/* Enhanced NEXA Sphere CSS with Material 3 Design */

/* --- CSS Custom Properties (Design Tokens) --- */
:root {
    --brand-primary: #7C3AED; 
    --brand-on-primary: #FFFFFF; 
    --brand-primary-container: #37304A; 
    --brand-on-primary-container: #EADDFF; 
    
    --brand-secondary: #CDC2DB; 
    --brand-on-secondary: #332D41; 
    --brand-secondary-container: #4A4458; 
    --brand-on-secondary-container: #E8DEF8; 

    --brand-tertiary: #EFB8C8; 
    --brand-on-tertiary: #492532; 
    --brand-tertiary-container: #633B48; 
    --brand-on-tertiary-container: #FFD8E4; 
    
    --vibrant-magenta-accent: #DB2777; 
    
    --text-color-primary: #F8F9FA; 
    --text-color-secondary: #CAC4D0; 
    --text-color-disabled: #938F99; 
    
    --surface-dim: #141218; 
    --surface: #0A1931; 
    --surface-bright: #3A383F; 
    --surface-container-lowest: #0F0D13; 
    --surface-container-low: #1D1B20; 
    --surface-container: #211F26;
    --surface-container-high: #2B2930;
    --surface-container-highest: #36343B; 

    --outline: #938F99; 
    --outline-variant: #49454F; 
    --error: #F2B8B5;
    --on-error: #601410;
    --error-container: #8C1D18;
    --on-error-container: #F9DEDC;

    --font-family-main: 'Open Sans', -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, sans-serif;
    --font-family-headings: 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, sans-serif;

    --shape-corner-extra-small: 4px;
    --shape-corner-small: 8px;
    --shape-corner-medium: 12px;
    --shape-corner-large: 16px;
    --shape-corner-extra-large: 28px;
    --shape-corner-full: 100px; 

    --elevation-0: none;
    --elevation-1: 0 1px 2px 0 rgba(0,0,0,0.1), 0 1px 3px 0 rgba(0,0,0,0.08);
    --elevation-2: 0 2px 4px -1px rgba(0,0,0,0.1), 0 4px 5px 0 rgba(0,0,0,0.08);
    --elevation-3: 0 3px 5px -1px rgba(0,0,0,0.1), 0 6px 10px 0 rgba(0,0,0,0.08);
    --elevation-4: 0 4px 5px -2px rgba(0,0,0,0.1), 0 7px 10px 1px rgba(0,0,0,0.08);
    --elevation-5: 0 6px 10px -5px rgba(0,0,0,0.1), 0 10px 18px 2px rgba(0,0,0,0.08);

    --brand-primary-rgb: 124, 58, 237; 
    --surface-dim-rgb: 20, 18, 24;
    --surface-container-highest-rgb: 54, 52, 59;
}

/* --- Reset & Base Styles --- */
*, *::before, *::after {
    box-sizing: border-box;
}

body {
    font-family: var(--font-family-main);
    background-color: var(--surface); 
    color: var(--text-color-primary);
    scroll-behavior: smooth;
    -webkit-font-smoothing: antialiased;
    -moz-osx-font-smoothing: grayscale;
    margin: 0;
    padding: 0;
    line-height: 1.7; 
    font-size: 16px; 
}

/* --- Enhanced Responsive Typography --- */
h1, h2, h3, h4, h5, h6 {
    font-family: var(--font-family-headings);
    font-weight: 700;
    color: var(--text-color-primary);
    margin-top: 0;
    margin-bottom: 1em; 
    line-height: 1.2; 
}

/* Improved header sizes as requested */
h1.page-title { 
    font-size: clamp(2rem, 4vw, 3.25rem); 
    font-weight: 900; 
    letter-spacing: -0.025em;
}

h2.section-title { 
    font-size: clamp(1.75rem, 3.5vw, 2.5rem); 
    font-weight: 800; 
    letter-spacing: -0.02em;
}

h3.sub-section-title { 
    font-size: clamp(1.25rem, 2.5vw, 1.75rem); 
    font-weight: 700;
}

p {
    margin-bottom: 1.5em; 
    color: var(--text-color-secondary);
    font-size: clamp(1rem, 2.5vw, 1.125rem); 
    max-width: 70ch;
}

p.lead { 
    font-size: clamp(1.125rem, 3vw, 1.375rem);
    color: var(--text-color-primary);
    font-weight: 500; 
    max-width: 65ch;
}

strong { 
    font-weight: 600; 
    color: var(--text-color-primary); 
}

em, .italic { 
    font-style: italic; 
}

a {
    color: var(--brand-primary);
    text-decoration: none;
    transition: color 0.2s ease-in-out, opacity 0.2s ease-in-out;
}

a:hover {
    color: color-mix(in srgb, var(--brand-primary) 85%, white);
    text-decoration: none; 
}

/* --- Enhanced Container System --- */
.container {
    width: 100%; 
    margin-left: auto;
    margin-right: auto;
}

.main-content-wrapper {
    max-width: 1320px;
    margin-left: auto;
    margin-right: auto;
    padding-left: 1.5rem; 
    padding-right: 1.5rem;
}

@media (min-width: 768px) {
    .main-content-wrapper {
        padding-left: 2rem;
        padding-right: 2rem;
    }
}

@media (min-width: 1024px) {
    .main-content-wrapper {
        padding-left: 2.5rem;
        padding-right: 2.5rem;
    }
}

/* --- Enhanced Material 3 Top App Bar --- */
#app-header {
    background: rgba(var(--surface-container-highest-rgb), 0.95);
    backdrop-filter: blur(12px);
    -webkit-backdrop-filter: blur(12px);
    box-shadow: var(--elevation-1);
    position: sticky;
    top: 0;
    z-index: 1000; 
    border-bottom: 1px solid rgba(var(--outline-variant), 0.3);
}

#app-header .container {
    max-width: 1320px;
    padding-left: 1.5rem; 
    padding-right: 1.5rem;
}

@media (min-width: 768px) {
    #app-header .container { 
        padding: 0 2rem; 
    }
}

@media (min-width: 1024px) {
    #app-header .container { 
        padding: 0 2.5rem; 
    }
}

.navbar-content {
    display: flex;
    align-items: center;
    justify-content: space-between;
    height: 4rem; 
}

.logo-link {
    display: flex;
    align-items: center;
    text-decoration: none;
    transition: opacity 0.2s ease;
}

.logo-link:hover { 
    opacity: 0.85; 
    text-decoration: none; 
}

.logo-icon {
    width: 2rem; 
    height: 2rem;
    margin-right: 0.5rem;
    color: var(--brand-primary);
}

.logo-text {
    font-family: var(--font-family-headings);
    font-size: 1.75rem; 
    font-weight: 900; 
    color: var(--brand-primary);
    letter-spacing: -0.025em;
}

/* --- Enhanced Navigation --- */
.nav-links-desktop {
    display: none; 
}

@media (min-width: 1024px) { 
    .nav-links-desktop {
        display: flex;
        align-items: center; 
        gap: 0.25rem;
    }
}

.nav-link {
    padding: 0.75rem 1rem; 
    border-radius: var(--shape-corner-full);
    font-size: 0.875rem; 
    font-weight: 500;
    color: var(--text-color-secondary);
    transition: all 0.2s cubic-bezier(0.4, 0, 0.2, 1);
    text-decoration: none;
    display: inline-flex; 
    align-items: center;
    line-height: 1; 
    position: relative; 
    overflow: hidden; 
}

.nav-link:hover {
    color: var(--brand-primary);
    background-color: rgba(var(--brand-primary-rgb),