/* CSS Variables */
:root {
    /* Colors */
    --primary: #6366f1;
    --primary-dark: #4f46e5;
    --primary-light: #818cf8;
    --secondary: #8b5cf6;
    --secondary-dark: #7c3aed;
    --secondary-light: #a78bfa;
    --success: #10b981;
    --success-dark: #059669;
    --success-light: #34d399;
    --danger: #ef4444;
    --danger-dark: #dc2626;
    --danger-light: #f87171;
    --warning: #f59e0b;
    --warning-dark: #d97706;
    --warning-light: #fbbf24;
    --info: #3b82f6;
    --info-dark: #2563eb;
    --info-light: #60a5fa;
    
    /* Theme Colors - Light */
    --bg-main: #ffffff;
    --bg-secondary: #f8fafc;
    --bg-tertiary: #f1f5f9;
    --text-primary: #1e293b;
    --text-secondary: #64748b;
    --text-tertiary: #94a3b8;
    --border-color: #e2e8f0;
    
    /* Shadows */
    --shadow-sm: 0 1px 2px 0 rgb(0 0 0 / 0.05);
    --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);
    
    /* Border Radius */
    --radius-sm: 0.375rem;
    --radius-md: 0.5rem;
    --radius-lg: 0.75rem;
    --radius-xl: 1rem;
    --radius-2xl: 1.5rem;
    --radius-full: 9999px;
    
    /* Transitions */
    --transition-fast: 150ms ease;
    --transition-base: 300ms ease;
    --transition-slow: 500ms ease;
}

/* Dark Theme */
[data-theme="dark"] {
    --bg-main: #0f172a;
    --bg-secondary: #1e293b;
    --bg-tertiary: #334155;
    --text-primary: #f8fafc;
    --text-secondary: #cbd5e1;
    --text-tertiary: #94a3b8;
    --border-color: #334155;
}

/* Reset & Base */
* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}

html {
    scroll-behavior: smooth;
}

body {
    font-family: 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, 'Helvetica Neue', Arial, sans-serif;
    font-size: 16px;
    line-height: 1.6;
    color: var(--text-primary);
    background-color: var(--bg-main);
    transition: background-color var(--transition-base), color var(--transition-base);
    -webkit-font-smoothing: antialiased;
    -moz-osx-font-smoothing: grayscale;
}

/* Container */
.container {
    width: 100%;
    max-width: 1280px;
    margin: 0 auto;
    padding: 0 1rem;
}

@media (min-width: 640px) {
    .container { padding: 0 1.5rem; }
}

@media (min-width: 1024px) {
    .container { padding: 0 2rem; }
}

/* Main Content */
.main-content {
    margin-top: 64px;
    min-height: calc(100vh - 64px);
    transition: opacity var(--transition-base);
}

/* Typography */
h1, h2, h3, h4, h5, h6 {
    font-weight: 700;
    line-height: 1.2;
    color: var(--text-primary);
}

h1 { font-size: 2.5rem; }
h2 { font-size: 2rem; }
h3 { font-size: 1.5rem; }
h4 { font-size: 1.25rem; }
h5 { font-size: 1.125rem; }
h6 { font-size: 1rem; }

p {
    margin-bottom: 1rem;
}

a {
    color: var(--primary);
    text-decoration: none;
    transition: color var(--transition-fast);
}

a:hover {
    color: var(--primary-dark);
}

/* Buttons */
.btn {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    gap: 0.5rem;
    padding: 0.625rem 1.25rem;
    font-size: 0.875rem;
    font-weight: 600;
    line-height: 1;
    border-radius: var(--radius-md);
    border: 1px solid transparent;
    cursor: pointer;
    transition: all var(--transition-fast);
    text-decoration: none;
    outline: none;
    position: relative;
    overflow: hidden;
}

.btn:disabled {
    opacity: 0.5;
    cursor: not-allowed;
}

.btn-sm {
    padding: 0.5rem 1rem;
    font-size: 0.8125rem;
}

.btn-lg {
    padding: 0.875rem 1.75rem;
    font-size: 1rem;
}

/* Button Variants */
.btn-primary {
    background: var(--primary);
    color: white;
}

.btn-primary:hover {
    background: var(--primary-dark);
    transform: translateY(-1px);
    box-shadow: var(--shadow-md);
}

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

.btn-secondary:hover {
    background: var(--bg-tertiary);
    border-color: var(--primary);
}

.btn-success {
    background: var(--success);
    color: white;
}

.btn-success:hover {
    background: var(--success-dark);
}

.btn-danger {
    background: var(--danger);
    color: white;
}

.btn-danger:hover {
    background: var(--danger-dark);
}

.btn-white {
    background: white;
    color: var(--primary);
}

.btn-white:hover {
    background: #f8fafc;
}

/* Forms */
.form-group {
    margin-bottom: 1.5rem;
}

.form-label {
    display: block;
    margin-bottom: 0.5rem;
    font-weight: 500;
    font-size: 0.875rem;
    color: var(--text-primary);
}

.form-control {
    width: 100%;
    padding: 0.625rem 1rem;
    font-size: 1rem;
    line-height: 1.5;
    color: var(--text-primary);
    background-color: var(--bg-secondary);
    border: 1px solid var(--border-color);
    border-radius: var(--radius-md);
    transition: all var(--transition-fast);
}

.form-control:focus {
    outline: none;
    border-color: var(--primary);
    box-shadow: 0 0 0 3px rgba(99, 102, 241, 0.1);
}

.form-control::placeholder {
    color: var(--text-tertiary);
}

/* Alerts */
.alert {
    position: fixed;
    top: 80px;
    right: 1rem;
    max-width: 400px;
    padding: 1rem 1.5rem;
    background: var(--bg-main);
    border: 1px solid var(--border-color);
    border-radius: var(--radius-lg);
    box-shadow: var(--shadow-lg);
    display: flex;
    align-items: center;
    gap: 0.75rem;
    font-size: 0.875rem;
    z-index: 1001;
    transform: translateX(calc(100% + 2rem));
    transition: transform var(--transition-base);
}

.alert.show {
    transform: translateX(0);
}

.alert-success {
    border-color: var(--success);
    color: var(--success-dark);
}

.alert-success i {
    color: var(--success);
}

.alert-warning {
    border-color: var(--warning);
    color: var(--warning-dark);
}

.alert-warning i {
    color: var(--warning);
}

.alert-danger {
    border-color: var(--danger);
    color: var(--danger-dark);
}

.alert-danger i {
    color: var(--danger);
}

.alert-close {
    margin-left: auto;
    background: none;
    border: none;
    color: var(--text-tertiary);
    cursor: pointer;
    padding: 0;
    font-size: 1.25rem;
    line-height: 1;
}

/* Cards */
.card {
    background: var(--bg-main);
    border: 1px solid var(--border-color);
    border-radius: var(--radius-lg);
    padding: 1.5rem;
    transition: all var(--transition-base);
}

.card:hover {
    box-shadow: var(--shadow-md);
}

/* Footer */
.site-footer {
    background: var(--bg-secondary);
    border-top: 1px solid var(--border-color);
    padding: 3rem 0 1.5rem;
    margin-top: 4rem;
}

.footer-content {
    display: grid;
    grid-template-columns: 2fr 1fr 1fr 1fr;
    gap: 2rem;
    margin-bottom: 2rem;
}

.footer-title {
    display: flex;
    align-items: center;
    gap: 0.75rem;
    font-size: 1.25rem;
    font-weight: 700;
    margin-bottom: 1rem;
}

.footer-logo {
    width: 32px;
    height: 32px;
}

.footer-desc {
    color: var(--text-secondary);
    margin-bottom: 1.5rem;
}

.footer-heading {
    font-size: 0.875rem;
    font-weight: 600;
    text-transform: uppercase;
    letter-spacing: 0.05em;
    margin-bottom: 1rem;
}

.footer-links {
    list-style: none;
}

.footer-links li {
    margin-bottom: 0.5rem;
}

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

.footer-links a:hover {
    color: var(--primary);
}

.social-links {
    display: flex;
    gap: 0.75rem;
}

.social-links a {
    width: 36px;
    height: 36px;
    background: var(--bg-tertiary);
    border-radius: var(--radius-md);
    display: flex;
    align-items: center;
    justify-content: center;
    color: var(--text-secondary);
    transition: all var(--transition-fast);
}

.social-links a:hover {
    background: var(--primary);
    color: white;
}

.footer-bottom {
    padding-top: 1.5rem;
    border-top: 1px solid var(--border-color);
    display: flex;
    justify-content: space-between;
    align-items: center;
    font-size: 0.875rem;
    color: var(--text-secondary);
}

.footer-stats {
    display: flex;
    gap: 1.5rem;
}

.footer-stats span {
    display: flex;
    align-items: center;
    gap: 0.5rem;
}

/* Preloader */
.preloader {
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    background: var(--bg-main);
    display: flex;
    align-items: center;
    justify-content: center;
    z-index: 9999;
    transition: opacity 0.5s, visibility 0.5s;
}

.preloader.hidden {
    opacity: 0;
    visibility: hidden;
}

.preloader-content {
    text-align: center;
}

.preloader-logo {
    width: 64px;
    height: 64px;
    margin-bottom: 1.5rem;
    animation: pulse 2s infinite;
}

@keyframes pulse {
    0% { transform: scale(1); opacity: 1; }
    50% { transform: scale(1.05); opacity: 0.8; }
    100% { transform: scale(1); opacity: 1; }
}

.preloader-spinner {
    width: 40px;
    height: 40px;
    margin: 0 auto;
    border: 3px solid var(--border-color);
    border-top-color: var(--primary);
    border-radius: 50%;
    animation: spin 1s linear infinite;
}

@keyframes spin {
    from { transform: rotate(0deg); }
    to { transform: rotate(360deg); }
}

/* Empty State */
.empty-state {
    text-align: center;
    padding: 3rem;
    color: var(--text-secondary);
}

.empty-state i {
    font-size: 3rem;
    margin-bottom: 1rem;
    opacity: 0.5;
}

.empty-state p {
    margin-bottom: 1.5rem;
}

/* Utility Classes */
.text-center { text-align: center; }
.text-left { text-align: left; }
.text-right { text-align: right; }

.text-primary { color: var(--primary) !important; }
.text-secondary { color: var(--text-secondary) !important; }
.text-success { color: var(--success) !important; }
.text-danger { color: var(--danger) !important; }
.text-warning { color: var(--warning) !important; }
.text-info { color: var(--info) !important; }

.bg-primary { background-color: var(--primary) !important; }
.bg-secondary { background-color: var(--bg-secondary) !important; }
.bg-success { background-color: var(--success) !important; }
.bg-danger { background-color: var(--danger) !important; }
.bg-warning { background-color: var(--warning) !important; }

.font-bold { font-weight: 700; }
.font-semibold { font-weight: 600; }
.font-medium { font-weight: 500; }

/* Margins */
.m-0 { margin: 0; }
.m-1 { margin: 0.5rem; }
.m-2 { margin: 1rem; }
.m-3 { margin: 1.5rem; }
.m-4 { margin: 2rem; }

.mt-0 { margin-top: 0; }
.mt-1 { margin-top: 0.5rem; }
.mt-2 { margin-top: 1rem; }
.mt-3 { margin-top: 1.5rem; }
.mt-4 { margin-top: 2rem; }

.mb-0 { margin-bottom: 0; }
.mb-1 { margin-bottom: 0.5rem; }
.mb-2 { margin-bottom: 1rem; }
.mb-3 { margin-bottom: 1.5rem; }
.mb-4 { margin-bottom: 2rem; }

/* Padding */
.p-0 { padding: 0; }
.p-1 { padding: 0.5rem; }
.p-2 { padding: 1rem; }
.p-3 { padding: 1.5rem; }
.p-4 { padding: 2rem; }

.py-1 { padding-top: 0.5rem; padding-bottom: 0.5rem; }
.py-2 { padding-top: 1rem; padding-bottom: 1rem; }
.py-3 { padding-top: 1.5rem; padding-bottom: 1.5rem; }
.py-4 { padding-top: 2rem; padding-bottom: 2rem; }
.py-5 { padding-top: 3rem; padding-bottom: 3rem; }

/* Responsive */
@media (max-width: 768px) {
    h1 { font-size: 2rem; }
    h2 { font-size: 1.5rem; }
    h3 { font-size: 1.25rem; }
    
    .footer-content {
        grid-template-columns: 1fr;
        gap: 2rem;
    }
    
    .footer-bottom {
        flex-direction: column;
        gap: 1rem;
        text-align: center;
    }
    
    .footer-stats {
        flex-direction: column;
        gap: 0.5rem;
    }
}

/* Animations */
@keyframes fadeIn {
    from { opacity: 0; }
    to { opacity: 1; }
}

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

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

.animate-fadeIn {
    animation: fadeIn 0.5s ease-out;
}

.animate-slideInUp {
    animation: slideInUp 0.5s ease-out;
}

.animate-slideInDown {
    animation: slideInDown 0.5s ease-out;
}