/* 沛雨霖科技 - 现代简洁企业风格 */
/* 无渐变，纯色块设计 */

:root {
    --primary: #1a56db;
    --bg: #ffffff;
    --bg-light: #f8fafc;
    --text: #0f172a;
    --text-secondary: #475569;
    --border: #e2e8f0;
    --radius: 8px;
}

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

body {
    font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei", sans-serif;
    color: var(--text);
    background: var(--bg);
    line-height: 1.6;
    -webkit-font-smoothing: antialiased;
}

.container {
    max-width: 1080px;
    margin: 0 auto;
    padding: 0 24px;
}

/* Header */
.site-header {
    background: var(--bg);
    border-bottom: 1px solid var(--border);
    position: sticky;
    top: 0;
    z-index: 100;
}

.header-inner {
    display: flex;
    align-items: center;
    justify-content: space-between;
    height: 64px;
}

.logo {
    font-size: 18px;
    font-weight: 700;
    color: var(--text);
    text-decoration: none;
}


.hero {
    background: var(--bg-light);
    border-bottom: 1px solid var(--border);
    padding: 96px 0;
    text-align: center;
}

.hero h1 {
    font-size: 44px;
    font-weight: 800;
    letter-spacing: -0.5px;
    margin-bottom: 16px;
}

.hero-sub {
    font-size: 18px;
    color: var(--text-secondary);
}

/* Features */
.features {
    padding: 72px 0;
}

.feature-grid {
    display: grid;
    grid-template-columns: repeat(4, 1fr);
    gap: 24px;
}

.feature-item {
    position: relative;
    min-height: 164px;
    overflow: hidden;
    background: var(--bg);
    border: 1px solid var(--border);
    border-radius: var(--radius);
    padding: 22px 24px 20px;
    text-align: left;
    transition: border-color 0.2s;
    visibility: hidden;
    animation: none;
}

.feature-item.is-visible:nth-child(1) { animation-delay: 0.08s; }
.feature-item.is-visible:nth-child(2) { animation-delay: 0.18s; }
.feature-item.is-visible:nth-child(3) { animation-delay: 0.28s; }
.feature-item.is-visible:nth-child(4) { animation-delay: 0.38s; }

.feature-item.is-visible {
    visibility: visible;
    animation: feature-rise 0.65s cubic-bezier(0.22, 1, 0.36, 1) both;
}

@keyframes feature-rise {
    from {
        opacity: 0;
        transform: translateY(28px);
    }
    to {
        opacity: 1;
        transform: translateY(0);
    }
}

.feature-item::before {
    content: "";
    position: absolute;
    top: 24px;
    left: 0;
    width: 3px;
    height: 30px;
    background: var(--border);
    transition: background-color 0.2s;
}

.feature-item:hover {
    border-color: #93c5fd;
}

.feature-item:hover::before {
    background: var(--primary);
}

.feature-number {
    position: relative;
    z-index: 1;
    display: block;
    color: #94a3b8;
    font: 600 12px/1 "SFMono-Regular", Consolas, monospace;
    letter-spacing: 0.08em;
}

.feature-copy {
    position: absolute;
    right: 24px;
    bottom: 38px;
    left: 24px;
    z-index: 1;
}

.feature-item h3 {
    font-size: 17px;
    font-weight: 700;
    margin-bottom: 8px;
}

.feature-item p {
    font-size: 14px;
    color: var(--text-secondary);
}

.feature-icon {
    position: absolute;
    right: 12px;
    bottom: 10px;
    z-index: 0;
    color: #3155c8;
    font-size: 64px;
    line-height: 1;
    opacity: 0.07;
    pointer-events: none;
}

/* Projects */
.projects,
.about,
.contact {
    padding: 72px 0;
}

.projects h2,
.about h2,
.contact h2 {
    font-size: 28px;
    font-weight: 700;
    margin-bottom: 32px;
    text-align: center;
}

.project-grid {
    display: grid;
    grid-template-columns: repeat(2, 1fr);
    gap: 24px;
}

.project-card {
    display: block;
    background: var(--bg);
    border: 1px solid var(--border);
    border-radius: var(--radius);
    padding: 32px 28px;
    color: var(--text);
    text-decoration: none;
    transition: border-color 0.2s, box-shadow 0.2s;
    visibility: hidden;
    animation: none;
}

.project-card.is-visible:nth-child(1) { animation-delay: 0.03s; }
.project-card.is-visible:nth-child(2) { animation-delay: 0.06s; }
.project-card.is-visible:nth-child(3) { animation-delay: 0.09s; }
.project-card.is-visible:nth-child(4) { animation-delay: 0.12s; }
.project-card.is-visible:nth-child(5) { animation-delay: 0.15s; }
.project-card.is-visible:nth-child(6) { animation-delay: 0.18s; }
.project-card.is-visible:nth-child(7) { animation-delay: 0.21s; }
.project-card.is-visible:nth-child(8) { animation-delay: 0.24s; }
.project-card.is-visible:nth-child(9) { animation-delay: 0.27s; }
.project-card.is-visible:nth-child(10) { animation-delay: 0.30s; }
.project-card.is-visible:nth-child(11) { animation-delay: 0.33s; }
.project-card.is-visible:nth-child(12) { animation-delay: 0.36s; }
.project-card.is-visible:nth-child(13) { animation-delay: 0.39s; }
.project-card.is-visible:nth-child(14) { animation-delay: 0.42s; }
.project-card.is-visible:nth-child(15) { animation-delay: 0.45s; }
.project-card.is-visible:nth-child(16) { animation-delay: 0.48s; }

.project-card.is-visible {
    visibility: visible;
    animation: project-rise 0.36s cubic-bezier(0.22, 1, 0.36, 1) both;
}

@keyframes project-rise {
    from {
        opacity: 0;
        transform: translateY(16px);
    }
    to {
        opacity: 1;
        transform: translateY(0);
    }
}

.project-card:hover {
    border-color: var(--primary);
    box-shadow: 0 4px 16px rgba(0, 0, 0, 0.06);
}

.project-card h3 {
    margin-bottom: 14px;
    font-size: 18px;
    font-weight: 700;
}

.project-links {
    display: flex;
    flex-wrap: wrap;
    gap: 8px;
}

.project-links a {
    display: inline-block;
    padding: 5px 10px;
    border: 1px solid var(--border);
    border-radius: 6px;
    color: var(--primary);
    font-size: 13px;
    text-decoration: none;
}

.project-links a:hover {
    border-color: var(--primary);
    background: #eff6ff;
}

.project-state {
    grid-column: 1 / -1;
    padding: 32px 24px;
    color: var(--text-secondary);
    text-align: center;
}

.project-error {
    color: #b42318;
}

/* About / Contact */
.about {
    background: var(--bg-light);
    border-top: 1px solid var(--border);
    border-bottom: 1px solid var(--border);
}

.about p,
.contact p {
    text-align: center;
    color: var(--text-secondary);
    max-width: 640px;
    margin: 0 auto;
}

/* Footer */
.site-footer {
    background: var(--text);
    color: #94a3b8;
    padding: 24px 0;
    text-align: center;
    font-size: 14px;
}

.site-footer > .container {
    display: flex;
    flex-direction: column;
    align-items: center;
}

.footer-group {
    display: flex;
    justify-content: center;
    align-items: center;
    gap: 24px;
    line-height: 22px;
}

.site-footer,
.site-footer a {
    color: #94a3b8;
    font-size: 14px;
}

.site-footer a {
    cursor: pointer;
    text-decoration: none;
}

.site-footer a:hover,
.site-footer a:focus,
.site-footer a:visited,
.site-footer a:active { color: #94a3b8; }

@media (max-width: 640px) {
    .footer-group {
        flex-direction: column;
        gap: 0;
    }
}

/* Responsive */
@media (max-width: 768px) {
    .hero {
        padding: 64px 0;
    }

    .hero h1 {
        font-size: 32px;
    }

    .feature-grid {
        grid-template-columns: repeat(2, 1fr);
    }

    .project-grid {
        grid-template-columns: 1fr;
    }

}

@media (max-width: 480px) {
    .feature-grid {
        grid-template-columns: 1fr;
    }
}

@media (prefers-reduced-motion: reduce) {
    .feature-item,
    .project-card {
        visibility: visible;
        opacity: 1;
        transform: none;
        animation: none;
    }
}