:root {
    /* Senior UI Color Tokens - Light */
    --primary: #0F5FBD;
    --primary-dark: #0a4d9a;
    --primary-light: #e7f0f9;
    --primary-glow: rgba(15, 95, 189, 0.15);
    
    --secondary: #1e293b;
    --accent: #6366f1;
    
    --background: #f8fafc;
    --surface: #ffffff;
    --surface-hover: #f1f5f9;
    --border: #e2e8f0;
    --border-hover: #cbd5e1;
    
    --text-main: #1e293b;
    --text-muted: #64748b;
    --text-inverse: #ffffff;
    
    --success: #10b981;
    --error: #ef4444;
    --warning: #f59e0b;
    
    /* Elevation / Shadows */
    --shadow-xs: 0 1px 2px 0 rgb(0 0 0 / 0.05);
    --shadow-sm: 0 1px 3px 0 rgb(0 0 0 / 0.1), 0 1px 2px -1px rgb(0 0 0 / 0.1);
    --shadow-md: 0 4px 6px -1px rgb(0 0 0 / 0.1), 0 2px 4px -2px rgb(0 0 0 / 0.1);
    --shadow-lg: 0 10px 15px -3px rgb(0 0 0 / 0.1), 0 4px 6px -4px rgb(0 0 0 / 0.1);
    --shadow-xl: 0 20px 25px -5px rgb(0 0 0 / 0.1), 0 8px 10px -6px rgb(0 0 0 / 0.1);
    
    /* Radius & Spacing */
    --radius-sm: 0.375rem;
    --radius: 0.5rem;
    --radius-md: 0.75rem;
    --radius-lg: 1rem;
    --radius-xl: 1.5rem;
    --radius-full: 9999px;
    
    /* Animation Tokens */
    --transition-fast: all 0.15s cubic-bezier(0.4, 0, 0.2, 1);
    --transition: all 0.3s cubic-bezier(0.4, 0, 0.2, 1);
    --transition-slow: all 0.5s cubic-bezier(0.4, 0, 0.2, 1);
}

[data-theme="dark"] {
    --background: #0f172a;
    --surface: #1e293b;
    --surface-hover: #334155;
    --border: #334155;
    --border-hover: #475569;
    --text-main: #f8fafc;
    --text-muted: #94a3b8;
    --secondary: #f1f5f9;
    --primary-light: rgba(15, 95, 189, 0.2);
    --shadow-sm: 0 1px 3px 0 rgb(0 0 0 / 0.3);
    --shadow-md: 0 4px 6px -1px rgb(0 0 0 / 0.4);
    --shadow-lg: 0 10px 15px -3px rgb(0 0 0 / 0.5);
    --shadow-xl: 0 20px 25px -5px rgb(0 0 0 / 0.6);
}

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

body {
    font-family: 'Outfit', 'Inter', system-ui, -apple-system, sans-serif;
    background-color: var(--background);
    color: var(--text-main);
    line-height: 1.6;
    min-height: 100vh;
    display: flex;
    flex-direction: column;
    -webkit-font-smoothing: antialiased;
}

.app-container {
    max-width: 1280px;
    margin: 0 auto;
    width: 100%;
    padding: 0 1.5rem;
}

/* Header & Navigation */
.navbar {
    background: var(--surface);
    border-bottom: 1px solid var(--border);
    height: 70px;
    display: flex;
    align-items: center;
    position: sticky;
    top: 0;
    z-index: 100;
    box-shadow: var(--shadow-sm);
}

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

.brand {
    display: flex;
    align-items: center;
    gap: 0.75rem;
    text-decoration: none;
}

/* CRITICAL: Logo Constraint */
.nav-logo {
    height: 42px;
    width: auto;
    max-width: 150px;
    object-fit: contain;
    display: block;
}

.brand span {
    font-size: 1.25rem;
    font-weight: 700;
    color: var(--secondary);
    letter-spacing: -0.025em;
}

.nav-links {
    display: flex;
    gap: 2rem;
}

.nav-link {
    text-decoration: none;
    color: var(--text-muted);
    font-weight: 500;
    transition: all 0.2s;
    font-size: 0.9375rem;
    position: relative;
    padding: 0.5rem 0;
}

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

.nav-link.active {
    color: var(--primary);
    font-weight: 600;
}

.nav-link.active::after {
    content: '';
    position: absolute;
    bottom: -1px;
    left: 0;
    width: 100%;
    height: 2px;
    background: var(--primary);
    box-shadow: 0 0 8px var(--primary-glow);
}

.theme-toggle {
    background: var(--surface-hover);
    border: 1px solid var(--border);
    color: var(--text-main);
    width: 40px;
    height: 40px;
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    cursor: pointer;
    transition: var(--transition);
    margin-left: 1rem;
}

.theme-toggle:hover {
    background: var(--primary-light);
    color: var(--primary);
    border-color: var(--primary);
}

.theme-toggle svg {
    width: 20px;
    height: 20px;
}

/* Content Area */
main {
    flex: 1;
    padding: 3rem 0;
}

/* Typography & Header Branding */
.page-header {
    text-align: center;
    margin-bottom: 4rem;
    display: flex;
    flex-direction: column;
    align-items: center;
    gap: 0.5rem;
    animation: fadeInDown 0.8s ease-out;
}

.page-header h1 {
    font-size: 3rem;
    font-weight: 800;
    letter-spacing: -0.05em;
    background: linear-gradient(135deg, var(--primary) 0%, var(--accent) 100%);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    margin-bottom: 0.25rem;
}

.page-header p {
    color: var(--text-muted);
    font-size: 1.125rem;
    max-width: 600px;
    margin: 0 auto;
}

@keyframes fadeInDown {
    from { opacity: 0; transform: translateY(-20px); }
    to { opacity: 1; transform: translateY(0); }
}

h1, h2, h3 { 
    text-align: center; 
    width: 100%;
}

h1 { font-size: 2.25rem; font-weight: 800; color: var(--secondary); margin-bottom: 0.5rem; letter-spacing: -0.025em; }
h2 { font-size: 1.5rem; font-weight: 700; color: var(--secondary); margin-bottom: 1.5rem; letter-spacing: -0.015em; }
h3 { font-size: 1.25rem; font-weight: 600; color: var(--secondary); margin-bottom: 1rem; }
p { color: var(--text-muted); }

/* Common Components */
.card {
    background: var(--surface);
    border-radius: var(--radius-lg);
    border: 1px solid var(--border);
    box-shadow: var(--shadow);
    padding: 1.5rem;
    transition: transform 0.3s, box-shadow 0.3s;
}

.btn {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    padding: 0.75rem 1.5rem;
    border-radius: var(--radius-md);
    font-weight: 600;
    font-size: 0.9375rem;
    cursor: pointer;
    transition: all 0.2s;
    border: none;
    gap: 0.5rem;
    text-decoration: none;
}

.btn-primary {
    background-color: var(--primary);
    color: white;
    box-shadow: 0 4px 12px var(--primary-glow);
}

.btn-primary:hover {
    background-color: var(--primary-dark);
    transform: translateY(-1px);
    box-shadow: 0 6px 16px var(--primary-glow);
}

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

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

/* Footer */
footer {
    background: var(--surface);
    border-top: 1px solid var(--border);
    padding: 2.5rem 0;
    margin-top: auto;
    text-align: center;
}

.footer-text {
    font-size: 0.875rem;
    color: var(--text-muted);
}

/* Alerts/Messages */
.alert {
    padding: 1.25rem 1.5rem;
    border-radius: var(--radius-md);
    margin-bottom: 2rem;
    border-left: 5px solid transparent;
    display: flex;
    align-items: center;
    gap: 0.75rem;
    box-shadow: var(--shadow-sm);
}

.alert-error, .alert-danger { 
    background-color: #fff1f2; 
    color: #e11d48; 
    border-left-color: #e11d48; 
}
.alert-success { 
    background-color: #f0fdf4; 
    color: #16a34a; 
    border-left-color: #16a34a; 
}
.alert-info { 
    background-color: #f0f9ff; 
    color: #0284c7; 
    border-left-color: #0284c7; 
}

/* Utility */
.mt-4 { margin-top: 1rem; }
.mb-4 { margin-bottom: 1rem; }
.mt-8 { margin-top: 2rem; }
.mb-8 { margin-bottom: 2rem; }
.text-center { text-align: center; }
.hidden { display: none; }

@media(max-width: 1000px) {
        .nav-links {
            display: none;
        }}