition: all 0.2s ease;
    border: none;
}
.btn-primary { background: #10b981; color: white; }
.btn-primary:hover { background: #059669; }
.btn-secondary { background: #f3f4f6; color: #374151; }
.btn-secondary:hover { background: #e5e7eb; }
.btn-danger { background: #ef4444; color: white; }
.btn-danger:hover { background: #dc2626; }
.btn-outline { background: transparent; border: 1px solid #e5e7eb; color: #374151; }
.btn-outline:hover { background: #f3f4f6; }
.btn-sm { padding: 0.25rem 0.75rem; font-size: 0.75rem; }
.btn-lg { padding: 0.75rem 1.5rem; font-size: 1rem; }

/* Badge */
.badge {
    display: inline-flex;
    align-items: center;
    padding: 0.125rem 0.5rem;
    font-size: 0.75rem;
    font-weight: 500;
    border-radius: 9999px;
}
.badge-emerald { background: #ecfdf5; color: #047857; }
.badge-blue { background: #eff6ff; color: #1d4ed8; }
.badge-red { background: #fef2f2; color: #b91c1c; }
.badge-yellow { background: #fffbeb; color: #b45309; }
.badge-gray { background: #f3f4f6; color: #4b5563; }

/* Form */
.form-input {
    width: 100%;
    padding: 0.5rem 0.75rem;
    font-size: 0.875rem;
    border: 1px solid #e5e7eb;
    border-radius: 0.5rem;
    transition: border-color 0.2s, box-shadow 0.2s;
}
.form-input:focus {
    outline: none;
    border-color: #10b981;
    box-shadow: 0 0 0 3px rgba(16, 185, 129, 0.1);
}
.form-label {
    display: block;
    font-size: 0.875rem;
    font-weight: 500;
    color: #374151;
    margin-bottom: 0.25rem;
}
.form-group { margin-bottom: 1rem; }

/* Table */
.table { width: 100%; border-collapse: collapse; }
.table th, .table td { padding: 0.75rem 1rem; text-align: left; border-bottom: 1px solid #e5e7eb; }
.table th { font-weight: 600; color: #6b7280; font-size: 0.75rem; text-transform: uppercase; letter-spacing: 0.05em; background: #f9fafb; }
.table tbody tr:hover { background: #f9fafb; }

/* Pagination */
.pagination { display: flex; align-items: center; justify-content: center; gap: 0.25rem; }
.pagination a, .pagination span {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    min-width: 2rem;
    height: 2rem;
    padding: 0 0.5rem;
    font-size: 0.875rem;
    border-radius: 0.375rem;
    transition: all 0.2s;
}
.pagination a { color: #4b5563; }
.pagination a:hover { background: #f3f4f6; }
.pagination .active { background: #10b981; color: white; }
.pagination .disabled { color: #d1d5db; pointer-events: none; }

/* Article Content */
.article-content { line-height: 1.8; font-size: 1.0625rem; color: #374151; }
.article-content p { margin-bottom: 1.25rem; }
.article-content h2 { font-size: 1.5rem; font-weight: 700; margin: 2rem 0 1rem; color: #111827; }
.article-content h3 { font-size: 1.25rem; font-weight: 600; margin: 1.5rem 0 0.75rem; color: #1f2937; }
.article-content img { border-radius: 0.5rem; margin: 1.5rem 0; }
.article-content blockquote {
    border-left: 4px solid #10b981;
    padding: 1rem 1.5rem;
    margin: 1.5rem 0;
    background: #ecfdf5;
    color: #065f46;
    border-radius: 0 0.5rem 0.5rem 0;
}
.article-content ul, .article-content ol { padding-left: 1.5rem; margin-bottom: 1.25rem; }
.article-content li { margin-bottom: 0.5rem; }
.article-content ul li { list-style: disc; }
.article-content ol li { list-style: decimal; }

/* Sidebar Widget */
.widget {
    background: white;
    border-radius: 0.75rem;
    padding: 1.25rem;
    margin-bottom: 1.5rem;
}
.widget-title {
    font-size: 1.125rem;
    font-weight: 600;
    color: #111827;
    margin-bottom: 1rem;
    padding-bottom: 0.75rem;
    border-bottom: 2px solid #10b981;
}

/* Alert */
.alert {
    padding: 1rem 1.25rem;
    border-radius: 0.5rem;
    margin-bottom: 1rem;
}
.alert-success { background: #ecfdf5; color: #065f46; border: 1px solid #a7f3d0; }
.alert-error { background: #fef2f2; color: #991b1b; border: 1px solid #fecaca; }
.alert-warning { background: #fffbeb; color: #92400e; border: 1px solid #fde68a; }
.alert-info { background: #eff6ff; color: #1e40af; border: 1px solid #bfdbfe; }

/* Animations */
@keyframes fadeIn {
    from { opacity: 0; transform: translateY(10px); }
    to { opacity: 1; transform: translateY(0); }
}
.animate-fadeIn { animation: fadeIn 0.3s ease forwards; }

/* Print */
@media print {
    header, footer, .sidebar, #back-to-top { display: none !important; }
    body { background: white; }
    .card { box-shadow: none; border: 1px solid #e5e7eb; }
}