/* ============================================
   Professional Volunteer Sign-Up System Styles
   ============================================ */

:root {
    --primary-color: #2563eb;
    --primary-dark: #1e40af;
    --primary-light: #3b82f6;
    --secondary-color: #64748b;
    --success-color: #10b981;
    --danger-color: #ef4444;
    --warning-color: #f59e0b;
    --info-color: #06b6d4;
    --light-bg: #f8fafc;
    --dark-text: #1e293b;
    --border-color: #e2e8f0;
    --shadow-sm: 0 1px 2px 0 rgba(0, 0, 0, 0.05);
    --shadow-md: 0 4px 6px -1px rgba(0, 0, 0, 0.1), 0 2px 4px -1px rgba(0, 0, 0, 0.06);
    --shadow-lg: 0 10px 15px -3px rgba(0, 0, 0, 0.1), 0 4px 6px -2px rgba(0, 0, 0, 0.05);
    --shadow-xl: 0 20px 25px -5px rgba(0, 0, 0, 0.1), 0 10px 10px -5px rgba(0, 0, 0, 0.04);
}

/* ============================================
   Base Styles
   ============================================ */

html {
    font-size: 14px;
    position: relative;
    min-height: 100%;
    scroll-behavior: smooth;
}

@media (min-width: 768px) {
    html {
        font-size: 16px;
    }
}

body {
    margin-bottom: 60px;
    font-family: 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, 'Helvetica Neue', Arial, sans-serif;
    color: var(--dark-text);
    background-color: var(--light-bg);
    line-height: 1.6;
}

/* ============================================
   Navigation
   ============================================ */

.navbar {
    background: linear-gradient(135deg, #667eea 0%, #764ba2 100%) !important;
    box-shadow: var(--shadow-md);
    padding: 1rem 0;
    border-bottom: none !important;
}

.navbar-brand {
    font-weight: 700;
    font-size: 1.5rem;
    color: white !important;
    text-shadow: 0 2px 4px rgba(0, 0, 0, 0.1);
    transition: transform 0.2s ease;
}

.navbar-brand:hover {
    transform: translateY(-2px);
    color: white !important;
}

.navbar-nav .nav-link {
    color: rgba(255, 255, 255, 0.9) !important;
    font-weight: 500;
    padding: 0.5rem 1rem !important;
    margin: 0 0.25rem;
    border-radius: 6px;
    transition: all 0.3s ease;
}

.navbar-nav .nav-link:hover {
    color: white !important;
    background-color: rgba(255, 255, 255, 0.15);
    transform: translateY(-1px);
}

.navbar-toggler {
    border-color: rgba(255, 255, 255, 0.3);
}

.navbar-toggler-icon {
    background-image: url("data:image/svg+xml,%3csvg xmlns='http://www.w3.org/2000/svg' viewBox='0 0 30 30'%3e%3cpath stroke='rgba%28255, 255, 255, 0.85%29' stroke-linecap='round' stroke-miterlimit='10' stroke-width='2' d='M4 7h22M4 15h22M4 23h22'/%3e%3c/svg%3e");
}

/* ============================================
   Buttons
   ============================================ */

.btn {
    border-radius: 8px;
    font-weight: 500;
    padding: 0.625rem 1.5rem;
    transition: all 0.3s ease;
    border: none;
    box-shadow: var(--shadow-sm);
}

.btn:hover {
    transform: translateY(-2px);
    box-shadow: var(--shadow-md);
}

.btn:active {
    transform: translateY(0);
}

.btn-primary {
    background: linear-gradient(135deg, var(--primary-color) 0%, var(--primary-dark) 100%);
    color: white;
}

.btn-primary:hover {
    background: linear-gradient(135deg, var(--primary-light) 0%, var(--primary-color) 100%);
    color: white;
}

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

.btn-secondary:hover {
    background-color: #475569;
    color: white;
}

.btn-outline-secondary {
    border: 2px solid var(--secondary-color);
    color: var(--secondary-color);
    background: transparent;
}

.btn-outline-secondary:hover {
    background-color: var(--secondary-color);
    color: white;
}

.btn-lg {
    padding: 0.875rem 2rem;
    font-size: 1.1rem;
}

/* ============================================
   Forms
   ============================================ */

.form-control {
    border-radius: 8px;
    border: 2px solid var(--border-color);
    padding: 0.75rem 1rem;
    transition: all 0.3s ease;
    background-color: white;
}

.form-control:focus {
    border-color: var(--primary-color);
    box-shadow: 0 0 0 3px rgba(37, 99, 235, 0.1);
    outline: none;
}

.form-label {
    font-weight: 600;
    color: var(--dark-text);
    margin-bottom: 0.5rem;
}

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

/* ============================================
   Cards
   ============================================ */

.card {
    border: none;
    border-radius: 12px;
    box-shadow: var(--shadow-md);
    overflow: hidden;
    transition: all 0.3s ease;
}

.card:hover {
    box-shadow: var(--shadow-lg);
    transform: translateY(-2px);
}

.card-body {
    padding: 1.5rem;
}

/* ============================================
   Tables
   ============================================ */

.table {
    border-collapse: separate;
    border-spacing: 0;
}

.table thead th {
    background: linear-gradient(135deg, #f1f5f9 0%, #e2e8f0 100%);
    color: var(--dark-text);
    font-weight: 600;
    text-transform: uppercase;
    font-size: 0.75rem;
    letter-spacing: 0.5px;
    padding: 1rem;
    border: none;
}

.table tbody tr {
    transition: all 0.2s ease;
    border-bottom: 1px solid var(--border-color);
}

.table tbody tr:hover {
    background-color: #f8fafc;
    transform: scale(1.01);
    box-shadow: var(--shadow-sm);
}

.table tbody td {
    padding: 1rem;
    vertical-align: middle;
}

.table-responsive {
    border-radius: 12px;
    overflow: hidden;
}

/* ============================================
   Alerts
   ============================================ */

.alert {
    border-radius: 10px;
    border: none;
    box-shadow: var(--shadow-sm);
    padding: 1rem 1.5rem;
    margin-bottom: 1.5rem;
}

.alert-success {
    background: linear-gradient(135deg, #d1fae5 0%, #a7f3d0 100%);
    color: #065f46;
    border-left: 4px solid var(--success-color);
}

.alert-info {
    background: linear-gradient(135deg, #cffafe 0%, #a5f3fc 100%);
    color: #164e63;
    border-left: 4px solid var(--info-color);
}

.alert-warning {
    background: linear-gradient(135deg, #fef3c7 0%, #fde68a 100%);
    color: #92400e;
    border-left: 4px solid var(--warning-color);
}

.alert-danger {
    background: linear-gradient(135deg, #fee2e2 0%, #fecaca 100%);
    color: #991b1b;
    border-left: 4px solid var(--danger-color);
}

/* ============================================
   Home Page
   ============================================ */

.text-center {
    padding: 3rem 0;
}

.display-4 {
    font-weight: 700;
    color: var(--dark-text);
    margin-bottom: 1.5rem;
    background: linear-gradient(135deg, var(--primary-color) 0%, #764ba2 100%);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
}

.lead {
    font-size: 1.25rem;
    color: var(--secondary-color);
    margin-bottom: 2rem;
}

/* ============================================
   Form Page
   ============================================ */

.row.justify-content-center {
    padding: 2rem 0;
}

h2 {
    color: var(--dark-text);
    font-weight: 700;
    margin-bottom: 2rem;
    padding-bottom: 1rem;
    border-bottom: 3px solid var(--primary-color);
    display: inline-block;
}

/* ============================================
   Validation
   ============================================ */

.text-danger {
    color: var(--danger-color) !important;
    font-size: 0.875rem;
    margin-top: 0.25rem;
    display: block;
}

.field-validation-error {
    color: var(--danger-color);
    font-size: 0.875rem;
}

.input-validation-error {
    border-color: var(--danger-color) !important;
}

/* ============================================
   Footer
   ============================================ */

.footer {
    position: absolute;
    bottom: 0;
    width: 100%;
    white-space: nowrap;
    line-height: 60px;
    background: linear-gradient(135deg, #1e293b 0%, #334155 100%);
    color: rgba(255, 255, 255, 0.8);
    box-shadow: 0 -2px 10px rgba(0, 0, 0, 0.1);
}

.footer .container {
    text-align: center;
}

/* ============================================
   Container & Spacing
   ============================================ */

.container {
    max-width: 1200px;
}

main {
    min-height: calc(100vh - 200px);
    padding: 2rem 0;
}

/* ============================================
   Links
   ============================================ */

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

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

.alert-link {
    font-weight: 600;
}

/* ============================================
   Utilities
   ============================================ */

.shadow-sm {
    box-shadow: var(--shadow-sm) !important;
}

.shadow-md {
    box-shadow: var(--shadow-md) !important;
}

.shadow-lg {
    box-shadow: var(--shadow-lg) !important;
}

/* ============================================
   Responsive Design
   ============================================ */

@media (max-width: 768px) {
    .display-4 {
        font-size: 2rem;
    }
    
    .btn-lg {
        padding: 0.75rem 1.5rem;
        font-size: 1rem;
    }
    
    .table-responsive {
        font-size: 0.875rem;
    }
    
    .navbar-brand {
        font-size: 1.25rem;
    }
}

/* ============================================
   Focus States (Accessibility)
   ============================================ */

.btn:focus,
.btn:active:focus,
.btn-link.nav-link:focus,
.form-control:focus,
.form-check-input:focus {
    box-shadow: 0 0 0 3px rgba(37, 99, 235, 0.25);
    outline: none;
}

/* ============================================
   Animations
   ============================================ */

@keyframes fadeIn {
    from {
        opacity: 0;
        transform: translateY(10px);
    }
    to {
        opacity: 1;
        transform: translateY(0);
    }
}

.card,
.alert {
    animation: fadeIn 0.5s ease-out;
}

/* ============================================
   Print Styles
   ============================================ */

@media print {
    .navbar,
    .footer,
    .btn {
        display: none;
    }
    
    body {
        background: white;
    }
}