/* Custom CSS Variables using HSL format */
:root {
    --primary: 210 40% 28%; /* #2D3748 */
    --secondary: 207 73% 57%; /* #4299E1 */
    --background: 210 11% 98%; /* #F7FAFC */
    --text: 220 26% 14%; /* #1A202C */
    --accent: 143 55% 63%; /* #48BB78 */
    --white: 0 0% 100%; /* #FFFFFF */
    --muted: 220 14% 46%; /* #718096 */
    --border: 210 14% 89%; /* #E2E8F0 */
    --shadow: 0 0% 0%; /* #000000 */
}

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

body {
    font-family: 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, 'Helvetica Neue', Arial, sans-serif;
    background-color: hsl(var(--background));
    color: hsl(var(--text));
    line-height: 1.6;
}

/* Header Styles */
.header {
    background-color: hsl(var(--primary));
    color: hsl(var(--white));
    padding: 2rem 0;
    margin-bottom: 2rem;
}

.header-title {
    font-size: 2rem;
    font-weight: 700;
    margin-bottom: 0.5rem;
    display: flex;
    align-items: center;
    gap: 0.75rem;
}

.header-subtitle {
    font-size: 1.1rem;
    opacity: 0.9;
    margin-bottom: 0;
}

/* Form Card Styles */
.form-card {
    background-color: hsl(var(--white));
    border: 1px solid hsl(var(--border));
    border-radius: 12px;
    box-shadow: 0 4px 6px -1px hsla(var(--shadow), 0.1), 0 2px 4px -1px hsla(var(--shadow), 0.06);
    transition: transform 0.2s ease, box-shadow 0.2s ease;
}

.form-card:hover {
    transform: translateY(-2px);
    box-shadow: 0 10px 15px -3px hsla(var(--shadow), 0.1), 0 4px 6px -2px hsla(var(--shadow), 0.05);
}

.card-header {
    background-color: hsl(var(--white));
    border-bottom: 1px solid hsl(var(--border));
    padding: 1.5rem;
    border-radius: 12px 12px 0 0;
}

.card-title {
    font-size: 1.5rem;
    font-weight: 600;
    color: hsl(var(--primary));
    margin-bottom: 0;
    display: flex;
    align-items: center;
    gap: 0.75rem;
}

.card-body {
    padding: 1.5rem;
}

/* Form Styles */
.form-label {
    font-weight: 500;
    color: hsl(var(--text));
    margin-bottom: 0.5rem;
}

.form-control, .form-select {
    border: 2px solid hsl(var(--border));
    border-radius: 8px;
    padding: 0.75rem 1rem;
    font-size: 1rem;
    transition: border-color 0.2s ease, box-shadow 0.2s ease;
}

.form-control:focus, .form-select:focus {
    border-color: hsl(var(--secondary));
    box-shadow: 0 0 0 3px hsla(var(--secondary), 0.1);
    outline: none;
}

.input-group-text {
    background-color: hsl(var(--background));
    border: 2px solid hsl(var(--border));
    border-right: none;
    color: hsl(var(--muted));
    font-weight: 500;
}

/* Button Styles */
.btn-primary {
    background-color: hsl(var(--secondary));
    border-color: hsl(var(--secondary));
    padding: 0.75rem 1.5rem;
    font-weight: 600;
    border-radius: 8px;
    transition: all 0.2s ease;
    display: flex;
    align-items: center;
    justify-content: center;
    gap: 0.5rem;
}

.btn-primary:hover {
    background-color: hsl(207 73% 47%);
    border-color: hsl(207 73% 47%);
    transform: translateY(-1px);
}

.btn-primary:focus {
    box-shadow: 0 0 0 3px hsla(var(--secondary), 0.25);
}

/* Checkbox Styles */
.project-checkboxes {
    display: flex;
    flex-direction: column;
    gap: 0.75rem;
    padding: 1rem;
    background-color: hsl(var(--background));
    border-radius: 8px;
    border: 1px solid hsl(var(--border));
}

.form-check {
    margin-bottom: 0;
}

.form-check-input {
    border: 2px solid hsl(var(--border));
    margin-top: 0.125rem;
}

.form-check-input:checked {
    background-color: hsl(var(--accent));
    border-color: hsl(var(--accent));
}

.form-check-input:focus {
    box-shadow: 0 0 0 2px hsla(var(--accent), 0.25);
}

.form-check-label {
    font-weight: 500;
    color: hsl(var(--text));
}

/* Alert Styles */
.alert {
    border-radius: 8px;
    padding: 1rem 1.25rem;
    border: none;
    display: flex;
    align-items: center;
    gap: 0.75rem;
}

.alert-success {
    background-color: hsla(var(--accent), 0.1);
    color: hsl(143 55% 35%);
}

.alert-danger {
    background-color: hsla(0 84% 60%, 0.1);
    color: hsl(0 84% 35%);
}

/* Footer Styles */
.footer {
    background-color: hsl(var(--white));
    border-top: 1px solid hsl(var(--border));
    padding: 2rem 0;
    margin-top: auto;
}

.footer p {
    margin-bottom: 0;
    display: flex;
    align-items: center;
    justify-content: center;
    gap: 0.5rem;
    font-size: 0.9rem;
}

/* Text Utilities */
.text-muted {
    color: hsl(var(--muted)) !important;
    font-size: 0.9rem;
}

.text-danger {
    color: hsl(0 84% 60%) !important;
}

/* Loading State */
.btn:disabled {
    opacity: 0.6;
    cursor: not-allowed;
}

/* Responsive Design */
@media (max-width: 768px) {
    .header-title {
        font-size: 1.5rem;
    }
    
    .header-subtitle {
        font-size: 1rem;
    }
    
    .card-body, .card-header {
        padding: 1rem;
    }
    
    .project-checkboxes {
        padding: 0.75rem;
    }
}

/* Animation for form submission */
@keyframes submitPulse {
    0% { transform: scale(1); }
    50% { transform: scale(1.05); }
    100% { transform: scale(1); }
}

.submitting {
    animation: submitPulse 0.3s ease;
}

/* Custom scrollbar */
::-webkit-scrollbar {
    width: 8px;
}

::-webkit-scrollbar-track {
    background: hsl(var(--background));
}

::-webkit-scrollbar-thumb {
    background: hsl(var(--border));
    border-radius: 4px;
}

::-webkit-scrollbar-thumb:hover {
    background: hsl(var(--muted));
}