body {
    background: var(--background-color);
}

.help-main-wrapper {
    display: flex;
    gap: 40px;
    max-width: 1100px;
    margin: 32px auto 40px auto;
    align-items: flex-start;
}

.help-content-wrapper, .help-contact-wrapper {
    align-self: stretch;
    box-sizing: border-box;
    display: flex;
    flex-direction: column;
    justify-content: flex-start;
    align-items: center;
    width: 100%;
}

.help-content-wrapper {
    flex: 2;
    margin-top: 0;
    padding-top: 0;
    min-width: 0;
}

.help-title {
    font-size: 28px;
    font-weight: 600;
    color: var(--primary-blue);
    margin-bottom: 32px;
}

.help-options {
    display: flex;
    gap: 24px;
    margin-bottom: 32px;
}

.help-btn {
    background: var(--primary-blue);
    color: #fff;
    border: none;
    border-radius: 999px;
    padding: 14px 36px;
    font-size: 18px;
    font-weight: 500;
    cursor: pointer;
    box-shadow: 0 2px 8px rgba(0,0,0,0.08);
    transition: background 0.2s, box-shadow 0.2s;
}
.help-btn:hover {
    background: var(--light-blue);
    box-shadow: 0 4px 16px rgba(0,0,0,0.12);
}

.help-details {
    position: relative;
    width: 100%;
    display: flex;
    justify-content: center;
    margin-bottom: 16px;
    max-height: 0;
    opacity: 0;
    transform: scale(0.98);
    pointer-events: none;
    transition: max-height 0.5s cubic-bezier(.4,1.2,.4,1), opacity 0.4s, transform 0.4s;
    overflow: hidden;
    will-change: opacity, max-height, transform;
}
.help-details.active {
    max-height: 500px;
    opacity: 1;
    transform: scale(1);
    pointer-events: auto;
}

.help-card {
    background: #f5f5f7;
    border-radius: 14px;
    box-shadow: 0 2px 8px rgba(0,0,0,0.06);
    padding: 28px 24px;
    font-size: 17px;
    color: var(--text-color);
    min-width: 260px;
    max-width: 100%;
    text-align: left;
    transition: padding 0.4s, font-size 0.4s, box-shadow 0.4s;
}

.help-contact-wrapper {
    flex: 1;
    background: #fff;
    border-radius: 18px;
    box-shadow: 0 4px 16px rgba(0,0,0,0.08);
    padding: 32px 20px;
    min-width: 260px;
    max-width: 340px;
    margin-top: 0;
    padding-top: 0;
    min-width: 0;
}
.contact-title {
    font-size: 28px;
    font-weight: 700;
    color: var(--primary-blue);
    margin-bottom: 12px;
}
.contact-desc {
    font-size: 14px;
    color: var(--secondary-text-color);
    margin-bottom: 18px;
    text-align: center;
}
.contact-btn {
    background: var(--primary-blue);
    color: #fff;
    border: none;
    border-radius: 999px;
    padding: 12px 32px;
    font-size: 16px;
    font-weight: 500;
    cursor: pointer;
    box-shadow: 0 2px 8px rgba(0,0,0,0.08);
    margin-bottom: 18px;
    transition: background 0.2s, box-shadow 0.2s;
}
.contact-btn:hover {
    background: #2196f3;
    box-shadow: 0 4px 16px rgba(0,0,0,0.12);
}
.contact-modal {
    position: fixed;
    left: 0; top: 0; right: 0; bottom: 0;
    display: flex;
    align-items: center;
    justify-content: center;
    background: rgba(0,0,0,0.08);
    z-index: 1000;
}
.contact-modal-content {
    background: #f5f5f7;
    border-radius: 14px;
    box-shadow: 0 2px 8px rgba(0,0,0,0.06);
    padding: 24px 12px;
    width: 260px;
    text-align: center;
    margin: 0 auto;
}
.contact-qr-img {
    width: 120px;
    height: 120px;
    object-fit: cover;
    border-radius: 12px;
    margin: 0 auto 12px auto;
    display: block;
    background: #e8e8ed;
}
.contact-wechat-placeholder {
    color: var(--secondary-text-color);
    font-size: 15px;
}

.fade-out {
    opacity: 0;
    transition: opacity 0.4s;
    will-change: opacity;
}

.help-close {
    position: absolute;
    top: 12px;
    right: 12px;
    background: none;
    border: none;
    font-size: 26px;
    color: #aaa;
    cursor: pointer;
    z-index: 2;
    transition: color 0.2s;
}
.help-close:hover {
    color: var(--primary-blue);
}

@media (max-width: 900px) {
    .help-main-wrapper {
        flex-direction: column;
        gap: 24px;
        max-width: 98vw;
        margin-top: 16px;
    }
    .help-contact-wrapper {
        max-width: 100%;
        margin-top: 24px;
    }
    .help-content-wrapper {
        margin-bottom: 0;
    }
}

@media (max-width: 600px) {
    .help-content-wrapper {
        margin: 0;
        padding: 16px 4px;
        border-radius: 0;
        box-shadow: none;
    }
    .help-options {
        flex-direction: column;
        gap: 16px;
        width: 100%;
    }
    .help-btn {
        width: 100%;
        font-size: 16px;
        padding: 12px 0;
    }
    .help-card {
        padding: 18px 10px;
        font-size: 15px;
    }
}

/* 帮助中心主布局 */
.help-center-main {
    display: flex;
    align-items: flex-start;
    justify-content: center;
    max-width: 1200px;
    margin: 48px auto 0 auto;
    min-height: 70vh;
    gap: 0 16px;
}

.help-sidebar {
    min-width: 180px;
    padding: 0 0 0 8px;
}
.help-categories {
    list-style: none;
    margin: 0;
    padding: 0;
    display: flex;
    flex-direction: column;
    gap: 8px;
}
.help-categories li {
    font-size: 1.08rem;
    color: #333;
    background: rgba(255,255,255,0.7);
    border-radius: 8px;
    padding: 14px 18px;
    cursor: pointer;
    transition: background 0.2s, color 0.2s, box-shadow 0.2s;
    user-select: none;
    position: relative;
}
.help-categories li.active {
    background: #e6f7f1;
    color: #1bbf83;
    font-weight: 600;
    box-shadow: 0 2px 8px 0 rgba(27,191,131,0.08);
}
.help-categories li .tutor-break {
    display: inline-block;
    white-space: nowrap;
}
.help-categories li .tutor-break br {
    display: none;
}

.help-qa-area {
    flex: 2 1 0;
    min-width: 0;
    display: flex;
    flex-direction: column;
    align-items: center;
    max-width: 700px;
}
.help-qa-list {
    width: 100%;
    max-width: 700px;
    display: flex;
    flex-direction: column;
    gap: 22px;
    margin: 0 auto 0 0;
}
.help-qa-item {
    background: rgba(255,255,255,0.97);
    border-radius: 14px;
    box-shadow: 0 2px 12px 0 rgba(27,191,131,0.07);
    padding: 0;
    overflow: hidden;
    transition: box-shadow 0.2s;
    cursor: pointer;
    position: relative;
}
.help-qa-item:focus {
    outline: 2px solid #1bbf83;
}
.help-qa-question {
    display: flex;
    align-items: center;
    font-size: 1.13rem;
    font-weight: 500;
    color: #222;
    padding: 20px 20px 20px 38px;
    position: relative;
    min-height: 32px;
    transition: color 0.2s;
}
.help-qa-item[data-open="1"] .help-qa-question {
    color: #1bbf83;
}
.qa-num {
    font-size: 1.13rem;
    font-weight: 600;
    color: #1bbf83;
    margin-right: 12px;
}
.qa-dot {
    display: inline-block;
    width: 12px;
    height: 12px;
    border-radius: 50%;
    background: #1bbf83;
    margin-left: auto;
    margin-right: 6px;
    opacity: 0;
    transform: scale(0.7);
    transition: opacity 0.3s, transform 0.3s;
}
.help-qa-item[data-open="1"] .qa-dot {
    opacity: 1;
    transform: scale(1);
}
.help-qa-answer {
    font-size: 1.04rem;
    color: #444;
    background: none;
    padding: 0 20px 0 38px;
    line-height: 1.7;
    max-height: 0;
    opacity: 0;
    overflow: hidden;
    transition: max-height 0.4s cubic-bezier(.4,1.2,.4,1), opacity 0.3s, padding 0.3s;
}
.help-qa-item[data-open="1"] .help-qa-answer {
    padding: 20px 20px 20px 38px;
    opacity: 1;
    max-height: 300px;
}

.help-contact-wrapper {
    flex: 1 1 0;
    background: #fff;
    border-radius: 18px;
    box-shadow: 0 4px 16px rgba(0,0,0,0.08);
    padding: 32px 20px;
    min-width: 220px;
    max-width: 320px;
    margin-left: 18px;
    margin-top: 0;
    align-self: flex-start;
    display: flex;
    flex-direction: column;
    align-items: center;
}
.contact-title {
    font-size: 28px;
    font-weight: 700;
    color: var(--primary-blue);
    margin-bottom: 12px;
}
.contact-desc {
    font-size: 15px;
    color: var(--secondary-text-color);
    margin-bottom: 18px;
    text-align: center;
}
.contact-btn {
    background: var(--primary-blue);
    color: #fff;
    border: none;
    border-radius: 999px;
    padding: 12px 32px;
    font-size: 16px;
    font-weight: 500;
    cursor: pointer;
    box-shadow: 0 2px 8px rgba(0,0,0,0.08);
    margin-bottom: 18px;
    transition: background 0.2s, box-shadow 0.2s;
}
.contact-btn:hover {
    background: #2196f3;
    box-shadow: 0 4px 16px rgba(0,0,0,0.12);
}

/* 联系客服弹窗 */
.modal {
    display: none;
    position: fixed;
    z-index: 1000;
    left: 0;
    top: 0;
    width: 100vw;
    height: 100vh;
    background-color: rgba(0,0,0,0.5);
    align-items: center;
    justify-content: center;
}
.modal-content {
    background-color: #fff;
    margin: auto;
    padding: 30px 20px 24px 20px;
    border: 1px solid #eee;
    width: 90%;
    max-width: 340px;
    border-radius: 16px;
    text-align: center;
    position: relative;
    box-shadow: 0 5px 25px rgba(0,0,0,0.18);
    animation: fadeInModal 0.4s ease-out;
}
.close-modal-btn {
    color: #aaa;
    position: absolute;
    top: 10px;
    right: 20px;
    font-size: 28px;
    font-weight: bold;
    cursor: pointer;
    background: none;
    border: none;
    transition: color 0.2s;
}
.close-modal-btn:hover,
.close-modal-btn:focus {
    color: #007aff;
    text-decoration: none;
}
.modal-content h2 {
    margin-top: 0;
    margin-bottom: 20px;
    font-size: 22px;
    color: var(--text-color);
}
.qr-code-modal {
    width: 160px;
    height: 160px;
    margin-bottom: 20px;
    border: 1px solid #eee;
    border-radius: 8px;
}
.wechat-id-modal {
    font-size: 16px;
    font-weight: 600;
    color: var(--dark-blue);
    background-color: #f0f5fa;
    padding: 10px 20px;
    border-radius: 8px;
    display: inline-block;
}
@keyframes fadeInModal {
    from {
        opacity: 0;
        transform: scale(0.9);
    }
    to {
        opacity: 1;
        transform: scale(1);
    }
}

@media (max-width: 1100px) {
    .help-center-main {
        max-width: 98vw;
    }
    .help-qa-list {
        max-width: 98vw;
    }
}
@media (max-width: 900px) {
    .help-center-main {
        flex-direction: column;
        align-items: stretch;
        gap: 0;
        margin-top: 24px;
    }
    .help-sidebar {
        min-width: 0;
        padding: 0 0 12px 0;
    }
    .help-categories {
        flex-direction: row;
        gap: 0;
        justify-content: space-between;
    }
    .help-categories li {
        flex: 1 1 0;
        text-align: center;
        padding: 12px 0;
        font-size: 1rem;
        border-radius: 0;
        border-bottom: 2px solid transparent;
        background: none;
        box-shadow: none;
    }
    .help-categories li.active {
        background: none;
        color: #1bbf83;
        border-bottom: 2px solid #1bbf83;
        box-shadow: none;
    }
    .help-qa-area {
        align-items: stretch;
        max-width: 100vw;
    }
    .help-qa-list {
        max-width: 100vw;
    }
    .help-contact-wrapper {
        max-width: 100vw;
        margin-left: 0;
        margin-top: 24px;
    }
}
@media (max-width: 600px) {
    .help-center-main {
        margin-top: 8px;
        padding: 0 16px 24px 16px;
    }
    .help-qa-list {
        gap: 12px;
        max-width: 100vw;
    }
    .help-qa-question, .help-qa-answer {
        padding-left: 12px;
        padding-right: 8px;
    }
    .qa-dot {
        margin-right: 0;
    }
    .help-contact-wrapper {
        padding: 18px 6px;
        min-width: 0;
        max-width: 100vw;
    }
    .modal-content {
        padding: 18px 6px 14px 6px;
        max-width: 98vw;
    }
    .help-categories li .tutor-break {
        white-space: normal;
        text-align: center;
        line-height: 1.2;
        display: inline-block;
    }
    .help-categories li .tutor-break br {
        display: inline;
    }
}