/* GoMind Website Styles */
/* Modern, clean design with professional aesthetics */

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

:root {
    /* Colors */
    --primary-color: #4a90e2;
    --primary-dark: #357abd;
    --primary-light: #6ba5e7;
    --secondary-color: #50c878;
    --accent-color: #ff6b6b;
    --text-dark: #2c3e50;
    --text-light: #7f8c8d;
    --bg-light: #f8f9fa;
    --bg-white: #ffffff;
    --border-color: #e0e0e0;
    --shadow-sm: 0 2px 8px rgba(0, 0, 0, 0.1);
    --shadow-md: 0 4px 16px rgba(0, 0, 0, 0.12);
    --shadow-lg: 0 8px 32px rgba(0, 0, 0, 0.15);
    
    /* Typography */
    --font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', 'Roboto', 'Oxygen', 'Ubuntu', 'Cantarell', 'Fira Sans', 'Droid Sans', 'Helvetica Neue', sans-serif;
    --font-family-zh: -apple-system, BlinkMacSystemFont, 'PingFang SC', 'Hiragino Sans GB', 'Microsoft YaHei', 'WenQuanYi Micro Hei', sans-serif;
    
    /* Spacing */
    --spacing-xs: 0.5rem;
    --spacing-sm: 1rem;
    --spacing-md: 2rem;
    --spacing-lg: 4rem;
    --spacing-xl: 6rem;
    
    /* Border radius */
    --radius-sm: 4px;
    --radius-md: 8px;
    --radius-lg: 12px;
    --radius-xl: 16px;
}

html {
    scroll-behavior: smooth;
}

body {
    font-family: var(--font-family);
    color: var(--text-dark);
    line-height: 1.6;
    background-color: var(--bg-white);
    -webkit-font-smoothing: antialiased;
    -moz-osx-font-smoothing: grayscale;
}

html[lang="zh"] body {
    font-family: var(--font-family-zh);
}

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

/* ===========================
   Navigation Bar
   =========================== */
.navbar {
    background-color: var(--bg-white);
    box-shadow: var(--shadow-sm);
    position: sticky;
    top: 0;
    z-index: 1000;
    padding: var(--spacing-sm) 0;
}

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

.nav-brand h1 {
    font-size: 1.8rem;
    font-weight: 700;
    color: var(--primary-color);
    cursor: pointer;
}

.nav-menu {
    display: flex;
    list-style: none;
    gap: var(--spacing-md);
    align-items: center;
}

.nav-menu a {
    text-decoration: none;
    color: var(--text-dark);
    font-weight: 500;
    transition: color 0.3s ease;
    padding: 0.5rem 1rem;
    border-radius: var(--radius-md);
}

.nav-menu a:hover {
    color: var(--primary-color);
    background-color: var(--bg-light);
}

.lang-switch {
    border: 2px solid var(--primary-color);
    color: var(--primary-color) !important;
    padding: 0.4rem 1rem !important;
}

.lang-switch:hover {
    background-color: var(--primary-color) !important;
    color: var(--bg-white) !important;
}

/* ===========================
   Hero Section
   =========================== */
.hero {
    background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    color: var(--bg-white);
    padding: var(--spacing-xl) 0;
    text-align: center;
}

.hero-content {
    max-width: 800px;
    margin: 0 auto;
}

.hero-title {
    font-size: 3.5rem;
    font-weight: 800;
    margin-bottom: var(--spacing-sm);
    line-height: 1.2;
}

.hero-subtitle {
    font-size: 1.8rem;
    margin-bottom: var(--spacing-md);
    font-weight: 600;
    opacity: 0.95;
}

.hero-description {
    font-size: 1.2rem;
    margin-bottom: var(--spacing-lg);
    line-height: 1.8;
    opacity: 0.9;
}

.hero-buttons {
    display: flex;
    gap: var(--spacing-sm);
    justify-content: center;
    margin-bottom: var(--spacing-lg);
}

.hero-stats {
    display: flex;
    justify-content: center;
    gap: var(--spacing-lg);
    margin-top: var(--spacing-lg);
}

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

.stat-number {
    font-size: 2.5rem;
    font-weight: 800;
    display: block;
}

.stat-label {
    font-size: 1rem;
    opacity: 0.9;
}

/* ===========================
   Buttons
   =========================== */
.btn {
    display: inline-block;
    padding: 0.8rem 2rem;
    border-radius: var(--radius-md);
    text-decoration: none;
    font-weight: 600;
    transition: all 0.3s ease;
    cursor: pointer;
    border: none;
    font-size: 1rem;
}

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

.btn-primary:hover {
    transform: translateY(-2px);
    box-shadow: var(--shadow-md);
}

.btn-secondary {
    background-color: transparent;
    color: var(--bg-white);
    border: 2px solid var(--bg-white);
}

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

.btn-large {
    padding: 1.2rem 3rem;
    font-size: 1.2rem;
}

.btn-download {
    width: 100%;
    margin-top: var(--spacing-sm);
}

/* ===========================
   Section Titles
   =========================== */
.section-title {
    font-size: 2.5rem;
    font-weight: 700;
    text-align: center;
    margin-bottom: var(--spacing-lg);
    color: var(--text-dark);
}

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

.features-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
    gap: var(--spacing-md);
}

.feature-card {
    padding: var(--spacing-md);
    background-color: var(--bg-light);
    border-radius: var(--radius-lg);
    transition: all 0.3s ease;
    border: 1px solid transparent;
}

.feature-card:hover {
    transform: translateY(-5px);
    box-shadow: var(--shadow-md);
    border-color: var(--primary-color);
}

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

.feature-card h3 {
    font-size: 1.5rem;
    margin-bottom: var(--spacing-sm);
    color: var(--text-dark);
}

.feature-card p {
    color: var(--text-light);
    line-height: 1.6;
}

/* ===========================
   Capabilities Section
   =========================== */
.capabilities {
    padding: var(--spacing-xl) 0;
    background-color: var(--bg-light);
}

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

.capability {
    padding: var(--spacing-md);
    background-color: var(--bg-white);
    border-radius: var(--radius-md);
    box-shadow: var(--shadow-sm);
}

.capability h3 {
    font-size: 1.3rem;
    margin-bottom: var(--spacing-sm);
    color: var(--text-dark);
}

.capability p {
    color: var(--text-light);
}

/* ===========================
   Use Cases Section
   =========================== */
.use-cases {
    padding: var(--spacing-xl) 0;
    background-color: var(--bg-white);
}

.use-cases-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
    gap: var(--spacing-md);
}

.use-case {
    padding: var(--spacing-md);
    background-color: var(--bg-light);
    border-radius: var(--radius-md);
    text-align: center;
}

.use-case h3 {
    font-size: 1.3rem;
    margin-bottom: var(--spacing-sm);
    color: var(--text-dark);
}

.use-case p {
    color: var(--text-light);
}

/* ===========================
   Comparison Section
   =========================== */
.comparison {
    padding: var(--spacing-xl) 0;
    background-color: var(--bg-light);
}

.comparison-intro {
    text-align: center;
    max-width: 800px;
    margin: 0 auto var(--spacing-lg);
    font-size: 1.1rem;
    color: var(--text-light);
}

.comparison-table {
    max-width: 900px;
    margin: 0 auto;
    background-color: var(--bg-white);
    border-radius: var(--radius-lg);
    overflow: hidden;
    box-shadow: var(--shadow-md);
}

.comparison-table table {
    width: 100%;
    border-collapse: collapse;
}

.comparison-table th,
.comparison-table td {
    padding: var(--spacing-sm) var(--spacing-md);
    text-align: left;
}

.comparison-table thead {
    background-color: var(--primary-color);
    color: var(--bg-white);
}

.comparison-table th {
    font-weight: 600;
}

.comparison-table tbody tr:nth-child(even) {
    background-color: var(--bg-light);
}

.comparison-table tbody tr:hover {
    background-color: #e3f2fd;
}

.comparison-table td:first-child {
    font-weight: 600;
    color: var(--text-dark);
}

/* ===========================
   CTA Section
   =========================== */
.cta {
    padding: var(--spacing-xl) 0;
    background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    color: var(--bg-white);
    text-align: center;
}

.cta h2 {
    font-size: 2.5rem;
    margin-bottom: var(--spacing-sm);
}

.cta p {
    font-size: 1.2rem;
    margin-bottom: var(--spacing-md);
    opacity: 0.95;
}

.cta-note {
    margin-top: var(--spacing-sm);
    font-size: 0.95rem;
    opacity: 0.85;
}

/* ===========================
   Download Page Styles
   =========================== */
.download-hero,
.privacy-hero,
.versions-hero {
    background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    color: var(--bg-white);
    padding: var(--spacing-lg) 0;
    text-align: center;
}

.download-hero h1,
.privacy-hero h1,
.versions-hero h1 {
    font-size: 3rem;
    margin-bottom: var(--spacing-sm);
}

.subtitle {
    font-size: 1.3rem;
    opacity: 0.9;
}

.downloads {
    padding: var(--spacing-xl) 0;
    background-color: var(--bg-light);
}

.download-card {
    background-color: var(--bg-white);
    border-radius: var(--radius-lg);
    padding: var(--spacing-md);
    margin-bottom: var(--spacing-md);
    box-shadow: var(--shadow-sm);
    transition: all 0.3s ease;
}

.download-card:hover {
    box-shadow: var(--shadow-md);
    transform: translateY(-3px);
}

.download-header {
    display: flex;
    align-items: center;
    gap: var(--spacing-sm);
    margin-bottom: var(--spacing-md);
    padding-bottom: var(--spacing-sm);
    border-bottom: 2px solid var(--bg-light);
}

.platform-icon {
    font-size: 3rem;
}

.platform-info h2 {
    font-size: 1.8rem;
    color: var(--text-dark);
    margin-bottom: 0.25rem;
}

.platform-desc {
    color: var(--text-light);
    font-size: 0.95rem;
}

.download-details {
    display: flex;
    flex-wrap: wrap;
    gap: var(--spacing-md);
    margin-bottom: var(--spacing-md);
}

.detail-item {
    flex: 1;
    min-width: 150px;
}

.detail-label {
    font-weight: 600;
    color: var(--text-light);
    margin-right: 0.5rem;
}

.detail-value {
    color: var(--text-dark);
    font-weight: 500;
}

.download-note {
    text-align: center;
    color: var(--text-light);
    font-size: 0.9rem;
    margin-top: var(--spacing-sm);
}

.android-downloads {
    display: flex;
    gap: var(--spacing-sm);
    margin-bottom: var(--spacing-sm);
}

.android-downloads .btn {
    flex: 1;
}

/* ===========================
   Instructions Section
   =========================== */
.instructions {
    padding: var(--spacing-xl) 0;
    background-color: var(--bg-white);
}

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

.instruction-card {
    background-color: var(--bg-light);
    padding: var(--spacing-md);
    border-radius: var(--radius-md);
}

.instruction-card h3 {
    font-size: 1.3rem;
    margin-bottom: var(--spacing-sm);
    color: var(--text-dark);
}

.instruction-card ol {
    margin-left: var(--spacing-md);
    color: var(--text-light);
}

.instruction-card li {
    margin-bottom: 0.5rem;
}

.instruction-card code {
    background-color: var(--bg-white);
    padding: 0.2rem 0.5rem;
    border-radius: var(--radius-sm);
    font-family: 'Courier New', monospace;
    color: var(--primary-color);
}

/* ===========================
   Requirements Section
   =========================== */
.requirements {
    padding: var(--spacing-xl) 0;
    background-color: var(--bg-light);
}

.requirements-table {
    max-width: 1000px;
    margin: 0 auto;
    background-color: var(--bg-white);
    border-radius: var(--radius-lg);
    overflow: hidden;
    box-shadow: var(--shadow-sm);
}

.requirements-table table {
    width: 100%;
    border-collapse: collapse;
}

.requirements-table th,
.requirements-table td {
    padding: var(--spacing-sm) var(--spacing-md);
    text-align: left;
}

.requirements-table thead {
    background-color: var(--primary-color);
    color: var(--bg-white);
}

.requirements-table tbody tr:nth-child(even) {
    background-color: var(--bg-light);
}

.requirements-table tbody tr:hover {
    background-color: #e3f2fd;
}

/* ===========================
   Support Section
   =========================== */
.support {
    padding: var(--spacing-xl) 0;
    background-color: var(--bg-white);
}

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

.support-card {
    background-color: var(--bg-light);
    padding: var(--spacing-md);
    border-radius: var(--radius-md);
    text-align: center;
}

.support-card h3 {
    font-size: 1.3rem;
    margin-bottom: var(--spacing-sm);
    color: var(--text-dark);
}

.support-card p {
    color: var(--text-light);
}

.support-card a {
    color: var(--primary-color);
    text-decoration: none;
    font-weight: 600;
}

.support-card a:hover {
    text-decoration: underline;
}

/* ===========================
   Privacy Page Styles
   =========================== */
.privacy-content {
    padding: var(--spacing-xl) 0;
    background-color: var(--bg-white);
}

.privacy-text {
    max-width: 900px;
    margin: 0 auto;
}

.privacy-text h2 {
    font-size: 2rem;
    color: var(--text-dark);
    margin-top: var(--spacing-lg);
    margin-bottom: var(--spacing-sm);
}

.privacy-text h3 {
    font-size: 1.5rem;
    color: var(--text-dark);
    margin-top: var(--spacing-md);
    margin-bottom: var(--spacing-sm);
}

.privacy-text p {
    margin-bottom: var(--spacing-sm);
    color: var(--text-light);
    line-height: 1.8;
}

.privacy-text ul {
    margin: var(--spacing-sm) 0 var(--spacing-md) var(--spacing-md);
    color: var(--text-light);
}

.privacy-text li {
    margin-bottom: 0.5rem;
}

.privacy-text a {
    color: var(--primary-color);
    text-decoration: none;
}

.privacy-text a:hover {
    text-decoration: underline;
}

.privacy-summary {
    background-color: var(--bg-light);
    padding: var(--spacing-md);
    border-radius: var(--radius-md);
    border-left: 4px solid var(--primary-color);
    margin-top: var(--spacing-lg);
}

.privacy-summary h3 {
    color: var(--primary-color);
    margin-top: 0 !important;
}

/* ===========================
   Versions Page Styles
   =========================== */
.versions {
    padding: var(--spacing-xl) 0;
    background-color: var(--bg-light);
}

.version-card {
    background-color: var(--bg-white);
    border-radius: var(--radius-lg);
    padding: var(--spacing-md);
    margin-bottom: var(--spacing-md);
    box-shadow: var(--shadow-sm);
}

.version-card.current {
    border: 3px solid var(--secondary-color);
}

.version-header {
    border-bottom: 2px solid var(--bg-light);
    padding-bottom: var(--spacing-sm);
    margin-bottom: var(--spacing-md);
}

.version-badge {
    display: inline-block;
    background-color: var(--secondary-color);
    color: var(--bg-white);
    padding: 0.3rem 1rem;
    border-radius: var(--radius-md);
    font-weight: 600;
    font-size: 0.9rem;
    margin-bottom: var(--spacing-sm);
}

.version-header h2 {
    font-size: 2rem;
    color: var(--text-dark);
    margin-bottom: 0.5rem;
}

.version-date {
    color: var(--text-light);
    font-size: 0.95rem;
}

.version-content h3 {
    font-size: 1.4rem;
    color: var(--text-dark);
    margin-top: var(--spacing-md);
    margin-bottom: var(--spacing-sm);
}

.version-content ul {
    margin-left: var(--spacing-md);
    margin-bottom: var(--spacing-md);
}

.version-content li {
    margin-bottom: 0.5rem;
    color: var(--text-light);
    line-height: 1.6;
}

/* ===========================
   Roadmap Section
   =========================== */
.roadmap {
    padding: var(--spacing-xl) 0;
    background-color: var(--bg-white);
}

.roadmap-content {
    max-width: 900px;
    margin: 0 auto;
}

.roadmap-content h3 {
    font-size: 1.8rem;
    color: var(--text-dark);
    margin-top: var(--spacing-md);
    margin-bottom: var(--spacing-sm);
}

.roadmap-content p {
    color: var(--text-light);
    margin-bottom: var(--spacing-md);
    line-height: 1.8;
}

.roadmap-list {
    margin: var(--spacing-sm) 0 var(--spacing-md) var(--spacing-md);
}

.roadmap-list li {
    margin-bottom: var(--spacing-sm);
    color: var(--text-light);
    line-height: 1.6;
}

.roadmap-note {
    background-color: var(--bg-light);
    padding: var(--spacing-sm);
    border-radius: var(--radius-md);
    margin-top: var(--spacing-md);
}

/* ===========================
   Footer
   =========================== */
.footer {
    background-color: var(--text-dark);
    color: var(--bg-white);
    padding: var(--spacing-lg) 0 var(--spacing-md);
}

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

.footer-section h3,
.footer-section h4 {
    margin-bottom: var(--spacing-sm);
    color: var(--bg-white);
}

.footer-section p {
    color: var(--text-light);
    font-size: 0.95rem;
}

.footer-section ul {
    list-style: none;
}

.footer-section ul li {
    margin-bottom: 0.5rem;
}

.footer-section a {
    color: var(--text-light);
    text-decoration: none;
    transition: color 0.3s ease;
}

.footer-section a:hover {
    color: var(--primary-light);
}

.footer-bottom {
    border-top: 1px solid rgba(255, 255, 255, 0.1);
    padding-top: var(--spacing-sm);
    text-align: center;
    color: var(--text-light);
    font-size: 0.9rem;
}

/* ===========================
   Responsive Design
   =========================== */
@media (max-width: 768px) {
    .hero-title {
        font-size: 2.5rem;
    }
    
    .hero-subtitle {
        font-size: 1.4rem;
    }
    
    .hero-description {
        font-size: 1rem;
    }
    
    .hero-buttons {
        flex-direction: column;
        align-items: stretch;
    }
    
    .hero-stats {
        flex-direction: column;
        gap: var(--spacing-md);
    }
    
    .section-title {
        font-size: 2rem;
    }
    
    .nav-menu {
        flex-wrap: wrap;
        gap: var(--spacing-sm);
        justify-content: center;
    }
    
    .features-grid,
    .capabilities-grid,
    .use-cases-grid {
        grid-template-columns: 1fr;
    }
    
    .comparison-table {
        overflow-x: auto;
    }
    
    .download-header {
        flex-direction: column;
        text-align: center;
    }
    
    .android-downloads {
        flex-direction: column;
    }
    
    .instructions-grid {
        grid-template-columns: 1fr;
    }
}

@media (max-width: 480px) {
    .container {
        padding: 0 var(--spacing-sm);
    }
    
    .hero-title {
        font-size: 2rem;
    }
    
    .hero-subtitle {
        font-size: 1.2rem;
    }
    
    .nav-brand h1 {
        font-size: 1.5rem;
    }
    
    .btn {
        padding: 0.7rem 1.5rem;
        font-size: 0.95rem;
    }
    
    .btn-large {
        padding: 1rem 2rem;
        font-size: 1.1rem;
    }
}

/* ===========================
   Utility Classes
   =========================== */
.text-center {
    text-align: center;
}

.mb-0 { margin-bottom: 0; }
.mb-1 { margin-bottom: var(--spacing-xs); }
.mb-2 { margin-bottom: var(--spacing-sm); }
.mb-3 { margin-bottom: var(--spacing-md); }
.mb-4 { margin-bottom: var(--spacing-lg); }

.mt-0 { margin-top: 0; }
.mt-1 { margin-top: var(--spacing-xs); }
.mt-2 { margin-top: var(--spacing-sm); }
.mt-3 { margin-top: var(--spacing-md); }
.mt-4 { margin-top: var(--spacing-lg); }