/* ========================================
   Apple-inspired Design System
   Clean, minimal, elegant
   ======================================== */

/* Reset & Base */
* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}

:root {
    /* Apple Color Palette */
    --color-text: #1d1d1f;
    --color-text-secondary: #6e6e73;
    --color-bg: #ffffff;
    --color-bg-secondary: #f5f5f7;
    --color-bg-dark: #000000;
    --color-link: #0066cc;
    --color-link-hover: #0077ed;
    --color-button-bg: #0071e3;
    --color-button-hover: #0077ed;
    --color-alipay: #1677ff;
    --color-wechat: #07c160;
    
    /* Typography */
    --font-family: -apple-system, BlinkMacSystemFont, "SF Pro Display", "SF Pro Text", 
                   "Helvetica Neue", "PingFang SC", "Hiragino Sans GB", 
                   "Microsoft YaHei", sans-serif;
    --font-weight-regular: 400;
    --font-weight-medium: 500;
    --font-weight-semibold: 600;
    --font-weight-bold: 700;
    
    /* Spacing */
    --spacing-xs: 8px;
    --spacing-sm: 16px;
    --spacing-md: 24px;
    --spacing-lg: 48px;
    --spacing-xl: 80px;
    
    /* Transitions */
    --transition-default: all 0.3s cubic-bezier(0.4, 0, 0.2, 1);
    --transition-smooth: all 0.4s cubic-bezier(0.25, 0.46, 0.45, 0.94);
}

html {
    font-size: 16px;
    scroll-behavior: smooth;
    -webkit-font-smoothing: antialiased;
    -moz-osx-font-smoothing: grayscale;
}

body {
    font-family: var(--font-family);
    color: var(--color-text);
    background: var(--color-bg);
    line-height: 1.47059;
    font-weight: var(--font-weight-regular);
    letter-spacing: -0.022em;
    overflow-x: hidden;
}

/* ========================================
   Navigation - Apple Style
   ======================================== */
.nav-global {
    position: fixed;
    top: 0;
    left: 0;
    right: 0;
    z-index: 9999;
    background: rgba(255, 255, 255, 0.72);
    backdrop-filter: saturate(180%) blur(20px);
    -webkit-backdrop-filter: saturate(180%) blur(20px);
    border-bottom: 1px solid rgba(0, 0, 0, 0.08);
    transition: var(--transition-default);
}

.nav-global.scrolled {
    background: rgba(255, 255, 255, 0.8);
    box-shadow: 0 1px 0 rgba(0, 0, 0, 0.1);
}

.nav-content {
    max-width: 980px;
    margin: 0 auto;
    padding: 0 22px;
    height: 44px;
    display: flex;
    align-items: center;
    justify-content: space-between;
}

.nav-brand {
    font-size: 21px;
    font-weight: var(--font-weight-semibold);
    color: var(--color-text);
    letter-spacing: -0.03em;
}

.nav-list {
    display: flex;
    list-style: none;
    gap: 0;
    align-items: center;
}

.nav-item {
    margin: 0;
}

.nav-link {
    display: block;
    padding: 0 12px;
    font-size: 12px;
    font-weight: var(--font-weight-regular);
    color: var(--color-text);
    text-decoration: none;
    opacity: 0.8;
    transition: opacity 0.3s ease;
    letter-spacing: -0.01em;
}

.nav-link:hover {
    opacity: 1;
}

/* ========================================
   Hero Section - Apple Style
   ======================================== */
.hero-section {
    min-height: 100vh;
    display: flex;
    align-items: center;
    justify-content: center;
    background: var(--color-bg);
    padding: 100px 22px 60px;
    position: relative;
}

.hero-content {
    text-align: center;
    max-width: 900px;
    margin: 0 auto;
}

.hero-eyebrow {
    font-size: 21px;
    line-height: 1.19048;
    font-weight: var(--font-weight-semibold);
    letter-spacing: 0.011em;
    color: var(--color-text-secondary);
    margin-bottom: 8px;
}

.hero-headline {
    font-size: 96px;
    line-height: 1.05;
    font-weight: var(--font-weight-bold);
    letter-spacing: -0.015em;
    color: var(--color-text);
    margin-bottom: 16px;
}

.hero-subheadline {
    font-size: 28px;
    line-height: 1.14286;
    font-weight: var(--font-weight-regular);
    letter-spacing: 0.007em;
    color: var(--color-text-secondary);
    margin-bottom: 32px;
}

.hero-cta {
    display: flex;
    gap: 16px;
    justify-content: center;
    align-items: center;
    flex-wrap: wrap;
}

.cta-button {
    display: inline-block;
    padding: 12px 22px;
    font-size: 17px;
    line-height: 1.17648;
    font-weight: var(--font-weight-regular);
    text-decoration: none;
    border-radius: 980px;
    transition: var(--transition-default);
    letter-spacing: -0.022em;
    min-width: 28px;
}

.cta-primary {
    background: var(--color-button-bg);
    color: #fff;
}

.cta-primary:hover {
    background: var(--color-button-hover);
    transform: scale(1.02);
}

.cta-secondary {
    background: transparent;
    color: var(--color-link);
    border: 1px solid var(--color-link);
}

.cta-secondary:hover {
    background: var(--color-link);
    color: #fff;
}

/* ========================================
   Section Wrappers - Apple Style
   ======================================== */
.section-wrapper {
    padding: var(--spacing-xl) 22px;
    background: var(--color-bg);
}

.section-wrapper.section-dark {
    background: var(--color-bg-secondary);
}

.section-content {
    max-width: 980px;
    margin: 0 auto;
}

.section-intro {
    text-align: center;
    margin-bottom: 60px;
}

.section-headline {
    font-size: 56px;
    line-height: 1.07143;
    font-weight: var(--font-weight-bold);
    letter-spacing: -0.005em;
    color: var(--color-text);
    margin-bottom: 12px;
}

.section-subheadline {
    font-size: 24px;
    line-height: 1.16667;
    font-weight: var(--font-weight-regular);
    letter-spacing: 0.009em;
    color: var(--color-text-secondary);
}

/* ========================================
   Tiles Grid - About Section
   ======================================== */
.tiles-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
    gap: 24px;
}

.tile {
    background: var(--color-bg);
    border-radius: 18px;
    padding: 40px 32px;
    transition: var(--transition-smooth);
    border: 1px solid rgba(0, 0, 0, 0.06);
}

.tile:hover {
    transform: translateY(-4px);
    box-shadow: 0 8px 24px rgba(0, 0, 0, 0.1);
}

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

.tile-headline {
    font-size: 24px;
    line-height: 1.16667;
    font-weight: var(--font-weight-semibold);
    letter-spacing: 0.009em;
    color: var(--color-text);
    margin-bottom: 12px;
}

.tile-copy {
    font-size: 17px;
    line-height: 1.47059;
    font-weight: var(--font-weight-regular);
    letter-spacing: -0.022em;
    color: var(--color-text-secondary);
}

/* ========================================
   Payment Section - Apple Style
   ======================================== */
.payment-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
    gap: 32px;
    max-width: 740px;
    margin: 0 auto;
}

.payment-tile {
    background: var(--color-bg);
    border-radius: 18px;
    padding: 48px 32px;
    text-align: center;
    transition: var(--transition-smooth);
    border: 1px solid rgba(0, 0, 0, 0.06);
}

.payment-tile:hover {
    transform: translateY(-4px);
    box-shadow: 0 8px 24px rgba(0, 0, 0, 0.1);
}

.payment-icon-wrapper {
    margin-bottom: 24px;
}

.payment-icon {
    width: 56px;
    height: 56px;
    margin: 0 auto;
    display: flex;
    align-items: center;
    justify-content: center;
    border-radius: 50%;
    transition: var(--transition-default);
}

.payment-icon.alipay {
    background: linear-gradient(135deg, #1677ff 0%, #0958d9 100%);
}

.payment-icon.wechat {
    background: linear-gradient(135deg, #07c160 0%, #05944f 100%);
}

.payment-tile:hover .payment-icon {
    transform: scale(1.1);
}

.payment-title {
    font-size: 21px;
    line-height: 1.19048;
    font-weight: var(--font-weight-semibold);
    letter-spacing: 0.011em;
    color: var(--color-text);
    margin-bottom: 24px;
}

.qr-container {
    position: relative;
    width: 200px;
    height: 200px;
    margin: 0 auto 20px;
    border-radius: 12px;
    overflow: hidden;
    background: var(--color-bg-secondary);
}

.qr-image {
    width: 100%;
    height: 100%;
    object-fit: cover;
    display: none;
}

.qr-image.loaded {
    display: block;
}

.qr-placeholder {
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    display: flex;
    flex-direction: column;
    align-items: center;
    justify-content: center;
    padding: 24px;
}

.placeholder-icon {
    font-size: 36px;
    margin-bottom: 12px;
    opacity: 0.5;
}

.placeholder-text {
    font-size: 14px;
    line-height: 1.42859;
    font-weight: var(--font-weight-regular);
    color: var(--color-text-secondary);
    margin-bottom: 8px;
}

.placeholder-hint {
    font-size: 11px;
    line-height: 1.27273;
    font-family: 'SF Mono', 'Monaco', 'Courier New', monospace;
    color: var(--color-text-secondary);
    opacity: 0.6;
    background: rgba(0, 0, 0, 0.03);
    padding: 4px 8px;
    border-radius: 4px;
}

.payment-caption {
    font-size: 14px;
    line-height: 1.42859;
    font-weight: var(--font-weight-regular);
    letter-spacing: -0.016em;
    color: var(--color-text-secondary);
}

/* ========================================
   Contact Section - Apple Style
   ======================================== */
.contact-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(260px, 1fr));
    gap: 24px;
}

.contact-item {
    background: var(--color-bg);
    border-radius: 18px;
    padding: 40px 32px;
    text-align: center;
    transition: var(--transition-smooth);
    border: 1px solid rgba(0, 0, 0, 0.06);
}

.contact-item:hover {
    transform: translateY(-4px);
    box-shadow: 0 8px 24px rgba(0, 0, 0, 0.1);
}

.contact-icon-wrapper {
    margin-bottom: 20px;
}

.contact-icon {
    font-size: 48px;
    line-height: 1;
    display: block;
}

.contact-title {
    font-size: 19px;
    line-height: 1.21053;
    font-weight: var(--font-weight-semibold);
    letter-spacing: 0.012em;
    color: var(--color-text);
    margin-bottom: 8px;
}

.contact-detail {
    font-size: 14px;
    line-height: 1.42859;
    font-weight: var(--font-weight-regular);
    letter-spacing: -0.016em;
    color: var(--color-text-secondary);
}

/* ========================================
   Footer - Apple Style
   ======================================== */
.footer-global {
    background: var(--color-bg-secondary);
    padding: 32px 22px;
    border-top: 1px solid rgba(0, 0, 0, 0.1);
}

.footer-content {
    max-width: 980px;
    margin: 0 auto;
}

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

.footer-copy {
    font-size: 12px;
    line-height: 1.33337;
    font-weight: var(--font-weight-regular);
    letter-spacing: -0.01em;
    color: var(--color-text-secondary);
    margin-bottom: 4px;
}

.footer-message {
    font-size: 12px;
    line-height: 1.33337;
    font-weight: var(--font-weight-regular);
    letter-spacing: -0.01em;
    color: var(--color-text-secondary);
    opacity: 0.7;
}

/* ========================================
   Animations & Transitions
   ======================================== */
@keyframes fadeIn {
    from {
        opacity: 0;
    }
    to {
        opacity: 1;
    }
}

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

/* Scroll animations */
.fade-in {
    animation: fadeIn 0.8s ease-out;
}

.slide-up {
    animation: slideUp 0.8s ease-out;
}

/* ========================================
   Responsive Design - Apple Breakpoints
   ======================================== */

/* Large devices (desktops, 1024px and up) */
@media only screen and (max-width: 1068px) {
    .hero-headline {
        font-size: 80px;
    }
    
    .hero-subheadline {
        font-size: 24px;
    }
    
    .section-headline {
        font-size: 48px;
    }
}

/* Medium devices (tablets, 768px and up) */
@media only screen and (max-width: 734px) {
    .nav-content {
        padding: 0 16px;
    }
    
    .nav-list {
        gap: 0;
    }
    
    .nav-link {
        padding: 0 8px;
        font-size: 11px;
    }
    
    .hero-section {
        padding: 80px 16px 40px;
    }
    
    .hero-headline {
        font-size: 48px;
    }
    
    .hero-subheadline {
        font-size: 19px;
    }
    
    .hero-eyebrow {
        font-size: 17px;
    }
    
    .section-wrapper {
        padding: 60px 16px;
    }
    
    .section-headline {
        font-size: 40px;
    }
    
    .section-subheadline {
        font-size: 19px;
    }
    
    .tiles-grid,
    .payment-grid,
    .contact-grid {
        grid-template-columns: 1fr;
        gap: 16px;
    }
    
    .tile,
    .payment-tile,
    .contact-item {
        padding: 32px 24px;
    }
    
    .cta-button {
        padding: 10px 20px;
        font-size: 14px;
    }
}

/* Small devices (phones, less than 480px) */
@media only screen and (max-width: 480px) {
    .nav-brand {
        font-size: 17px;
    }
    
    .nav-link {
        padding: 0 6px;
        font-size: 10px;
    }
    
    .hero-headline {
        font-size: 40px;
    }
    
    .hero-subheadline {
        font-size: 17px;
    }
    
    .section-headline {
        font-size: 32px;
    }
    
    .section-subheadline {
        font-size: 17px;
    }
    
    .hero-cta {
        flex-direction: column;
        gap: 12px;
    }
    
    .cta-button {
        width: 100%;
        max-width: 280px;
    }
    
    .qr-container {
        width: 180px;
        height: 180px;
    }
}

/* Extra small devices */
@media only screen and (max-width: 375px) {
    .hero-headline {
        font-size: 36px;
    }
    
    .section-headline {
        font-size: 28px;
    }
}