/* ============================================
   基础样式 / Base Styles
   ============================================ */

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

:root {
    --color-dark-wood: #2b1b17;
    --color-gold: #c49a6c;
    --color-purple: #7b4bb7;
    --color-light-beige: #faf7f5;
    --color-white: #ffffff;
    --color-text: #333333;
    --color-text-light: #666666;
}

html {
    scroll-behavior: smooth;
}

body {
    font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei", "Helvetica Neue", Helvetica, Arial, sans-serif;
    background-color: var(--color-light-beige);
    color: var(--color-text);
    line-height: 1.8;
}

img {
    max-width: 100%;
    height: auto;
    display: block;
}

a {
    text-decoration: none;
    color: inherit;
    transition: all 0.3s ease;
}

.container {
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 20px;
}

/* ============================================
   布局 / Layout
   ============================================ */

section {
    padding: 80px 0;
}

.section-title {
    font-size: 2.5rem;
    color: var(--color-dark-wood);
    text-align: center;
    margin-bottom: 20px;
    font-weight: 600;
}

.section-intro {
    font-size: 1.1rem;
    color: var(--color-text-light);
    text-align: center;
    max-width: 800px;
    margin: 0 auto 60px;
    line-height: 2.2;
}

/* ============================================
   导航栏 / Navigation
   ============================================ */

.navbar {
    position: fixed;
    top: 0;
    left: 0;
    right: 0;
    background-color: var(--color-white);
    box-shadow: 0 2px 10px rgba(0, 0, 0, 0.1);
    z-index: 1000;
    transition: all 0.3s ease;
}

.navbar.scrolled {
    box-shadow: 0 4px 20px rgba(0, 0, 0, 0.15);
}

.nav-content {
    display: flex;
    align-items: center;
    justify-content: space-between;
    padding: 15px 0;
    position: relative;
}

.logo {
    font-size: 1.5rem;
    font-weight: bold;
    color: var(--color-dark-wood);
    flex-shrink: 0;
}

.nav-menu {
    display: flex;
    list-style: none;
    gap: 30px;
    align-items: center;
    flex: 1;
    justify-content: center;
}

.nav-menu a {
    color: var(--color-text);
    font-size: 1rem;
    position: relative;
    padding: 5px 0;
}

.nav-menu a:hover {
    color: var(--color-gold);
}

.nav-menu a::after {
    content: '';
    position: absolute;
    bottom: 0;
    left: 0;
    width: 0;
    height: 2px;
    background-color: var(--color-gold);
    transition: width 0.3s ease;
}

.nav-menu a:hover::after {
    width: 100%;
}

.btn-download-nav {
    background: linear-gradient(135deg, var(--color-gold), #d4a574);
    color: var(--color-white);
    padding: 10px 25px;
    border-radius: 25px;
    font-weight: 500;
    box-shadow: 0 4px 15px rgba(196, 154, 108, 0.3);
    transition: all 0.3s ease;
}

.btn-download-nav:hover {
    transform: translateY(-2px);
    box-shadow: 0 6px 20px rgba(196, 154, 108, 0.4);
}

.mobile-menu-toggle {
    display: none;
    flex-direction: column;
    gap: 5px;
    background: none;
    border: none;
    cursor: pointer;
    padding: 5px;
    flex-shrink: 0;
}

.mobile-menu-toggle span {
    width: 25px;
    height: 3px;
    background-color: var(--color-dark-wood);
    transition: all 0.3s ease;
}

/* ============================================
   首屏 Hero / Hero Section
   ============================================ */

.section-hero {
    margin-top: 80px;
    padding: 100px 0;
    background: linear-gradient(135deg, var(--color-light-beige) 0%, #f5f0eb 100%);
}

.hero-content {
    display: flex;
    align-items: stretch;
    gap: 60px;
}

.hero-text {
    flex: 1;
    display: flex;
    flex-direction: column;
    justify-content: center;
}

.hero-title {
    font-size: 3rem;
    color: var(--color-dark-wood);
    margin-bottom: 25px;
    line-height: 1.2;
    font-weight: 700;
    text-align: left;
}

.hero-subtitle {
    font-size: 1.2rem;
    color: var(--color-text-light);
    margin-bottom: 50px;
    line-height: 2.2;
    text-align: left;
}

.hero-buttons {
    display: flex;
    gap: 20px;
    flex-wrap: wrap;
    justify-content: flex-start;
    align-items: flex-start;
    margin-left: 0;
}

.hero-image {
    flex: 1;
    max-width: 900px;
    display: flex;
    align-items: center;
    justify-content: center;
    margin-left: -20px;
}

.hero-image img {
    max-height: 100%;
    width: auto;
    object-fit: contain;
    border-radius: 24px;
    box-shadow: 0 20px 50px rgba(0, 0, 0, 0.25);
}

/* 首屏 Hero 轮播图样式 */
.hero-carousel {
    position: relative;
    width: 100%;
    max-width: 900px;
    height: 100%;
    display: flex;
    align-items: center;
    justify-content: center;
}

.hero-carousel-container {
    position: relative;
    width: 100%;
    height: 100%;
    overflow: hidden;
    border-radius: 24px;
}

.hero-carousel-track {
    position: relative;
    width: 100%;
    height: 100%;
    display: flex;
    transition: transform 0.5s ease-in-out;
}

.hero-carousel-slide {
    min-width: 100%;
    width: 100%;
    height: 100%;
    display: flex;
    align-items: center;
    justify-content: center;
    flex-shrink: 0;
}

.hero-carousel-slide img {
    max-height: 100%;
    width: auto;
    object-fit: contain;
    border-radius: 24px;
    box-shadow: 0 20px 50px rgba(0, 0, 0, 0.25);
}

.hero-carousel-btn {
    position: absolute;
    top: 50%;
    transform: translateY(-50%);
    background-color: rgba(255, 255, 255, 0.9);
    border: none;
    width: 48px;
    height: 48px;
    border-radius: 50%;
    font-size: 24px;
    color: var(--color-dark-wood);
    cursor: pointer;
    display: flex;
    align-items: center;
    justify-content: center;
    transition: all 0.3s ease;
    z-index: 10;
    box-shadow: 0 2px 10px rgba(0, 0, 0, 0.1);
}

.hero-carousel-btn:hover {
    background-color: rgba(255, 255, 255, 1);
    transform: translateY(-50%) scale(1.1);
    box-shadow: 0 4px 15px rgba(0, 0, 0, 0.2);
}

.hero-carousel-prev {
    left: 16px;
}

.hero-carousel-next {
    right: 16px;
}

.hero-carousel-dots {
    position: absolute;
    bottom: 20px;
    left: 50%;
    transform: translateX(-50%);
    display: flex;
    gap: 10px;
    z-index: 10;
}

.hero-dot {
    width: 12px;
    height: 12px;
    border-radius: 50%;
    background-color: rgba(255, 255, 255, 0.5);
    cursor: pointer;
    transition: all 0.3s ease;
}

.hero-dot.active {
    background-color: var(--color-gold);
    transform: scale(1.2);
}

/* ============================================
   按钮样式 / Buttons
   ============================================ */

.btn-primary {
    background: linear-gradient(135deg, var(--color-gold), #d4a574);
    color: var(--color-white);
    padding: 15px 35px;
    border-radius: 30px;
    font-size: 1.1rem;
    font-weight: 600;
    display: inline-block;
    box-shadow: 0 6px 20px rgba(196, 154, 108, 0.4);
    transition: all 0.3s ease;
    border: none;
    cursor: pointer;
}

.btn-primary:hover {
    transform: translateY(-3px);
    box-shadow: 0 8px 25px rgba(196, 154, 108, 0.5);
}

.btn-primary.btn-large {
    padding: 18px 45px;
    font-size: 1.2rem;
}

.btn-secondary {
    background: transparent;
    color: var(--color-dark-wood);
    padding: 15px 35px;
    border-radius: 30px;
    font-size: 1.1rem;
    font-weight: 600;
    display: inline-block;
    border: 2px solid var(--color-dark-wood);
    transition: all 0.3s ease;
}

.btn-secondary:hover {
    background-color: var(--color-dark-wood);
    color: var(--color-white);
    transform: translateY(-3px);
}

/* ============================================
   品牌故事区块 / Brand Section
   ============================================ */

.section-brand {
    background-color: var(--color-white);
}

.brand-cards {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: 30px;
    margin-top: 50px;
}

.brand-card {
    background: linear-gradient(135deg, #ffffff 0%, #faf7f5 100%);
    padding: 40px 30px;
    border-radius: 15px;
    text-align: center;
    box-shadow: 0 5px 20px rgba(0, 0, 0, 0.08);
    transition: all 0.3s ease;
    border-top: 3px solid var(--color-gold);
}

.brand-card:hover {
    transform: translateY(-5px);
    box-shadow: 0 8px 30px rgba(0, 0, 0, 0.12);
}

.brand-card h3 {
    font-size: 1.4rem;
    color: var(--color-dark-wood);
    margin-bottom: 15px;
    font-weight: 600;
}

.brand-card p {
    color: var(--color-text-light);
    line-height: 2;
}

/* ============================================
   权威背书区块 / Authority Section
   ============================================ */

.section-authority {
    background-color: var(--color-light-beige);
}

.certificate-grid {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: 30px;
    margin-top: 50px;
}

.certificate-item {
    background-color: var(--color-white);
    padding: 15px;
    border-radius: 10px;
    box-shadow: 0 5px 15px rgba(0, 0, 0, 0.08);
    transition: all 0.3s ease;
    overflow: hidden;
}

.certificate-item:hover {
    transform: translateY(-5px);
    box-shadow: 0 8px 25px rgba(0, 0, 0, 0.12);
}

.certificate-item img {
    width: 100%;
    height: auto;
    border-radius: 5px;
}

.certificate-item-double {
    display: flex;
    flex-direction: column;
    gap: 15px;
}

.certificate-item-double img {
    width: 100%;
    height: auto;
    border-radius: 5px;
}

/* ============================================
   APP 功能区块 / App Features Section
   ============================================ */

.section-app {
    background-color: var(--color-white);
}

.app-features {
    display: grid;
    grid-template-columns: repeat(2, 1fr);
    gap: 30px;
}

.feature-card {
    background: linear-gradient(135deg, #ffffff 0%, #faf7f5 100%);
    padding: 40px;
    border-radius: 15px;
    box-shadow: 0 5px 20px rgba(0, 0, 0, 0.08);
    transition: all 0.3s ease;
    border-left: 4px solid var(--color-purple);
}

.feature-card:hover {
    transform: translateY(-5px);
    box-shadow: 0 8px 30px rgba(123, 75, 183, 0.15);
}

.feature-card h3 {
    font-size: 1.5rem;
    color: var(--color-dark-wood);
    margin-bottom: 15px;
    font-weight: 600;
}

.feature-card p {
    color: var(--color-text-light);
    line-height: 2;
    font-size: 1.05rem;
}

/* ============================================
   钢琴产品区块 / Piano Section
   ============================================ */

.section-piano {
    background-color: var(--color-light-beige);
}

.piano-gallery {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: 30px;
    margin-top: 50px;
}

.piano-item {
    background-color: var(--color-white);
    border-radius: 15px;
    overflow: hidden;
    box-shadow: 0 5px 20px rgba(0, 0, 0, 0.08);
    transition: all 0.3s ease;
}

.piano-item:hover {
    transform: translateY(-5px);
    box-shadow: 0 8px 30px rgba(0, 0, 0, 0.12);
}

.piano-item img {
    width: 100%;
    height: auto;
    object-fit: contain;
    display: block;
}

.piano-item p {
    padding: 20px;
    text-align: center;
    color: var(--color-text-light);
}

/* ============================================
   用户评价区块 / Feedback Section
   ============================================ */

.section-feedback {
    background-color: var(--color-white);
}

.feedback-carousel {
    max-width: 800px;
    margin: 0 auto;
    position: relative;
}

.carousel-container {
    position: relative;
    overflow: hidden;
    border-radius: 15px;
    min-height: 200px;
}

.carousel-track {
    display: flex;
    transition: transform 0.5s ease;
}

.feedback-card {
    min-width: 100%;
    padding: 50px 40px;
    background: linear-gradient(135deg, var(--color-light-beige) 0%, #ffffff 100%);
    text-align: center;
    display: none;
    box-shadow: 0 5px 20px rgba(0, 0, 0, 0.08);
    border-radius: 15px;
}

.feedback-card.active {
    display: block;
}

.feedback-text {
    font-size: 1.3rem;
    color: var(--color-text);
    line-height: 2;
    margin-bottom: 25px;
    font-style: italic;
}

.feedback-author {
    font-size: 1rem;
    color: var(--color-gold);
    font-weight: 600;
}

.carousel-controls {
    display: flex;
    justify-content: center;
    align-items: center;
    gap: 20px;
    margin-top: 30px;
}

.carousel-btn {
    background-color: var(--color-gold);
    color: var(--color-white);
    border: none;
    width: 45px;
    height: 45px;
    border-radius: 50%;
    font-size: 1.5rem;
    cursor: pointer;
    transition: all 0.3s ease;
    display: flex;
    align-items: center;
    justify-content: center;
}

.carousel-btn:hover {
    background-color: var(--color-dark-wood);
    transform: scale(1.1);
}

.carousel-dots {
    display: flex;
    gap: 10px;
}

.dot {
    width: 12px;
    height: 12px;
    border-radius: 50%;
    background-color: #ddd;
    cursor: pointer;
    transition: all 0.3s ease;
}

.dot.active {
    background-color: var(--color-gold);
    transform: scale(1.2);
}

/* ============================================
   常见问题区块 / FAQ Section
   ============================================ */

.section-faq {
    background-color: var(--color-light-beige);
}

.faq-list {
    max-width: 900px;
    margin: 0 auto;
}

.faq-item {
    background-color: var(--color-white);
    border-radius: 10px;
    margin-bottom: 20px;
    box-shadow: 0 3px 10px rgba(0, 0, 0, 0.08);
    overflow: hidden;
    transition: all 0.3s ease;
}

.faq-item:hover {
    box-shadow: 0 5px 15px rgba(0, 0, 0, 0.12);
}

.faq-question {
    padding: 25px 30px;
    cursor: pointer;
    display: flex;
    justify-content: space-between;
    align-items: center;
    background-color: var(--color-white);
    transition: background-color 0.3s ease;
}

.faq-question:hover {
    background-color: var(--color-light-beige);
}

.faq-question h3 {
    font-size: 1.2rem;
    color: var(--color-dark-wood);
    font-weight: 600;
    flex: 1;
}

.faq-toggle {
    font-size: 1.5rem;
    color: var(--color-gold);
    font-weight: bold;
    width: 30px;
    height: 30px;
    display: flex;
    align-items: center;
    justify-content: center;
    transition: transform 0.3s ease;
}

.faq-item.active .faq-toggle {
    transform: rotate(180deg);
}

.faq-answer {
    max-height: 0;
    overflow: hidden;
    transition: max-height 0.3s ease, padding 0.3s ease;
    padding: 0 30px;
}

.faq-item.active .faq-answer {
    max-height: 500px;
    padding: 0 30px 25px;
}

.faq-answer p {
    color: var(--color-text-light);
    line-height: 2;
    font-size: 1.05rem;
}

/* ============================================
   底部信息 / Footer
   ============================================ */

.footer {
    background-color: var(--color-dark-wood);
    color: var(--color-white);
    padding: 60px 0 30px;
}

.footer-content {
    display: grid;
    grid-template-columns: repeat(2, 1fr);
    gap: 50px;
    margin-bottom: 40px;
}

.footer-section h3 {
    font-size: 1.3rem;
    margin-bottom: 20px;
    color: var(--color-gold);
}

.footer-section p {
    margin-bottom: 12px;
    line-height: 2;
    color: rgba(255, 255, 255, 0.9);
}

.footer-section a {
    color: var(--color-gold);
}

.footer-section a:hover {
    text-decoration: underline;
}

.qr-code {
    margin-top: 15px;
}

.qr-code img {
    border-radius: 10px;
    box-shadow: 0 5px 15px rgba(0, 0, 0, 0.2);
}

.footer-bottom {
    text-align: center;
    padding-top: 30px;
    border-top: 1px solid rgba(255, 255, 255, 0.1);
    color: rgba(255, 255, 255, 0.7);
}

.footer-bottom p {
    margin-bottom: 10px;
}

.footer-bottom a {
    color: var(--color-gold);
}

.footer-bottom a:hover {
    text-decoration: underline;
}

/* ============================================
   响应式设计 / Responsive Design
   ============================================ */

/* 平板设备 (768px - 1024px) */
@media (max-width: 1024px) {
    .hero-content {
        flex-direction: column;
    }

    .hero-title {
        font-size: 2.5rem;
        text-align: left;
    }

    .hero-subtitle {
        text-align: left;
    }

    .hero-image {
        max-width: 100%;
        margin-left: 0;
        margin-top: 24px;
    }

    .hero-carousel {
        max-width: 100%;
    }

    .hero-carousel-btn {
        width: 40px;
        height: 40px;
        font-size: 20px;
    }

    .hero-carousel-prev {
        left: 8px;
    }

    .hero-carousel-next {
        right: 8px;
    }

    .hero-buttons {
        justify-content: flex-start;
    }

    .brand-cards,
    .certificate-grid,
    .piano-gallery {
        grid-template-columns: repeat(2, 1fr);
    }

    .app-features {
        grid-template-columns: repeat(2, 1fr);
    }

    .section-title {
        font-size: 2rem;
    }
}

/* 移动设备 (最大 768px) */
@media (max-width: 768px) {
    .nav-menu {
        position: fixed;
        top: 70px;
        left: -100%;
        width: 100%;
        background-color: var(--color-white);
        flex-direction: column;
        padding: 30px 0;
        box-shadow: 0 5px 20px rgba(0, 0, 0, 0.1);
        transition: left 0.3s ease;
        gap: 0;
        justify-content: flex-start;
    }

    .nav-menu.active {
        left: 0;
    }

    .nav-menu li {
        width: 100%;
        text-align: center;
        padding: 15px 0;
    }

    .nav-menu a {
        font-size: 1.1rem;
    }

    .mobile-menu-toggle {
        display: flex;
    }

    .mobile-menu-toggle.active span:nth-child(1) {
        transform: rotate(45deg) translate(8px, 8px);
    }

    .mobile-menu-toggle.active span:nth-child(2) {
        opacity: 0;
    }

    .mobile-menu-toggle.active span:nth-child(3) {
        transform: rotate(-45deg) translate(7px, -7px);
    }

    .section-hero {
        padding: 60px 0;
        margin-top: 70px;
    }

    .hero-title {
        font-size: 2rem;
    }

    .hero-subtitle {
        font-size: 1rem;
    }

    .hero-buttons {
        flex-direction: column;
        width: 100%;
        align-items: flex-start;
        justify-content: flex-start;
    }

    .hero-title {
        text-align: left;
    }

    .hero-subtitle {
        text-align: left;
    }

    .btn-primary,
    .btn-secondary {
        width: 100%;
        text-align: center;
    }

    section {
        padding: 50px 0;
    }

    .section-title {
        font-size: 1.8rem;
    }

    .section-intro {
        font-size: 1rem;
        margin-bottom: 40px;
    }

    .brand-cards,
    .certificate-grid,
    .piano-gallery,
    .app-features {
        grid-template-columns: 1fr;
    }

    .brand-card,
    .feature-card {
        padding: 30px 20px;
    }

    .feedback-text {
        font-size: 1.1rem;
    }

    .footer-content {
        grid-template-columns: 1fr;
        gap: 30px;
    }

    .carousel-controls {
        flex-wrap: wrap;
    }
}

/* 小屏移动设备 (最大 480px) */
@media (max-width: 480px) {
    .container {
        padding: 0 15px;
    }

    .hero-title {
        font-size: 1.6rem;
    }

    .section-title {
        font-size: 1.5rem;
    }

    .brand-card h3,
    .feature-card h3 {
        font-size: 1.2rem;
    }

    .btn-primary.btn-large {
        padding: 15px 30px;
        font-size: 1rem;
    }

    .feedback-card {
        padding: 30px 20px;
    }

    .faq-question {
        padding: 20px;
    }

    .faq-question h3 {
        font-size: 1rem;
    }
}