/* ========================================
   有风无界 - 宣传网站样式
   设计风格：极简白色，Apple风格
   ======================================== */

/* CSS Variables */
:root {
    --color-bg: #ffffff;
    --color-bg-secondary: #f5f5f7;
    --color-text: #1d1d1f;
    --color-text-secondary: #86868b;
    --color-accent: #0071e3;
    --color-accent-hover: #0077ed;
    --color-border: #d2d2d7;
    --color-card-bg: #ffffff;
    --color-card-shadow: rgba(0, 0, 0, 0.08);
    
    --font-sans: 'Noto Sans SC', -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, sans-serif;
    --font-mono: 'SF Mono', Monaco, 'Cascadia Code', monospace;
    
    --container-max: 1200px;
    --section-padding: 120px;
    --header-height: 60px;
    
    --transition-fast: 0.2s ease;
    --transition-normal: 0.3s ease;
    --transition-slow: 0.5s ease;
}

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

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

body {
    font-family: var(--font-sans);
    font-size: 16px;
    line-height: 1.6;
    color: var(--color-text);
    background-color: var(--color-bg);
}

a {
    color: inherit;
    text-decoration: none;
}

button {
    font-family: inherit;
    cursor: pointer;
    border: none;
    background: none;
}

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

/* Container */
.container {
    max-width: var(--container-max);
    margin: 0 auto;
    padding: 0 24px;
}

/* ========================================
   Header
   ======================================== */
.header {
    position: fixed;
    top: 0;
    left: 0;
    right: 0;
    height: var(--header-height);
    background: rgba(255, 255, 255, 0.8);
    backdrop-filter: blur(20px);
    -webkit-backdrop-filter: blur(20px);
    z-index: 1000;
    border-bottom: 1px solid transparent;
    transition: border-color var(--transition-normal);
}

.header.scrolled {
    border-bottom-color: var(--color-border);
}

.header .container {
    display: flex;
    align-items: center;
    justify-content: space-between;
    height: 100%;
}

.logo {
    display: flex;
    align-items: center;
    gap: 8px;
    font-size: 18px;
    font-weight: 500;
}

.logo-icon {
    font-size: 24px;
}

.nav {
    display: flex;
    align-items: center;
    gap: 32px;
}

.nav-link {
    font-size: 14px;
    color: var(--color-text-secondary);
    transition: color var(--transition-fast);
}

.nav-link:hover {
    color: var(--color-text);
}

.nav-link--cta {
    background: var(--color-accent);
    color: #fff;
    padding: 8px 16px;
    border-radius: 20px;
}

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

.menu-toggle {
    display: none;
    flex-direction: column;
    gap: 5px;
    padding: 8px;
}

.menu-toggle span {
    display: block;
    width: 20px;
    height: 2px;
    background: var(--color-text);
    transition: transform var(--transition-fast);
}

/* ========================================
   Hero Section
   ======================================== */
.hero {
    padding-top: calc(var(--header-height) + 80px);
    padding-bottom: var(--section-padding);
    min-height: 100vh;
    display: flex;
    align-items: center;
}

.hero .container {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 60px;
    align-items: center;
}

.hero-title {
    font-size: clamp(48px, 8vw, 80px);
    font-weight: 700;
    line-height: 1.1;
    letter-spacing: -0.02em;
    margin-bottom: 24px;
}

.hero-title-line {
    display: block;
}

.hero-title-line--accent {
    background: linear-gradient(135deg, var(--color-accent), #5856d6);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
}

.hero-subtitle {
    font-size: 24px;
    color: var(--color-text-secondary);
    margin-bottom: 16px;
}

.hero-description {
    font-size: 17px;
    color: var(--color-text-secondary);
    line-height: 1.7;
    margin-bottom: 40px;
    max-width: 480px;
}

.hero-actions {
    display: flex;
    gap: 16px;
    margin-bottom: 32px;
}

.hero-meta {
    display: flex;
    align-items: center;
    gap: 12px;
    font-size: 14px;
    color: var(--color-text-secondary);
}

.hero-separator {
    opacity: 0.4;
}

/* Phone Mockup */
.hero-visual {
    display: flex;
    justify-content: center;
}

.phone-mockup {
    width: 280px;
    height: 560px;
    background: #1d1d1f;
    border-radius: 40px;
    padding: 12px;
    box-shadow: 
        0 25px 50px -12px rgba(0, 0, 0, 0.25),
        0 0 0 1px rgba(0, 0, 0, 0.1);
}

.phone-screen {
    width: 100%;
    height: 100%;
    background: var(--color-bg);
    border-radius: 30px;
    overflow: hidden;
    display: flex;
    flex-direction: column;
}

.phone-status-bar {
    display: flex;
    justify-content: space-between;
    padding: 12px 20px;
    font-size: 12px;
    font-weight: 500;
}

.phone-app {
    flex: 1;
    display: flex;
    flex-direction: column;
    background: var(--color-bg-secondary);
}

.phone-app-header {
    padding: 16px 20px;
    background: var(--color-bg);
    font-weight: 500;
    font-size: 14px;
}

.phone-app-content {
    flex: 1;
    padding: 16px;
    display: flex;
    flex-direction: column;
    gap: 12px;
}

.phone-card {
    height: 80px;
    background: var(--color-bg);
    border-radius: 12px;
    box-shadow: 0 1px 3px var(--color-card-shadow);
}

.phone-card--short {
    height: 60px;
}

/* ========================================
   Buttons
   ======================================== */
.btn {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    gap: 8px;
    padding: 14px 28px;
    font-size: 16px;
    font-weight: 500;
    border-radius: 24px;
    transition: all var(--transition-fast);
    cursor: pointer;
}

.btn-icon {
    width: 18px;
    height: 18px;
}

.btn--primary {
    background: var(--color-accent);
    color: #fff;
}

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

.btn--secondary {
    background: var(--color-bg-secondary);
    color: var(--color-text);
}

.btn--secondary:hover {
    background: var(--color-border);
}

.btn--large {
    padding: 18px 36px;
    font-size: 18px;
}

/* ========================================
   Section Common
   ======================================== */
.section-header {
    text-align: center;
    margin-bottom: 64px;
}

.section-title {
    font-size: clamp(32px, 5vw, 48px);
    font-weight: 600;
    letter-spacing: -0.02em;
    margin-bottom: 12px;
}

.section-subtitle {
    font-size: 18px;
    color: var(--color-text-secondary);
}

/* ========================================
   Features Section
   ======================================== */
.features {
    padding: var(--section-padding) 0;
    background: var(--color-bg-secondary);
}

.features-grid {
    display: grid;
    grid-template-columns: repeat(4, 1fr);
    gap: 24px;
}

.feature-card {
    background: var(--color-card-bg);
    padding: 32px 24px;
    border-radius: 20px;
    box-shadow: 0 2px 8px var(--color-card-shadow);
    transition: transform var(--transition-normal), box-shadow var(--transition-normal);
}

.feature-card:hover {
    transform: translateY(-4px);
    box-shadow: 0 12px 24px var(--color-card-shadow);
}

.feature-icon {
    width: 48px;
    height: 48px;
    margin-bottom: 20px;
    color: var(--color-accent);
}

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

.feature-title {
    font-size: 18px;
    font-weight: 500;
    margin-bottom: 8px;
}

.feature-desc {
    font-size: 14px;
    color: var(--color-text-secondary);
    line-height: 1.6;
}

/* ========================================
   Guide Section
   ======================================== */
.guide {
    padding: var(--section-padding) 0;
}

.guide-list {
    max-width: 800px;
    margin: 0 auto;
}

.guide-item {
    border-bottom: 1px solid var(--color-border);
}

.guide-trigger {
    width: 100%;
    display: flex;
    align-items: center;
    gap: 20px;
    padding: 24px 0;
    text-align: left;
    transition: color var(--transition-fast);
}

.guide-trigger:hover {
    color: var(--color-accent);
}

.guide-number {
    font-size: 14px;
    font-weight: 500;
    color: var(--color-accent);
    min-width: 32px;
}

.guide-question {
    flex: 1;
    font-size: 18px;
    font-weight: 500;
}

.guide-arrow {
    width: 20px;
    height: 20px;
    transition: transform var(--transition-normal);
}

.guide-item.active .guide-arrow {
    transform: rotate(180deg);
}

.guide-answer {
    max-height: 0;
    overflow: hidden;
    transition: max-height var(--transition-slow), padding var(--transition-slow);
}

.guide-item.active .guide-answer {
    max-height: 500px;
    padding-bottom: 24px;
}

.guide-answer p {
    font-size: 15px;
    color: var(--color-text-secondary);
    line-height: 1.8;
    margin-bottom: 8px;
}

.guide-answer p:last-child {
    margin-bottom: 0;
}

.guide-answer strong {
    color: var(--color-text);
    font-weight: 500;
}

/* ========================================
   Changelog Section
   ======================================== */
.changelog {
    padding: var(--section-padding) 0;
    background: var(--color-bg-secondary);
}

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

.timeline::before {
    content: '';
    position: absolute;
    left: 140px;
    top: 0;
    bottom: 0;
    width: 2px;
    background: var(--color-border);
}

.timeline-item {
    display: flex;
    gap: 40px;
    margin-bottom: 48px;
    position: relative;
}

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

.timeline-marker {
    min-width: 120px;
    text-align: right;
    position: relative;
}

.timeline-marker::after {
    content: '';
    position: absolute;
    right: -26px;
    top: 8px;
    width: 10px;
    height: 10px;
    background: var(--color-accent);
    border-radius: 50%;
    border: 2px solid var(--color-bg-secondary);
}

.timeline-version {
    display: block;
    font-size: 18px;
    font-weight: 600;
    color: var(--color-accent);
}

.timeline-date {
    display: block;
    font-size: 14px;
    color: var(--color-text-secondary);
}

.timeline-content {
    flex: 1;
    background: var(--color-card-bg);
    padding: 24px;
    border-radius: 16px;
    box-shadow: 0 2px 8px var(--color-card-shadow);
}

.timeline-title {
    font-size: 18px;
    font-weight: 500;
    margin-bottom: 16px;
}

.timeline-list {
    list-style: none;
}

.timeline-list li {
    font-size: 14px;
    color: var(--color-text-secondary);
    line-height: 1.8;
    padding-left: 16px;
    position: relative;
}

.timeline-list li::before {
    content: '·';
    position: absolute;
    left: 0;
    color: var(--color-accent);
}

/* ========================================
   Download Section
   ======================================== */
.download {
    padding: var(--section-padding) 0;
}

.download-card {
    max-width: 600px;
    margin: 0 auto;
    background: var(--color-bg-secondary);
    border-radius: 24px;
    padding: 40px;
    display: flex;
    flex-direction: column;
    gap: 32px;
}

.download-app {
    display: flex;
    align-items: center;
    gap: 16px;
    margin-bottom: 24px;
}

.download-icon {
    font-size: 48px;
}

.download-name {
    font-size: 24px;
    font-weight: 600;
}

.download-version {
    font-size: 14px;
    color: var(--color-text-secondary);
}

.download-specs {
    display: flex;
    gap: 32px;
}

.spec-item {
    display: flex;
    flex-direction: column;
    gap: 4px;
}

.spec-label {
    font-size: 12px;
    color: var(--color-text-secondary);
    text-transform: uppercase;
}

.spec-value {
    font-size: 16px;
    font-weight: 500;
}

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

.download-note {
    font-size: 13px;
    color: var(--color-text-secondary);
    margin-top: 12px;
}

/* ========================================
   Contact Section
   ======================================== */
.contact {
    padding: var(--section-padding) 0;
    background: var(--color-bg-secondary);
}

.contact-grid {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: 24px;
    max-width: 800px;
    margin: 0 auto;
}

.contact-card {
    background: var(--color-card-bg);
    padding: 32px 24px;
    border-radius: 20px;
    text-align: center;
    box-shadow: 0 2px 8px var(--color-card-shadow);
    transition: transform var(--transition-normal), box-shadow var(--transition-normal);
}

.contact-card:hover {
    transform: translateY(-4px);
    box-shadow: 0 12px 24px var(--color-card-shadow);
}

.contact-card--placeholder {
    opacity: 0.6;
}

.contact-icon {
    width: 40px;
    height: 40px;
    margin-bottom: 16px;
    color: var(--color-text-secondary);
}

.contact-card:hover .contact-icon {
    color: var(--color-accent);
}

.contact-title {
    font-size: 16px;
    font-weight: 500;
    margin-bottom: 4px;
}

.contact-desc {
    font-size: 13px;
    color: var(--color-text-secondary);
}

/* ========================================
   Footer
   ======================================== */
.footer {
    padding: 40px 0;
    border-top: 1px solid var(--color-border);
}

.footer-content {
    display: flex;
    justify-content: space-between;
    align-items: center;
    margin-bottom: 24px;
}

.footer-brand {
    display: flex;
    flex-direction: column;
    gap: 8px;
}

.footer-logo {
    font-size: 18px;
    font-weight: 500;
}

.footer-copyright {
    font-size: 13px;
    color: var(--color-text-secondary);
}

.footer-links {
    display: flex;
    gap: 24px;
}

.footer-links a {
    font-size: 14px;
    color: var(--color-text-secondary);
    transition: color var(--transition-fast);
}

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

.footer-license {
    text-align: center;
    padding-top: 24px;
    border-top: 1px solid var(--color-border);
}

.footer-license p {
    font-size: 12px;
    color: var(--color-text-secondary);
}

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

.hero-content,
.hero-visual {
    animation: fadeInUp 0.8s ease forwards;
}

.hero-visual {
    animation-delay: 0.2s;
}

/* ========================================
   Responsive
   ======================================== */
@media (max-width: 1024px) {
    .features-grid {
        grid-template-columns: repeat(2, 1fr);
    }
    
    .timeline::before {
        left: 20px;
    }
    
    .timeline-marker {
        min-width: auto;
        text-align: left;
    }
    
    .timeline-marker::after {
        left: -4px;
        right: auto;
    }
    
    .timeline-item {
        flex-direction: column;
        gap: 12px;
        padding-left: 40px;
    }
}

@media (max-width: 768px) {
    :root {
        --section-padding: 80px;
    }
    
    .nav {
        display: none;
    }
    
    .menu-toggle {
        display: flex;
    }
    
    .hero .container {
        grid-template-columns: 1fr;
        text-align: center;
    }
    
    .hero-description {
        margin-left: auto;
        margin-right: auto;
    }
    
    .hero-actions {
        justify-content: center;
    }
    
    .hero-meta {
        justify-content: center;
    }
    
    .hero-visual {
        display: none;
    }
    
    .features-grid {
        grid-template-columns: 1fr;
    }
    
    .contact-grid {
        grid-template-columns: 1fr;
    }
    
    .footer-content {
        flex-direction: column;
        gap: 24px;
        text-align: center;
    }
    
    .footer-links {
        flex-wrap: wrap;
        justify-content: center;
    }
}

/* Mobile Menu */
.nav.active {
    display: flex;
    position: fixed;
    top: var(--header-height);
    left: 0;
    right: 0;
    bottom: 0;
    background: var(--color-bg);
    flex-direction: column;
    align-items: center;
    justify-content: center;
    gap: 32px;
}

.nav.active .nav-link {
    font-size: 24px;
}