* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}

:root {
    --primary-color: #0f4c81;
    --secondary-color: #1e3a8a;
    --accent-color: #ff6b35;
    --text-color: #1e293b;
    --text-light: #64748b;
    --background-light: #f1f5f9;
    --background-white: #ffffff;
    --border-color: #e2e8f0;
    --success-color: #10b981;
    --error-color: #ef4444;
    --shadow-sm: 0 1px 2px 0 rgba(0, 0, 0, 0.05);
    --shadow-md: 0 4px 6px -1px rgba(0, 0, 0, 0.1), 0 2px 4px -1px rgba(0, 0, 0, 0.06);
    --shadow-lg: 0 10px 15px -3px rgba(0, 0, 0, 0.1), 0 4px 6px -2px rgba(0, 0, 0, 0.05);
    --shadow-xl: 0 20px 25px -5px rgba(0, 0, 0, 0.1), 0 10px 10px -5px rgba(0, 0, 0, 0.04);
    --border-radius-sm: 6px;
    --border-radius-md: 12px;
    --border-radius-lg: 20px;
    --transition: all 0.3s cubic-bezier(0.4, 0, 0.2, 1);
}

body {
    font-family: 'Inter', 'Segoe UI', 'Roboto', 'Helvetica Neue', Arial, sans-serif;
    line-height: 1.6;
    color: var(--text-color);
    background-color: var(--background-light);
    overflow-x: hidden;
}

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

header {
    background: linear-gradient(135deg, var(--primary-color) 0%, var(--secondary-color) 100%);
    color: white;
    padding: 100px 0;
    text-align: center;
    position: relative;
    overflow: hidden;
}

header::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    background: url('data:image/svg+xml;utf8,<svg xmlns="http://www.w3.org/2000/svg" viewBox="0 0 100 100" preserveAspectRatio="none"><path fill="rgba(255,255,255,0.1)" d="M0,0 L100,0 L100,100 L0,100 Z" /></svg>');
    background-size: cover;
}

header .container {
    position: relative;
    z-index: 1;
}

header h1 {
    font-size: 3.2rem;
    font-weight: 800;
    margin-bottom: 20px;
    letter-spacing: -0.5px;
    line-height: 1.2;
    text-shadow: 0 2px 4px rgba(0, 0, 0, 0.1);
}

header p {
    font-size: 1.4rem;
    opacity: 0.9;
    max-width: 800px;
    margin: 0 auto;
    font-weight: 300;
}

.main-nav {
    background: rgba(255, 255, 255, 0.95);
    backdrop-filter: blur(10px);
    box-shadow: var(--shadow-md);
    margin-bottom: 40px;
    position: sticky;
    top: 0;
    z-index: 100;
}

.main-nav ul {
    display: flex;
    list-style: none;
    justify-content: center;
}

.main-nav button {
    padding: 20px 36px;
    background: transparent;
    border: none;
    font-size: 16px;
    font-weight: 500;
    cursor: pointer;
    transition: var(--transition);
    position: relative;
    overflow: hidden;
    color: var(--text-color);
}

.main-nav button::after {
    content: '';
    position: absolute;
    bottom: 0;
    left: 0;
    width: 0;
    height: 3px;
    background: var(--accent-color);
    transition: var(--transition);
}

.main-nav button.active {
    color: var(--accent-color);
    font-weight: 600;
}

.main-nav button.active::after {
    width: 100%;
}

.main-nav button:hover {
    color: var(--accent-color);
    background: rgba(255, 107, 53, 0.05);
}

.main-nav button:hover::after {
    width: 100%;
}

main {
    padding: 60px 0;
}

.search-section {
    background: var(--background-white);
    border-radius: var(--border-radius-lg);
    box-shadow: var(--shadow-md);
    padding: 48px;
    margin-bottom: 48px;
    transition: var(--transition);
    border: 1px solid var(--border-color);
}

.search-section:hover {
    box-shadow: var(--shadow-xl);
    transform: translateY(-2px);
}

.search-container {
    display: flex;
    margin-bottom: 30px;
    gap: 16px;
}

#search-input,
#project-search-input {
    flex: 1;
    padding: 18px 24px;
    font-size: 16px;
    border: 2px solid var(--border-color);
    border-radius: var(--border-radius-md);
    transition: var(--transition);
    font-weight: 400;
    background: var(--background-white);
}

#search-input:focus,
#project-search-input:focus {
    outline: none;
    border-color: var(--accent-color);
    box-shadow: 0 0 0 4px rgba(255, 107, 53, 0.1);
    transform: translateY(-1px);
}

#search-btn,
#project-search-btn {
    background: var(--accent-color);
    color: white;
    border: none;
    padding: 0 36px;
    font-size: 16px;
    font-weight: 600;
    border-radius: var(--border-radius-md);
    cursor: pointer;
    transition: var(--transition);
    white-space: nowrap;
    display: flex;
    align-items: center;
    justify-content: center;
    gap: 8px;
}

#search-btn:hover,
#project-search-btn:hover {
    background: #e55a2b;
    transform: translateY(-2px);
    box-shadow: 0 8px 24px rgba(255, 107, 53, 0.3);
}

.filters {
    display: flex;
    gap: 24px;
    flex-wrap: wrap;
}

.filters select {
    padding: 14px 20px;
    font-size: 15px;
    border: 2px solid var(--border-color);
    border-radius: var(--border-radius-md);
    flex: 1;
    min-width: 220px;
    transition: var(--transition);
    background: var(--background-white);
    appearance: none;
    background-image: url('data:image/svg+xml;utf8,<svg xmlns="http://www.w3.org/2000/svg" fill="none" viewBox="0 0 24 24" stroke="%2364748b"><path stroke-linecap="round" stroke-linejoin="round" stroke-width="2" d="M19 9l-7 7-7-7" /></svg>');
    background-repeat: no-repeat;
    background-position: right 16px center;
    background-size: 16px;
}

.filters select:focus {
    outline: none;
    border-color: var(--accent-color);
    box-shadow: 0 0 0 4px rgba(255, 107, 53, 0.1);
    transform: translateY(-1px);
}

.results-section {
    background: var(--background-white);
    border-radius: var(--border-radius-lg);
    box-shadow: var(--shadow-md);
    padding: 48px;
    transition: var(--transition);
    border: 1px solid var(--border-color);
}

.results-section:hover {
    box-shadow: var(--shadow-xl);
}

#results-count,
#project-results-count {
    margin-bottom: 30px;
    font-size: 16px;
    color: var(--text-light);
    font-weight: 500;
    display: flex;
    align-items: center;
    gap: 8px;
}

.cards-container {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: 32px;
}

@media (max-width: 1200px) {
    .cards-container {
        grid-template-columns: repeat(2, 1fr);
    }
}

@media (max-width: 768px) {
    .cards-container {
        grid-template-columns: 1fr;
    }
}

.company-card {
    border: 1px solid var(--border-color);
    border-radius: var(--border-radius-md);
    padding: 32px;
    transition: var(--transition);
    background: var(--background-white);
    position: relative;
    overflow: hidden;
    display: flex;
    flex-direction: column;
}

.company-card::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 4px;
    background: linear-gradient(90deg, var(--accent-color), var(--primary-color));
    transform: scaleX(0);
    transition: var(--transition);
}

.company-card:hover {
    transform: translateY(-8px);
    box-shadow: var(--shadow-xl);
}

.company-card:hover::before {
    transform: scaleX(1);
}

.company-card h3 {
    color: var(--primary-color);
    margin-bottom: 20px;
    font-size: 1.4rem;
    font-weight: 700;
    line-height: 1.3;
}

.company-card .info-item {
    display: flex;
    margin-bottom: 12px;
    font-size: 14px;
    align-items: center;
}

.company-card .info-label {
    font-weight: 600;
    width: 90px;
    color: var(--text-light);
}

.company-card .tech-tags {
    margin-top: 24px;
    margin-bottom: auto;
}

.company-card .tech-tag {
    display: inline-block;
    background: rgba(15, 76, 129, 0.1);
    color: var(--primary-color);
    padding: 8px 16px;
    border-radius: 24px;
    font-size: 13px;
    font-weight: 500;
    margin-right: 12px;
    margin-bottom: 12px;
    transition: var(--transition);
    border: 1px solid rgba(15, 76, 129, 0.2);
}

.company-card .tech-tag:hover {
    background: var(--primary-color);
    color: white;
    transform: translateY(-2px);
    box-shadow: var(--shadow-md);
}

.project-card {
    border: 1px solid var(--border-color);
    border-radius: var(--border-radius-md);
    padding: 36px;
    margin-bottom: 32px;
    transition: var(--transition);
    background: var(--background-white);
    position: relative;
    overflow: hidden;
}

.project-card::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 4px;
    background: linear-gradient(90deg, var(--primary-color), var(--accent-color));
    transform: scaleX(0);
    transition: var(--transition);
}

.project-card:hover {
    transform: translateY(-6px);
    box-shadow: var(--shadow-xl);
}

.project-card:hover::before {
    transform: scaleX(1);
}

.project-card h3 {
    color: var(--primary-color);
    margin-bottom: 24px;
    font-size: 1.6rem;
    font-weight: 700;
    line-height: 1.3;
}

.project-details {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(240px, 1fr));
    gap: 24px;
    margin-bottom: 24px;
}

.project-detail-item {
    font-size: 14px;
}

.project-detail-item strong {
    color: var(--secondary-color);
    display: block;
    margin-bottom: 8px;
    font-weight: 600;
    font-size: 12px;
    text-transform: uppercase;
    letter-spacing: 0.5px;
}

.project-progress {
    margin-top: 30px;
    padding-top: 30px;
    border-top: 1px solid var(--border-color);
}

.project-progress h4 {
    color: var(--primary-color);
    margin-bottom: 16px;
    font-size: 16px;
    font-weight: 600;
}

.project-progress p {
    font-size: 15px;
    line-height: 1.6;
    color: var(--text-color);
}

footer {
    background: var(--primary-color);
    color: white;
    text-align: center;
    padding: 60px 0;
    margin-top: 80px;
    position: relative;
    overflow: hidden;
}

footer::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    background: url('data:image/svg+xml;utf8,<svg xmlns="http://www.w3.org/2000/svg" viewBox="0 0 100 100" preserveAspectRatio="none"><path fill="rgba(255,255,255,0.05)" d="M0,0 L100,0 L100,100 L0,100 Z" /></svg>');
    background-size: cover;
}

footer .container {
    position: relative;
    z-index: 1;
}

footer p {
    opacity: 0.8;
    font-size: 14px;
    line-height: 1.6;
}

footer p:first-child {
    margin-bottom: 12px;
    font-weight: 500;
    opacity: 0.9;
    font-size: 16px;
}

/* 加载动画 */
.loading {
    display: flex;
    justify-content: center;
    align-items: center;
    padding: 60px;
}

.loading-spinner {
    width: 50px;
    height: 50px;
    border: 3px solid rgba(255, 255, 255, 0.3);
    border-radius: 50%;
    border-top-color: var(--accent-color);
    animation: spin 1s ease-in-out infinite;
}

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

/* 响应式设计 */
@media (max-width: 768px) {
    header {
        padding: 80px 0;
    }
    
    header h1 {
        font-size: 2.4rem;
    }
    
    header p {
        font-size: 1.2rem;
    }
    
    .main-nav ul {
        flex-direction: column;
    }
    
    .main-nav button {
        padding: 16px 24px;
        text-align: center;
    }
    
    .search-container {
        flex-direction: column;
    }
    
    #search-input,
    #project-search-input {
        border-radius: var(--border-radius-md);
    }
    
    #search-btn,
    #project-search-btn {
        border-radius: var(--border-radius-md);
        padding: 16px;
    }
    
    .filters {
        flex-direction: column;
    }
    
    .cards-container {
        grid-template-columns: 1fr;
        gap: 24px;
    }
    
    .project-details {
        grid-template-columns: 1fr;
        gap: 20px;
    }
    
    .search-section,
    .results-section {
        padding: 32px;
    }
    
    main {
        padding: 40px 0;
    }
    
    footer {
        padding: 48px 0;
    }
}

/* 滚动条样式 */
::-webkit-scrollbar {
    width: 8px;
}

::-webkit-scrollbar-track {
    background: var(--background-light);
}

::-webkit-scrollbar-thumb {
    background: var(--text-light);
    border-radius: 4px;
}

::-webkit-scrollbar-thumb:hover {
    background: var(--primary-color);
}

/* 平滑滚动 */
html {
    scroll-behavior: smooth;
}

/* 焦点样式 */
*:focus {
    outline: none;
}

/* 选择文本样式 */
::selection {
    background: var(--accent-color);
    color: white;
}

/* 动画效果 */
@keyframes fadeIn {
    from {
        opacity: 0;
        transform: translateY(20px);
    }
    to {
        opacity: 1;
        transform: translateY(0);
    }
}

.search-section,
.results-section,
.company-card,
.project-card {
    animation: fadeIn 0.5s ease forwards;
}

.company-card {
    animation-delay: 0.1s;
}

.project-card {
    animation-delay: 0.2s;
}