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

body {
    font-family: 'Microsoft YaHei', sans-serif;
    background-color: #f9f5f0;
    min-height: 100vh;
    display: flex;
    flex-direction: column;
    align-items: center;
    justify-content: center;
    padding: 20px;
    user-select: none;
    -webkit-user-select: none;
    -moz-user-select: none;
    -ms-user-select: none;
}

.container {
    max-width: 480px;
    width: 100%;
    aspect-ratio: 9/16;
    background-color: #fff;
    border-radius: 20px;
    box-shadow: 0 10px 30px rgba(0, 0, 0, 0.1);
    padding: 30px 20px;
    display: flex;
    flex-direction: column;
    gap: 30px;
    position: relative;
}

.page {
    display: none;
    flex-direction: column;
    height: 100%;
    gap: 20px;
}

.page.active {
    display: flex;
}

.header {
    display: flex;
    align-items: center;
    gap: 15px;
}

.back-btn {
    width: 40px;
    height: 40px;
    background-color: #f8f0e3;
    border-radius: 12px;
    display: flex;
    align-items: center;
    justify-content: center;
    cursor: pointer;
    transition: all 0.2s ease;
    font-size: 20px;
    color: #333;
    border: none;
    text-decoration: none;
}

.back-btn:hover {
    background-color: #f0e6d6;
    transform: translateX(-2px);
}

.page-title {
    font-size: 20px;
    font-weight: 600;
    color: #333;
    display: flex;
    align-items: center;
    gap: 10px;
}

.title-icon {
    width: 40px;
    height: 40px;
    border-radius: 12px;
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 20px;
}

.content-area {
    flex: 1;
    background-color: #faf8f5;
    border-radius: 16px;
    padding: 20px;
    overflow-y: auto;
}

.placeholder-text {
    color: #999;
    text-align: center;
    font-size: 14px;
    line-height: 2;
    padding: 40px 20px;
}

.feedback-link {
    text-align: right;
    font-size: 12px;
    color: #999;
}

.feedback-link a {
    color: #999;
    text-decoration: none;
    cursor: pointer;
}

.feedback-link a:hover {
    color: #666;
}

.modal-overlay {
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    background-color: rgba(0, 0, 0, 0.5);
    display: flex;
    align-items: center;
    justify-content: center;
    z-index: 1000;
    opacity: 0;
    visibility: hidden;
    transition: all 0.3s ease;
}

.modal-overlay.show {
    opacity: 1;
    visibility: visible;
}

.modal-content {
    background-color: #fff;
    border-radius: 20px;
    padding: 30px;
    max-width: 400px;
    width: 90%;
    box-shadow: 0 10px 40px rgba(0, 0, 0, 0.2);
    position: relative;
    transform: scale(0.9);
    transition: transform 0.3s ease;
}

.modal-overlay.show .modal-content {
    transform: scale(1);
}

.modal-close {
    position: absolute;
    top: 15px;
    right: 15px;
    width: 30px;
    height: 30px;
    background-color: #f5f5f5;
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    cursor: pointer;
    font-size: 18px;
    color: #666;
    transition: all 0.2s ease;
}

.modal-close:hover {
    background-color: #eee;
    color: #333;
}

.modal-title {
    font-size: 20px;
    font-weight: 600;
    color: #333;
    text-align: center;
    margin-bottom: 20px;
}

.modal-text {
    font-size: 14px;
    color: #555;
    line-height: 1.8;
    text-align: center;
}

.success-toast {
    position: fixed;
    top: 50%;
    left: 50%;
    transform: translate(-50%, -50%);
    background-color: rgba(0, 0, 0, 0.8);
    color: #fff;
    padding: 15px 30px;
    border-radius: 12px;
    font-size: 14px;
    z-index: 1001;
    opacity: 0;
    visibility: hidden;
    transition: all 0.3s ease;
}

.success-toast.show {
    opacity: 1;
    visibility: visible;
}

@media (max-width: 480px) {
    body {
        padding: 0;
    }

    .container {
        max-width: 100%;
        height: 100vh;
        height: 100dvh;
        border-radius: 0;
        padding: 16px 12px;
        gap: 20px;
    }

    .header {
        gap: 10px;
    }

    .back-btn {
        width: 36px;
        height: 36px;
        font-size: 18px;
        border-radius: 10px;
    }

    .page-title {
        font-size: 17px;
    }

    .title-icon {
        width: 36px;
        height: 36px;
        font-size: 18px;
        border-radius: 10px;
    }

    .content-area {
        padding: 16px;
        border-radius: 12px;
    }

    .placeholder-text {
        font-size: 13px;
        padding: 30px 16px;
    }

    .feedback-link {
        font-size: 11px;
    }

    .modal-content {
        padding: 24px 20px;
        border-radius: 16px;
    }

    .modal-title {
        font-size: 18px;
    }

    .modal-text {
        font-size: 13px;
    }
}

@media (min-width: 768px) {
    .container {
        max-width: 600px;
    }
}