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

:root {
    /* Color Palette - Light Theme (Default) */
    --bg-primary: #f6f8fb;
    --bg-secondary: #ffffff;
    --bg-tertiary: #e9eff9;
    --text-primary: #0f172a;
    --text-secondary: #4b5563;
    --accent-primary: #0ea5e9;
    --accent-hover: #0284c7;
    --accent-gradient: linear-gradient(135deg, #0ea5e9 0%, #f97316 100%);
    --border-color: rgba(0, 0, 0, 0.1);
    --glass-bg: rgba(255, 255, 255, 0.7);
    --glass-border: rgba(255, 255, 255, 0.5);
    --glass-shadow: 0 8px 32px 0 rgba(31, 38, 135, 0.1);
    --header-bg: rgba(255, 255, 255, 0.1);

    /* Spacing */
    --space-xs: 0.5rem;
    --space-sm: 1rem;
    --space-md: 2rem;
    --space-lg: 4rem;
    --space-xl: 8rem;

    /* Typography */
    --font-sans: 'Outfit', sans-serif;

    /* Transitions */
    --transition-fast: 0.2s ease;
    --transition-medium: 0.3s ease;
}

[data-theme="dark"] {
    /* Color Palette - Dark Theme */
    --bg-primary: #0b1020;
    --bg-secondary: #121829;
    --bg-tertiary: #1c2537;
    --text-primary: #e5ecf5;
    --text-secondary: #9aa4b5;
    --accent-primary: #22d3ee;
    --accent-hover: #38bdf8;
    --accent-gradient: linear-gradient(135deg, #22d3ee 0%, #f97316 100%);
    --border-color: rgba(255, 255, 255, 0.1);
    --glass-bg: rgba(22, 27, 34, 0.7);
    --glass-border: rgba(255, 255, 255, 0.1);
    --glass-shadow: 0 8px 32px 0 rgba(0, 0, 0, 0.37);
    --header-bg: rgba(15, 17, 21, 0.1);
}

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

body {
    font-family: var(--font-sans);
    background-color: var(--bg-primary);
    color: var(--text-primary);
    line-height: 1.6;
    overflow-x: hidden;
    transition: background-color var(--transition-medium), color var(--transition-medium);
}

a {
    text-decoration: none;
    color: inherit;
    transition: var(--transition-fast);
}

ul {
    list-style: none;
}

/* Typography */
h1,
h2,
h3,
h4,
h5,
h6 {
    line-height: 1.1;
    font-weight: 600;
    margin-bottom: var(--space-sm);
    color: var(--text-primary);
    letter-spacing: -0.02em;
}

h1 {
    font-size: 4.5rem;
    margin-bottom: var(--space-md);
}

h2 {
    font-size: 3rem;
}

p {
    color: var(--text-secondary);
    margin-bottom: var(--space-sm);
    font-size: 1.1rem;
}

/* Layout */
.container {
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 var(--space-md);
}

section {
    padding: var(--space-lg) 0;
}

/* Glassmorphism Utility */
.glass-panel {
    background: var(--glass-bg);
    backdrop-filter: blur(12px);
    -webkit-backdrop-filter: blur(12px);
    border: 1px solid var(--glass-border);
    box-shadow: var(--glass-shadow);
    border-radius: 24px;
}

/* Header */
header {
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    background: var(--header-bg);
    backdrop-filter: blur(10px);
    -webkit-backdrop-filter: blur(10px);
    z-index: 1000;
    border-bottom: 1px solid rgba(255, 255, 255, 0.05);
    transition: all var(--transition-medium);
    padding: 1rem 0;
}

nav {
    display: flex;
    justify-content: space-between;
    align-items: center;
}

.logo {
    font-size: 1.5rem;
    font-weight: 700;
    color: var(--text-primary);
    display: flex;
    align-items: center;
    gap: var(--space-xs);
}

.nav-links {
    display: flex;
    gap: var(--space-md);
    align-items: center;
    background: var(--glass-bg);
    padding: 0.5rem 1.5rem;
    border-radius: 50px;
    border: 1px solid var(--glass-border);
    backdrop-filter: blur(8px);
}

.nav-links a {
    color: var(--text-secondary);
    font-weight: 500;
    font-size: 0.95rem;
}

.nav-links a:hover,
.nav-links a.active {
    color: var(--text-primary);
}

/* Controls */
.controls {
    display: flex;
    gap: var(--space-xs);
    align-items: center;
    margin-left: var(--space-sm);
    padding-left: var(--space-sm);
    border-left: 1px solid var(--border-color);
}

.control-btn {
    background: none;
    border: none;
    color: var(--text-secondary);
    font-size: 1rem;
    cursor: pointer;
    padding: 0.5rem;
    border-radius: 50%;
    transition: var(--transition-fast);
    display: flex;
    align-items: center;
    justify-content: center;
    width: 36px;
    height: 36px;
}

.control-btn:hover {
    background: var(--bg-tertiary);
    color: var(--text-primary);
}

.mobile-menu-btn {
    display: none;
    background: none;
    border: none;
    color: var(--text-primary);
    font-size: 1.5rem;
    cursor: pointer;
}

/* Buttons */
.btn {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    padding: 1rem 2rem;
    border-radius: 50px;
    font-weight: 600;
    cursor: pointer;
    transition: var(--transition-medium);
    border: none;
    font-size: 1rem;
}

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

.btn-primary:hover {
    transform: translateY(-2px);
    box-shadow: 0 10px 20px rgba(0, 0, 0, 0.1);
    opacity: 0.9;
}

.btn-secondary {
    background: var(--glass-bg);
    color: var(--text-primary);
    border: 1px solid var(--border-color);
    backdrop-filter: blur(4px);
}

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

/* Hero Section */
.hero {
    position: relative;
    min-height: 100vh;
    display: flex;
    align-items: center;
    justify-content: center;
    text-align: center;
    padding: 0;
    overflow: hidden;
}

.hero-bg {
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    background-image: url('https://images.unsplash.com/photo-1451187580459-43490279c0fa?auto=format&fit=crop&w=1920&q=80');
    background-size: cover;
    background-position: center;
    z-index: -1;
}

.hero-overlay {
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    background: linear-gradient(to bottom, rgba(255, 255, 255, 0.2) 0%, var(--bg-primary) 100%);
    z-index: -1;
}

[data-theme="dark"] .hero-overlay {
    background: linear-gradient(to bottom, rgba(0, 0, 0, 0.3) 0%, var(--bg-primary) 100%);
}

.hero-content {
    margin: 0 auto;
    max-width: 800px;
    padding: var(--space-md);
}

/* Features Section */
.section-header {
    text-align: center;
    margin-bottom: var(--space-xl);
    max-width: 600px;
    margin-left: auto;
    margin-right: auto;
}

.feature-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
    gap: var(--space-md);
}

.feature-card {
    padding: var(--space-md);
    transition: var(--transition-medium);
}

.feature-card:hover {
    transform: translateY(-10px);
    box-shadow: 0 20px 40px rgba(0, 0, 0, 0.1);
}

.feature-card i {
    font-size: 2.5rem;
    color: var(--text-primary);
    margin-bottom: var(--space-md);
    background: var(--bg-tertiary);
    width: 60px;
    height: 60px;
    display: flex;
    align-items: center;
    justify-content: center;
    border-radius: 16px;
}

/* Footer */
footer {
    background: var(--bg-secondary);
    padding: var(--space-xl) 0 var(--space-md);
    border-top: 1px solid var(--border-color);
}

.footer-content {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(200px, 1fr));
    gap: var(--space-lg);
    margin-bottom: var(--space-lg);
}

.footer-col h4 {
    margin-bottom: var(--space-md);
}

.footer-col ul li {
    margin-bottom: var(--space-sm);
}

.footer-col a {
    color: var(--text-secondary);
    transition: color var(--transition-fast);
}

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

.footer-bottom {
    text-align: center;
    padding-top: var(--space-md);
    border-top: 1px solid var(--border-color);
    color: var(--text-secondary);
    font-size: 0.9rem;
}

/* Animations */
@keyframes fadeIn {
    from {
        opacity: 0;
        transform: translateY(30px);
    }

    to {
        opacity: 1;
        transform: translateY(0);
    }
}

.fade-in {
    animation: fadeIn 1s cubic-bezier(0.2, 0.8, 0.2, 1) forwards;
}

/* Responsive */
@media (max-width: 768px) {
    h1 {
        font-size: 3rem;
    }

    .nav-links {
        position: fixed;
        top: 80px;
        left: var(--space-md);
        right: var(--space-md);
        background: var(--bg-secondary);
        flex-direction: column;
        padding: var(--space-md);
        gap: var(--space-sm);
        transform: translateY(-10px);
        opacity: 0;
        visibility: hidden;
        transition: all var(--transition-medium);
        border-radius: 24px;
        box-shadow: 0 10px 40px rgba(0, 0, 0, 0.1);
    }

    .nav-links.active {
        transform: translateY(0);
        opacity: 1;
        visibility: visible;
    }

    .controls {
        margin-left: 0;
        margin-top: var(--space-sm);
        border-left: none;
        border-top: 1px solid var(--border-color);
        padding-left: 0;
        padding-top: var(--space-sm);
        width: 100%;
        justify-content: center;
    }

    .mobile-menu-btn {
        display: block;
    }
}

/* Other Pages Specifics */
.page-header {
    text-align: center;
    padding: 160px 0 80px;
    background: linear-gradient(to bottom, var(--bg-tertiary) 0%, var(--bg-primary) 100%);
}

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

/* Hero Section */
.hero {
    position: relative;
    min-height: 100vh;
    display: flex;
    align-items: center;
    justify-content: center;
    text-align: center;
    padding: 0;
    overflow: hidden;
}

.hero-bg {
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    background-image: url('https://images.unsplash.com/photo-1451187580459-43490279c0fa?auto=format&fit=crop&w=1920&q=80');
    background-size: cover;
    background-position: center;
    z-index: -1;
}

.hero-overlay {
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    background: linear-gradient(to bottom, rgba(255, 255, 255, 0.2) 0%, var(--bg-primary) 100%);
    z-index: -1;
}

[data-theme="dark"] .hero-overlay {
    background: linear-gradient(to bottom, rgba(0, 0, 0, 0.3) 0%, var(--bg-primary) 100%);
}

.hero-content {
    max-width: 800px;
    padding: var(--space-md);
}

/* Features Section */
.section-header {
    text-align: center;
    margin-bottom: var(--space-xl);
    max-width: 600px;
    margin-left: auto;
    margin-right: auto;
}

.feature-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
    gap: var(--space-md);
}

.feature-card {
    padding: var(--space-md);
    transition: var(--transition-medium);
}

.feature-card:hover {
    transform: translateY(-10px);
    box-shadow: 0 20px 40px rgba(0, 0, 0, 0.1);
}

.feature-card i {
    font-size: 2.5rem;
    color: var(--text-primary);
    margin-bottom: var(--space-md);
    background: var(--bg-tertiary);
    width: 60px;
    height: 60px;
    display: flex;
    align-items: center;
    justify-content: center;
    border-radius: 16px;
}

/* Footer */
footer {
    background: var(--bg-secondary);
    padding: var(--space-xl) 0 var(--space-md);
    border-top: 1px solid var(--border-color);
}

.footer-content {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(200px, 1fr));
    gap: var(--space-lg);
    margin-bottom: var(--space-lg);
}

.footer-col h4 {
    margin-bottom: var(--space-md);
}

.footer-col ul li {
    margin-bottom: var(--space-sm);
}

.footer-col a {
    color: var(--text-secondary);
    transition: color var(--transition-fast);
}

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

.footer-bottom {
    text-align: center;
    padding-top: var(--space-md);
    border-top: 1px solid var(--border-color);
    color: var(--text-secondary);
    font-size: 0.9rem;
}

/* Animations */
@keyframes fadeIn {
    from {
        opacity: 0;
        transform: translateY(30px);
    }

    to {
        opacity: 1;
        transform: translateY(0);
    }
}

.fade-in {
    animation: fadeIn 1s cubic-bezier(0.2, 0.8, 0.2, 1) forwards;
}

/* Responsive */
@media (max-width: 768px) {
    h1 {
        font-size: 3rem;
    }

    .nav-links {
        position: fixed;
        top: 80px;
        left: var(--space-md);
        right: var(--space-md);
        background: var(--bg-secondary);
        flex-direction: column;
        padding: var(--space-md);
        gap: var(--space-sm);
        transform: translateY(-10px);
        opacity: 0;
        visibility: hidden;
        transition: all var(--transition-medium);
        border-radius: 24px;
        box-shadow: 0 10px 40px rgba(0, 0, 0, 0.1);
    }

    .nav-links.active {
        transform: translateY(0);
        opacity: 1;
        visibility: visible;
    }

    .controls {
        margin-left: 0;
        margin-top: var(--space-sm);
        border-left: none;
        border-top: 1px solid var(--border-color);
        padding-left: 0;
        padding-top: var(--space-sm);
        width: 100%;
        justify-content: center;
    }

    .mobile-menu-btn {
        display: block;
    }
}

/* Other Pages Specifics */
.page-header {
    text-align: center;
    padding: 160px 0 80px;
    background: linear-gradient(to bottom, var(--bg-tertiary) 0%, var(--bg-primary) 100%);
}

.download-hero {
    text-align: center;
    padding: 160px 0 80px;
}

.store-buttons {
    display: flex;
    gap: 20px;
    justify-content: center;
    flex-wrap: wrap;
    margin-top: var(--space-md);
}

.store-btn {
    display: inline-flex;
    align-items: center;
    gap: var(--space-sm);
    background: var(--text-primary);
    color: var(--bg-primary);
    padding: 12px 24px;
    border-radius: 12px;
    transition: var(--transition-medium);
    text-align: left;
    min-width: 200px;
}

.store-btn:hover {
    transform: translateY(-2px);
    opacity: 0.9;
}

.store-btn i {
    font-size: 2rem;
    color: var(--bg-primary);
}

.store-btn .btn-text span {
    color: var(--bg-primary);
    opacity: 0.8;
}

.store-btn .btn-text strong {
    color: var(--bg-primary);
}

/* Timeline */
.timeline-item::before {
    background: var(--bg-primary);
    border: 2px solid var(--text-primary);
}

.timeline-content {
    background: var(--glass-bg);
    backdrop-filter: blur(12px);
    border: 1px solid var(--glass-border);
    border-radius: 24px;
    padding: var(--space-md);
}

/* Contact Card */
.contact-card {
    background: var(--glass-bg);
    backdrop-filter: blur(12px);
    border: 1px solid var(--glass-border);
    border-radius: 24px;
    transition: color var(--transition-fast);
}

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

.footer-bottom {
    text-align: center;
    padding-top: var(--space-md);
    border-top: 1px solid var(--border-color);
    color: var(--text-secondary);
    font-size: 0.9rem;
}

/* Animations */
@keyframes fadeIn {
    from {
        opacity: 0;
        transform: translateY(30px);
    }

    to {
        opacity: 1;
        transform: translateY(0);
    }
}

.fade-in {
    animation: fadeIn 1s cubic-bezier(0.2, 0.8, 0.2, 1) forwards;
}

/* Responsive */
@media (max-width: 768px) {
    h1 {
        font-size: 3rem;
    }

    .nav-links {
        position: fixed;
        top: 80px;
        left: var(--space-md);
        right: var(--space-md);
        background: var(--bg-secondary);
        flex-direction: column;
        padding: var(--space-md);
        gap: var(--space-sm);
        transform: translateY(-10px);
        opacity: 0;
        visibility: hidden;
        transition: all var(--transition-medium);
        border-radius: 24px;
        box-shadow: 0 10px 40px rgba(0, 0, 0, 0.1);
    }

    .nav-links.active {
        transform: translateY(0);
        opacity: 1;
        visibility: visible;
    }

    .controls {
        margin-left: 0;
        margin-top: var(--space-sm);
        border-left: none;
        border-top: 1px solid var(--border-color);
        padding-left: 0;
        padding-top: var(--space-sm);
        width: 100%;
        justify-content: center;
    }

    .mobile-menu-btn {
        display: block;
    }
}

/* Other Pages Specifics */
.page-header {
    text-align: center;
    padding: 160px 0 80px;
    background: linear-gradient(to bottom, var(--bg-tertiary) 0%, var(--bg-primary) 100%);
}

.download-hero {
    text-align: center;
    padding: 160px 0 80px;
}

.store-buttons {
    display: flex;
    gap: 20px;
    justify-content: center;
    flex-wrap: wrap;
    margin-top: var(--space-md);
}

.store-btn {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    gap: var(--space-sm);
    background: var(--text-primary);
    color: var(--bg-primary);
    padding: 0 24px;
    border-radius: 12px;
    transition: var(--transition-medium);
    text-align: left;
    width: 320px;
    height: 80px;
    max-width: 100%;
}

.store-btn:hover {
    transform: translateY(-2px);
    opacity: 0.9;
}

.store-btn i {
    font-size: 2rem;
    color: var(--bg-primary);
}

.store-btn .btn-text span {
    color: var(--bg-primary);
    opacity: 0.8;
}

.store-btn .btn-text strong {
    color: var(--bg-primary);
}

/* Timeline */
.timeline-item::before {
    background: var(--bg-primary);
    border: 2px solid var(--text-primary);
}

.timeline-content {
    background: var(--glass-bg);
    backdrop-filter: blur(12px);
    border: 1px solid var(--glass-border);
    border-radius: 24px;
    padding: var(--space-md);
}

/* Contact Card */
.contact-card {
    background: var(--glass-bg);
    backdrop-filter: blur(12px);
    border: 1px solid var(--glass-border);
    border-radius: 24px;
    padding: var(--space-lg);
    max-width: 1000px;
    margin: 0 auto;
}

.contact-info {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
    gap: var(--space-lg);
    text-align: center;
}

.info-item {
    display: flex;
    flex-direction: column;
    align-items: center;
}

.info-item i {
    color: var(--text-primary);
    background: var(--bg-tertiary);
    width: 80px;
    height: 80px;
    display: flex;
    align-items: center;
    justify-content: center;
    border-radius: 50%;
    margin: 0 auto var(--space-sm);
    font-size: 2rem;
}

.contact-link {
    color: var(--text-primary);
    text-decoration: underline;
}

/* FAQ Section */
.faq {
    padding: var(--space-xl) 0;
    background: var(--bg-secondary);
}

.faq-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
    gap: var(--space-md);
    margin-top: var(--space-lg);
}

.faq-item {
    padding: var(--space-lg);
    transition: all var(--transition-medium);
    height: 100%;
    display: flex;
    flex-direction: column;
    justify-content: flex-start;
    text-align: left;
    border: 1px solid var(--border-color);
    background: var(--bg-primary);
}

.faq-item:hover {
    transform: translateY(-5px);
    box-shadow: 0 10px 30px rgba(0, 0, 0, 0.05);
    border-color: var(--text-primary);
}

.faq-item h3 {
    font-size: 1.25rem;
    margin-bottom: var(--space-sm);
    color: var(--text-primary);
    font-weight: 600;
}

.faq-item p {
    color: var(--text-secondary);
    font-size: 1rem;
    line-height: 1.6;
    margin-bottom: 0;
}

[data-theme="dark"] .faq-item {
    background: var(--bg-tertiary);
    border-color: var(--border-color);
}

[data-theme="dark"] .faq-item:hover {
    border-color: var(--text-secondary);
    background: var(--bg-secondary);
}

/* Changelog Timeline */
.timeline {
    max-width: 800px;
    margin: 0 auto;
    position: relative;
    padding-left: 40px;
}

.timeline::before {
    content: '';
    position: absolute;
    left: 19px;
    top: 0;
    bottom: 0;
    width: 2px;
    background: var(--border-color);
}

.timeline-item {
    margin-bottom: var(--space-xl);
    position: relative;
}

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

.timeline-item::before {
    content: '';
    position: absolute;
    left: -29px;
    top: 0;
    width: 12px;
    height: 12px;
    border-radius: 50%;
    background: var(--bg-primary);
    border: 2px solid var(--text-primary);
    z-index: 1;
    box-sizing: content-box;
}

.timeline-date {
    font-size: 0.9rem;
    color: var(--text-secondary);
    margin-bottom: var(--space-xs);
    font-weight: 600;
    text-transform: uppercase;
    letter-spacing: 0.05em;
}

.timeline-content ul {
    list-style: none;
    padding: 0;
}

.timeline-content li {
    margin-bottom: var(--space-sm);
    display: flex;
    align-items: flex-start;
    gap: var(--space-sm);
}

.tag {
    font-size: 0.75rem;
    padding: 2px 8px;
    border-radius: 4px;
    font-weight: 600;
    text-transform: uppercase;
    white-space: nowrap;
    display: inline-block;
    min-width: 80px;
    text-align: center;
}

.tag.new {
    background: rgba(46, 204, 113, 0.15);
    color: #27ae60;
}

.tag.improvement {
    background: rgba(52, 152, 219, 0.15);
    color: #2980b9;
}

.tag.fix {
    background: rgba(231, 76, 60, 0.15);
    color: #c0392b;
}

/* Legal Pages (Terms & Privacy) */
.legal-content {
    max-width: 800px;
    margin: 0 auto;
    padding: var(--space-lg);
}

.text-block {
    margin-bottom: var(--space-md);
    padding-bottom: var(--space-md);
    border-bottom: 1px solid var(--border-color);
}

.text-block:last-child {
    border-bottom: none;
    margin-bottom: 0;
    padding-bottom: 0;
}

.text-block h2 {
    font-size: 1.75rem;
    margin-bottom: var(--space-sm);
    color: var(--text-primary);
}

.text-block p {
    color: var(--text-secondary);
    line-height: 1.65;
    font-size: 1.05rem;
    margin-bottom: var(--space-xs);
}

.text-block p.zh {
    margin-top: calc(var(--space-xs) / 2);
}

@media (max-width: 768px) {
    .legal-content {
        padding: var(--space-md);
    }

    .timeline {
        padding-left: 20px;
    }

    .timeline::before {
        left: 9px;
    }

    .timeline-item::before {
        left: -19px;
    }
}