/* CSS Variables - Theme Colors */
:root {
    --primary: #1e3a8a;
    --primary-hover: #1e40af;
    --secondary: #10b981;
    --secondary-hover: #059669;
    --accent: #fbbf24;
    --accent-hover: #f59e0b;
    --background: #ffffff;
    --foreground: #0f172a;
    --muted: #f1f5f9;
    --muted-foreground: #64748b;
    --border: #e2e8f0;
    --card: #ffffff;
    --destructive: #ef4444;
    
    --font-sans: -apple-system, BlinkMacSystemFont, 'Segoe UI', 'Roboto', 'Oxygen', 'Ubuntu', 'Cantarell', sans-serif;
}

/* Dark Mode */
.dark-mode {
    --background: #0f172a;
    --foreground: #f8fafc;
    --muted: #1e293b;
    --muted-foreground: #94a3b8;
    --border: #334155;
    --card: #1e293b;
}

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

body {
    font-family: var(--font-sans);
    background-color: var(--background);
    color: var(--foreground);
    line-height: 1.6;
    overflow-x: hidden;
}

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

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

/* Navbar */
.navbar {
    position: fixed;
    top: 0;
    left: 0;
    right: 0;
    background: rgba(255, 255, 255, 0.95);
    backdrop-filter: blur(10px);
    border-bottom: 1px solid var(--border);
    z-index: 1000;
    padding: 1rem 0;
}

.dark-mode .navbar {
    background: rgba(15, 23, 42, 0.95);
}

.nav-content {
    display: flex;
    align-items: center;
    justify-content: space-between;
}

.logo {
    display: flex;
    align-items: center;
    gap: 0.5rem;
    text-decoration: none;
    color: var(--foreground);
    font-weight: 700;
    font-size: 1.25rem;
}

.logo-icon {
    font-size: 1.5rem;
}

.nav-links {
    display: none;
    align-items: center;
    gap: 2rem;
}

@media (min-width: 768px) {
    .nav-links {
        display: flex;
    }
}

.nav-links a {
    text-decoration: none;
    color: var(--foreground);
    font-weight: 500;
    transition: color 0.3s;
}

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

.mobile-menu-btn {
    display: flex;
    flex-direction: column;
    gap: 4px;
    background: none;
    border: none;
    cursor: pointer;
    padding: 0.5rem;
}

@media (min-width: 768px) {
    .mobile-menu-btn {
        display: none;
    }
}

.mobile-menu-btn span {
    width: 24px;
    height: 2px;
    background: var(--foreground);
    transition: all 0.3s;
}

/* Buttons */
.btn-primary, .btn-secondary {
    padding: 0.75rem 1.5rem;
    border-radius: 0.5rem;
    font-weight: 600;
    text-decoration: none;
    display: inline-block;
    transition: all 0.3s;
    border: none;
    cursor: pointer;
    font-size: 0.875rem;
}

.btn-primary {
    background: linear-gradient(135deg, var(--primary), var(--secondary));
    color: white;
}

.btn-primary:hover {
    transform: translateY(-2px);
    box-shadow: 0 10px 25px rgba(30, 58, 138, 0.3);
}

.btn-secondary {
    background: var(--muted);
    color: var(--foreground);
}

.btn-secondary:hover {
    background: var(--border);
}

.btn-lg {
    padding: 1rem 2rem;
    font-size: 1rem;
}

.btn-block {
    width: 100%;
    text-align: center;
}

/* Cards */
.card {
    background: var(--card);
    border: 1px solid var(--border);
    border-radius: 0.75rem;
    padding: 1.5rem;
    transition: all 0.3s;
}

.card:hover {
    box-shadow: 0 10px 30px rgba(0, 0, 0, 0.1);
}

/* Badge */
.badge {
    display: inline-block;
    padding: 0.5rem 1rem;
    background: linear-gradient(135deg, var(--accent), #fcd34d);
    color: var(--primary);
    border-radius: 9999px;
    font-size: 0.875rem;
    font-weight: 600;
    margin-bottom: 1.5rem;
}

/* Progress Bar */
.progress {
    width: 100%;
    height: 0.5rem;
    background: var(--muted);
    border-radius: 9999px;
    overflow: hidden;
}

.progress-bar {
    height: 100%;
    background: linear-gradient(90deg, var(--primary), var(--secondary));
    transition: width 0.3s;
}

/* Input */
input, select, textarea {
    width: 100%;
    padding: 0.75rem 1rem;
    border: 1px solid var(--border);
    border-radius: 0.5rem;
    background: var(--background);
    color: var(--foreground);
    font-family: var(--font-sans);
    font-size: 0.875rem;
    transition: all 0.3s;
}

input:focus, select:focus, textarea:focus {
    outline: none;
    border-color: var(--primary);
    box-shadow: 0 0 0 3px rgba(30, 58, 138, 0.1);
}

label {
    display: block;
    margin-bottom: 0.5rem;
    font-weight: 600;
    font-size: 0.875rem;
}

/* Utilities */
.text-center {
    text-align: center;
}

.mt-4 {
    margin-top: 1rem;
}

.mb-4 {
    margin-bottom: 1rem;
}

.hidden {
    display: none;
}

/* Grid */
.grid {
    display: grid;
    gap: 1.5rem;
}

.grid-2 {
    grid-template-columns: repeat(1, 1fr);
}

@media (min-width: 768px) {
    .grid-2 {
        grid-template-columns: repeat(2, 1fr);
    }
}

.grid-3 {
    grid-template-columns: repeat(1, 1fr);
}

@media (min-width: 768px) {
    .grid-3 {
        grid-template-columns: repeat(2, 1fr);
    }
}

@media (min-width: 1024px) {
    .grid-3 {
        grid-template-columns: repeat(3, 1fr);
    }
}

.grid-4 {
    grid-template-columns: repeat(1, 1fr);
}

@media (min-width: 768px) {
    .grid-4 {
        grid-template-columns: repeat(2, 1fr);
    }
}

@media (min-width: 1024px) {
    .grid-4 {
        grid-template-columns: repeat(4, 1fr);
    }
}

/* Back Button */
.back-btn {
    display: inline-flex;
    align-items: center;
    gap: 0.5rem;
    color: var(--muted-foreground);
    text-decoration: none;
    font-weight: 500;
    margin-bottom: 1.5rem;
    transition: color 0.3s;
}

.back-btn:hover {
    color: var(--foreground);
}

/* Toast Notification */
.toast {
    position: fixed;
    bottom: 2rem;
    right: 2rem;
    background: var(--card);
    border: 1px solid var(--border);
    border-radius: 0.5rem;
    padding: 1rem 1.5rem;
    box-shadow: 0 10px 40px rgba(0, 0, 0, 0.2);
    z-index: 9999;
    animation: slideIn 0.3s ease-out;
}

@keyframes slideIn {
    from {
        transform: translateX(400px);
        opacity: 0;
    }
    to {
        transform: translateX(0);
        opacity: 1;
    }
}

.toast-success {
    border-left: 4px solid var(--secondary);
}

.toast-error {
    border-left: 4px solid var(--destructive);
}

/* Loading Spinner */
.spinner {
    border: 3px solid var(--muted);
    border-top: 3px solid var(--primary);
    border-radius: 50%;
    width: 40px;
    height: 40px;
    animation: spin 1s linear infinite;
    margin: 2rem auto;
}

@keyframes spin {
    0% { transform: rotate(0deg); }
    100% { transform: rotate(360deg); }
}