/* CSS Reset & Variables */
:root {
    --primary: #4f46e5; /* Indigo 600 */
    --primary-hover: #4338ca;
    --secondary: #0ea5e9; /* Sky 500 */
    --text-main: #1e293b;
    --text-muted: #64748b;
    --bg-white: #ffffff;
    --bg-gray: #f8fafc;
    --border: #e2e8f0;
    --radius: 8px;
    --radius-lg: 12px;
    --shadow-sm: 0 1px 2px 0 rgb(0 0 0 / 0.05);
    --shadow-card: 0 4px 6px -1px rgb(0 0 0 / 0.05), 0 2px 4px -2px rgb(0 0 0 / 0.05);
    --font-main: system-ui, -apple-system, "Segoe UI", Roboto, "Helvetica Neue", Arial, sans-serif;
}

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

html {
    scroll-behavior: smooth;
}

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

a {
    text-decoration: none;
    color: inherit;
    transition: color 0.2s;
}

ul {
    list-style: none;
}

/* Utilities */
.container {
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 20px;
}

.btn {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    padding: 10px 24px;
    border-radius: var(--radius);
    font-weight: 600;
    cursor: pointer;
    transition: all 0.2s ease;
    font-size: 1rem;
    gap: 8px;
    border: 1px solid transparent;
}

.btn-sm {
    padding: 8px 16px;
    font-size: 0.9rem;
}

.btn-lg {
    padding: 14px 32px;
    font-size: 1.1rem;
}

.btn-block {
    display: flex;
    width: 100%;
}

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

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

.btn-outline {
    background-color: transparent;
    border: 1px solid var(--border);
    color: var(--text-main);
}

.btn-outline:hover {
    border-color: var(--text-muted);
    background-color: var(--bg-gray);
}

.section {
    padding: 80px 0;
}

.bg-gray {
    background-color: var(--bg-gray);
}

.section-header {
    text-align: center;
    max-width: 700px;
    margin: 0 auto 48px;
}

.section-header h2 {
    font-size: 2rem;
    margin-bottom: 12px;
    color: var(--text-main);
}

.section-header p {
    color: var(--text-muted);
    font-size: 1.1rem;
}

/* Header */
.site-header {
    position: sticky;
    top: 0;
    z-index: 100;
    background: rgba(255, 255, 255, 0.9);
    backdrop-filter: blur(10px);
    border-bottom: 1px solid var(--border);
    height: 70px;
    display: flex;
    align-items: center;
}

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

.logo {
    display: flex;
    align-items: center;
    gap: 8px;
    font-weight: 700;
    font-size: 1.2rem;
    color: var(--text-main);
}

.logo-icon {
    font-size: 1.5rem;
}

.main-nav {
    display: none;
}

.nav-list {
    display: flex;
    gap: 32px;
}

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

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

.header-actions {
    display: flex;
    align-items: center;
    gap: 16px;
}

.mobile-menu-toggle {
    display: flex;
    flex-direction: column;
    gap: 5px;
    background: none;
    border: none;
    cursor: pointer;
}

.mobile-menu-toggle span {
    width: 24px;
    height: 2px;
    background-color: var(--text-main);
    transition: 0.3s;
}

.mobile-menu {
    position: absolute;
    top: 70px;
    left: 0;
    width: 100%;
    background: white;
    border-bottom: 1px solid var(--border);
    padding: 20px;
    display: flex;
    flex-direction: column;
    gap: 16px;
    transform: translateY(-150%);
    transition: transform 0.3s ease;
    z-index: 90;
}

.mobile-menu.active {
    transform: translateY(0);
    box-shadow: var(--shadow-sm);
}

/* Hero */
.hero {
    padding: 80px 0 100px;
    overflow: hidden;
}

.hero-grid {
    display: grid;
    grid-template-columns: 1fr;
    gap: 40px;
    align-items: center;
}

.hero-content {
    max-width: 600px;
}

.badge {
    display: inline-block;
    padding: 4px 12px;
    background-color: #eef2ff;
    color: var(--primary);
    border-radius: 100px;
    font-size: 0.85rem;
    font-weight: 600;
    margin-bottom: 20px;
}

.hero h1 {
    font-size: 2.5rem;
    line-height: 1.2;
    margin-bottom: 20px;
    color: #111827;
}

.hero-desc {
    font-size: 1.125rem;
    color: var(--text-muted);
    margin-bottom: 32px;
}

.hero-btns {
    display: flex;
    flex-wrap: wrap;
    gap: 16px;
    margin-bottom: 40px;
}

.hero-stats {
    display: flex;
    gap: 40px;
    border-top: 1px solid var(--border);
    padding-top: 24px;
}

.stat-item {
    display: flex;
    flex-direction: column;
}

.stat-item strong {
    font-size: 1.2rem;
    color: var(--text-main);
}

.stat-item span {
    font-size: 0.85rem;
    color: var(--text-muted);
}

/* Hero Visual (Abstract App Window) */
.hero-visual {
    display: none; /* Hidden on mobile */
    position: relative;
}

.app-window {
    background: white;
    border: 1px solid var(--border);
    border-radius: var(--radius-lg);
    box-shadow: 0 20px 25px -5px rgb(0 0 0 / 0.1), 0 8px 10px -6px rgb(0 0 0 / 0.1);
    width: 100%;
    height: 350px;
    position: relative;
    overflow: hidden;
    z-index: 2;
}

.window-header {
    background: #f1f5f9;
    height: 40px;
    display: flex;
    align-items: center;
    padding: 0 16px;
    border-bottom: 1px solid var(--border);
    gap: 16px;
}

.dots {
    display: flex;
    gap: 6px;
}

.dot {
    width: 10px;
    height: 10px;
    border-radius: 50%;
}

.dot.red { background: #ef4444; }
.dot.yellow { background: #f59e0b; }
.dot.green { background: #10b981; }

.address-bar {
    background: white;
    flex: 1;
    height: 24px;
    border-radius: 4px;
    font-size: 12px;
    display: flex;
    align-items: center;
    padding-left: 10px;
    color: #94a3b8;
    border: 1px solid #e2e8f0;
}

.window-content {
    display: flex;
    height: calc(100% - 40px);
}

.ui-sidebar {
    width: 80px;
    background: #f8fafc;
    border-right: 1px solid var(--border);
    padding: 16px;
    display: flex;
    flex-direction: column;
    gap: 12px;
}

.ui-nav-item {
    height: 8px;
    background: #cbd5e1;
    border-radius: 4px;
    width: 100%;
}

.ui-nav-item.active {
    background: var(--primary);
    width: 60%;
}

.ui-main {
    flex: 1;
    padding: 20px;
    background: white;
}

.ui-hero-card {
    height: 100px;
    background: linear-gradient(135deg, #e0e7ff 0%, #eef2ff 100%);
    border-radius: 8px;
    margin-bottom: 20px;
    display: flex;
    align-items: center;
    padding: 16px;
    gap: 16px;
}

.ui-avatar {
    width: 48px;
    height: 48px;
    background: white;
    border-radius: 8px;
    opacity: 0.6;
}

.ui-text-lines .line {
    height: 8px;
    background: white;
    border-radius: 4px;
    margin-bottom: 8px;
}
.ui-text-lines .line.long { width: 120px; }
.ui-text-lines .line.short { width: 80px; }

.ui-grid {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: 16px;
}

.ui-card {
    height: 80px;
    border: 1px solid var(--border);
    border-radius: 6px;
    background: #f9fafb;
}

.glow-effect {
    position: absolute;
    top: -20%;
    right: -20%;
    width: 140%;
    height: 140%;
    background: radial-gradient(circle, rgba(79, 70, 229, 0.1) 0%, rgba(255,255,255,0) 70%);
    z-index: 1;
    pointer-events: none;
}

/* Features */
.features-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
    gap: 32px;
}

.feature-card {
    background: white;
    padding: 32px;
    border-radius: var(--radius);
    border: 1px solid var(--border);
    transition: transform 0.2s, box-shadow 0.2s;
}

.feature-card:hover {
    transform: translateY(-4px);
    box-shadow: var(--shadow-card);
    border-color: var(--primary);
}

.icon-box {
    width: 48px;
    height: 48px;
    border-radius: 12px;
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 24px;
    margin-bottom: 20px;
    background: #f1f5f9;
}

.icon-box.blue { background: #e0e7ff; color: #4f46e5; }
.icon-box.purple { background: #f3e8ff; color: #9333ea; }
.icon-box.green { background: #dcfce7; color: #16a34a; }
.icon-box.orange { background: #ffedd5; color: #ea580c; }
.icon-box.red { background: #fee2e2; color: #dc2626; }
.icon-box.cyan { background: #cffafe; color: #0891b2; }

.feature-card h3 {
    margin-bottom: 12px;
    font-size: 1.25rem;
}

.feature-card p {
    color: var(--text-muted);
    font-size: 0.95rem;
    line-height: 1.6;
}

/* Download */
.download-versions {
    display: flex;
    flex-direction: column;
    gap: 32px;
    max-width: 800px;
    margin: 0 auto 48px;
}

.version-card {
    border: 1px solid var(--border);
    border-radius: var(--radius-lg);
    padding: 32px;
    position: relative;
    display: flex;
    flex-direction: column;
    align-items: center;
    text-align: center;
}

.version-card.featured {
    border: 2px solid var(--primary);
    background: linear-gradient(to bottom, #fff, #eef2ff);
}

.card-tag {
    position: absolute;
    top: -12px;
    background: var(--primary);
    color: white;
    padding: 4px 16px;
    border-radius: 100px;
    font-size: 0.8rem;
    font-weight: 700;
    text-transform: uppercase;
}

.ver-num {
    font-family: monospace;
    background: #f1f5f9;
    padding: 4px 12px;
    border-radius: 4px;
    margin: 8px 0 24px;
    color: var(--text-main);
}

.ver-features {
    margin-bottom: 24px;
    text-align: left;
}

.ver-features li {
    margin-bottom: 8px;
    color: var(--text-muted);
    font-size: 0.95rem;
}

.ver-meta {
    margin-top: 16px;
    font-size: 0.85rem;
    color: #94a3b8;
}

.system-req {
    max-width: 700px;
    margin: 0 auto;
    background: #fff7ed;
    border: 1px solid #ffedd5;
    padding: 16px;
    border-radius: 8px;
    color: #9a3412;
    font-size: 0.9rem;
}

.system-req h4 {
    display: flex;
    align-items: center;
    gap: 8px;
    margin-bottom: 8px;
}

/* Steps */
.steps-container {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
    gap: 32px;
}

.step-item {
    text-align: center;
}

.step-num {
    width: 40px;
    height: 40px;
    background: var(--text-main);
    color: white;
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    font-weight: 700;
    margin: 0 auto 20px;
}

.step-item h3 {
    margin-bottom: 12px;
}

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

/* Content Article */
.content-article article {
    max-width: 800px;
    margin: 0 auto;
    color: var(--text-muted);
}

.content-article h3 {
    color: var(--text-main);
    margin-bottom: 16px;
}

.content-article h4 {
    color: var(--text-main);
    margin: 24px 0 12px;
}

.content-article p {
    margin-bottom: 16px;
}

.content-article ul {
    list-style: disc;
    padding-left: 20px;
}

.content-article li {
    margin-bottom: 8px;
}

/* FAQ */
.faq-grid {
    max-width: 800px;
    margin: 0 auto;
    display: flex;
    flex-direction: column;
    gap: 16px;
}

.faq-item {
    border: 1px solid var(--border);
    border-radius: var(--radius);
    overflow: hidden;
    background: white;
}

.faq-question {
    padding: 20px;
    display: flex;
    justify-content: space-between;
    align-items: center;
    cursor: pointer;
    font-weight: 600;
    background: white;
    transition: background 0.2s;
}

.faq-question:hover {
    background: #f8fafc;
}

.faq-toggle {
    background: none;
    border: none;
    font-size: 1.5rem;
    color: var(--primary);
    cursor: pointer;
}

.faq-answer {
    max-height: 0;
    overflow: hidden;
    padding: 0 20px;
    transition: max-height 0.3s ease, padding 0.3s ease;
    background: #f8fafc;
    color: var(--text-muted);
}

.faq-answer.active {
    padding: 20px;
    max-height: 200px; /* Arbitrary height for animation */
    border-top: 1px solid var(--border);
}

/* Footer */
.site-footer {
    background: #1e293b;
    color: #e2e8f0;
    padding: 60px 0 30px;
}

.footer-content {
    display: grid;
    grid-template-columns: 2fr 1fr 1fr;
    gap: 40px;
    margin-bottom: 40px;
}

.footer-brand .logo-text {
    font-size: 1.5rem;
    font-weight: 700;
    color: white;
    display: block;
    margin-bottom: 16px;
}

.footer-brand p {
    color: #94a3b8;
    max-width: 300px;
}

.footer-links h4 {
    color: white;
    margin-bottom: 20px;
    font-size: 1.1rem;
}

.footer-links ul {
    display: flex;
    flex-direction: column;
    gap: 12px;
}

.footer-links a {
    color: #94a3b8;
}

.footer-links a:hover {
    color: white;
}

.footer-bottom {
    border-top: 1px solid #334155;
    padding-top: 30px;
    text-align: center;
    font-size: 0.85rem;
    color: #64748b;
}

/* Responsive Media Queries */
@media (min-width: 768px) {
    .main-nav {
        display: block;
    }
    
    .mobile-menu-toggle {
        display: none;
    }

    .hero-grid {
        grid-template-columns: 1fr 1fr;
    }
    
    .hero-visual {
        display: block;
    }

    .hero h1 {
        font-size: 3.5rem;
    }

    .download-versions {
        flex-direction: row;
        align-items: flex-start;
    }

    .version-card {
        flex: 1;
    }
}

@media (max-width: 480px) {
    .hero-btns {
        flex-direction: column;
    }
    
    .btn {
        width: 100%;
    }
    
    .footer-content {
        grid-template-columns: 1fr;
    }
}