/* 基础样式 */
@import url('https://fonts.googleapis.com/css2?family=Noto+Serif+SC:wght@400;500;600;700&family=Noto+Sans+SC:wght@300;400;500;700&display=swap');

:root {
    --primary-color: #2c3e50;
    --secondary-color: #3498db;
    --accent-color: #e74c3c;
    --primary-700: #334e68;
    --primary-800: #243b53;
    --primary-900: #102a43;
    --primary-200: #bcccdc;
    --primary-100: #d9e2ec;
    --primary-50: #f0f4f8;
}

body {
    font-family: 'Noto Sans SC', sans-serif;
    margin: 0;
    padding: 0;
    background-color: #f8fafc;
    color: var(--primary-800);
}

h1, h2, h3, h4, h5, h6 {
    font-family: 'Noto Serif SC', serif;
    font-weight: 700;
}

a {
    text-decoration: none;
    color: inherit;
}

ul {
    list-style: none;
    padding: 0;
    margin: 0;
}

.container {
    width: 100%;
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 1rem;
}

.grid {
    display: grid;
    gap: 2rem;
}

@media (min-width: 768px) {
    .grid-cols-2 {
        grid-template-columns: repeat(2, 1fr);
    }
    .grid-cols-3 {
        grid-template-columns: repeat(3, 1fr);
    }
}

@media (min-width: 1024px) {
    .grid-cols-3 {
        grid-template-columns: repeat(3, 1fr);
    }
}

.flex {
    display: flex;
}

.flex-col {
    flex-direction: column;
}

.flex-row {
    flex-direction: row;
}

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

.justify-between {
    justify-content: space-between;
}

.justify-center {
    justify-content: center;
}

.space-x-8 > * + * {
    margin-left: 2rem;
}

.space-y-2 > * + * {
    margin-top: 0.5rem;
}

.space-y-3 > * + * {
    margin-top: 0.75rem;
}

.space-y-4 > * + * {
    margin-top: 1rem;
}

.gap-6 {
    gap: 1.5rem;
}

.gap-8 {
    gap: 2rem;
}

.hidden {
    display: none;
}

@media (min-width: 768px) {
    .md\:flex {
        display: flex;
    }
    .md\:hidden {
        display: none;
    }
    .md\:flex-row {
        flex-direction: row;
    }
}

@media (min-width: 1024px) {
    .lg\:flex-row {
        flex-direction: row;
    }
    .lg\:w-1\/4 {
        width: 25%;
    }
    .lg\:w-3\/4 {
        width: 75%;
    }
}

.card {
    background: white;
    border-radius: 0.5rem;
    box-shadow: 0 4px 6px rgba(0, 0, 0, 0.1);
    overflow: hidden;
}

.model-card {
    background-color: white;
    padding: 1.5rem;
    border-radius: 0.5rem;
    box-shadow: 0 4px 6px rgba(0, 0, 0, 0.1);
    margin-bottom: 2rem;
    border-top-width: 4px;
}

.bg-primary-800 {
    background-color: var(--primary-800);
}

.bg-primary-700 {
    background-color: var(--primary-700);
}

.bg-primary-900 {
    background-color: var(--primary-900);
}

.bg-primary-100 {
    background-color: var(--primary-100);
}

.bg-primary-50 {
    background-color: var(--primary-50);
}

.bg-white {
    background-color: white;
}

.bg-gray-50 {
    background-color: #f9fafb;
}

.bg-gray-100 {
    background-color: #f3f4f6;
}

.text-white {
    color: white;
}

.text-primary-800 {
    color: var(--primary-800);
}

.text-primary-200 {
    color: var(--primary-200);
}

.text-primary-700 {
    color: var(--primary-700);
}

.text-green-500 {
    color: #10b981;
}

.font-serif {
    font-family: 'Noto Serif SC', serif;
}

.sticky {
    position: sticky;
}

.top-0 {
    top: 0;
}

.top-24 {
    top: 6rem;
}

.z-50 {
    z-index: 50;
}

.p-6 {
    padding: 1.5rem;
}

.p-4 {
    padding: 1rem;
}

.py-4 {
    padding-top: 1rem;
    padding-bottom: 1rem;
}

.py-12 {
    padding-top: 3rem;
    padding-bottom: 3rem;
}

.py-16 {
    padding-top: 4rem;
    padding-bottom: 4rem;
}

.py-20 {
    padding-top: 5rem;
    padding-bottom: 5rem;
}

.px-4 {
    padding-left: 1rem;
    padding-right: 1rem;
}

.mb-2 {
    margin-bottom: 0.5rem;
}

.mb-4 {
    margin-bottom: 1rem;
}

.mb-6 {
    margin-bottom: 1.5rem;
}

.mb-8 {
    margin-bottom: 2rem;
}

.mb-10 {
    margin-bottom: 2.5rem;
}

.mb-12 {
    margin-bottom: 3rem;
}

.mt-1 {
    margin-top: 0.25rem;
}

.mt-2 {
    margin-top: 0.5rem;
}

.mt-3 {
    margin-top: 0.75rem;
}

.mr-2 {
    margin-right: 0.5rem;
}

.mr-4 {
    margin-right: 1rem;
}

.ml-2 {
    margin-left: 0.5rem;
}

.rounded-full {
    border-radius: 9999px;
}

.rounded-lg {
    border-radius: 0.5rem;
}

.rounded-r {
    border-top-right-radius: 0.25rem;
    border-bottom-right-radius: 0.25rem;
}

.w-12 {
    width: 3rem;
}

.h-12 {
    height: 3rem;
}

.h-2 {
    height: 0.5rem;
}

.w-1\.5 {
    width: 0.375rem;
}

.h-1\.5 {
    height: 0.375rem;
}

.text-2xl {
    font-size: 1.5rem;
}

.text-xl {
    font-size: 1.25rem;
}

.text-lg {
    font-size: 1.125rem;
}

.text-sm {
    font-size: 0.875rem;
}

.text-3xl {
    font-size: 1.875rem;
}

.text-4xl {
    font-size: 2.25rem;
}

.font-bold {
    font-weight: 700;
}

.font-medium {
    font-weight: 500;
}

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

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

.shadow-md {
    box-shadow: 0 4px 6px rgba(0, 0, 0, 0.1);
}

.shadow {
    box-shadow: 0 1px 3px rgba(0, 0, 0, 0.1);
}

.relative {
    position: relative;
}

.absolute {
    position: absolute;
}

.inset-0 {
    top: 0;
    right: 0;
    bottom: 0;
    left: 0;
}

.opacity-20 {
    opacity: 0.2;
}

.opacity-90 {
    opacity: 0.9;
}

.z-10 {
    z-index: 10;
}

.bg-gradient-to-r {
    background-image: linear-gradient(to right, var(--primary-800), var(--primary-900));
}

.btn {
    display: inline-block;
    padding: 0.75rem 1.5rem;
    border-radius: 0.375rem;
    color: white;
    font-weight: 500;
    transition: background-color 0.3s;
}

.btn-primary {
    background-color: var(--primary-700);
}

.btn-primary:hover {
    background-color: var(--primary-800);
}

.max-w-3xl {
    max-width: 48rem;
}

.max-w-4xl {
    max-width: 56rem;
}

.max-w-5xl {
    max-width: 64rem;
}

.max-w-none {
    max-width: none;
}

.mx-auto {
    margin-left: auto;
    margin-right: auto;
}

.my-6 {
    margin-top: 1.5rem;
    margin-bottom: 1.5rem;
}

.my-8 {
    margin-top: 2rem;
    margin-bottom: 2rem;
}

.border-b {
    border-bottom-width: 1px;
}

.border-gray-200 {
    border-color: #e5e8eb;
}

.border-l-4 {
    border-left-width: 4px;
}

.border-t-4 {
    border-top-width: 4px;
}

.border-blue-500 {
    border-color: #3b82f6;
}

.border-purple-500 {
    border-color: #8b5cf6;
}

.border-red-500 {
    border-color: #ef4444;
}

.border-green-500 {
    border-color: #10b981;
}

.border-orange-500 {
    border-color: #f97316;
}

.border-primary-500 {
    border-color: var(--primary-500);
}

.border-primary-800 {
    border-color: var(--primary-800);
}

.prose {
    max-width: 65ch;
}

.bg-blue-100 {
    background-color: #dbeafe;
}

.bg-purple-100 {
    background-color: #ede9fe;
}

.bg-red-100 {
    background-color: #fee2e2;
}

.bg-green-100 {
    background-color: #d1fae5;
}

.bg-orange-100 {
    background-color: #ffedd5;
}

.text-blue-500 {
    color: #3b82f6;
}

.text-purple-500 {
    color: #8b5cf6;
}

.text-red-500 {
    color: #ef4444;
}

.text-green-500 {
    color: #10b981;
}

.text-orange-500 {
    color: #f97316;
}

.italic {
    font-style: italic;
}

.pb-2 {
    padding-bottom: 0.5rem;
}

.pb-3 {
    padding-bottom: 0.75rem;
}

.pt-6 {
    padding-top: 1.5rem;
}

@media (min-width: 768px) {
    .md\:text-2xl {
        font-size: 1.5rem;
    }
    .md\:text-4xl {
        font-size: 2.25rem;
    }
    .md\:text-6xl {
        font-size: 3.75rem;
    }
    .md\:text-xl {
        font-size: 1.25rem;
    }
    .md\:py-24 {
        padding-top: 6rem;
        padding-bottom: 6rem;
    }
    .md\:py-32 {
        padding-top: 8rem;
        padding-bottom: 8rem;
    }
    .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\:p-8 {
        padding: 2rem;
    }
    .md\:w-2\/3 {
        width: 66.666667%;
    }
    .md\:w-1\/3 {
        width: 33.333333%;
    }
}

.section-title {
    font-size: 1.875rem;
    font-weight: 700;
    margin-bottom: 2rem;
    color: var(--primary-800);
    position: relative;
    padding-bottom: 0.75rem;
}

.section-title::after {
    content: '';
    position: absolute;
    left: 0;
    bottom: 0;
    height: 0.25rem;
    width: 4rem;
    background-color: var(--secondary-color);
}

.section-title.text-center::after {
    left: 50%;
    transform: translateX(-50%);
}

.hover\:text-secondary:hover {
    color: var(--secondary-color);
}

.hover\:text-white:hover {
    color: white;
}

.transition-colors {
    transition: color 0.3s;
}

.group:hover .group-hover\:translate-x-1 {
    transform: translateX(0.25rem);
}

.transition-transform {
    transition: transform 0.3s;
}

.transition-all {
    transition: all 0.3s ease;
}

.model-icon {
    width: 3rem;
    height: 3rem;
    border-radius: 9999px;
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 1.5rem;
    margin-right: 1rem;
}

.toc-link {
    display: flex;
    align-items: center;
    color: var(--primary-700);
    transition: color 0.3s;
    padding-top: 0.25rem;
    padding-bottom: 0.25rem;
}

.toc-link:hover {
    color: var(--primary-900);
}

.toc-dot {
    width: 0.375rem;
    height: 0.375rem;
    border-radius: 9999px;
    background-color: var(--primary-500);
    margin-right: 0.5rem;
    transition: background-color 0.3s;
}

.toc-link:hover .toc-dot {
    background-color: var(--primary-700);
}

.quote-box {
    background-color: var(--primary-50);
    border-left-width: 4px;
    border-color: var(--primary-500);
    padding: 1rem;
    border-top-right-radius: 0.25rem;
    border-bottom-right-radius: 0.25rem;
    margin-top: 1.5rem;
    margin-bottom: 1.5rem;
}

/* 返回顶部按钮 */
#back-to-top {
    position: fixed;
    bottom: 2rem;
    right: 2rem;
    width: 3rem;
    height: 3rem;
    border-radius: 9999px;
    background-color: var(--primary-700);
    color: white;
    display: flex;
    align-items: center;
    justify-content: center;
    transition: all 0.3s ease;
    opacity: 0;
    visibility: hidden;
    cursor: pointer;
    border: none;
    outline: none;
    box-shadow: 0 10px 15px -3px rgba(0, 0, 0, 0.1);
}

#back-to-top:hover {
    background-color: var(--primary-800);
}

#back-to-top.opacity-100 {
    opacity: 1;
    visibility: visible;
}

#back-to-top.invisible {
    visibility: hidden;
}