/* ===== Design Tokens ===== */
:root {
    --color-primary: #2563EB;
    --color-primary-dark: #1D4ED8;
    --color-primary-light: #DBEAFE;
    --color-accent: #10B981;
    --color-bg: #FFFFFF;
    --color-bg-alt: #F8FAFC;
    --color-text: #1E293B;
    --color-text-muted: #64748B;
    --color-border: #E2E8F0;
    --font-family: 'Inter', system-ui, -apple-system, sans-serif;
    --shadow-sm: 0 1px 2px rgba(0, 0, 0, 0.05);
    --shadow-md: 0 4px 6px -1px rgba(0, 0, 0, 0.1), 0 2px 4px -2px rgba(0, 0, 0, 0.1);
    --shadow-lg: 0 10px 15px -3px rgba(0, 0, 0, 0.1), 0 4px 6px -4px rgba(0, 0, 0, 0.1);
    --shadow-xl: 0 20px 25px -5px rgba(0, 0, 0, 0.1), 0 8px 10px -6px rgba(0, 0, 0, 0.1);
    --radius-sm: 6px;
    --radius-md: 10px;
    --radius-lg: 16px;
    --radius-xl: 24px;
}

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

html {
    scroll-behavior: smooth;
    scroll-padding-top: 80px;
}

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

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

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

/* ===== Layout ===== */
.container {
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 24px;
}

/* ===== Navbar ===== */
.navbar {
    position: fixed;
    top: 0;
    left: 0;
    right: 0;
    z-index: 1000;
    background: rgba(255, 255, 255, 0.95);
    backdrop-filter: blur(10px);
    -webkit-backdrop-filter: blur(10px);
    border-bottom: 1px solid transparent;
    transition: border-color 0.3s, box-shadow 0.3s;
}

.navbar.scrolled {
    border-bottom-color: var(--color-border);
    box-shadow: var(--shadow-sm);
}

.nav-container {
    display: flex;
    align-items: center;
    justify-content: space-between;
    height: 72px;
}

.nav-brand {
    display: flex;
    align-items: center;
    gap: 10px;
    color: var(--color-text);
    font-weight: 700;
    font-size: 1.1rem;
}

.nav-logo {
    width: 36px;
    height: 36px;
    border-radius: var(--radius-sm);
}

.nav-links {
    display: flex;
    align-items: center;
    gap: 32px;
    list-style: none;
}

.nav-links a {
    color: var(--color-text-muted);
    font-weight: 500;
    font-size: 0.95rem;
    transition: color 0.2s;
}

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

.nav-cta {
    background: var(--color-primary);
    color: #fff !important;
    padding: 8px 20px;
    border-radius: var(--radius-sm);
    font-weight: 600 !important;
    transition: background 0.2s !important;
}

.nav-cta:hover {
    background: var(--color-primary-dark) !important;
}

.nav-toggle {
    display: none;
    flex-direction: column;
    gap: 5px;
    background: none;
    border: none;
    cursor: pointer;
    padding: 4px;
}

.nav-toggle span {
    display: block;
    width: 24px;
    height: 2px;
    background: var(--color-text);
    border-radius: 2px;
    transition: transform 0.3s, opacity 0.3s;
}

.nav-toggle.active span:nth-child(1) {
    transform: translateY(7px) rotate(45deg);
}

.nav-toggle.active span:nth-child(2) {
    opacity: 0;
}

.nav-toggle.active span:nth-child(3) {
    transform: translateY(-7px) rotate(-45deg);
}

/* ===== Buttons ===== */
.btn {
    display: inline-flex;
    align-items: center;
    gap: 8px;
    font-family: var(--font-family);
    font-weight: 600;
    border: none;
    border-radius: var(--radius-sm);
    cursor: pointer;
    transition: all 0.2s;
    text-decoration: none;
}

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

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

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

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

.btn-lg {
    padding: 14px 28px;
    font-size: 1.05rem;
}

.btn-xl {
    padding: 18px 40px;
    font-size: 1.15rem;
    border-radius: var(--radius-md);
}

/* ===== Hero ===== */
.hero {
    padding: 140px 0 80px;
    background: linear-gradient(180deg, var(--color-primary-light) 0%, var(--color-bg) 100%);
}

.hero .container {
    display: flex;
    flex-direction: column;
    align-items: center;
    text-align: center;
    gap: 48px;
}

.hero-content {
    max-width: 720px;
}

.hero h1 {
    font-size: 3rem;
    font-weight: 800;
    line-height: 1.15;
    letter-spacing: -0.02em;
    margin-bottom: 20px;
    color: var(--color-text);
}

.hero-subtitle {
    font-size: 1.2rem;
    color: var(--color-text-muted);
    line-height: 1.7;
    margin-bottom: 32px;
}

.hero-actions {
    display: flex;
    gap: 16px;
    justify-content: center;
    flex-wrap: wrap;
    margin-bottom: 40px;
}

.hero-badges {
    display: flex;
    gap: 24px;
    justify-content: center;
    flex-wrap: wrap;
}

.badge {
    display: flex;
    align-items: center;
    gap: 8px;
    font-size: 0.9rem;
    font-weight: 500;
    color: var(--color-text-muted);
}

.badge svg {
    color: var(--color-accent);
    flex-shrink: 0;
}

.hero-image {
    width: 100%;
    max-width: 960px;
}

/* Window frame mockup */
.window-frame {
    border-radius: var(--radius-lg);
    overflow: hidden;
    box-shadow: var(--shadow-xl);
    border: 1px solid var(--color-border);
    background: #fff;
}

.window-titlebar {
    display: flex;
    gap: 8px;
    padding: 12px 16px;
    background: #F1F5F9;
    border-bottom: 1px solid var(--color-border);
}

.window-dot {
    width: 12px;
    height: 12px;
    border-radius: 50%;
    background: #CBD5E1;
}

.window-frame img {
    width: 100%;
}

/* ===== Stats Bar ===== */
.stats-bar {
    background: var(--color-primary);
    padding: 40px 0;
}

.stats-grid {
    display: grid;
    grid-template-columns: repeat(4, 1fr);
    gap: 32px;
    text-align: center;
}

.stat-number {
    display: block;
    font-size: 2.5rem;
    font-weight: 800;
    color: #fff;
    line-height: 1.2;
}

.stat-label {
    display: block;
    font-size: 0.95rem;
    color: rgba(255, 255, 255, 0.8);
    margin-top: 4px;
}

/* ===== Section Headers ===== */
.section-header {
    text-align: center;
    max-width: 600px;
    margin: 0 auto 56px;
}

.section-header h2 {
    font-size: 2.2rem;
    font-weight: 800;
    letter-spacing: -0.02em;
    margin-bottom: 12px;
}

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

/* ===== Features ===== */
.features {
    padding: 96px 0;
}

.features-grid {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: 32px;
}

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

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

.feature-icon {
    width: 56px;
    height: 56px;
    display: flex;
    align-items: center;
    justify-content: center;
    background: var(--color-primary-light);
    color: var(--color-primary);
    border-radius: var(--radius-md);
    margin-bottom: 20px;
}

.feature-card h3 {
    font-size: 1.15rem;
    font-weight: 700;
    margin-bottom: 10px;
}

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

/* ===== Screenshots ===== */
.screenshots {
    padding: 96px 0;
    background: var(--color-bg-alt);
}

.screenshots-grid {
    display: grid;
    grid-template-columns: repeat(2, 1fr);
    gap: 32px;
}

.screenshot-card {
    border-radius: var(--radius-lg);
    overflow: hidden;
    border: 1px solid var(--color-border);
    background: var(--color-bg);
    cursor: pointer;
    transition: transform 0.2s, box-shadow 0.2s;
}

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

.screenshot-card img {
    width: 100%;
    display: block;
}

.screenshot-caption {
    padding: 16px 20px;
    font-size: 0.9rem;
    font-weight: 500;
    color: var(--color-text-muted);
    text-align: center;
}

/* ===== How It Works ===== */
.how-it-works {
    padding: 96px 0;
}

.steps-grid {
    display: flex;
    align-items: center;
    justify-content: center;
    gap: 24px;
}

.step {
    flex: 1;
    max-width: 300px;
    text-align: center;
    padding: 40px 24px;
}

.step-number {
    width: 56px;
    height: 56px;
    display: flex;
    align-items: center;
    justify-content: center;
    margin: 0 auto 20px;
    background: var(--color-primary);
    color: #fff;
    font-size: 1.5rem;
    font-weight: 800;
    border-radius: 50%;
}

.step h3 {
    font-size: 1.3rem;
    font-weight: 700;
    margin-bottom: 12px;
}

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

.step-arrow {
    color: var(--color-primary);
    flex-shrink: 0;
}

/* ===== Download ===== */
.download {
    padding: 96px 0;
    background: var(--color-bg-alt);
}

.download-card {
    max-width: 720px;
    margin: 0 auto;
    text-align: center;
}

.download-header {
    margin-bottom: 32px;
}

.download-logo {
    width: 80px;
    height: 80px;
    margin: 0 auto 20px;
    border-radius: var(--radius-md);
}

.download-header h2 {
    font-size: 2rem;
    font-weight: 800;
    letter-spacing: -0.02em;
    margin-bottom: 12px;
}

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

.download-count {
    margin-top: 12px;
    font-size: 0.95rem;
    color: var(--color-text-muted);
}

.download-details {
    margin-top: 40px;
    text-align: left;
}

.download-info-grid {
    display: grid;
    grid-template-columns: repeat(2, 1fr);
    gap: 16px;
    margin-bottom: 32px;
}

.download-info {
    padding: 16px 20px;
    background: var(--color-bg);
    border: 1px solid var(--color-border);
    border-radius: var(--radius-sm);
}

.download-info strong {
    display: block;
    font-size: 0.8rem;
    text-transform: uppercase;
    letter-spacing: 0.05em;
    color: var(--color-text-muted);
    margin-bottom: 4px;
}

.download-info span {
    font-weight: 500;
    font-size: 0.95rem;
}

.checksums {
    padding: 24px;
    background: var(--color-bg);
    border: 1px solid var(--color-border);
    border-radius: var(--radius-md);
    margin-bottom: 24px;
}

.checksums h4 {
    font-size: 0.95rem;
    font-weight: 700;
    margin-bottom: 16px;
}

.checksum-row {
    display: flex;
    align-items: center;
    gap: 12px;
    margin-bottom: 8px;
}

.checksum-row:last-child {
    margin-bottom: 0;
}

.checksum-label {
    font-size: 0.8rem;
    font-weight: 700;
    text-transform: uppercase;
    letter-spacing: 0.05em;
    color: var(--color-text-muted);
    min-width: 70px;
}

.checksum-value {
    font-size: 0.85rem;
    font-family: 'Courier New', monospace;
    color: var(--color-text-muted);
    background: var(--color-bg-alt);
    padding: 4px 10px;
    border-radius: 4px;
    word-break: break-all;
}

.smartscreen-note {
    padding: 20px;
    background: #FEF9C3;
    border: 1px solid #FDE68A;
    border-radius: var(--radius-md);
}

.smartscreen-note-text {
    display: flex;
    gap: 12px;
}

.smartscreen-note svg {
    flex-shrink: 0;
    color: #D97706;
    margin-top: 2px;
}

.smartscreen-note p {
    font-size: 0.9rem;
    color: #92400E;
    line-height: 1.6;
}

.smartscreen-img {
    margin-top: 16px;
    border-radius: var(--radius-sm);
    border: 1px solid #FDE68A;
}

/* ===== Support / Donate ===== */
.support {
    padding: 64px 0;
}

.support-card {
    max-width: 520px;
    margin: 0 auto;
    text-align: center;
    padding: 40px 32px;
    border-radius: var(--radius-lg);
    border: 1px solid var(--color-border);
    background: var(--color-bg);
}

.support-icon {
    color: #FF5E5B;
    margin-bottom: 16px;
}

.support-card h3 {
    font-size: 1.4rem;
    font-weight: 700;
    margin-bottom: 8px;
}

.support-card p {
    font-size: 0.95rem;
    color: var(--color-text-muted);
    line-height: 1.6;
    margin-bottom: 24px;
}

.btn-kofi {
    background: #FF5E5B;
    color: #fff;
    padding: 14px 28px;
    font-size: 1.05rem;
    border-radius: var(--radius-sm);
}

.btn-kofi:hover {
    background: #e84e4b;
    transform: translateY(-1px);
    box-shadow: var(--shadow-md);
}

/* ===== Footer ===== */
.footer {
    padding: 32px 0;
    border-top: 1px solid var(--color-border);
}

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

.footer-brand {
    display: flex;
    align-items: center;
    gap: 10px;
    font-weight: 600;
    color: var(--color-text);
}

.footer-logo {
    width: 28px;
    height: 28px;
    border-radius: 4px;
}

.footer-contact {
    font-size: 0.9rem;
    color: var(--color-text-muted);
    margin-bottom: 0.5rem;
}

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

.footer-contact a:hover {
    text-decoration: underline;
}

.footer-copy {
    font-size: 0.85rem;
    color: var(--color-text-muted);
}

/* ===== Lightbox ===== */
.lightbox {
    display: none;
    position: fixed;
    inset: 0;
    z-index: 2000;
    background: rgba(0, 0, 0, 0.85);
    align-items: center;
    justify-content: center;
    padding: 40px;
    cursor: zoom-out;
}

.lightbox.active {
    display: flex;
}

.lightbox-close {
    position: absolute;
    top: 20px;
    right: 28px;
    background: none;
    border: none;
    color: #fff;
    font-size: 2.5rem;
    cursor: pointer;
    line-height: 1;
    opacity: 0.8;
    transition: opacity 0.2s;
}

.lightbox-close:hover {
    opacity: 1;
}

.lightbox-img {
    max-width: 90vw;
    max-height: 85vh;
    border-radius: var(--radius-md);
    box-shadow: var(--shadow-xl);
}

/* ===== Scroll Animations ===== */
.fade-in {
    opacity: 0;
    transform: translateY(20px);
    transition: opacity 0.6s ease-out, transform 0.6s ease-out;
}

.fade-in.visible {
    opacity: 1;
    transform: translateY(0);
}

/* ===== Responsive ===== */
@media (max-width: 1024px) {
    .features-grid {
        grid-template-columns: repeat(2, 1fr);
    }
}

@media (max-width: 768px) {
    .nav-toggle {
        display: flex;
    }

    .nav-links {
        display: none;
        position: absolute;
        top: 72px;
        left: 0;
        right: 0;
        flex-direction: column;
        background: var(--color-bg);
        padding: 16px 24px 24px;
        gap: 0;
        border-bottom: 1px solid var(--color-border);
        box-shadow: var(--shadow-md);
    }

    .nav-links.active {
        display: flex;
    }

    .nav-links li {
        width: 100%;
    }

    .nav-links a {
        display: block;
        padding: 12px 0;
        border-bottom: 1px solid var(--color-border);
    }

    .nav-links li:last-child a {
        border-bottom: none;
        text-align: center;
        margin-top: 8px;
    }

    .hero {
        padding: 120px 0 60px;
    }

    .hero h1 {
        font-size: 2.2rem;
    }

    .hero-subtitle {
        font-size: 1.05rem;
    }

    .hero-badges {
        gap: 16px;
    }

    .stats-grid {
        grid-template-columns: repeat(2, 1fr);
        gap: 24px;
    }

    .stat-number {
        font-size: 2rem;
    }

    .features-grid {
        grid-template-columns: 1fr;
        gap: 20px;
    }

    .feature-card {
        padding: 24px;
    }

    .screenshots-grid {
        grid-template-columns: 1fr;
    }

    .steps-grid {
        flex-direction: column;
        gap: 8px;
    }

    .step-arrow {
        transform: rotate(90deg);
    }

    .download-info-grid {
        grid-template-columns: 1fr;
    }

    .footer-content {
        flex-direction: column;
        gap: 12px;
        text-align: center;
    }

    .section-header h2 {
        font-size: 1.8rem;
    }
}

@media (max-width: 480px) {
    .hero h1 {
        font-size: 1.8rem;
    }

    .btn-lg {
        padding: 12px 22px;
        font-size: 0.95rem;
    }

    .btn-xl {
        padding: 16px 32px;
        font-size: 1.05rem;
    }

    .hero-badges {
        flex-direction: column;
        align-items: center;
    }

    .checksum-row {
        flex-direction: column;
        align-items: flex-start;
        gap: 4px;
    }
}