.projects {
    background-color: #f5f5f5;
    padding: 80px 60px;
    text-align: center;
}

.projects-title {
    font-size: 32px;
    color: #333;
    margin-bottom: 50px;
    position: relative;
    display: inline-block;
    padding-bottom: 12px;
    animation: anim-fade-down 0.6s cubic-bezier(0.2, 0.7, 0.2, 1) both;
}

.projects-title::after {
    content: "";
    position: absolute;
    bottom: 0;
    left: 50%;
    width: 56px;
    height: 3px;
    background-color: #4a90d9;
    border-radius: 2px;
    transform: translateX(-50%) scaleX(0);
    transform-origin: center;
    animation: anim-underline-grow 0.6s cubic-bezier(0.2, 0.7, 0.2, 1) 0.35s forwards;
}

.project-grid {
    display: grid;
    grid-template-columns: repeat(2, minmax(0, 1fr));
    gap: 40px;
    max-width: 1200px;
    margin: 0 auto;
    text-align: left;
}

.project-card {
    background-color: #f9f9f9;
    border-radius: 12px;
    box-shadow: 0 4px 15px rgba(0, 0, 0, 0.08);
    padding: 28px 32px;
    transition: transform 0.35s cubic-bezier(0.2, 0.7, 0.2, 1),
                box-shadow 0.35s ease,
                border-color 0.35s ease;
    border: 1px solid transparent;
    position: relative;
    overflow: hidden;
    animation: anim-fade-up 0.6s cubic-bezier(0.2, 0.7, 0.2, 1) both;
}

.project-card:nth-child(1) { animation-delay: 0.15s; }
.project-card:nth-child(2) { animation-delay: 0.30s; }
.project-card:nth-child(3) { animation-delay: 0.45s; }
.project-card:nth-child(4) { animation-delay: 0.60s; }

.project-card::before {
    content: "";
    position: absolute;
    top: 0;
    left: 0;
    width: 4px;
    height: 100%;
    background: linear-gradient(180deg, #4a90d9, #357abd);
    transform: scaleY(0);
    transform-origin: top;
    transition: transform 0.4s cubic-bezier(0.2, 0.7, 0.2, 1);
}

.project-card:hover {
    transform: translateY(-5px);
    box-shadow: 0 12px 28px rgba(0, 0, 0, 0.14);
    border-color: rgba(74, 144, 217, 0.3);
}

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

.project-card h3 {
    font-size: 20px;
    color: #2c3e50;
    margin-bottom: 14px;
    transition: color 0.25s ease;
}

.project-card:hover h3 {
    color: #4a90d9;
}

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

.project-card ul li {
    font-size: 14px;
    line-height: 1.8;
    color: #4a5a6a;
    margin-bottom: 8px;
    padding: 4px 0 4px 4px;
    border-radius: 4px;
    transition: background-color 0.2s ease, transform 0.2s ease, padding-left 0.25s ease;
}

.project-card ul li:hover {
    background-color: rgba(74, 144, 217, 0.06);
    transform: translateX(4px);
    padding-left: 10px;
}

.project-card ul li strong {
    color: #2c3e50;
}

.project-card a {
    color: #4a90d9;
    text-decoration: none;
    word-break: break-all;
    transition: color 0.2s ease;
}

.project-card a:hover {
    color: #357abd;
    text-decoration: underline;
}

/* ========== 响应式 ========== */
@media (max-width: 1024px) {
    .projects {
        padding: 60px 30px;
    }
}

@media (max-width: 768px) {
    .projects {
        padding: 40px 22px;
    }

    .projects-title {
        font-size: 24px;
        margin-bottom: 30px;
    }

    .project-grid {
        grid-template-columns: 1fr;
        gap: 22px;
    }

    .project-card {
        padding: 22px 24px;
    }

    .project-card h3 {
        font-size: 17px;
    }
}