@import url('https://fonts.googleapis.com/css2?family=Inter:wght@300;400;500;600;700&display=swap');

:root {
    --primary-50: #f0f9ff;
    --primary-100: #e0f2fe;
    --primary-500: #0ea5e9;
    --primary-600: #0284c7;
    --primary-700: #0369a1;
    
    --gray-50: #f9fafb;
    --gray-100: #f3f4f6;
    --gray-200: #e5e7eb;
    --gray-300: #d1d5db;
    --gray-400: #9ca3af;
    --gray-500: #6b7280;
    --gray-600: #4b5563;
    --gray-700: #374151;
    --gray-800: #1f2937;
    --gray-900: #111827;
    
    --green-50: #f0fdf4;
    --green-500: #22c55e;
    --green-600: #16a34a;
    
    --red-50: #fef2f2;
    --red-500: #ef4444;
    --red-600: #dc2626;
    
    --orange-50: #fff7ed;
    --orange-500: #f97316;
    --orange-600: #ea580c;
    
    --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);
    
    --radius-sm: 0.375rem;
    --radius-md: 0.5rem;
    --radius-lg: 0.75rem;
    --radius-xl: 1rem;
}

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

body {
    font-family: 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', sans-serif;
    background: linear-gradient(135deg, var(--gray-50) 0%, var(--primary-50) 100%);
    color: var(--gray-800);
    line-height: 1.6;
    min-height: 100vh;
    font-size: 16px;
}

.app-container {
    min-height: 100vh;
    display: flex;
    flex-direction: column;
}

.container {
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 1.5rem;
}

/* Header */
header {
    background: linear-gradient(135deg, var(--primary-600) 0%, var(--primary-700) 100%);
    color: white;
    padding: 3rem 0;
    position: relative;
    overflow: hidden;
}

header::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    background: url("data:image/svg+xml,%3Csvg width='60' height='60' viewBox='0 0 60 60' xmlns='http://www.w3.org/2000/svg'%3E%3Cg fill='none' fill-rule='evenodd'%3E%3Cg fill='%23ffffff' fill-opacity='0.05'%3E%3Ccircle cx='30' cy='30' r='4'/%3E%3C/g%3E%3C/g%3E%3C/svg%3E");
    opacity: 0.1;
}

.header-content {
    position: relative;
    text-align: center;
}

header h1 {
    font-size: 2.5rem;
    font-weight: 700;
    margin-bottom: 0.5rem;
    letter-spacing: -0.025em;
}

header p {
    font-size: 1.125rem;
    opacity: 0.9;
    font-weight: 400;
}

/* Back Link */
.back-link {
    display: inline-flex;
    align-items: center;
    gap: 8px;
    color: rgba(255, 255, 255, 0.8);
    text-decoration: none;
    font-size: 14px;
    font-weight: 500;
    margin-bottom: 16px;
    padding: 8px 16px;
    border-radius: 8px;
    background: rgba(255, 255, 255, 0.1);
    border: 1px solid rgba(255, 255, 255, 0.2);
    transition: all 0.3s ease;
}

.back-link:hover {
    background: rgba(255, 255, 255, 0.15);
    color: rgba(255, 255, 255, 1);
    transform: translateX(-4px);
    border-color: rgba(255, 255, 255, 0.3);
}

.back-link svg {
    transition: transform 0.3s ease;
}

.back-link:hover svg {
    transform: translateX(-2px);
}

/* Main Content */
main {
    flex: 1;
    padding: 2rem 0 3rem;
}

/* Cards */
.card {
    background: white;
    border-radius: var(--radius-xl);
    box-shadow: var(--shadow-md);
    margin-bottom: 2rem;
    border: 1px solid var(--gray-100);
    overflow: hidden;
    transition: all 0.2s ease;
}

.card:hover {
    box-shadow: var(--shadow-lg);
    transform: translateY(-1px);
}

.card-header {
    padding: 2rem 2rem 1rem;
    border-bottom: 1px solid var(--gray-100);
    background: var(--gray-50);
    display: flex;
    justify-content: space-between;
    align-items: flex-start;
    gap: 1rem;
}

.header-title-section h2 {
    font-size: 1.5rem;
    font-weight: 600;
    color: var(--gray-800);
    margin-bottom: 0.5rem;
    display: flex;
    align-items: center;
    gap: 0.5rem;
}

.header-title-section p {
    color: var(--gray-600);
    font-size: 0.875rem;
}

.card-header h2 {
    font-size: 1.5rem;
    font-weight: 600;
    color: var(--gray-800);
    margin-bottom: 0.5rem;
    display: flex;
    align-items: center;
    gap: 0.5rem;
}

.card-header p {
    color: var(--gray-600);
    font-size: 0.875rem;
}

/* Input Groups */
.input-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
    gap: 2rem;
    padding: 2rem;
}

.input-group {
    display: flex;
    flex-direction: column;
    gap: 0.5rem;
}

.input-group label {
    font-weight: 500;
    color: var(--gray-700);
    font-size: 0.875rem;
    margin-bottom: 0.25rem;
}

.input-wrapper {
    position: relative;
    display: flex;
    align-items: center;
}

.input-wrapper input {
    flex: 1;
    padding: 0.75rem 1rem;
    border: 2px solid var(--gray-200);
    border-radius: var(--radius-md);
    font-size: 1rem;
    transition: all 0.2s ease;
    background: white;
}

.input-wrapper input:focus {
    outline: none;
    border-color: var(--primary-500);
    box-shadow: 0 0 0 3px rgb(14 165 233 / 0.1);
}

.input-suffix {
    position: absolute;
    right: 2.5rem;
    color: var(--gray-400);
    font-size: 0.875rem;
    pointer-events: none;
}

/* Course Items */
.courses-container {
    padding: 2rem;
    display: flex;
    flex-direction: column;
    gap: 1rem;
}

.course-item {
    background: var(--gray-50);
    border: 2px solid var(--gray-100);
    border-radius: var(--radius-lg);
    padding: 1.5rem;
    position: relative;
    transition: all 0.2s ease;
}

.course-item:hover {
    border-color: var(--gray-200);
    background: white;
}

.course-header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    margin-bottom: 1rem;
}

.course-number {
    font-weight: 600;
    color: var(--gray-700);
    font-size: 1rem;
}

.remove-course {
    position: absolute;
    top: 1rem;
    right: 1rem;
    background: var(--red-50);
    border: 1px solid var(--red-200);
    color: var(--red-600);
    border-radius: var(--radius-md);
    width: 2rem;
    height: 2rem;
    display: flex;
    align-items: center;
    justify-content: center;
    cursor: pointer;
    transition: all 0.2s ease;
    font-size: 1rem;
}

.remove-course:hover {
    background: var(--red-500);
    color: white;
    transform: scale(1.05);
}

.course-inputs {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 1.5rem;
}

.course-field {
    display: flex;
    flex-direction: column;
    gap: 0.5rem;
}

.course-field label {
    font-weight: 500;
    color: var(--gray-600);
    font-size: 0.75rem;
    text-transform: uppercase;
    letter-spacing: 0.05em;
}

.course-inputs select {
    padding: 0.75rem 1rem;
    border: 2px solid var(--gray-200);
    border-radius: var(--radius-md);
    font-size: 1rem;
    background: white;
    color: var(--gray-700);
    cursor: pointer;
    transition: all 0.2s ease;
}

.course-inputs select:focus {
    outline: none;
    border-color: var(--primary-500);
    box-shadow: 0 0 0 3px rgb(14 165 233 / 0.1);
}


/* Retake Course Styling */
.course-item.retake-course {
    background: linear-gradient(135deg, #fff7ed 0%, #fed7aa 50%, #fdba74 100%);
    border: 2px solid #fb923c;
    position: relative;
    padding-left: 3.5rem;
}

.course-item.retake-course::before {
    content: '🔄';
    position: absolute;
    top: 1.5rem;
    left: 1rem;
    font-size: 1.2rem;
    background: var(--orange-500);
    color: white;
    width: 2rem;
    height: 2rem;
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 0.875rem;
    box-shadow: 0 2px 4px rgba(0, 0, 0, 0.1);
}

.course-item.retake-course .course-header {
    margin-left: 0;
    margin-bottom: 1.5rem;
}

.course-item.retake-course .course-number {
    color: var(--orange-700);
    font-weight: 700;
}

.course-item.retake-course .course-type.retake {
    color: var(--orange-600);
    font-weight: 600;
}

.course-item.retake-course:hover {
    border-color: var(--orange-400);
    background: linear-gradient(135deg, #fed7aa 0%, white 100%);
    transform: translateY(-1px);
    box-shadow: 0 4px 12px rgba(251, 146, 60, 0.15);
}

.course-item.retake-course .remove-course {
    top: 1rem;
    right: 1rem;
    background: rgba(239, 68, 68, 0.1);
    border: 1px solid var(--red-300);
    color: var(--red-600);
}

.course-item.retake-course .remove-course:hover {
    background: var(--red-500);
    color: white;
}

/* Retake specific inputs */
.retake-inputs {
    display: grid;
    grid-template-columns: 1fr 1fr 1fr;
    gap: 1.5rem;
}

.retake-inputs .course-field {
    display: flex;
    flex-direction: column;
    gap: 0.5rem;
}

.retake-inputs .course-field label {
    font-weight: 600;
    color: var(--orange-700);
    font-size: 0.75rem;
    text-transform: uppercase;
    letter-spacing: 0.05em;
}

.retake-inputs select {
    padding: 0.75rem 1rem;
    border: 2px solid var(--orange-200);
    border-radius: var(--radius-md);
    font-size: 1rem;
    background: white;
    color: var(--gray-700);
    cursor: pointer;
    transition: all 0.2s ease;
}

.retake-inputs select:focus {
    outline: none;
    border-color: var(--orange-500);
    box-shadow: 0 0 0 3px rgb(251 146 60 / 0.1);
}

/* Course type indicator */
.course-type {
    font-size: 0.75rem;
    color: var(--gray-500);
    font-weight: 500;
    text-transform: uppercase;
    letter-spacing: 0.05em;
}

.course-type.retake {
    color: var(--orange-600);
}

/* Course Actions */
.course-actions {
    display: flex;
    gap: 1rem;
    justify-content: center;
    padding: 1rem 2rem 2rem;
}

/* Buttons */
.btn {
    display: inline-flex;
    align-items: center;
    gap: 0.5rem;
    padding: 0.75rem 1.5rem;
    border-radius: var(--radius-md);
    font-size: 0.875rem;
    font-weight: 500;
    cursor: pointer;
    transition: all 0.2s ease;
    text-decoration: none;
    border: none;
    line-height: 1;
}

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

.btn-primary {
    background: var(--primary-600);
    color: white;
    border: 2px solid var(--primary-600);
}

.btn-primary:hover {
    background: var(--primary-700);
    border-color: var(--primary-700);
    transform: translateY(-1px);
    box-shadow: var(--shadow-md);
}

.btn-secondary {
    background: var(--orange-500);
    color: white;
    border: 2px solid var(--orange-500);
}

.btn-secondary:hover {
    background: var(--orange-600);
    border-color: var(--orange-600);
    transform: translateY(-1px);
    box-shadow: var(--shadow-md);
}

.btn-outline {
    background: white;
    color: var(--gray-600);
    border: 2px solid var(--gray-200);
}

.btn-outline:hover {
    background: var(--gray-50);
    border-color: var(--gray-300);
    color: var(--gray-700);
    transform: translateY(-1px);
}

.full-width {
    width: 100%;
    justify-content: center;
}

/* Calculate Button */
.calculate-btn {
    width: 100%;
    background: linear-gradient(135deg, var(--green-500) 0%, var(--green-600) 100%);
    color: white;
    border: none;
    padding: 1.25rem 2rem;
    border-radius: var(--radius-xl);
    font-size: 1.125rem;
    font-weight: 600;
    cursor: pointer;
    transition: all 0.3s ease;
    margin-bottom: 2rem;
    display: flex;
    align-items: center;
    justify-content: center;
    gap: 0.75rem;
    box-shadow: var(--shadow-lg);
}

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

/* Results */
.results-card {
    background: linear-gradient(135deg, var(--primary-50) 0%, white 100%);
    border: 2px solid var(--primary-100);
}

.result-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(200px, 1fr));
    gap: 2rem;
    padding: 2rem;
}

.result-card {
    background: white;
    border: 2px solid var(--gray-100);
    border-radius: var(--radius-lg);
    padding: 1.5rem;
    text-align: center;
    transition: all 0.2s ease;
}

.result-card:hover {
    border-color: var(--primary-200);
    transform: translateY(-2px);
    box-shadow: var(--shadow-md);
}

.result-label {
    font-size: 0.875rem;
    color: var(--gray-600);
    font-weight: 500;
    margin-bottom: 0.5rem;
    text-transform: uppercase;
    letter-spacing: 0.05em;
}

.result-value {
    font-size: 2.5rem;
    font-weight: 700;
    color: var(--gray-800);
    margin-bottom: 0.5rem;
    line-height: 1;
}

.result-description {
    font-size: 0.875rem;
    color: var(--gray-500);
}

/* Modals */
.modal {
    display: none;
    position: fixed;
    z-index: 1000;
    left: 0;
    top: 0;
    width: 100%;
    height: 100%;
}

.modal-backdrop {
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    background: rgba(0, 0, 0, 0.5);
    backdrop-filter: blur(4px);
}

.modal-content {
    position: relative;
    background: white;
    margin: 5% auto;
    border-radius: var(--radius-xl);
    width: 90%;
    max-width: 500px;
    box-shadow: var(--shadow-xl);
    animation: modalSlideIn 0.3s ease-out;
    overflow: hidden;
}

@keyframes modalSlideIn {
    from {
        opacity: 0;
        transform: translateY(-50px) scale(0.95);
    }
    to {
        opacity: 1;
        transform: translateY(0) scale(1);
    }
}

.modal-header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: 1.5rem 2rem;
    border-bottom: 1px solid var(--gray-200);
    background: var(--gray-50);
}

.modal-header h3 {
    margin: 0;
    font-size: 1.25rem;
    font-weight: 600;
    color: var(--gray-800);
}

.modal-close {
    background: none;
    border: none;
    font-size: 1.5rem;
    color: var(--gray-400);
    cursor: pointer;
    padding: 0.25rem;
    border-radius: var(--radius-sm);
    transition: all 0.2s ease;
}

.modal-close:hover {
    color: var(--gray-600);
    background: var(--gray-100);
}

.modal-form {
    padding: 2rem;
}

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

.form-group label {
    display: block;
    font-weight: 500;
    color: var(--gray-700);
    font-size: 0.875rem;
    margin-bottom: 0.5rem;
}

.form-group input,
.form-group select {
    width: 100%;
    padding: 0.75rem 1rem;
    border: 2px solid var(--gray-200);
    border-radius: var(--radius-md);
    font-size: 1rem;
    transition: all 0.2s ease;
    background: white;
}

.form-group input:focus,
.form-group select:focus {
    outline: none;
    border-color: var(--primary-500);
    box-shadow: 0 0 0 3px rgb(14 165 233 / 0.1);
}

.form-row {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(120px, 1fr));
    gap: 1rem;
}

/* Empty State */
.empty-state {
    text-align: center;
    padding: 3rem 2rem;
    color: var(--gray-400);
}

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

.empty-state-text {
    font-size: 1.125rem;
    font-weight: 500;
    margin-bottom: 0.5rem;
    color: var(--gray-500);
}

.empty-state-subtext {
    font-size: 0.875rem;
    opacity: 0.8;
}

/* Alert Messages */
.alert {
    position: fixed;
    top: 2rem;
    right: 2rem;
    padding: 1rem 1.5rem;
    border-radius: var(--radius-lg);
    color: white;
    font-weight: 500;
    z-index: 1001;
    max-width: 320px;
    opacity: 0;
    transform: translateX(100px);
    transition: all 0.3s ease;
    box-shadow: var(--shadow-lg);
}

.alert.show {
    opacity: 1;
    transform: translateX(0);
}

.alert-success { 
    background: linear-gradient(135deg, var(--green-500), var(--green-600));
}
.alert-error { 
    background: linear-gradient(135deg, var(--red-500), var(--red-600));
}
.alert-warning { 
    background: linear-gradient(135deg, var(--orange-500), var(--orange-600));
}
.alert-info { 
    background: linear-gradient(135deg, var(--primary-500), var(--primary-600));
}


/* Reset Button */
.btn-danger {
    background: var(--red-500);
    color: white;
    border: 2px solid var(--red-500);
}

.btn-danger:hover {
    background: var(--red-600);
    border-color: var(--red-600);
    transform: translateY(-1px);
    box-shadow: var(--shadow-md);
}











/* For larger screens, make it even wider */
@media (min-width: 1024px) {
    .container {
        max-width: 1400px; /* Even wider on large screens */
    }
    
    .input-grid {
        grid-template-columns: 1fr 1fr; /* Force 2 columns on desktop */
        max-width: 800px; /* Limit width of input section */
        margin: 0 auto; /* Center it */
    }
    
    .course-inputs {
        grid-template-columns: 1fr 1fr;
        gap: 2rem;
    }
    
    .result-grid {
        grid-template-columns: repeat(4, 1fr); /* 4 columns on desktop */
    }
}

@media (min-width: 768px) and (max-width: 1023px) {
    .result-grid {
        grid-template-columns: repeat(2, 1fr); /* 2 columns on tablet */
    }
}