/* Material Design 3 — Monochrome (Grey) Color Scheme */
:root {
    --md-sys-color-primary: #9AA0A6;
    --md-sys-color-on-primary: #1F1F1F;
    --md-sys-color-primary-container: #3C4043;
    --md-sys-color-on-primary-container: #E8EAED;
    --md-sys-color-secondary: #BDC1C6;
    --md-sys-color-on-secondary: #202124;
    --md-sys-color-secondary-container: #5F6368;
    --md-sys-color-on-secondary-container: #F1F3F4;
    --md-sys-color-surface: #1E1E1E;
    --md-sys-color-on-surface: #E8EAED;
    --md-sys-color-surface-variant: #494C50;
    --md-sys-color-on-surface-variant: #C4C7C5;
    --md-sys-color-background: #121212;
    --md-sys-color-on-background: #E8EAED;
    --md-sys-color-outline: #8E918F;
    --md-sys-elevation-1: 0px 1px 2px rgba(0,0,0,0.3), 0px 1px 3px 1px rgba(0,0,0,0.15);
    --md-sys-elevation-2: 0px 1px 2px rgba(0,0,0,0.3), 0px 2px 6px 2px rgba(0,0,0,0.15);
    --spacing-xs: 4px; --spacing-sm: 8px; --spacing-md: 16px; --spacing-lg: 24px; --spacing-xl: 32px; --spacing-2xl: 48px;
    --typescale-headline-large: 400 32px/40px 'Roboto', sans-serif;
    --typescale-headline-medium: 400 28px/36px 'Roboto', sans-serif;
    --typescale-title-large: 400 22px/28px 'Roboto', sans-serif;
    --typescale-title-medium: 500 16px/24px 'Roboto', sans-serif;
    --typescale-title-small: 500 14px/20px 'Roboto', sans-serif;
    --typescale-body-large: 400 16px/24px 'Roboto', sans-serif;
    --typescale-body-medium: 400 14px/20px 'Roboto', sans-serif;
    --typescale-body-small: 400 12px/16px 'Roboto', sans-serif;
    --typescale-label-large: 500 14px/20px 'Roboto', sans-serif;
    --font-mono: 'Roboto Mono', monospace;
}
* { margin: 0; padding: 0; box-sizing: border-box; }
body { background-color: var(--md-sys-color-background); color: var(--md-sys-color-on-background); font: var(--typescale-body-medium); }
.container { max-width: 1200px; margin: 0 auto; padding: 0 var(--spacing-lg); }
.container.narrow { max-width: 800px; }

/* Navigation */
.top-app-bar { background-color: var(--md-sys-color-surface); border-bottom: 1px solid var(--md-sys-color-outline); position: sticky; top: 0; z-index: 10; box-shadow: var(--md-sys-elevation-1); }
.nav-container { display: flex; align-items: center; justify-content: space-between; height: 80px; padding: 0 var(--spacing-lg); max-width: 1200px; margin: 0 auto; }
.nav-brand { display: flex; align-items: center; gap: var(--spacing-sm); color: var(--md-sys-color-on-surface); }
.logo { height: 48px; width: auto; margin-right: 8px; }
.brand-text { font: var(--typescale-title-large); font-weight: 500; }
.nav-links { display: flex; list-style: none; gap: var(--spacing-sm); align-items: center; }
.nav-links a { color: var(--md-sys-color-on-surface-variant); text-decoration: none; font: var(--typescale-label-large); padding: var(--spacing-sm) var(--spacing-md); border-radius: 20px; transition: background 0.2s, color 0.2s; display: flex; align-items: center; gap: 4px; }
.nav-links a:hover { background-color: rgba(255,255,255,0.08); color: var(--md-sys-color-on-surface); }
.nav-links a.active { background-color: var(--md-sys-color-secondary-container); color: var(--md-sys-color-on-secondary-container); }
.menu-toggle { display: none; background: none; border: none; color: var(--md-sys-color-on-surface); cursor: pointer; padding: var(--spacing-sm); border-radius: 20px; }

/* Sections */
.page-section { display: none; padding: var(--spacing-2xl) 0; }
.page-section.active-section { display: block; }

/* Home */
.hero-content { max-width: 800px; margin-bottom: var(--spacing-2xl); }
.headline-large { font: var(--typescale-headline-large); margin-bottom: var(--spacing-md); }
.body-large { font: var(--typescale-body-large); color: var(--md-sys-color-on-surface-variant); margin-bottom: var(--spacing-xl); }
.button-group { display: flex; gap: var(--spacing-md); flex-wrap: wrap; }
.btn-filled, .btn-outlined { display: inline-flex; align-items: center; justify-content: center; padding: 10px 24px; border-radius: 20px; font: var(--typescale-label-large); text-decoration: none; transition: all 0.2s; cursor: pointer; border: 1px solid transparent; }
.btn-filled { background-color: var(--md-sys-color-primary); color: var(--md-sys-color-on-primary); box-shadow: var(--md-sys-elevation-1); }
.btn-filled:hover { background-color: #A9AEB3; }
.btn-outlined { background-color: transparent; color: var(--md-sys-color-primary); border-color: var(--md-sys-color-outline); }
.btn-outlined:hover { background-color: rgba(154,160,166,0.08); }
.hero-cards { display: grid; grid-template-columns: repeat(auto-fit, minmax(240px, 1fr)); gap: var(--spacing-lg); margin-bottom: var(--spacing-xl); }
.feature-card { background-color: var(--md-sys-color-surface); border-radius: 20px; padding: var(--spacing-lg); border: 1px solid var(--md-sys-color-outline); }
.handbook-note { background-color: var(--md-sys-color-surface-variant); border-radius: 20px; padding: var(--spacing-md) var(--spacing-lg); display: inline-flex; align-items: center; gap: var(--spacing-sm); }

/* Download */
.download-card { background-color: var(--md-sys-color-surface); border-radius: 24px; padding: var(--spacing-2xl); text-align: center; border: 1px solid var(--md-sys-color-outline); margin-bottom: var(--spacing-xl); }
.status-badge { display: inline-block; background-color: var(--md-sys-color-secondary-container); color: var(--md-sys-color-on-secondary-container); padding: 6px 16px; border-radius: 20px; margin-top: var(--spacing-md); }
.security-note { background-color: var(--md-sys-color-surface-variant); border-radius: 20px; padding: var(--spacing-lg); }

/* Packages */
.packages-header { display: flex; align-items: center; justify-content: space-between; margin-bottom: var(--spacing-sm); }
.request-btn { gap: var(--spacing-xs); }
.tabs { display: flex; gap: var(--spacing-sm); margin: var(--spacing-lg) 0; border-bottom: 1px solid var(--md-sys-color-outline); padding-bottom: var(--spacing-sm); }
.tab-btn { background: none; border: none; padding: var(--spacing-sm) var(--spacing-lg); font: var(--typescale-label-large); color: var(--md-sys-color-on-surface-variant); border-radius: 20px; cursor: pointer; }
.tab-btn.active { background-color: var(--md-sys-color-secondary-container); color: var(--md-sys-color-on-secondary-container); }
.tab-content { display: none; }
.tab-content.active { display: block; }
.table-container { overflow-x: auto; margin: var(--spacing-lg) 0; border-radius: 16px; border: 1px solid var(--md-sys-color-outline); background-color: var(--md-sys-color-surface); }
.package-table { width: 100%; border-collapse: collapse; }
.package-table th { text-align: left; padding: var(--spacing-md); background-color: var(--md-sys-color-surface-variant); }
.package-table td { padding: var(--spacing-md); border-bottom: 1px solid var(--md-sys-color-outline); }
.file-links { display: flex; gap: var(--spacing-sm); flex-wrap: wrap; }
.file-link { color: var(--md-sys-color-primary); text-decoration: none; padding: 2px 8px; border-radius: 12px; background-color: rgba(154,160,166,0.08); }
.file-link:hover { background-color: rgba(154,160,166,0.16); }
.security-footer { margin-top: var(--spacing-lg); padding: var(--spacing-md); background-color: var(--md-sys-color-surface-variant); border-radius: 16px; display: flex; align-items: center; gap: var(--spacing-sm); }

/* Footer */
.footer { border-top: 1px solid var(--md-sys-color-outline); padding: var(--spacing-lg) 0; margin-top: var(--spacing-2xl); }
.footer-content { display: flex; justify-content: space-between; align-items: center; }

/* Responsive */
@media (max-width: 768px) {
    .nav-links { display: none; position: absolute; top: 64px; left: 0; right: 0; background-color: var(--md-sys-color-surface); flex-direction: column; padding: var(--spacing-md); border-bottom: 1px solid var(--md-sys-color-outline); }
    .nav-links.show { display: flex; }
    .menu-toggle { display: block; }
    .packages-header { flex-direction: column; align-items: flex-start; gap: var(--spacing-md); }
}
.request-form {
    background: var(--md-sys-color-surface);
    padding: var(--spacing-xl);
    border-radius: 24px;
    border: 1px solid var(--md-sys-color-outline);
    margin-top: var(--spacing-lg);
}
.request-form label {
    display: block;
    margin: var(--spacing-md) 0 var(--spacing-xs);
    font: var(--typescale-label-large);
}
.request-form input,
.request-form textarea {
    width: 100%;
    padding: var(--spacing-sm) var(--spacing-md);
    background: var(--md-sys-color-background);
    border: 1px solid var(--md-sys-color-outline);
    border-radius: 12px;
    color: var(--md-sys-color-on-background);
    font: var(--typescale-body-medium);
}
.request-form button {
    margin-top: var(--spacing-xl);
}