/* public/css/about.css (v1.1 - Mobile UX Optimized - Truly Complete Version) */

/* --- 变量与通用 --- */
:root {
    --section-padding: 6rem 0;
    --brand-color: #007AFF;
}
.fade-in {
    opacity: 0;
    transform: translateY(20px);
    transition: opacity 0.6s ease-out, transform 0.6s ease-out;
}
.fade-in.visible {
    opacity: 1;
    transform: translateY(0);
}
.btn {
    padding: 0.6rem 1.2rem;
    border-radius: 50px;
    text-decoration: none;
    font-family: var(--font-bold);
    transition: all 0.3s ease;
    border: 1px solid transparent;
    cursor: pointer;
    white-space: nowrap;
}
.btn-secondary {
    background-color: var(--brand-color);
    color: #fff;
}
.btn-secondary:hover {
    background-color: #0056b3;
}
.btn-outline {
    background-color: transparent;
    color: var(--brand-color);
    border-color: var(--brand-color);
}
.btn-outline:hover {
    background-color: var(--brand-color);
    color: #fff;
}


/* --- 1. Hero Section --- */
.about-hero {
    background-color: #f7f7f7;
    text-align: center;
    padding: 100px 20px;
}
.about-hero .page-title {
    font-size: clamp(2.5rem, 6vw, 4.5rem);
}
.about-hero .page-subtitle {
    font-size: clamp(1.1rem, 2.5vw, 1.5rem);
    color: #555;
    min-height: 3.2em;
    line-height: 1.6;
}
.typewriter-line + .typewriter-line { margin-top: 0.5rem; }
.typewriter-line::after {
    content: '|';
    animation: blink 0.7s infinite;
}
@keyframes blink { 50% { opacity: 0; } }

/* --- 2. Promise Carousel --- */
.about-features-section {
    padding: var(--section-padding);
    background-color: #fff;
}
.section-title {
    text-align: center;
    font-family: var(--font-bold);
    font-size: clamp(2rem, 5vw, 2.8rem);
    margin-bottom: 3rem;
}
.promise-carousel {
    overflow: hidden;
    position: relative;
    max-width: 1000px;
    margin: 0 auto;
}
.promise-card-container {
    display: flex;
    transition: transform 0.5s ease-in-out;
}
.promise-card {
    flex: 0 0 100%;
    padding: 2rem;
    box-sizing: border-box;
    text-align: center;
}
.promise-card h3 { font-size: 1.8rem; margin-bottom: 1rem; }
.promise-card p { font-size: 1.1rem; line-height: 1.8; color: #555; max-width: 600px; margin: 0 auto; }
.carousel-nav {
    display: flex;
    justify-content: center;
    gap: 10px;
    margin-top: 2rem;
}
.carousel-dot {
    width: 12px;
    height: 12px;
    border-radius: 50%;
    background-color: #ccc;
    border: none;
    cursor: pointer;
    transition: background-color 0.3s;
}
.carousel-dot.active { background-color: var(--brand-color); }

/* --- 3. Credentials Section --- */
.credentials-section {
    padding: var(--section-padding);
    background-color: #f7f7f7;
    text-align: center;
}
.license-code-info { color: #555; font-size: 1.2rem; margin-bottom: 2rem; word-break: break-all; }
.license-container {
    max-width: 600px;
    margin: 0 auto;
    border: 1px solid #e0e0e0;
    padding: 1rem;
    background: #fff;
    box-shadow: 0 5px 15px rgba(0,0,0,0.05);
}
.license-image {
    max-width: 100%;
    cursor: pointer;
    transition: transform 0.3s;
}
.license-image:hover { transform: scale(1.03); }

/* --- 4. Contact Section --- */
.contact-methods-section { padding: var(--section-padding); background-color: #fff; }
.contact-list { max-width: 800px; margin: 0 auto; display: flex; flex-direction: column; gap: 1.5rem; }
.contact-item {
    display: flex;
    align-items: center;
    gap: 1.5rem;
    padding: 1.5rem;
    border: 1px solid #eee;
    border-radius: 12px;
    position: relative; /* 为二维码定位提供基准 */
}
.contact-icon { font-size: 2rem; }
.app-icon { height: 32px; width: 32px; }
.contact-info { flex-grow: 1; }
.contact-info strong { display: block; font-size: 1.2rem; margin-bottom: 0.2rem; }
.contact-info span { color: #555; word-break: break-all; }
.contact-actions { display: flex; gap: 0.8rem; flex-shrink: 0; }

/* ✅【核心修改】二维码样式与交互 */
.show-qr-btn {
    display: inline-block;
    user-select: none; /* 让 span 的行为更像按钮 */
    cursor: pointer;
}
.qr-code-display {
    display: block;
    position: absolute;
    bottom: calc(100% + 10px);
    left: 50%;
    transform: translateX(-50%) translateY(10px);
    width: 150px;
    height: 150px;
    padding: 10px;
    background: #fff;
    border: 1px solid #ccc;
    border-radius: 8px;
    box-shadow: 0 4px 12px rgba(0,0,0,0.15);
    z-index: 10;
    opacity: 0;
    visibility: hidden;
    transition: opacity 0.3s ease, transform 0.3s ease, visibility 0.3s ease;
}

.contact-item.show-qr .qr-code-display {
    opacity: 1;
    visibility: visible;
    transform: translateX(-50%) translateY(0);
}

/* --- 5. Lightbox for License --- */
.lightbox-overlay {
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    background-color: rgba(0, 0, 0, 0.85);
    display: flex;
    justify-content: center;
    align-items: center;
    z-index: 9999;
    opacity: 0;
    visibility: hidden;
    transition: opacity 0.3s, visibility 0.3s;
}
.lightbox-overlay.visible {
    opacity: 1;
    visibility: visible;
}
.lightbox-content {
    position: relative;
    max-width: 90%;
    max-height: 90%;
}
.lightbox-content img {
    width: 100%;
    height: 100%;
    object-fit: contain;
}
.lightbox-close {
    position: absolute;
    top: -40px;
    right: 0;
    font-size: 2rem;
    color: #fff;
    cursor: pointer;
    border: none;
    background: none;
}

/* --- 6. 响应式设计 --- */
@media (max-width: 768px) {
    :root {
        --section-padding: 4rem 0;
    }
    .contact-item {
        flex-direction: column;
        align-items: flex-start;
        text-align: left;
    }
    .contact-actions {
        width: 100%;
        margin-top: 1rem;
    }
    .contact-actions .btn,
    .contact-actions .show-qr-btn {
        flex-grow: 1;
        text-align: center;
    }
    .qr-code-display {
        left: auto;
        right: 1.5rem;
        bottom: auto;
        top: 1.5rem;
        transform: none;
    }
    
    /* 当二维码在移动端显示时，确保它在最上层 */
    .contact-item.show-qr {
        z-index: 11;
    }
}