/* 基础样式 */
* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}

body {
    font-family: 'Inter', system-ui, sans-serif;
    background-color: #f9fafb;
    color: #1f2937;
    line-height: 1.6;
}

.container {
    width: 100%;
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 20px;
}

/* 颜色定义 */
:root {
    --primary: #3B82F6;
    --secondary: #10B981;
    --accent: #F59E0B;
    --dark: #1E293B;
    --light-gray: #f3f4f6;
    --medium-gray: #e5e7eb;
    --text-gray: #6b7280;
    --white: #ffffff;
}

/* 通用样式 */
.text-shadow {
    text-shadow: 0 2px 4px rgba(0,0,0,0.1);
}

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

.bg-gradient-custom {
    background: linear-gradient(135deg, var(--primary) 0%, var(--secondary) 100%);
}

.rounded-xl {
    border-radius: 0.75rem;
}

.shadow-sm {
    box-shadow: 0 1px 2px rgba(0,0,0,0.05);
}

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

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

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

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

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

.pt-16 {
    padding-top: 4rem;
}

.pb-8 {
    padding-bottom: 2rem;
}

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

.px-5 {
    padding-left: 1.25rem;
    padding-right: 1.25rem;
}

.pl-4 {
    padding-left: 1rem;
}

.pl-6 {
    padding-left: 1.5rem;
}

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

.text-white {
    color: white;
}

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

.text-dark {
    color: var(--dark);
}

.text-gray-400 {
    color: #9ca3af;
}

.text-gray-700 {
    color: #374151;
}

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

.font-semibold {
    font-weight: 600;
}

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

.text-base {
    font-size: 1rem;
}

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

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

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

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

.text-5xl {
    font-size: 3rem;
}

.opacity-80 {
    opacity: 0.8;
}

.opacity-90 {
    opacity: 0.9;
}

.leading-relaxed {
    line-height: 1.625;
}

/* 布局样式 */
.flex {
    display: flex;
}

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

.flex-grow {
    flex-grow: 1;
    margin-top: 90px;
}

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

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

.items-start {
    align-items: flex-start;
}

.space-x-2 > * + * {
    margin-left: 0.5rem;
}

.space-x-4 > * + * {
    margin-left: 1rem;
}

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

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

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

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

.space-y-6 > * + * {
    margin-top: 1.5rem;
}

.max-w-3xl {
    max-width: 42rem;
}

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

.mt-4 {
    margin-top: 1rem;
}

/* 组件样式 */
header {
    background-color: var(--white);
    box-shadow: 0 4px 6px -1px rgba(0,0,0,0.1);
    position: sticky;
    top: 0;
    z-index: 50;
}

nav {
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: 1rem 0;
}

ul {
    list-style: none;
}

a {
    text-decoration: none;
    color: var(--text-gray);
    transition: all 0.3s ease;
}

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

main {
    min-height: calc(100vh - 13rem);
}

footer {
    background-color: var(--dark);
    color: var(--white);
}

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

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

.border-t {
    border-top: 1px solid var(--medium-gray);
}

.border-b {
    border-bottom: 1px solid var(--medium-gray);
}

.border-gray-200 {
    border-color: var(--medium-gray);
}

.block {
    display: block;
}

.list-disc {
    list-style-type: disc;
}

button {
    background: none;
    border: none;
    cursor: pointer;
    outline: none;
}

/* 响应式样式 */
@media (min-width: 768px) {
    .md:flex {
        display: flex;
    }
    
    .md:hidden {
        display: none;
    }
    
    .md:grid-cols-4 {
        grid-template-columns: repeat(4, minmax(0, 1fr));
    }
    
    .md:py-24 {
        padding-top: 6rem;
        padding-bottom: 6rem;
    }
    
    .md:text-xl {
        font-size: 1.25rem;
    }
    
    .md:text-5xl {
        font-size: 3rem;
    }
    
    .md:text-base {
        font-size: 1rem;
    }
    
    .md:p-8 {
        padding: 2rem;
    }
}

@media (max-width: 767px) {
    .hidden {
        display: none;
    }
    
    .grid {
        display: grid;
    }
    

}

/* 关于我们页面特有样式 */
.team-member {
    text-align: center;
    padding: 1.5rem;
}

.team-member img {
    width: 180px;
    height: 180px;
    border-radius: 50%;
    object-fit: cover;
    margin-bottom: 1rem;
    border: 4px solid var(--white);
    box-shadow: 0 4px 12px rgba(0,0,0,0.1);
}

.feature-card {
    background-color: var(--white);
    border-radius: 0.75rem;
    padding: 2rem;
    box-shadow: 0 4px 6px rgba(0,0,0,0.05);
    transition: transform 0.3s ease, box-shadow 0.3s ease;
}

.feature-card:hover {
    transform: translateY(-5px);
    box-shadow: 0 10px 15px rgba(0,0,0,0.1);
}

.feature-card i {
    font-size: 2.5rem;
    color: var(--primary);
    margin-bottom: 1rem;
}

.timeline {
    position: relative;
    max-width: 800px;
    margin: 0 auto;
}

.timeline::after {
    content: '';
    position: absolute;
    width: 6px;
    background-color: var(--medium-gray);
    top: 0;
    bottom: 0;
    left: 50%;
    margin-left: -3px;
}

.timeline-item {
    padding: 10px 40px;
    position: relative;
    width: 50%;
    box-sizing: border-box;
}

.timeline-item::after {
    content: '';
    position: absolute;
    width: 20px;
    height: 20px;
    background-color: var(--white);
    border: 4px solid var(--primary);
    border-radius: 50%;
    top: 15px;
    z-index: 1;
}

.timeline-left {
    left: 0;
}

.timeline-right {
    left: 50%;
}

.timeline-left::after {
    right: -13px;
}

.timeline-right::after {
    left: -13px;
}

.timeline-content {
    padding: 20px;
    background-color: var(--white);
    border-radius: 0.75rem;
    box-shadow: 0 4px 6px rgba(0,0,0,0.05);
}

@media screen and (max-width: 768px) {
    .timeline::after {
        left: 31px;
    }
    
    .timeline-item {
        width: 100%;
        padding-left: 70px;
        padding-right: 25px;
    }
    
    .timeline-right {
        left: 0;
    }
    
    .timeline-left::after, .timeline-right::after {
        left: 18px;
    }
}