/* =========================================
   THEME VARIABLES (CSS Custom Properties)
   Maruti Makwana Training Portal
   Production-Ready Dual Theme System
   ========================================= */

/* --- PHASE 1: DEFAULT THEME - EXECUTIVE DARK --- */
:root {
    /* Core Backgrounds */
    --bg-body-main: #0f172a;
    --bg-surface-glass: rgba(30, 41, 59, 0.7);
    --bg-surface-solid: #1e293b;
    --bg-input: rgba(255, 255, 255, 0.05);
    --bg-hover: rgba(255, 255, 255, 0.1);

    /* Typography Colors */
    --text-primary: #ffffff;
    --text-body: #cbd5e1;
    --text-muted: #94a3b8;
    --text-inverse: #0f172a;

    /* Borders & Dividers */
    --border-subtle: rgba(255, 255, 255, 0.1);
    --border-strong: rgba(255, 255, 255, 0.2);

    /* Brand Accents */
    --accent-purple: #a78bfa;
    --accent-cyan: #22d3ee;

    /* Shadows & Effects */
    --shadow-elevation: 0 10px 30px -10px rgba(167, 139, 250, 0.3);
    --backdrop-blur: blur(12px);
    
    /* Extended Palette (PHASE 2 additions) */
    --bg-card: #1e293b;
    --bg-navbar: rgba(15, 23, 42, 0.95);
    --bg-footer: #0a0f1a;
    --bg-modal-overlay: rgba(0, 0, 0, 0.8);
    
    /* Status Colors */
    --status-success: #10b981;
    --status-warning: #f59e0b;
    --status-error: #ef4444;
    --status-info: #3b82f6;
    
    /* Interactive States */
    --state-focus-ring: rgba(167, 139, 250, 0.5);
    --state-active: rgba(167, 139, 250, 0.2);
    
    /* Spacing & Layout */
    --radius-sm: 0.375rem;
    --radius-md: 0.5rem;
    --radius-lg: 0.75rem;
    
    /* Transitions */
    --transition-base: 200ms cubic-bezier(0.4, 0, 0.2, 1);
    --transition-slow: 350ms cubic-bezier(0.4, 0, 0.2, 1);
}

/* --- PHASE 2: OVERRIDE THEME - EXECUTIVE LIGHT --- */
html.light-mode {
    --bg-body-main: #f8fafc;
    --bg-surface-glass: #ffffff;
    --bg-surface-solid: #ffffff;
    --bg-input: #f1f5f9;
    --bg-hover: #e2e8f0;

    --text-primary: #0f172a;
    --text-body: #475569;
    --text-muted: #64748b;
    --text-inverse: #ffffff;

    --border-subtle: #e2e8f0;
    --border-strong: #cbd5e1;

    --accent-purple: #7c3aed;
    --accent-cyan: #06b6d4;

    --shadow-elevation: 0 4px 6px -1px rgba(0, 0, 0, 0.1), 0 2px 4px -1px rgba(0, 0, 0, 0.06);
    --backdrop-blur: none;
    
    /* Extended Palette Overrides */
    --bg-card: #ffffff;
    --bg-navbar: rgba(255, 255, 255, 0.95);
    --bg-footer: #f1f5f9;
    --bg-modal-overlay: rgba(15, 23, 42, 0.7);
    
    /* Status Colors (slightly adjusted) */
    --status-success: #059669;
    --status-warning: #d97706;
    --status-error: #dc2626;
    --status-info: #2563eb;
    
    /* Interactive States */
    --state-focus-ring: rgba(124, 58, 237, 0.5);
    --state-active: rgba(124, 58, 237, 0.1);
}

/* =========================================
   PHASE 3: BASE ELEMENT STYLES
   ========================================= */

body {
    background-color: var(--bg-body-main);
    color: var(--text-body);
    transition: background-color var(--transition-base), color var(--transition-base);
}

/* =========================================
   COMPONENT EXAMPLES
   ========================================= */

/* --- Card Component --- */
.card,
.modern-card {
    background: var(--bg-surface-solid);
    border: 1px solid var(--border-subtle);
    border-radius: var(--radius-lg);
    box-shadow: var(--shadow-elevation);
    transition: transform var(--transition-base), box-shadow var(--transition-base);
}

.card:hover,
.modern-card:hover {
    transform: translateY(-2px);
    box-shadow: 0 20px 40px -15px rgba(167, 139, 250, 0.4);
}

html.light-mode .card:hover,
html.light-mode .modern-card:hover {
    box-shadow: 0 10px 20px -5px rgba(0, 0, 0, 0.15);
}

/* --- Glass Surface --- */
.surface-glass {
    background: var(--bg-surface-glass);
    backdrop-filter: var(--backdrop-blur);
    -webkit-backdrop-filter: var(--backdrop-blur);
    border: 1px solid var(--border-subtle);
}

/* --- Header/Navbar --- */
.site-header,
.navbar {
    background: var(--bg-navbar);
    border-bottom: 1px solid var(--border-subtle);
    backdrop-filter: blur(8px);
    -webkit-backdrop-filter: blur(8px);
}

/* --- Navigation Links --- */
.nav-link {
    color: var(--text-body);
    transition: color var(--transition-base), background-color var(--transition-base);
}

.nav-link:hover,
.nav-link.active {
    color: var(--text-primary);
    background-color: var(--bg-hover);
}

/* --- Buttons --- */
.btn-primary,
.modern-btn-primary {
    background: linear-gradient(135deg, var(--accent-purple), var(--accent-cyan));
    color: var(--text-inverse);
    border: none;
    border-radius: var(--radius-md);
    padding: 0.625rem 1.5rem;
    font-weight: 600;
    transition: transform var(--transition-base), box-shadow var(--transition-base);
}

.btn-primary:hover,
.modern-btn-primary:hover {
    transform: translateY(-1px);
    box-shadow: var(--shadow-elevation);
}

.btn-outline {
    background: transparent;
    color: var(--text-primary);
    border: 1px solid var(--border-strong);
    border-radius: var(--radius-md);
    padding: 0.625rem 1.5rem;
    font-weight: 600;
    transition: all var(--transition-base);
}

.btn-outline:hover {
    background: var(--bg-hover);
    border-color: var(--accent-purple);
    color: var(--accent-purple);
}

/* --- Icon Button (Theme Toggle) --- */
.btn-icon {
    display: flex;
    align-items: center;
    justify-content: center;
    width: 2.5rem;
    height: 2.5rem;
    background: var(--bg-input);
    border: 1px solid var(--border-subtle);
    border-radius: var(--radius-md);
    color: var(--text-body);
    cursor: pointer;
    transition: all var(--transition-base);
}

.btn-icon:hover {
    background: var(--bg-hover);
    border-color: var(--border-strong);
    color: var(--text-primary);
}

.btn-icon:focus-visible {
    outline: 2px solid var(--state-focus-ring);
    outline-offset: 2px;
}

/* --- Form Inputs --- */
.input,
.form-control,
input[type="text"],
input[type="email"],
input[type="password"],
textarea,
select {
    background-color: var(--bg-input);
    border: 1px solid var(--border-subtle);
    color: var(--text-primary);
    border-radius: var(--radius-md);
    padding: 0.625rem 1rem;
    transition: all var(--transition-base);
}

.input:focus,
.form-control:focus,
input:focus,
textarea:focus,
select:focus {
    outline: none;
    border-color: var(--accent-purple);
    box-shadow: 0 0 0 3px var(--state-focus-ring);
    background-color: var(--bg-surface-solid);
}

.input::placeholder,
.form-control::placeholder {
    color: var(--text-muted);
}

/* --- Skeleton Loader --- */
.skeleton {
    background: linear-gradient(
        90deg,
        var(--bg-surface-solid) 25%,
        var(--bg-hover) 50%,
        var(--bg-surface-solid) 75%
    );
    background-size: 200% 100%;
    animation: skeleton-loading 1.5s ease-in-out infinite;
    border-radius: var(--radius-md);
}

@keyframes skeleton-loading {
    0% { background-position: 200% 0; }
    100% { background-position: -200% 0; }
}

/* --- Status Badges --- */
.badge-success { background: var(--status-success); }
.badge-warning { background: var(--status-warning); }
.badge-error { background: var(--status-error); }
.badge-info { background: var(--status-info); }

/* =========================================
   ACCESSIBILITY
   ========================================= */

/* Reduced Motion Support */
@media (prefers-reduced-motion: reduce) {
    *,
    *::before,
    *::after {
        animation-duration: 0.01ms !important;
        animation-iteration-count: 1 !important;
        transition-duration: 0.01ms !important;
    }
    
    .skeleton {
        animation: none;
        background: var(--bg-surface-solid);
    }
}

/* Focus Visible (Keyboard Navigation) */
*:focus-visible {
    outline: 2px solid var(--state-focus-ring);
    outline-offset: 2px;
}

/* High Contrast Mode Detection */
@media (prefers-contrast: high) {
    :root {
        --border-subtle: rgba(255, 255, 255, 0.3);
        --border-strong: rgba(255, 255, 255, 0.5);
    }
    
    html.light-mode {
        --border-subtle: rgba(0, 0, 0, 0.3);
        --border-strong: rgba(0, 0, 0, 0.5);
    }
}

/* =========================================
   UTILITY CLASSES
   ========================================= */

.text-primary { color: var(--text-primary); }
.text-body { color: var(--text-body); }
.text-muted { color: var(--text-muted); }

.bg-surface { background: var(--bg-surface-solid); }
.bg-glass { background: var(--bg-surface-glass); }

.border-subtle { border-color: var(--border-subtle); }
.border-strong { border-color: var(--border-strong); }

/* Shadow Utilities */
.shadow-sm { box-shadow: 0 1px 2px 0 rgba(0, 0, 0, 0.05); }
.shadow-md { box-shadow: var(--shadow-elevation); }
.shadow-lg { box-shadow: 0 20px 40px -15px rgba(167, 139, 250, 0.4); }

html.light-mode .shadow-lg {
    box-shadow: 0 20px 40px -15px rgba(0, 0, 0, 0.15);
}