.btn {
    display: inline-block;
    background: linear-gradient(135deg, #5c6bc0, #3949ab);
    color: white;
    padding: 16px 40px;
    border-radius: 50px;
    text-decoration: none;
    font-weight: 600;
    font-size: 18px;
    box-shadow: 0 10px 25px rgba(92, 107, 192, 0.3);
    transition: all 0.4s ease;
    border: none;
    cursor: pointer;
    position: relative;
    overflow: hidden;
}

.btn::before {
    content: '';
    position: absolute;
    top: 0;
    left: -100%;
    width: 100%;
    height: 100%;
    background: linear-gradient(90deg, transparent, rgba(255, 255, 255, 0.3), transparent);
    transition: 0.5s;
}

.btn:hover {
    transform: translateY(-5px);
    box-shadow: 0 15px 30px rgba(92, 107, 192, 0.4);
}

.btn:hover::before {
    left: 100%;
}

/* 特性部分 */
.features {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
    gap: 40px;
    margin: 80px 0;
}

.feature-card {
    background: white;
    padding: 40px 30px;
    border-radius: 20px;
    text-align: center;
    transition: all 0.4s ease;
    box-shadow: 0 15px 35px rgba(0, 0, 0, 0.05);
    border: 1px solid rgba(0, 0, 0, 0.03);
}

.feature-card:hover {
    transform: translateY(-15px);
    box-shadow: 0 20px 40px rgba(0, 0, 0, 0.08);
}

.feature-icon {
    width: 100px;
    height: 100px;
    background: rgba(92, 107, 192, 0.08);
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    margin: 0 auto 25px;
    font-size: 40px;
    color: #5c6bc0;
    box-shadow: 0 10px 20px rgba(0, 0, 0, 0.05);
    transition: all 0.4s ease;
}

.feature-card:hover .feature-icon {
    transform: rotateY(360deg);
    background: rgba(92, 107, 192, 0.15);
}

.feature-card h3 {
    font-size: 26px;
    margin-bottom: 20px;
    color: #2d3748;
}

.feature-card p {
    color: #4a5568;
    font-size: 18px;
    line-height: 1.6;
}

/* 客服聊天系统 */
.chat-btn {
    position: fixed;
    bottom: 400px;
    right: 26px;
    width: 60px;
    height: 60px;
    background: linear-gradient(135deg, #5c6bc0, #3949ab);
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    cursor: pointer;
    box-shadow: 0 10px 30px rgba(92, 107, 192, 0.4);
    z-index: 99;
    transition: all 0.4s ease;
    animation: pulse 2s infinite;
}

.chat-btn:hover {
    transform: scale(1.1) rotate(10deg);
    box-shadow: 0 15px 40px rgba(92, 107, 192, 0.6);
    animation: none;
}

.chat-btn i {
    font-size: 28px;
    color: white;
}

.chat-overlay {
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    background: rgba(0, 0, 0, 0.4);
    display: flex;
    align-items: center;
    justify-content: center;
    z-index: 200;
    opacity: 0;
    visibility: hidden;
    transition: all 0.5s cubic-bezier(0.175, 0.885, 0.32, 1.275);
    backdrop-filter: blur(5px);
}

.chat-overlay.active {
    opacity: 1;
    visibility: visible;
}

.chat-box {
    width: 100%;
    max-width: 800px;
    background: white;
    border-radius: 25px;
    overflow: hidden;
    box-shadow: 0 30px 60px rgba(0, 0, 0, 0.15);
    transform: translateY(50px) scale(0.8);
    opacity: 0;
    transition: all 0.5s cubic-bezier(0.175, 0.885, 0.32, 1.275);
}

.chat-overlay.active .chat-box {
    transform: translateY(0) scale(1);
    opacity: 1;
}

.chat-header {
    background: linear-gradient(135deg, #5c6bc0, #3949ab);
    color: white;
    padding: 25px;
    display: flex;
    align-items: center;
    justify-content: space-between;
}

.chat-header h3 {
    font-size: 22px;
    display: flex;
    align-items: center;
    font-weight: 600;
}

.chat-header h3 i {
    margin-right: 12px;
}

.close-btn {
    background: rgba(255, 255, 255, 0.2);
    border: none;
    color: white;
    width: 40px;
    height: 40px;
    border-radius: 50%;
    font-size: 20px;
    cursor: pointer;
    transition: all 0.3s ease;
}

.close-btn:hover {
    background: rgba(255, 255, 255, 0.3);
    transform: rotate(90deg);
}

.chat-body {
    height: 450px;
    padding: 25px;
    overflow-y: auto;
    display: flex;
    flex-direction: column;
    background: #f8f9fc;
}

.message {
    max-width: 80%;
    padding: 18px 22px;
    margin-bottom: 25px;
    border-radius: 25px;
    position: relative;
    animation: fadeIn 0.4s ease;
    display: flex;
    align-items: flex-start;
}

@keyframes fadeIn {
    from { opacity: 0; transform: translateY(15px); }
    to { opacity: 1; transform: translateY(0); }
}

.received {
    align-self: flex-start;
    background: white;
    border: 1px solid rgba(0, 0, 0, 0.05);
}

.sent {
    align-self: flex-end;
    background: linear-gradient(135deg, #5c6bc0, #3949ab);
    color: white;
}

.avatar {
    width: 45px;
    height: 45px;
    border-radius: 50%;
    margin-right: 15px;
    flex-shrink: 0;
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 20px;
    background: rgba(92, 107, 192, 0.1);
    color: #5c6bc0;
}

.sent .avatar {
    background: rgba(255, 255, 255, 0.2);
    color: white;
}

.message-content {
    flex: 1;
}

.message-content p {
    font-size: 17px;
    line-height: 1.5;
}

.message-info {
    display: flex;
    justify-content: space-between;
    margin-top: 10px;
    font-size: 13px;
    color: rgba(0, 0, 0, 0.5);
}

.sent .message-info {
    color: rgba(255, 255, 255, 0.7);
}

.chat-footer {
    padding: 20px;
    background: white;
    display: flex;
    border-top: 1px solid rgba(0, 0, 0, 0.05);
}

.chat-input {
    flex: 1;
    padding: 16px 25px;
    border: 1px solid rgba(0, 0, 0, 0.1);
    border-radius: 30px;
    font-size: 17px;
    outline: none;
    color: #333;
    transition: all 0.3s ease;
    background: #f8f9fc;
}

.chat-input:focus {
    border-color: #5c6bc0;
    box-shadow: 0 0 15px rgba(92, 107, 192, 0.2);
}

.chat-input::placeholder {
    color: rgba(0, 0, 0, 0.3);
}

.send-btn {
    width: 55px;
    height: 55px;
    border-radius: 50%;
    background: linear-gradient(135deg, #5c6bc0, #3949ab);
    color: white;
    border: none;
    margin-left: 15px;
    cursor: pointer;
    transition: all 0.3s ease;
    box-shadow: 0 5px 15px rgba(92, 107, 192, 0.3);
}

.send-btn:hover {
    transform: rotate(15deg) scale(1.1);
}

/* 动画效果 */
@keyframes float {
    0% { transform: translateY(0px); }
    50% { transform: translateY(-20px); }
    100% { transform: translateY(0px); }
}

@keyframes pulse {
    0% { box-shadow: 0 0 0 0 rgba(92, 107, 192, 0.4); }
    70% { box-shadow: 0 0 0 20px rgba(92, 107, 192, 0); }
    100% { box-shadow: 0 0 0 0 rgba(92, 107, 192, 0); }
}

@keyframes fadeInUp {
    from { opacity: 0; transform: translateY(40px); }
    to { opacity: 1; transform: translateY(0); }
}