/* 基础变量 */
:root {
    --color-warm-white: #FAF8F5;
    --color-deep-ink: #2C2C2C;
    --color-postmark-red: #E63946;
    --color-postal-green: #2D6A4F;
    --color-warm-yellow: #F4A261;
    --color-light-gray: #F0F0F0;
    --color-medium-gray: #E0E0E0;
    --color-text-gray: #666666;

    --font-serif: 'Noto Serif SC', serif;
    --font-sans: 'Noto Sans SC', sans-serif;

    --spacing-xs: 0.5rem;
    --spacing-sm: 1rem;
    --spacing-md: 1.5rem;
    --spacing-lg: 2rem;
    --spacing-xl: 3rem;
    --spacing-xxl: 4rem;

    --border-radius: 8px;
    --shadow-soft: 0 4px 20px rgba(0, 0, 0, 0.08);
    --shadow-medium: 0 8px 30px rgba(0, 0, 0, 0.12);
}

/* 重置与基础 */
* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}

html {
    scroll-behavior: smooth;
    font-size: 16px;
}

body {
    font-family: var(--font-sans);
    background-color: var(--color-warm-white);
    color: var(--color-deep-ink);
    line-height: 1.6;
}

.container {
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 var(--spacing-md);
}

/* 导航 */
.navbar {
    position: fixed;
    top: 0;
    left: 0;
    right: 0;
    background: rgba(250, 248, 245, 0.95);
    backdrop-filter: blur(10px);
    z-index: 1000;
    padding: var(--spacing-sm) 0;
    box-shadow: var(--shadow-soft);
}

.navbar .container {
    display: flex;
    justify-content: space-between;
    align-items: center;
}

.nav-logo {
    font-family: var(--font-serif);
    font-size: 1.5rem;
    font-weight: 700;
    color: var(--color-deep-ink);
    text-decoration: none;
}

.nav-links {
    display: flex;
    gap: var(--spacing-lg);
    list-style: none;
}

.nav-links a {
    color: var(--color-text-gray);
    text-decoration: none;
    font-size: 0.9rem;
    transition: color 0.3s ease;
}

.nav-links a:hover {
    color: var(--color-postmark-red);
}

/* 英雄区域 */
.hero {
    min-height: 100vh;
    display: flex;
    align-items: center;
    padding-top: 80px;
    background: linear-gradient(135deg, var(--color-warm-white) 0%, #F5F0EB 100%);
}

.hero .container {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: var(--spacing-xl);
    align-items: center;
}

.hero-logo {
    width: 280px;
    height: auto;
    margin-bottom: var(--spacing-md);
    object-fit: contain;
}

.hero-subtitle {
    font-size: 1.8rem;
    color: var(--color-postmark-red);
    margin-bottom: var(--spacing-md);
    font-weight: 500;
}

.hero-desc {
    font-size: 1.2rem;
    color: var(--color-text-gray);
    margin-bottom: var(--spacing-lg);
}

.cta-button {
    display: inline-block;
    padding: var(--spacing-sm) var(--spacing-lg);
    background: var(--color-postmark-red);
    color: white;
    text-decoration: none;
    border-radius: var(--border-radius);
    font-weight: 500;
    transition: all 0.3s ease;
}

.cta-button:hover {
    background: #D62839;
    transform: translateY(-2px);
    box-shadow: var(--shadow-medium);
}

/* 明信片堆叠效果 */
.postcard-stack {
    position: relative;
    width: 300px;
    height: 400px;
    margin: 0 auto;
}

.postcard {
    position: absolute;
    width: 280px;
    height: 180px;
    background: white;
    border-radius: var(--border-radius);
    box-shadow: var(--shadow-soft);
    transition: transform 0.3s ease;
}

.postcard-1 {
    top: 0;
    left: 0;
    transform: rotate(-5deg);
    background: linear-gradient(135deg, #FFF5F5 0%, #FFF 100%);
    border: 1px solid var(--color-medium-gray);
}

.postcard-2 {
    top: 60px;
    left: 30px;
    transform: rotate(2deg);
    background: linear-gradient(135deg, #F5FFF5 0%, #FFF 100%);
    border: 1px solid var(--color-medium-gray);
}

.postcard-3 {
    top: 120px;
    left: 10px;
    transform: rotate(-2deg);
    background: linear-gradient(135deg, #F5F5FF 0%, #FFF 100%);
    border: 1px solid var(--color-medium-gray);
}

/* 通用区域样式 */
.section {
    padding: var(--spacing-xxl) 0;
}

.section-title {
    font-family: var(--font-serif);
    font-size: 2.5rem;
    text-align: center;
    margin-bottom: var(--spacing-md);
    color: var(--color-deep-ink);
}

.section-subtitle {
    text-align: center;
    color: var(--color-text-gray);
    margin-bottom: var(--spacing-xl);
    font-size: 1.1rem;
}

/* 故事区域 */
.story-section {
    background: white;
}

.story-content {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: var(--spacing-xl);
    align-items: center;
}

.story-text p {
    font-size: 1.2rem;
    margin-bottom: var(--spacing-md);
    line-height: 1.8;
}

.story-text p:last-child {
    color: var(--color-postmark-red);
    font-weight: 500;
}

.inbox-illustration {
    position: relative;
    height: 300px;
    background: var(--color-light-gray);
    border-radius: var(--border-radius);
    display: flex;
    align-items: center;
    justify-content: center;
}

.postcard-waiting {
    width: 120px;
    height: 80px;
    background: white;
    border: 2px dashed var(--color-medium-gray);
    border-radius: 4px;
}

.notification-bell {
    position: absolute;
    top: 20px;
    right: 20px;
    width: 40px;
    height: 40px;
    background: var(--color-warm-yellow);
    border-radius: 50%;
    animation: pulse 2s infinite;
}

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

/* 收藏区域 */
.collect-section {
    background: var(--color-warm-white);
}

.collect-grid {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: var(--spacing-lg);
}

.collect-item {
    background: white;
    padding: var(--spacing-lg);
    border-radius: var(--border-radius);
    text-align: center;
    box-shadow: var(--shadow-soft);
    transition: transform 0.3s ease, box-shadow 0.3s ease;
}

.collect-item:hover {
    transform: translateY(-5px);
    box-shadow: var(--shadow-medium);
}

.item-icon {
    font-size: 3rem;
    margin-bottom: var(--spacing-sm);
}

.collect-item h3 {
    font-family: var(--font-serif);
    font-size: 1.3rem;
    margin-bottom: var(--spacing-xs);
    color: var(--color-deep-ink);
}

.collect-item p {
    color: var(--color-text-gray);
    font-size: 0.95rem;
}

/* 工作原理区域 */
.how-section {
    background: white;
}

.how-steps {
    display: flex;
    justify-content: space-between;
    gap: var(--spacing-md);
    flex-wrap: wrap;
}

.step {
    flex: 1;
    min-width: 200px;
    text-align: center;
    padding: var(--spacing-lg);
}

.step-number {
    width: 50px;
    height: 50px;
    background: var(--color-postmark-red);
    color: white;
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 1.5rem;
    font-weight: 700;
    margin: 0 auto var(--spacing-sm);
}

.step h3 {
    font-family: var(--font-serif);
    font-size: 1.2rem;
    margin-bottom: var(--spacing-xs);
    color: var(--color-deep-ink);
}

.step p {
    color: var(--color-text-gray);
    font-size: 0.95rem;
}

/* 应用场景区域 */
.scenarios-section {
    background: var(--color-warm-white);
}

.scenarios-grid {
    display: grid;
    grid-template-columns: repeat(2, 1fr);
    gap: var(--spacing-lg);
}

.scenario-card {
    background: white;
    padding: var(--spacing-xl);
    border-radius: var(--border-radius);
    box-shadow: var(--shadow-soft);
    transition: transform 0.3s ease;
}

.scenario-card:hover {
    transform: translateY(-3px);
}

.scenario-icon {
    font-size: 2.5rem;
    margin-bottom: var(--spacing-sm);
}

.scenario-card h3 {
    font-family: var(--font-serif);
    font-size: 1.4rem;
    margin-bottom: var(--spacing-xs);
    color: var(--color-deep-ink);
}

.scenario-card p {
    color: var(--color-text-gray);
}

/* Demo 区域 */
.demo-section {
    background: white;
}

.demo-content {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: var(--spacing-xl);
    align-items: center;
}

.demo-text ul {
    list-style: none;
    margin: var(--spacing-md) 0;
}

.demo-text li {
    padding: var(--spacing-xs) 0;
    padding-left: var(--spacing-md);
    position: relative;
    color: var(--color-text-gray);
}

.demo-text li::before {
    content: "✓";
    position: absolute;
    left: 0;
    color: var(--color-postal-green);
    font-weight: 700;
}

.demo-qr {
    text-align: center;
    margin-top: var(--spacing-lg);
}

.qr-image {
    width: 150px;
    height: auto;
    margin: 0 auto var(--spacing-sm);
    display: block;
    border-radius: var(--border-radius);
    box-shadow: var(--shadow-soft);
}

.demo-screenshots {
    display: flex;
    gap: var(--spacing-sm);
    justify-content: center;
}

.screenshot {
    width: 150px;
    height: 260px;
    background: var(--color-light-gray);
    border-radius: var(--border-radius);
    border: 1px solid var(--color-medium-gray);
}

/* 团队区域 */
.team-section {
    background: var(--color-warm-white);
}

.team-content {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: var(--spacing-xl);
}

.team-info h3,
.team-contact h3 {
    font-family: var(--font-serif);
    font-size: 1.5rem;
    margin-bottom: var(--spacing-md);
    color: var(--color-deep-ink);
}

.team-info p {
    color: var(--color-text-gray);
    margin-bottom: var(--spacing-sm);
    line-height: 1.8;
}

.contact-item {
    margin-bottom: var(--spacing-sm);
}

.contact-label {
    font-weight: 500;
    color: var(--color-deep-ink);
}

.contact-value {
    color: var(--color-text-gray);
}

/* One More Thing 区域 */
.one-more-thing {
    margin-top: var(--spacing-xxl);
    padding-top: var(--spacing-xl);
    border-top: 2px solid var(--color-medium-gray);
    text-align: center;
}

.omt-title {
    font-family: var(--font-serif);
    font-size: 2rem;
    color: var(--color-postmark-red);
    margin-bottom: var(--spacing-sm);
}

.omt-subtitle {
    color: var(--color-text-gray);
    margin-bottom: var(--spacing-xl);
    font-size: 1.1rem;
}

.omt-features {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: var(--spacing-lg);
    text-align: left;
}

.omt-feature {
    padding: var(--spacing-lg);
    background: var(--color-warm-white);
    border-radius: var(--border-radius);
    border: 1px solid var(--color-medium-gray);
}

.omt-icon {
    font-size: 2rem;
    margin-bottom: var(--spacing-sm);
}

.omt-feature h4 {
    font-family: var(--font-serif);
    font-size: 1.1rem;
    margin-bottom: var(--spacing-xs);
    color: var(--color-deep-ink);
}

.omt-feature p {
    color: var(--color-text-gray);
    font-size: 0.9rem;
    line-height: 1.6;
}

/* 页脚 */
.footer {
    background: var(--color-deep-ink);
    color: white;
    padding: var(--spacing-xl) 0;
    text-align: center;
}

.footer-logo-img {
    width: 180px;
    height: auto;
    margin-bottom: var(--spacing-sm);
    filter: invert(1);
}

.footer-tagline {
    color: var(--color-warm-yellow);
    margin-bottom: var(--spacing-md);
}

.footer-copyright {
    color: #888;
    font-size: 0.9rem;
}

/* 响应式设计 */
@media (max-width: 1024px) {
    .hero .container {
        grid-template-columns: 1fr;
        text-align: center;
    }

    .hero-visual {
        order: -1;
        margin-bottom: var(--spacing-lg);
    }

    .postcard-stack {
        width: 250px;
        height: 350px;
    }

    .postcard {
        width: 230px;
        height: 150px;
    }

    .story-content,
    .demo-content,
    .team-content {
        grid-template-columns: 1fr;
    }

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

    .how-steps {
        flex-direction: column;
        align-items: center;
    }

    .step {
        width: 100%;
        max-width: 400px;
    }
}

@media (max-width: 768px) {
    html {
        font-size: 14px;
    }

    .hero-logo {
        width: 220px;
    }

    .hero-subtitle {
        font-size: 1.4rem;
    }

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

    .collect-grid {
        grid-template-columns: 1fr;
    }

    .scenarios-grid {
        grid-template-columns: 1fr;
    }

    .nav-links {
        display: none;
    }

    .demo-screenshots {
        flex-direction: column;
        align-items: center;
    }

    .screenshot {
        width: 200px;
        height: 350px;
    }

    .omt-features {
        grid-template-columns: 1fr;
    }
}

@media (max-width: 480px) {
    .hero-logo {
        width: 180px;
    }

    .hero-subtitle {
        font-size: 1.2rem;
    }

    .cta-button {
        width: 100%;
        text-align: center;
    }

    .postcard-stack {
        width: 200px;
        height: 300px;
    }

    .postcard {
        width: 180px;
        height: 120px;
    }
}

/* 动画效果 */
.fade-in {
    opacity: 0;
    transform: translateY(20px);
    transition: opacity 0.6s ease, transform 0.6s ease;
}

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

/* 邮戳装饰 */
.postmark-decoration {
    position: absolute;
    width: 60px;
    height: 60px;
    border: 2px solid var(--color-postmark-red);
    border-radius: 50%;
    opacity: 0.3;
    transform: rotate(-15deg);
}