/* ========================================
   全局样式 - Apple Style
   ======================================== */

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

:root {
    --primary-color: #1d1d1f;
    --secondary-color: #86868b;
    --accent-color: #0071e3;
    --accent-hover: #0077ed;
    --bg-color: #ffffff;
    --bg-secondary: #f5f5f7;
    --bg-tertiary: #fafafa;
    --text-primary: #1d1d1f;
    --text-secondary: #86868b;
    --text-tertiary: #6e6e73;
    --border-color: rgba(0, 0, 0, 0.1);
    --border-radius: 18px;
    --border-radius-sm: 12px;
    --transition: all 0.3s cubic-bezier(0.25, 0.46, 0.45, 0.94);
    --transition-fast: all 0.2s cubic-bezier(0.25, 0.46, 0.45, 0.94);
    --shadow-sm: 0 2px 8px rgba(0, 0, 0, 0.04);
    --shadow-md: 0 4px 16px rgba(0, 0, 0, 0.08);
    --shadow-lg: 0 8px 32px rgba(0, 0, 0, 0.12);
    --shadow-xl: 0 16px 64px rgba(0, 0, 0, 0.16);
}

body {
    font-family: -apple-system, BlinkMacSystemFont, 'SF Pro Display', 'SF Pro Text', 'Segoe UI', 'PingFang SC', 'Hiragino Sans GB', 'Microsoft YaHei', sans-serif;
    color: var(--text-primary);
    background: var(--bg-color);
    line-height: 1.47059;
    font-weight: 400;
    letter-spacing: -0.022em;
    overflow-x: hidden;
    -webkit-font-smoothing: antialiased;
    -moz-osx-font-smoothing: grayscale;
}

html {
    scroll-behavior: smooth;
}

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

.navbar {
    position: fixed;
    top: 0;
    width: 100%;
    background: rgba(251, 251, 253, 0.8);
    backdrop-filter: saturate(180%) blur(20px);
    -webkit-backdrop-filter: saturate(180%) blur(20px);
    z-index: 1000;
    border-bottom: 0.5px solid var(--border-color);
    transition: var(--transition-fast);
}

.nav-container {
    max-width: 1200px;
    margin: 0 auto;
    padding: 1rem 2rem;
    display: flex;
    justify-content: space-between;
    align-items: center;
}

.logo {
    font-size: 1.25rem;
    font-weight: 600;
    color: var(--text-primary);
    letter-spacing: -0.01em;
}

.nav-menu {
    display: flex;
    list-style: none;
    gap: 2rem;
    align-items: center;
}

.nav-menu a {
    text-decoration: none;
    color: var(--text-secondary);
    font-size: 0.8125rem;
    font-weight: 400;
    letter-spacing: -0.01em;
    transition: var(--transition-fast);
    position: relative;
}

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

.nav-menu a::after {
    content: '';
    position: absolute;
    bottom: -4px;
    left: 0;
    width: 0;
    height: 1px;
    background: var(--text-primary);
    transition: width var(--transition-fast);
}

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

.btn-buy {
    background: var(--accent-color);
    color: white !important;
    padding: 0.5rem 1.125rem;
    border-radius: 980px;
    font-weight: 400;
    letter-spacing: -0.01em;
}

.btn-buy:hover {
    background: var(--accent-hover);
    transform: translateY(-1px);
}

.btn-buy::after {
    display: none;
}

.hamburger {
    display: none;
    flex-direction: column;
    gap: 4px;
    cursor: pointer;
}

.hamburger span {
    width: 22px;
    height: 2px;
    background: var(--text-primary);
    transition: var(--transition);
}

/* ========================================
   Hero 主视觉区
   ======================================== */

.hero {
    min-height: 100vh;
    display: flex;
    flex-direction: column;
    align-items: center;
    justify-content: center;
    text-align: center;
    padding: 10rem 2rem 6rem;
    background: var(--bg-color);
    position: relative;
    overflow: hidden;
}

.hero::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    background: radial-gradient(circle at 50% 0%, rgba(0, 113, 227, 0.03) 0%, transparent 50%);
    pointer-events: none;
}

.hero-content {
    max-width: 800px;
    z-index: 2;
    animation: fadeInUp 1s ease-out;
}

.hero-title {
    font-size: clamp(3.5rem, 9vw, 7rem);
    font-weight: 700;
    letter-spacing: -0.04em;
    line-height: 1.05;
    margin-bottom: 1.5rem;
    color: var(--text-primary);
}

.hero-subtitle {
    font-size: clamp(1.75rem, 4vw, 3rem);
    font-weight: 600;
    letter-spacing: -0.03em;
    line-height: 1.1;
    margin-bottom: 1.5rem;
    color: var(--text-primary);
}

.hero-description {
    font-size: clamp(1.0625rem, 2vw, 1.25rem);
    color: var(--text-secondary);
    font-weight: 400;
    line-height: 1.47059;
    letter-spacing: -0.01em;
    margin-bottom: 3rem;
    max-width: 680px;
    margin-left: auto;
    margin-right: auto;
}

.hero-cta {
    display: flex;
    gap: 1rem;
    justify-content: center;
    margin-bottom: 1rem;
}

.btn-primary {
    padding: 0.75rem 1.75rem;
    background: var(--accent-color);
    color: white;
    text-decoration: none;
    border-radius: 980px;
    font-weight: 400;
    letter-spacing: -0.01em;
    transition: var(--transition-fast);
    border: none;
    cursor: pointer;
    font-size: 0.9375rem;
    display: inline-block;
}

.btn-primary:hover {
    background: var(--accent-hover);
    transform: translateY(-2px);
    box-shadow: 0 4px 12px rgba(0, 113, 227, 0.3);
}

.btn-primary:active {
    transform: translateY(0);
}

.btn-secondary {
    padding: 0.75rem 1.75rem;
    background: transparent;
    color: var(--accent-color);
    text-decoration: none;
    border: 1px solid var(--accent-color);
    border-radius: 980px;
    font-weight: 400;
    letter-spacing: -0.01em;
    transition: var(--transition-fast);
    font-size: 0.9375rem;
    display: inline-block;
}

.btn-secondary:hover {
    background: var(--accent-color);
    color: white;
    transform: translateY(-2px);
    box-shadow: 0 4px 12px rgba(0, 113, 227, 0.2);
}

.btn-secondary:active {
    transform: translateY(0);
}

.hero-price {
    font-size: 0.9375rem;
    color: var(--text-secondary);
    margin-top: 2rem;
    font-weight: 400;
    letter-spacing: -0.01em;
}

.hero-image {
    margin-top: 6rem;
    width: 100%;
    max-width: 900px;
    position: relative;
    z-index: 1;
}

.product-showcase {
    width: 100%;
    height: 500px;
    background: var(--bg-secondary);
    border-radius: var(--border-radius);
    box-shadow: var(--shadow-xl);
    position: relative;
    overflow: hidden;
    display: flex;
    align-items: center;
    justify-content: center;
}

.product-3d {
    width: 80%;
    height: 80%;
    background: linear-gradient(135deg, rgba(0, 113, 227, 0.08) 0%, rgba(0, 113, 227, 0.02) 100%);
    border-radius: var(--border-radius-sm);
    position: relative;
    border: 1px solid var(--border-color);
}

.product-3d::before {
    content: '';
    position: absolute;
    top: 20%;
    left: 50%;
    transform: translateX(-50%);
    width: 60%;
    height: 60%;
    background: radial-gradient(circle, rgba(0, 113, 227, 0.15) 0%, transparent 70%);
    border-radius: 50%;
    animation: pulse-glow 3s ease-in-out infinite;
}

.product-3d::after {
    content: '';
    position: absolute;
    top: 50%;
    left: 50%;
    transform: translate(-50%, -50%);
    width: 200px;
    height: 200px;
    border: 2px solid rgba(0, 113, 227, 0.2);
    border-radius: 50%;
    animation: ripple 2s ease-out infinite;
}

/* ========================================
   功能区
   ======================================== */

.features {
    max-width: 1200px;
    margin: 0 auto;
    padding: 10rem 2rem;
}

.feature-item {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 6rem;
    align-items: center;
    margin-bottom: 12rem;
    opacity: 0;
    transform: translateY(50px);
    transition: opacity 0.8s cubic-bezier(0.25, 0.46, 0.45, 0.94), transform 0.8s cubic-bezier(0.25, 0.46, 0.45, 0.94);
}

.feature-item:last-child {
    margin-bottom: 0;
}

.feature-item.visible {
    opacity: 1;
    transform: translateY(0);
}

.feature-item.reverse {
    direction: rtl;
}

.feature-item.reverse > * {
    direction: ltr;
}

.feature-title {
    font-size: clamp(2.5rem, 5vw, 4rem);
    font-weight: 700;
    line-height: 1.1;
    margin-bottom: 2rem;
    letter-spacing: -0.03em;
    color: var(--text-primary);
}

.feature-description {
    font-size: clamp(1.0625rem, 1.5vw, 1.1875rem);
    color: var(--text-secondary);
    line-height: 1.47059;
    letter-spacing: -0.01em;
    font-weight: 400;
}

.feature-visual {
    width: 100%;
}

.visual-placeholder {
    width: 100%;
    height: 500px;
    border-radius: var(--border-radius);
    box-shadow: var(--shadow-lg);
    position: relative;
    overflow: hidden;
    background: var(--bg-secondary);
    display: flex;
    align-items: center;
    justify-content: center;
    border: 1px solid var(--border-color);
    transition: var(--transition);
}

.visual-placeholder:hover {
    transform: translateY(-4px);
    box-shadow: var(--shadow-xl);
}

.feature-icon {
    width: 120px;
    height: 120px;
    color: var(--accent-color);
    opacity: 0.9;
    transition: var(--transition);
}

.visual-placeholder:hover .feature-icon {
    transform: scale(1.1);
    opacity: 1;
}

.gps-visual {
    background: linear-gradient(135deg, rgba(0, 113, 227, 0.05) 0%, rgba(0, 113, 227, 0.02) 100%);
}

.health-visual {
    background: linear-gradient(135deg, rgba(0, 113, 227, 0.05) 0%, rgba(0, 113, 227, 0.02) 100%);
}

.battery-visual {
    background: linear-gradient(135deg, rgba(0, 113, 227, 0.05) 0%, rgba(0, 113, 227, 0.02) 100%);
}

/* ========================================
   设计工艺区
   ======================================== */

.design-section {
    background: var(--bg-secondary);
    padding: 10rem 2rem;
    text-align: center;
}

.design-content {
    max-width: 800px;
    margin: 0 auto 4rem;
}

.section-title {
    font-size: clamp(2.5rem, 5vw, 4.5rem);
    font-weight: 700;
    line-height: 1.1;
    margin-bottom: 2rem;
    letter-spacing: -0.03em;
    color: var(--text-primary);
}

.section-description {
    font-size: clamp(1.0625rem, 1.5vw, 1.1875rem);
    color: var(--text-secondary);
    line-height: 1.47059;
    letter-spacing: -0.01em;
    font-weight: 400;
    max-width: 680px;
    margin: 0 auto;
}

.design-details {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
    gap: 3rem;
    max-width: 1000px;
    margin: 0 auto;
}

.detail-item {
    padding: 3rem 2rem;
    opacity: 0;
    transform: translateY(30px);
    transition: opacity 0.6s cubic-bezier(0.25, 0.46, 0.45, 0.94), transform 0.6s cubic-bezier(0.25, 0.46, 0.45, 0.94);
}

.detail-item.visible {
    opacity: 1;
    transform: translateY(0);
}

.detail-icon {
    width: 48px;
    height: 48px;
    margin: 0 auto 1.5rem;
    color: var(--accent-color);
    opacity: 0.9;
    transition: var(--transition);
}

.detail-icon svg {
    width: 100%;
    height: 100%;
}

.detail-item:hover .detail-icon {
    transform: scale(1.1);
    opacity: 1;
}

.detail-item h3 {
    font-size: clamp(1.3125rem, 2vw, 1.5rem);
    font-weight: 600;
    letter-spacing: -0.02em;
    margin-bottom: 0.75rem;
    color: var(--text-primary);
}

.detail-item p {
    color: var(--text-secondary);
    font-size: 0.9375rem;
    line-height: 1.47059;
    letter-spacing: -0.01em;
    font-weight: 400;
}

/* ========================================
   技术规格区
   ======================================== */

.specs-section {
    padding: 10rem 2rem;
    max-width: 1200px;
    margin: 0 auto;
}

.specs-container {
    text-align: center;
    opacity: 0;
    transform: translateY(30px);
    transition: opacity 0.8s ease, transform 0.8s ease;
}

.specs-container.visible {
    opacity: 1;
    transform: translateY(0);
}

.specs-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(200px, 1fr));
    gap: 2rem;
    margin-top: 3rem;
    text-align: left;
}

.spec-item {
    padding: 2rem;
    background: var(--bg-secondary);
    border-radius: var(--border-radius-sm);
    transition: var(--transition-fast);
    border: 1px solid var(--border-color);
}

.spec-item:hover {
    transform: translateY(-4px);
    box-shadow: var(--shadow-md);
    border-color: rgba(0, 113, 227, 0.2);
}

.spec-item h4 {
    font-size: 1rem;
    font-weight: 600;
    letter-spacing: -0.01em;
    margin-bottom: 0.5rem;
    color: var(--text-primary);
}

.spec-item p {
    color: var(--text-secondary);
    font-size: 0.9375rem;
    line-height: 1.47059;
    letter-spacing: -0.01em;
    font-weight: 400;
}

/* ========================================
   用户评价区
   ======================================== */

.reviews-section {
    background: var(--bg-secondary);
    padding: 10rem 2rem;
    text-align: center;
}

.reviews-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
    gap: 2rem;
    max-width: 1200px;
    margin: 3rem auto 0;
}

.review-card {
    background: var(--bg-color);
    padding: 2.5rem;
    border-radius: var(--border-radius);
    box-shadow: var(--shadow-sm);
    border: 1px solid var(--border-color);
    opacity: 0;
    transform: translateY(30px);
    transition: opacity 0.6s cubic-bezier(0.25, 0.46, 0.45, 0.94), transform 0.6s cubic-bezier(0.25, 0.46, 0.45, 0.94), box-shadow var(--transition-fast);
}

.review-card:hover {
    box-shadow: var(--shadow-md);
    transform: translateY(-4px);
}

.review-card.visible {
    opacity: 1;
    transform: translateY(0);
}

.stars {
    color: #ffb800;
    font-size: 1.25rem;
    margin-bottom: 1rem;
}

.review-text {
    font-size: 1.0625rem;
    line-height: 1.47059;
    letter-spacing: -0.01em;
    margin-bottom: 1.5rem;
    color: var(--text-primary);
    font-weight: 400;
}

.review-author {
    color: var(--text-secondary);
    font-size: 0.875rem;
    font-weight: 400;
    letter-spacing: -0.01em;
}

/* ========================================
   CTA 购买区
   ======================================== */

.cta-section {
    padding: 10rem 2rem;
    text-align: center;
    background: var(--text-primary);
    color: white;
    position: relative;
    overflow: hidden;
}

.cta-section::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    background: radial-gradient(circle at 50% 50%, rgba(0, 113, 227, 0.2) 0%, transparent 70%);
    pointer-events: none;
}

.cta-content {
    max-width: 1200px;
    margin: 0 auto;
    opacity: 0;
    transform: translateY(30px);
    transition: opacity 0.8s ease, transform 0.8s ease;
}

.cta-content.visible {
    opacity: 1;
    transform: translateY(0);
}

.cta-title {
    font-size: clamp(2.5rem, 5vw, 4.5rem);
    font-weight: 700;
    letter-spacing: -0.03em;
    line-height: 1.1;
    margin-bottom: 1.5rem;
    position: relative;
    z-index: 1;
}

.cta-subtitle {
    font-size: clamp(1.1875rem, 2vw, 1.5rem);
    margin-bottom: 4rem;
    opacity: 0.85;
    font-weight: 400;
    letter-spacing: -0.01em;
    position: relative;
    z-index: 1;
}

.cta-options {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
    gap: 2rem;
    max-width: 800px;
    margin: 0 auto;
}

.product-option {
    background: rgba(255, 255, 255, 0.08);
    backdrop-filter: blur(20px);
    -webkit-backdrop-filter: blur(20px);
    padding: 3rem;
    border-radius: var(--border-radius);
    border: 1px solid rgba(255, 255, 255, 0.15);
    transition: var(--transition-fast);
    position: relative;
    z-index: 1;
}

.product-option.featured {
    border-color: rgba(255, 255, 255, 0.3);
    background: rgba(255, 255, 255, 0.12);
}

.badge {
    position: absolute;
    top: 1rem;
    right: 1rem;
    background: #ffb800;
    color: #1d1d1f;
    padding: 0.5rem 1rem;
    border-radius: 20px;
    font-size: 0.875rem;
    font-weight: 600;
}

.product-option h3 {
    font-size: clamp(1.5rem, 2vw, 1.75rem);
    font-weight: 600;
    letter-spacing: -0.02em;
    margin-bottom: 1.5rem;
}

.price {
    font-size: clamp(2rem, 3vw, 2.5rem);
    font-weight: 700;
    letter-spacing: -0.03em;
    margin-bottom: 2rem;
}

.product-option ul {
    list-style: none;
    margin-bottom: 2rem;
    text-align: left;
}

.product-option li {
    padding: 0.5rem 0;
    border-bottom: 1px solid rgba(255, 255, 255, 0.1);
}

.product-option li:last-child {
    border-bottom: none;
}

.product-option:hover {
    transform: translateY(-4px);
    border-color: rgba(255, 255, 255, 0.4);
    background: rgba(255, 255, 255, 0.15);
}

.product-option.featured:hover {
    transform: translateY(-6px);
    border-color: rgba(255, 255, 255, 0.5);
}

.product-option .btn-primary {
    background: white;
    color: var(--accent-color);
    width: 100%;
}

.product-option .btn-primary:hover {
    background: #f0f0f0;
}

/* ========================================
   页脚
   ======================================== */

.footer {
    background: var(--bg-secondary);
    padding: 4rem 2rem 1.5rem;
}

.footer-content {
    max-width: 1200px;
    margin: 0 auto;
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(200px, 1fr));
    gap: 2rem;
    margin-bottom: 2rem;
}

.footer-section h4 {
    margin-bottom: 1rem;
    color: var(--text-primary);
}

.footer-section ul {
    list-style: none;
}

.footer-section li {
    margin-bottom: 0.5rem;
}

.footer-section a {
    color: var(--text-secondary);
    text-decoration: none;
    font-size: 0.875rem;
    transition: var(--transition);
}

.footer-section a:hover {
    color: var(--text-primary);
}

/* ========================================
   语言切换器
   ======================================== */

.language-switcher {
    max-width: 1200px;
    margin: 3rem auto 2rem;
    text-align: center;
    padding: 2rem;
    background: white;
    border-radius: 12px;
    box-shadow: 0 2px 10px rgba(0, 0, 0, 0.05);
}

.language-label {
    font-size: 1rem;
    color: var(--text-secondary);
    margin-bottom: 1rem;
    font-weight: 500;
}

.language-buttons {
    display: flex;
    flex-wrap: wrap;
    gap: 1rem;
    justify-content: center;
    align-items: center;
}

.lang-btn {
    padding: 0.625rem 1.5rem;
    background: transparent;
    border: 2px solid var(--text-secondary);
    color: var(--text-secondary);
    border-radius: 50px;
    font-size: 0.875rem;
    font-weight: 500;
    cursor: pointer;
    transition: var(--transition);
    font-family: inherit;
}

.lang-btn:hover {
    border-color: var(--accent-color);
    color: var(--accent-color);
    transform: translateY(-2px);
}

.lang-btn.active {
    background: var(--accent-color);
    border-color: var(--accent-color);
    color: white;
}

.lang-btn.active:hover {
    background: #0077ed;
    border-color: #0077ed;
}

.footer-bottom {
    text-align: center;
    padding-top: 2rem;
    border-top: 1px solid rgba(0, 0, 0, 0.1);
    color: var(--text-secondary);
    font-size: 0.875rem;
}

/* ========================================
   动画效果
   ======================================== */

@keyframes fadeInUp {
    from {
        opacity: 0;
        transform: translateY(30px);
    }
    to {
        opacity: 1;
        transform: translateY(0);
    }
}

@keyframes float {
    0%, 100% {
        transform: translateY(0);
    }
    50% {
        transform: translateY(-20px);
    }
}

@keyframes pulse-glow {
    0%, 100% {
        opacity: 0.5;
        transform: scale(1);
    }
    50% {
        opacity: 0.8;
        transform: scale(1.1);
    }
}

@keyframes ripple {
    0% {
        transform: translate(-50%, -50%) scale(0.8);
        opacity: 1;
    }
    100% {
        transform: translate(-50%, -50%) scale(1.5);
        opacity: 0;
    }
}

.fade-in {
    opacity: 0;
    transform: translateY(30px);
    transition: opacity 0.8s ease, transform 0.8s ease;
}

.fade-in.visible {
    opacity: 1;
    transform: translateY(0);
}

/* ========================================
   响应式设计
   ======================================== */

@media (max-width: 768px) {
    .nav-menu {
        position: fixed;
        left: -100%;
        top: 70px;
        flex-direction: column;
        background: rgba(255, 255, 255, 0.95);
        backdrop-filter: blur(20px);
        width: 100%;
        text-align: center;
        transition: 0.3s;
        padding: 2rem;
        box-shadow: 0 10px 30px rgba(0, 0, 0, 0.1);
    }

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

    .hamburger {
        display: flex;
    }

    .feature-item,
    .feature-item.reverse {
        grid-template-columns: 1fr;
        direction: ltr;
        gap: 2rem;
    }

    .hero-cta {
        flex-direction: column;
    }

    .cta-options {
        grid-template-columns: 1fr;
    }

    .product-option.featured {
        transform: scale(1);
    }
}

/* ========================================
   工具类
   ======================================== */

.text-center {
    text-align: center;
}

.mt-1 { margin-top: 1rem; }
.mt-2 { margin-top: 2rem; }
.mt-3 { margin-top: 3rem; }
.mb-1 { margin-bottom: 1rem; }
.mb-2 { margin-bottom: 2rem; }
.mb-3 { margin-bottom: 3rem; }