@import url('https://fonts.googleapis.com/css2?family=Inter:wght@300;400;500;600;700;800&display=swap');

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

:root {
    /* 温暖的米色/橙色主题 */
    --bg-primary: #FFF9F5;
    --bg-secondary: #FFF5ED;
    --surface-1: #FFFFFF;
    --surface-2: #FFF0E5;
    
    /* 边框和分割线 */
    --border-subtle: rgba(255, 140, 66, 0.1);
    --border-light: rgba(255, 140, 66, 0.2);
    --border-medium: rgba(255, 140, 66, 0.3);
    
    /* 文字层级 */
    --text-primary: #2D2A26;
    --text-secondary: #6B6560;
    --text-tertiary: #9A938C;
    --text-disabled: #C4BDB5;
    
    /* 强调色 - 温暖的橙色调 */
    --accent-primary: #FF8C42;
    --accent-secondary: #FFA566;
    --accent-muted: rgba(255, 140, 66, 0.1);
    --accent-glow: rgba(255, 140, 66, 0.2);
    
    /* 渐变 */
    --gradient-accent: linear-gradient(135deg, #FF8C42 0%, #FFA566 100%);
    --gradient-bg: linear-gradient(180deg, #FFF9F5 0%, #FFF5ED 100%);
    
    /* 导航栏背景 */
    --nav-bg: rgba(255, 249, 245, 0.95);
    
    /* 阴影 */
    --shadow-sm: 0 2px 8px rgba(0, 0, 0, 0.04);
    --shadow-md: 0 4px 20px rgba(0, 0, 0, 0.04);
    --shadow-lg: 0 8px 32px rgba(0, 0, 0, 0.08);
    --shadow-xl: 0 24px 80px rgba(0, 0, 0, 0.1);
    
    /* 主题切换按钮 */
    --theme-toggle-bg: var(--surface-2);
    --theme-toggle-hover: var(--accent-muted);
}

/* ===== 深色主题 ===== */
[data-theme="dark"] {
    --bg-primary: #1A1714;
    --bg-secondary: #1E1B17;
    --surface-1: #252220;
    --surface-2: #2E2A26;
    
    --border-subtle: rgba(255, 140, 66, 0.08);
    --border-light: rgba(255, 140, 66, 0.15);
    --border-medium: rgba(255, 140, 66, 0.25);
    
    --text-primary: #F0EBE6;
    --text-secondary: #A8A099;
    --text-tertiary: #7A736C;
    --text-disabled: #4A4540;
    
    --accent-primary: #FF9955;
    --accent-secondary: #FFB07A;
    --accent-muted: rgba(255, 153, 85, 0.12);
    --accent-glow: rgba(255, 153, 85, 0.2);
    
    --gradient-accent: linear-gradient(135deg, #FF9955 0%, #FFB07A 100%);
    --gradient-bg: linear-gradient(180deg, #1A1714 0%, #1E1B17 100%);
    
    --nav-bg: rgba(26, 23, 20, 0.95);
    
    --shadow-sm: 0 2px 8px rgba(0, 0, 0, 0.2);
    --shadow-md: 0 4px 20px rgba(0, 0, 0, 0.2);
    --shadow-lg: 0 8px 32px rgba(0, 0, 0, 0.3);
    --shadow-xl: 0 24px 80px rgba(0, 0, 0, 0.4);
    
    --theme-toggle-bg: var(--surface-2);
    --theme-toggle-hover: var(--accent-muted);
}

html {
    scroll-behavior: smooth;
}

body {
    font-family: 'Inter', -apple-system, BlinkMacSystemFont, 'PingFang SC', 'Microsoft YaHei', sans-serif;
    background: var(--bg-primary);
    color: var(--text-primary);
    line-height: 1.6;
    overflow-x: hidden;
    -webkit-font-smoothing: antialiased;
    -moz-osx-font-smoothing: grayscale;
}

/* ===== CONTAINER ===== */
.container {
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 2rem;
}

/* ===== NAVIGATION ===== */
nav {
    position: fixed;
    top: 0;
    left: 0;
    right: 0;
    z-index: 100;
    height: 72px;
    background: var(--nav-bg);
    backdrop-filter: blur(12px);
    -webkit-backdrop-filter: blur(12px);
    border-bottom: 1px solid var(--border-subtle);
}

.nav-container {
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 2rem;
    height: 100%;
    display: flex;
    align-items: center;
    justify-content: space-between;
}

.logo-section {
    display: flex;
    align-items: center;
    gap: 0.5rem;
}

.logo {
    height: 28px;
    width: auto;
}

.beta-badge {
    font-size: 0.65rem;
    font-weight: 700;
    padding: 0.2rem 0.5rem;
    border-radius: 4px;
    background: var(--accent-primary);
    color: white;
    letter-spacing: 0.5px;
}

.nav-links {
    display: flex;
    gap: 2.5rem;
    list-style: none;
}

.nav-links a {
    color: var(--text-secondary);
    text-decoration: none;
    font-size: 0.9rem;
    font-weight: 500;
    transition: all 0.3s ease;
    position: relative;
}

.nav-links a:hover {
    color: var(--accent-primary);
}

.nav-actions {
    display: flex;
    align-items: center;
    gap: 1rem;
}

/* ===== BUTTONS ===== */
.btn-primary {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    gap: 0.5rem;
    padding: 0.75rem 1.5rem;
    background: var(--accent-primary);
    color: white;
    font-size: 0.9rem;
    font-weight: 600;
    text-decoration: none;
    border: none;
    cursor: pointer;
    border-radius: 8px;
    transition: all 0.3s ease;
    box-shadow: 0 2px 8px rgba(255, 140, 66, 0.3);
    white-space: nowrap;
}

.btn-primary:hover {
    background: var(--accent-secondary);
    transform: translateY(-2px);
    box-shadow: 0 4px 12px rgba(255, 140, 66, 0.4);
}

.btn-secondary {
    display: inline-flex;
    align-items: center;
    gap: 0.5rem;
    padding: 0.75rem 1.5rem;
    background: transparent;
    color: var(--text-primary);
    font-size: 0.9rem;
    font-weight: 500;
    text-decoration: none;
    border: 1px solid var(--border-light);
    cursor: pointer;
    border-radius: 8px;
    transition: all 0.3s ease;
}

.btn-secondary:hover {
    background: var(--surface-2);
    border-color: var(--border-medium);
    transform: translateY(-2px);
}

.guide-link {
    display: inline-flex;
    align-items: center;
    gap: 0.5rem;
    color: var(--text-secondary);
    font-size: 0.95rem;
    font-weight: 500;
    text-decoration: none;
    transition: all 0.3s ease;
}

.guide-link:hover {
    color: var(--accent-primary);
    gap: 0.75rem;
}

.btn-small {
    padding: 0.6rem 1.2rem;
    font-size: 0.85rem;
}

/* ===== DOWNLOAD DROPDOWN ===== */
.download-dropdown,
.download-dropdown-mobile,
.download-dropdown-cta {
    position: relative;
    display: inline-block;
}

.download-btn .arrow {
    width: 12px;
    height: 12px;
    transition: transform 0.3s ease;
}

.download-dropdown.active .download-btn .arrow,
.download-dropdown-mobile.active .btn-primary .arrow,
.download-dropdown-cta.active .btn-primary .arrow {
    transform: rotate(180deg);
}

.download-menu {
    position: absolute;
    top: calc(100% + 0.5rem);
    left: 0;
    min-width: 260px;
    background: var(--surface-1);
    border: 1px solid var(--border-light);
    border-radius: 12px;
    box-shadow: var(--shadow-lg);
    opacity: 0;
    visibility: hidden;
    transform: translateY(-8px);
    transition: all 0.3s cubic-bezier(0.16, 1, 0.3, 1);
    z-index: 10;
    overflow: hidden;
}

.download-dropdown.active .download-menu,
.download-dropdown-mobile.active .download-menu,
.download-dropdown-cta.active .download-menu {
    opacity: 1;
    visibility: visible;
    transform: translateY(0);
}

.download-item {
    display: flex;
    align-items: center;
    gap: 1rem;
    padding: 1rem 1.25rem;
    color: var(--text-primary);
    text-decoration: none;
    transition: all 0.2s ease;
    border-bottom: 1px solid var(--border-subtle);
}

.download-item:last-child {
    border-bottom: none;
}

.download-item:hover {
    background: var(--surface-2);
}

.download-item.disabled {
    opacity: 0.4;
    cursor: not-allowed;
    pointer-events: none;
}

.download-item-icon {
    width: 36px;
    height: 36px;
    display: flex;
    align-items: center;
    justify-content: center;
    background: var(--accent-muted);
    border-radius: 8px;
    flex-shrink: 0;
    color: var(--accent-primary);
}

.download-item-icon svg {
    width: 20px;
    height: 20px;
}

.download-item-info {
    flex: 1;
}

.download-item-name {
    font-size: 0.9rem;
    font-weight: 600;
    margin-bottom: 0.2rem;
}

.download-item-desc {
    font-size: 0.75rem;
    color: var(--text-tertiary);
}

.download-item-badge {
    font-size: 0.65rem;
    padding: 0.2rem 0.5rem;
    background: var(--accent-muted);
    color: var(--accent-primary);
    border-radius: 4px;
    font-weight: 600;
}

/* ===== HERO SECTION ===== */
.hero {
    padding: 140px 0 80px;
    min-height: 100vh;
    display: flex;
    align-items: center;
    background: var(--gradient-bg);
}

.hero-container {
    display: flex;
    flex-direction: column;
    gap: 3rem;
}

.hero-main {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 4rem;
    align-items: center;
}

.hero-content h1 {
    font-size: clamp(2rem, 4vw, 2.8rem);
    font-weight: 800;
    line-height: 1.3;
    letter-spacing: -1px;
    margin-bottom: 1.5rem;
    color: var(--text-primary);
}

.hero-title {
    display: flex;
    flex-direction: column;
    gap: 0.2em;
}

.title-line {
    display: inline-block;
    transition: all 0.3s ease;
}

.title-line:first-child {
    animation: slideInLeft 0.6s ease-out forwards;
    opacity: 0;
}

.title-line:last-child {
    animation: slideInRight 0.6s ease-out 0.2s forwards;
    opacity: 0;
}

@keyframes slideInLeft {
    from {
        opacity: 0;
        transform: translateX(-20px);
    }
    to {
        opacity: 1;
        transform: translateX(0);
    }
}

@keyframes slideInRight {
    from {
        opacity: 0;
        transform: translateX(20px);
    }
    to {
        opacity: 1;
        transform: translateX(0);
    }
}

.highlight-gradient {
    background: linear-gradient(135deg, #FF8C42 0%, #FF6B35 50%, #FFA726 100%);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
    position: relative;
    font-weight: 900;
}

.hero-desc {
    font-size: 1.1rem;
    color: var(--text-secondary);
    line-height: 1.8;
    margin-bottom: 2rem;
    max-width: 500px;
}

.hero-features {
    display: flex;
    gap: 1.5rem;
    margin-bottom: 2rem;
}

.hero-feature-item {
    display: flex;
    align-items: flex-start;
    gap: 0.6rem;
}

.hero-feature-item .feature-icon {
    width: 22px;
    height: 22px;
    display: flex;
    align-items: center;
    justify-content: center;
    background: var(--accent-muted);
    border-radius: 6px;
    flex-shrink: 0;
}

.hero-feature-item .feature-icon svg {
    width: 16px;
    height: 16px;
    stroke: var(--accent-primary);
}

.feature-text {
    display: flex;
    flex-direction: column;
    gap: 0.2rem;
}

.feature-title {
    font-size: 0.85rem;
    font-weight: 600;
    color: var(--text-primary);
    white-space: nowrap;
}

.feature-desc {
    font-size: 0.75rem;
    color: var(--text-tertiary);
    white-space: nowrap;
}

.hero-buttons {
    display: flex;
    gap: 1rem;
    margin-bottom: 1rem;
}

/* Hero Image */
.hero-image {
    position: relative;
    display: flex;
    justify-content: center;
    align-items: center;
}

.hero-image img {
    max-width: 100%;
    height: auto;
    border-radius: 16px;
    box-shadow: var(--shadow-xl),
                0 0 0 1px var(--border-subtle);
}

/* ===== FEATURES BAR ===== */
.features-bar {
    display: grid;
    grid-template-columns: repeat(4, 1fr);
    gap: 1.5rem;
    background: var(--surface-1);
    border-radius: 16px;
    padding: 2rem;
    box-shadow: var(--shadow-md);
    max-width: calc(1200px - 4rem);
    margin: 3rem 0 0;
}

.feature-bar-item {
    display: flex;
    align-items: flex-start;
    gap: 0.8rem;
}

.bar-icon {
    width: 36px;
    height: 36px;
    display: flex;
    align-items: center;
    justify-content: center;
    background: var(--accent-muted);
    border-radius: 8px;
    flex-shrink: 0;
}

.bar-icon svg {
    width: 18px;
    height: 18px;
    stroke: var(--accent-primary);
}

.bar-content h4 {
    font-size: 0.9rem;
    font-weight: 700;
    margin-bottom: 0.4rem;
    color: var(--text-primary);
    white-space: nowrap;
}

.bar-content p {
    font-size: 0.8rem;
    color: var(--text-secondary);
    line-height: 1.5;
    white-space: nowrap;
}

/* ===== SECTIONS COMMON ===== */
section {
    padding: 100px 0;
}

.section-header {
    text-align: center;
    margin-bottom: 4rem;
}

.section-header h2 {
    font-size: clamp(1.75rem, 3.5vw, 2.25rem);
    font-weight: 800;
    letter-spacing: -1px;
    margin-bottom: 1rem;
    color: var(--text-primary);
}

.section-header p {
    font-size: 1.05rem;
    color: var(--text-secondary);
    max-width: 600px;
    margin: 0 auto;
}

/* ===== SCENARIOS SECTION ===== */
.scenarios-section {
    background: var(--bg-secondary);
    padding: 120px 0;
}

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

/* ===== STEPS SECTION ===== */
.steps-section {
    background: var(--bg-primary);
    padding: 120px 0;
}

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

.step-card {
    background: var(--surface-1);
    border-radius: 16px;
    overflow: hidden;
    border: 1px solid var(--border-subtle);
    transition: all 0.3s ease;
}

.step-card:hover {
    transform: translateY(-4px);
    box-shadow: var(--shadow-lg);
    border-color: var(--border-light);
}

.step-card img {
    width: 100%;
    height: 100%;
    object-fit: cover;
    display: block;
}

.scenario-card {
    background: var(--surface-1);
    border-radius: 16px;
    overflow: hidden;
    border: 1px solid var(--border-subtle);
    transition: all 0.3s ease;
}

.scenario-card > .scenario-text {
    padding: 1.5rem;
}

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

.scenario-image {
    width: 100%;
    overflow: hidden;
    display: flex;
    align-items: center;
    justify-content: center;
    background: var(--bg-primary);
    border-radius: 12px;
}

.scenario-image img {
    max-width: 100%;
    height: auto;
    display: block;
    transition: all 0.3s ease;
}

.scenario-card:hover .scenario-image img {
    transform: scale(1.05);
}

.scenario-text h3 {
    font-size: 1.5rem;
    font-weight: 700;
    margin-bottom: 0.5rem;
    color: var(--text-primary);
}

.scenario-subtitle {
    font-size: 0.95rem;
    color: var(--text-secondary);
    margin-bottom: 1rem;
    line-height: 1.6;
}

.scenario-features {
    list-style: none;
    padding: 0;
    margin: 0;
    display: flex;
    flex-direction: column;
    gap: 0.5rem;
}

.scenario-features li {
    font-size: 0.85rem;
    color: var(--text-secondary);
}

/* ===== CTA SECTION ===== */
.cta-section {
    background: var(--surface-2);
}

.cta-container {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 4rem;
    align-items: center;
}

.cta-content h2 {
    font-size: clamp(1.75rem, 3.5vw, 2.25rem);
    font-weight: 800;
    letter-spacing: -1px;
    margin-bottom: 1rem;
    color: var(--text-primary);
}

.cta-content p {
    font-size: 1.05rem;
    color: var(--text-secondary);
    margin-bottom: 2rem;
}

.cta-buttons {
    display: flex;
    gap: 1rem;
}

.cta-image img {
    max-width: 100%;
    height: auto;
    border-radius: 16px;
    box-shadow: var(--shadow-xl),
                0 0 0 1px var(--border-subtle);
}

/* ===== FOOTER ===== */
footer {
    background: var(--surface-1);
    border-top: 1px solid var(--border-subtle);
    padding: 10px 0 10px;
}

.footer-bottom {
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding-top: 1rem;
    border-top: 1px solid var(--border-subtle);
}

.footer-bottom p {
    font-size: 0.8rem;
    color: var(--text-tertiary);
}

.footer-legal {
    display: flex;
    gap: 2rem;
}

.footer-legal a {
    font-size: 0.8rem;
    color: var(--text-tertiary);
    text-decoration: none;
    transition: all 0.3s ease;
}

.footer-legal a:hover {
    color: var(--accent-primary);
}

/* ===== RESPONSIVE ===== */
@media (max-width: 1024px) {
    .hero-main,
    .cta-container {
        grid-template-columns: 1fr;
        gap: 3rem;
    }
    
    .scenarios-grid,
    .steps-grid {
        grid-template-columns: repeat(2, 1fr);
    }
    
    .features-bar {
        grid-template-columns: repeat(2, 1fr);
        padding: 2rem;
    }
}

@media (max-width: 768px) {
    .nav-links {
        display: none;
    }
    
    .hero {
        padding: 120px 0 60px;
    }
    
    .hero-features {
        flex-direction: column;
        gap: 1.5rem;
    }
    
    .scenarios-grid,
    .steps-grid {
        grid-template-columns: 1fr;
    }
    
    .features-bar {
        grid-template-columns: 1fr;
        padding: 1.5rem;
    }
    
    .hero-buttons,
    .cta-buttons {
        flex-direction: column;
    }
    
    .footer-bottom {
        flex-direction: column;
        gap: 1rem;
        text-align: center;
    }
    
    .footer-legal {
        justify-content: center;
    }
}

/* ===== 主题切换按钮 ===== */
.theme-toggle {
    position: relative;
    display: flex;
    align-items: center;
    justify-content: center;
    width: 38px;
    height: 38px;
    border: none;
    border-radius: 10px;
    background: var(--theme-toggle-bg);
    color: var(--text-secondary);
    cursor: pointer;
    transition: all 0.3s ease;
    flex-shrink: 0;
}

.theme-toggle:hover {
    background: var(--theme-toggle-hover);
    color: var(--accent-primary);
    transform: translateY(-1px);
}

.theme-toggle svg {
    width: 18px;
    height: 18px;
    transition: all 0.3s ease;
}

/* ===== 语言切换按钮 ===== */
.lang-switcher {
    position: relative;
    display: inline-block;
    margin-right: 0.5rem;
}

.lang-btn {
    display: flex;
    align-items: center;
    gap: 0.4rem;
    padding: 0.5rem 0.9rem;
    background: var(--theme-toggle-bg);
    color: var(--text-secondary);
    font-size: 0.85rem;
    font-weight: 500;
    border: none;
    border-radius: 10px;
    cursor: pointer;
    transition: all 0.3s ease;
}

.lang-btn:hover {
    background: var(--theme-toggle-hover);
    color: var(--accent-primary);
}

.lang-btn .arrow {
    width: 14px;
    height: 14px;
    transition: transform 0.3s ease;
}

.lang-switcher.active .lang-btn .arrow {
    transform: rotate(180deg);
}

.lang-menu {
    position: absolute;
    top: calc(100% + 0.5rem);
    right: 0;
    min-width: 120px;
    background: var(--surface-1);
    border: 1px solid var(--border-light);
    border-radius: 10px;
    box-shadow: var(--shadow-lg);
    opacity: 0;
    visibility: hidden;
    transform: translateY(-8px);
    transition: all 0.3s cubic-bezier(0.16, 1, 0.3, 1);
    z-index: 10;
    overflow: hidden;
}

.lang-switcher.active .lang-menu {
    opacity: 1;
    visibility: visible;
    transform: translateY(0);
}

.lang-menu a {
    display: block;
    padding: 0.75rem 1rem;
    color: var(--text-primary);
    text-decoration: none;
    font-size: 0.85rem;
    transition: all 0.2s ease;
    border-bottom: 1px solid var(--border-subtle);
}

.lang-menu a:last-child {
    border-bottom: none;
}

.lang-menu a:hover {
    background: var(--surface-2);
    color: var(--accent-primary);
}

.theme-toggle .icon-sun,
.theme-toggle .icon-moon {
    position: absolute;
    transition: all 0.3s ease;
}

/* 浅色模式：显示月亮图标（点击切到深色） */
[data-theme="light"] .theme-toggle .icon-moon,
:root:not([data-theme="dark"]) .theme-toggle .icon-moon {
    opacity: 1;
    transform: rotate(0deg);
}

[data-theme="light"] .theme-toggle .icon-sun,
:root:not([data-theme="dark"]) .theme-toggle .icon-sun {
    opacity: 0;
    transform: rotate(-90deg);
}

/* 深色模式：显示太阳图标（点击切到浅色） */
[data-theme="dark"] .theme-toggle .icon-moon {
    opacity: 0;
    transform: rotate(90deg);
}

[data-theme="dark"] .theme-toggle .icon-sun {
    opacity: 1;
    transform: rotate(0deg);
}

/* 深色模式下 highlight-gradient 调整 */
[data-theme="dark"] .highlight-gradient {
    background: linear-gradient(135deg, #FF9955 0%, #FF7744 50%, #FFB07A 100%);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
}

/* 平滑过渡 */
body,
nav,
.scenario-card,
.step-card,
.download-menu,
footer {
    transition: background 0.3s ease, color 0.3s ease, border-color 0.3s ease, box-shadow 0.3s ease;
}