/* Global Design System */
:root {
    /* Colors */
    --primary-color: #667eea;
    --primary-gradient: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    --secondary-color: #764ba2;
    --accent-color: #00d2ff;

    --bg-color: #f4f7f6;
    --surface-color: #ffffff;
    --text-primary: #2c3e50;
    --text-secondary: #6c757d;
    --border-color: #e1e5e9;

    --success-color: #28a745;
    --warning-color: #ffc107;
    --danger-color: #dc3545;

    /* Typography */
    --font-family: 'Inter', 'Segoe UI', Roboto, Helvetica, Arial, sans-serif;
    --font-size-base: 16px;
    --font-size-sm: 14px;
    --font-size-lg: 18px;
    --font-size-xl: 24px;
    --font-size-xxl: 32px;

    /* Spacing */
    --spacing-xs: 4px;
    --spacing-sm: 8px;
    --spacing-md: 16px;
    --spacing-lg: 24px;
    --spacing-xl: 32px;
    --spacing-xxl: 48px;

    /* Border Radius */
    --radius-sm: 4px;
    --radius-md: 8px;
    --radius-lg: 12px;
    --radius-xl: 18px;
    --radius-full: 50%;

    /* Shadows */
    --shadow-sm: 0 2px 4px rgba(0, 0, 0, 0.05);
    --shadow-md: 0 4px 6px rgba(0, 0, 0, 0.07);
    --shadow-lg: 0 10px 15px rgba(0, 0, 0, 0.1);
    --shadow-hover: 0 15px 30px rgba(0, 0, 0, 0.15);
}

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

body {
    font-family: var(--font-family);
    background-color: var(--bg-color);
    color: var(--text-primary);
    line-height: 1.6;
    font-size: var(--font-size-base);
    min-height: 100vh;
    display: flex;
    flex-direction: column;
}

a {
    color: var(--primary-color);
    text-decoration: none;
    transition: color 0.2s ease;
}

a:hover {
    color: var(--secondary-color);
}

/* Layout Utilities */
.container {
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 var(--spacing-md);
    width: 100%;
}

.container-narrow {
    max-width: 700px;
    margin: 0 auto;
    padding: 0 var(--spacing-md);
    width: 100%;
}

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

/* Card Component */
.card {
    background: var(--surface-color);
    border-radius: var(--radius-lg);
    box-shadow: var(--shadow-md);
    padding: var(--spacing-lg);
    transition: box-shadow 0.3s ease, transform 0.3s ease;
    border: 1px solid rgba(0, 0, 0, 0.03);
}

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

/* Button Component */
.btn {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    padding: 10px 20px;
    border-radius: var(--radius-md);
    font-weight: 600;
    cursor: pointer;
    transition: all 0.2s ease;
    border: none;
    font-size: var(--font-size-base);
    text-align: center;
    text-decoration: none;
}

.btn-primary {
    background: var(--primary-gradient);
    color: white;
    box-shadow: 0 4px 15px rgba(102, 126, 234, 0.3);
}

.btn-primary:hover {
    transform: translateY(-2px);
    box-shadow: 0 8px 25px rgba(102, 126, 234, 0.5);
    color: white;
}

.btn-secondary {
    background: white;
    color: var(--text-primary);
    border: 1px solid var(--border-color);
}

.btn-secondary:hover {
    background: #f8f9fa;
    border-color: var(--primary-color);
    color: var(--primary-color);
}

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

.btn-danger:hover {
    background: #c82333;
    color: white;
}

.btn-sm {
    padding: 6px 12px;
    font-size: var(--font-size-sm);
}

.btn-block {
    display: flex;
    width: 100%;
}

/* Input Styles */
input[type="text"],
input[type="email"],
input[type="password"],
input[type="number"],
input[type="date"],
select,
textarea {
    width: 100%;
    padding: 12px 16px;
    border: 1px solid var(--border-color);
    border-radius: var(--radius-md);
    font-size: var(--font-size-base);
    transition: border-color 0.2s ease, box-shadow 0.2s ease;
    font-family: inherit;
    background: var(--surface-color);
}

input:focus,
select:focus,
textarea:focus {
    outline: none;
    border-color: var(--primary-color);
    box-shadow: 0 0 0 3px rgba(102, 126, 234, 0.1);
}

label {
    display: block;
    margin-bottom: var(--spacing-xs);
    font-weight: 500;
    color: var(--text-primary);
    font-size: var(--font-size-sm);
}

/* Header & Footer */
.main-header {
    background: var(--surface-color);
    box-shadow: var(--shadow-sm);
    padding: var(--spacing-md) 0;
    position: sticky;
    top: 0;
    z-index: 1000;
}

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

.logo {
    font-weight: 700;
    font-size: var(--font-size-lg);
    background: var(--primary-gradient);
    -webkit-background-clip: text;
    background-clip: text;
    -webkit-text-fill-color: transparent;
    text-decoration: none;
}

.main-footer {
    margin-top: auto;
    padding: var(--spacing-lg) 0;
    text-align: center;
    color: var(--text-secondary);
    font-size: var(--font-size-sm);
}

/* Utility Animations */
@keyframes fadeIn {
    from {
        opacity: 0;
        transform: translateY(10px);
    }

    to {
        opacity: 1;
        transform: translateY(0);
    }
}

.fade-in {
    animation: fadeIn 0.4s ease-out forwards;
}

/* Flash Messages */
.flash-messages {
    position: fixed;
    top: 20px;
    right: 20px;
    z-index: 9999;
}

.flash-message {
    background: var(--surface-color);
    border-left: 4px solid var(--primary-color);
    padding: 15px 20px;
    border-radius: var(--radius-sm);
    box-shadow: var(--shadow-lg);
    margin-bottom: 10px;
    min-width: 300px;
    display: flex;
    justify-content: space-between;
    align-items: center;
    animation: slideInRight 0.3s ease-out;
}

.flash-message.success {
    border-left-color: var(--success-color);
}

.flash-message.error {
    border-left-color: var(--danger-color);
}

.flash-message.warning {
    border-left-color: var(--warning-color);
}

@keyframes slideInRight {
    from {
        transform: translateX(100%);
        opacity: 0;
    }

    to {
        transform: translateX(0);
        opacity: 1;
    }
}

/* Responsive */
@media (max-width: 768px) {
    .container {
        padding: 0 var(--spacing-md);
    }

    .dashboard-grid {
        grid-template-columns: 1fr;
    }
}