:root {
    /* Colors - Light Theme Default */
    --bg-color: #FAFAFA;
    --surface-color: #FFFFFF;
    --text-primary: #1A1A1A;
    --text-secondary: #666666;
    --border-color: #EAEAEA;
    --accent-color: #2C2C2C;
    --accent-hover: #000000;
    --success-color: #2E7D32;
    
    /* Premium Multi-Layered Ambient Gradient Matrix (Light Mode Optimization) */
    --ambient-glow: 
        radial-gradient(circle at top left, rgba(34, 197, 94, 0.07), transparent 55%),
        radial-gradient(circle at bottom right, rgba(56, 189, 248, 0.08), transparent 55%),
        radial-gradient(circle at top right, rgba(129, 140, 248, 0.10), transparent 65%),
        #FAFAFA;
    
    /* Typography */
    --font-ui: 'Inter', system-ui, sans-serif;
    --font-editorial: 'Newsreader', serif;
    
    /* Spacing & Layout */
    --radius: 8px;
    --spacing-sm: 8px;
    --spacing-md: 16px;
    --spacing-lg: 24px;
    --spacing-xl: 48px;
    --max-width: 800px;
}

@media (prefers-color-scheme: dark) {
    :root {
        --bg-color: #050816; /* Dark-sky canvas container base */
        --surface-color: #111322;
        --text-primary: #EDEDED;
        --text-secondary: #A0A0A0;
        --border-color: rgba(148, 163, 184, 0.15);
        --accent-color: #FFFFFF;
        --accent-hover: #E0E0E0;
        
        /* High-Contrast Luminous Ambient Gradient Stack (Dark Mode Mastery) */
        --ambient-glow: 
            radial-gradient(circle at top left, rgba(34, 197, 94, 0.16), transparent 55%),
            radial-gradient(circle at bottom right, rgba(56, 189, 248, 0.18), transparent 55%),
            radial-gradient(circle at top right, rgba(129, 140, 248, 0.26), transparent 65%),
            #050816;
    }
}

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

body {
    background: var(--ambient-glow);
    background-attachment: fixed; /* Keeps ambient vectors static while elements roll over them */
    color: var(--text-primary);
    font-family: var(--font-ui);
    line-height: 1.6;
    -webkit-font-smoothing: antialiased;
    padding-bottom: 80px; /* Mobile navigation viewport buffer */
}

h1, h2, h3, h4 { font-family: var(--font-editorial); font-weight: 500; line-height: 1.3; }
h1 { font-size: 2.5rem; margin-bottom: var(--spacing-md); letter-spacing: -0.02em; }
h2 { font-size: 1.75rem; margin-bottom: var(--spacing-md); }

a { color: inherit; text-decoration: none; transition: opacity 0.2s; }
a:hover { opacity: 0.7; }

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

/* Header Elements Configuration */
.site-header { padding: var(--spacing-lg) 0; border-bottom: 1px solid var(--border-color); margin-bottom: var(--spacing-xl); backdrop-filter: blur(12px); -webkit-backdrop-filter: blur(12px); }
.nav-container { display: flex; justify-content: space-between; align-items: center; }
.brand { display: flex; flex-direction: column; }
.brand-name { font-family: var(--font-editorial); font-size: 1.25rem; font-weight: 600; }
.brand-byline { font-size: 0.75rem; color: var(--text-secondary); text-transform: uppercase; letter-spacing: 0.05em; margin-top: 2px;}
.site-header nav a { margin-left: var(--spacing-lg); font-size: 0.9rem; font-weight: 500; color: var(--text-secondary); transition: color 0.2s; }
.site-header nav a:hover { color: var(--text-primary); }

/* Cards Architecture */
.card {
    background: var(--surface-color);
    border: 1px solid var(--border-color);
    border-radius: var(--radius);
    padding: var(--spacing-lg);
    margin-bottom: var(--spacing-md);
    transition: transform 0.2s ease, box-shadow 0.2s ease, border-color 0.2s ease;
    box-shadow: 0 4px 30px rgba(0, 0, 0, 0.03);
}
a.card { display: block; }
a.card:active { transform: scale(0.99); }
.card:hover { border-color: var(--text-secondary); }

.card-meta { display: flex; gap: var(--spacing-md); font-size: 0.85rem; color: var(--text-secondary); margin-bottom: var(--spacing-sm); text-transform: uppercase; letter-spacing: 0.02em;}
.card-title { font-size: 1.25rem; margin-bottom: var(--spacing-sm); }
.card-desc { color: var(--text-secondary); font-size: 0.95rem; }

/* Argument Struct Blocks */
.argument-block { border-left: 3px solid var(--border-color); padding-left: var(--spacing-md); margin-bottom: var(--spacing-lg); }
.claim { font-weight: 600; font-size: 1.1rem; margin-bottom: var(--spacing-sm); }
.reasoning { color: var(--text-secondary); margin-bottom: var(--spacing-sm); }
.evidence-box { background: rgba(0, 0, 0, 0.05); padding: var(--spacing-md); border-radius: var(--radius); font-size: 0.9rem; margin-top: var(--spacing-sm); border: 1px solid var(--border-color); }
@media (prefers-color-scheme: dark) { .evidence-box { background: rgba(255, 255, 255, 0.03); } }
.evidence-box strong { font-family: var(--font-editorial); display: block; margin-bottom: 4px;}

/* Interactive Action Buttons */
.btn {
    display: inline-flex; align-items: center; justify-content: center;
    padding: 10px 20px; border-radius: var(--radius);
    font-weight: 500; font-size: 0.95rem; cursor: pointer;
    transition: background 0.2s, color 0.2s, transform 0.1s ease; border: none;
}
.btn-primary { background: var(--accent-color); color: var(--bg-color); }
.btn-primary:hover { background: var(--accent-hover); }
.btn-outline { background: transparent; border: 1px solid var(--border-color); color: var(--text-primary); }
.btn:active { transform: scale(0.98); }

/* Form Field Matrices */
.form-group { margin-bottom: var(--spacing-lg); }
label { display: block; font-weight: 500; margin-bottom: var(--spacing-sm); font-size: 0.95rem; }
input[type="text"], input[type="email"], input[type="password"], textarea, select {
    width: 100%; padding: 12px; border: 1px solid var(--border-color);
    border-radius: var(--radius); background: var(--surface-color);
    color: var(--text-primary); font-family: var(--font-ui); font-size: 1rem;
    transition: border-color 0.2s, box-shadow 0.2s;
}
input:focus, textarea:focus, select:focus { outline: none; border-color: var(--accent-color); box-shadow: 0 0 0 1px var(--accent-color); }
textarea { resize: vertical; min-height: 100px; }

/* Linear Submission Progress Indicators */
.step-container { display: none; animation: fadeIn 0.3s ease; }
.step-container.active { display: block; }
.progress-bar { height: 4px; background: var(--border-color); margin-bottom: var(--spacing-xl); border-radius: 2px; overflow: hidden;}
.progress-fill { height: 100%; background: var(--accent-color); transition: width 0.3s ease; }

/* --- PROFILE EXTRA ARCHITECTURE RULES --- */
.identity-header { border-bottom: 1px solid var(--border-color); padding-bottom: var(--spacing-lg); margin-bottom: var(--spacing-xl); }
.human-id-mark { font-family: var(--font-editorial); font-size: 2.5rem; font-weight: 500; letter-spacing: -0.02em; margin-bottom: 4px; }
.human-meta-line { font-size: 0.85rem; color: var(--text-secondary); font-family: monospace; letter-spacing: 0.02em; }

.metrics-display { background: var(--surface-color); border: 1px solid var(--border-color); border-radius: var(--radius); padding: var(--spacing-lg); margin-bottom: var(--spacing-xl); display: flex; align-items: center; justify-content: space-between; gap: var(--spacing-md); }
.metrics-label { font-size: 0.9rem; color: var(--text-secondary); max-width: 400px; line-height: 1.5; }
.metrics-number-wrapper { text-align: right; min-width: 100px; }
.metrics-big-number { font-family: var(--font-editorial); font-size: 3.5rem; font-weight: 400; line-height: 1; color: var(--text-primary); }
.metrics-subtext { font-size: 0.7rem; text-transform: uppercase; color: var(--text-secondary); letter-spacing: 0.05em; margin-top: var(--spacing-sm); display: block; white-space: nowrap; }

.ledger-title { font-family: var(--font-editorial); font-size: 1.5rem; font-weight: 500; margin-bottom: var(--spacing-lg); }
.ledger-stream-list { display: flex; flex-direction: column; }
.ledger-row-card { background: transparent; border-bottom: 1px solid var(--border-color); padding: var(--spacing-lg) 0; }
.ledger-row-card:last-child { border-bottom: none; }
.ledger-row-meta { font-size: 0.8rem; color: var(--text-secondary); margin-bottom: var(--spacing-sm); display: flex; justify-content: space-between; gap: var(--spacing-md); }
.ledger-row-claim { font-family: var(--font-editorial); font-size: 1.25rem; font-weight: 500; line-height: 1.4; color: var(--text-primary); margin-bottom: var(--spacing-sm); }
.ledger-row-reasoning { font-size: 0.95rem; color: var(--text-secondary); line-height: 1.6; }

.cta-footer-block { border-top: 1px solid var(--border-color); margin-top: var(--spacing-xl); padding-top: var(--spacing-xl); text-align: center; }
.cta-footer-text { font-size: 0.9rem; color: var(--text-secondary); margin-bottom: var(--spacing-sm); }
.cta-footer-link { color: var(--text-primary); font-weight: 500; border-bottom: 1px solid var(--text-secondary); padding-bottom: 2px; }
.cta-footer-link:hover { border-color: var(--text-primary); opacity: 1; }

@keyframes fadeIn { from { opacity: 0; transform: translateY(5px); } to { opacity: 1; transform: translateY(0); } }

/* Layout Footers & Mobile Adaptive Navigation */
.site-footer { text-align: center; padding: var(--spacing-xl) 0; color: var(--text-secondary); border-top: 1px solid var(--border-color); margin-top: var(--spacing-xl); }
.mobile-nav {
    display: none; position: fixed; bottom: 0; left: 0; right: 0;
    background: var(--surface-color); border-top: 1px solid var(--border-color);
    padding: env(safe-area-inset-bottom, 15px) 0; z-index: 100;
}
.mobile-nav a { flex: 1; text-align: center; font-size: 0.8rem; font-weight: 500; color: var(--text-secondary); }

@media (max-width: 768px) {
    .desktop-nav { display: none; }
    .mobile-nav { display: flex; justify-content: space-around; }
    body { padding-bottom: 80px; }
    h1 { font-size: 2rem; }

    /* --- MOBILE BRAND ACCENTS COMPRESSION --- */
    .brand-mark {
        display: none !important;
    }
    .brand-name {
        font-size: 0.95rem !important; 
        white-space: nowrap;        
    }
    .brand a {
        gap: 0 !important; 
    }
    .site-header nav {
        gap: 12px !important;
    }
    .site-header nav a {
        font-size: 0.85rem;
        margin-left: 0; /* Clean up desktop margin offsets */
    }
    
    /* Metrics panel mobile stack fallback */
    .metrics-display { flex-direction: column; align-items: flex-start; text-align: left; padding: var(--spacing-md); }
    .metrics-number-wrapper { text-align: left; margin-top: var(--spacing-sm); }
    .ledger-row-meta { flex-direction: column; gap: 4px; }
}

/* Structural Utilities */
.text-center { text-align: center; }
.mt-2 { margin-top: var(--spacing-md); }
.mb-2 { margin-bottom: var(--spacing-md); }
.mb-4 { margin-bottom: var(--spacing-xl); }
.flex-between { display: flex; justify-content: space-between; align-items: center; }