/* ===========================
   Normalization Assistant - Light Theme
   =========================== */

*, *::before, *::after {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
    -webkit-tap-highlight-color: transparent;
}

html {
    font-size: 16px;
    -webkit-text-size-adjust: 100%;
    scroll-behavior: smooth;
}

body {
    min-width: 320px;
    overflow-x: hidden;
    -webkit-font-smoothing: antialiased;
}

:root {
    --primary: #6366f1;
    --primary-dark: #4f46e5;
    --primary-light: #818cf8;
    --primary-bg: rgba(99, 102, 241, 0.1);
    
    --success: #10b981;
    --success-bg: rgba(16, 185, 129, 0.1);
    --danger: #ef4444;
    --danger-bg: rgba(239, 68, 68, 0.1);
    --warning: #f59e0b;
    --warning-bg: rgba(245, 158, 11, 0.1);
    
    --white: #ffffff;
    --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;
    
    --shadow-sm: 0 1px 2px rgba(0, 0, 0, 0.05);
    --shadow: 0 1px 3px rgba(0, 0, 0, 0.1);
    --shadow-md: 0 4px 6px rgba(0, 0, 0, 0.1);
    --shadow-lg: 0 10px 15px rgba(0, 0, 0, 0.1);
    --shadow-xl: 0 20px 25px rgba(0, 0, 0, 0.15);
    
    --radius: 8px;
    --radius-md: 12px;
    --radius-lg: 16px;
    
    --transition: 0.3s cubic-bezier(0.4, 0, 0.2, 1);
}

html {
    scroll-behavior: smooth;
}

body {
    font-family: 'Inter', -apple-system, sans-serif;
    background: var(--gray-50);
    color: var(--gray-800);
    line-height: 1.6;
    min-height: 100vh;
}

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

/* ===========================
   Header
   =========================== */
.header {
    background: var(--white);
    border-bottom: 1px solid var(--gray-200);
    padding: 16px 24px;
    display: flex;
    align-items: center;
    justify-content: space-between;
    position: sticky;
    top: 0;
    z-index: 100;
    box-shadow: var(--shadow-sm);
}

.header-left {
    display: flex;
    align-items: center;
    gap: 16px;
}

.btn-back {
    display: flex;
    align-items: center;
    justify-content: center;
    width: 40px;
    height: 40px;
    background: var(--gray-100);
    border: none;
    border-radius: var(--radius);
    color: var(--gray-600);
    text-decoration: none;
    transition: var(--transition);
}

.btn-back:hover {
    background: var(--primary-bg);
    color: var(--primary);
}

.logo {
    display: flex;
    align-items: center;
    gap: 12px;
}

.logo i {
    font-size: 1.75rem;
    color: var(--primary);
}

.logo h1 {
    font-size: 1.35rem;
    font-weight: 700;
    color: var(--gray-900);
}

.header-right {
    display: flex;
    align-items: center;
    gap: 12px;
}

/* ===========================
   Buttons
   =========================== */
.btn {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    gap: 8px;
    padding: 10px 18px;
    border-radius: var(--radius);
    font-weight: 600;
    font-size: 0.9rem;
    border: none;
    cursor: pointer;
    transition: var(--transition);
}

.btn i {
    font-size: 0.9rem;
}

.btn-primary {
    background: linear-gradient(135deg, var(--primary), var(--primary-dark));
    color: var(--white);
    box-shadow: 0 4px 12px rgba(99, 102, 241, 0.3);
}

.btn-primary:hover {
    transform: translateY(-2px);
    box-shadow: 0 6px 16px rgba(99, 102, 241, 0.4);
}

.btn-secondary {
    background: var(--gray-100);
    color: var(--gray-700);
}

.btn-secondary:hover {
    background: var(--gray-200);
}

.btn-outline {
    background: var(--white);
    color: var(--gray-700);
    border: 2px solid var(--gray-200);
}

.btn-outline:hover {
    border-color: var(--primary);
    color: var(--primary);
}

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

.btn-success:hover {
    background: #059669;
}

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

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

.btn-large {
    padding: 14px 28px;
    font-size: 1rem;
}

.btn-block {
    width: 100%;
}

/* ===========================
   Main Content
   =========================== */
.main-content {
    flex: 1;
    padding: 24px;
    max-width: 1200px;
    margin: 0 auto;
    width: 100%;
    display: flex;
    flex-direction: column;
    gap: 24px;
}

/* ===========================
   Cards
   =========================== */
.card {
    background: var(--white);
    border-radius: var(--radius-lg);
    border: 1px solid var(--gray-200);
    box-shadow: var(--shadow);
    overflow: hidden;
    transition: var(--transition);
}

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

.card-header {
    padding: 20px 24px;
    border-bottom: 1px solid var(--gray-100);
    background: var(--gray-50);
}

.card-header h2 {
    font-size: 1.15rem;
    font-weight: 600;
    color: var(--gray-900);
    display: flex;
    align-items: center;
    gap: 10px;
}

.card-header h2 i {
    color: var(--primary);
}

.card-body {
    padding: 24px;
}

/* ===========================
   Forms
   =========================== */
.form-group {
    margin-bottom: 20px;
}

.form-group label {
    display: block;
    font-weight: 600;
    font-size: 0.9rem;
    color: var(--gray-700);
    margin-bottom: 8px;
}

.form-group small {
    display: block;
    font-size: 0.8rem;
    color: var(--gray-500);
    margin-top: 6px;
}

.input {
    width: 100%;
    padding: 12px 16px;
    border: 2px solid var(--gray-200);
    border-radius: var(--radius);
    font-size: 0.95rem;
    font-family: inherit;
    transition: var(--transition);
    background: var(--white);
}

.input:focus {
    outline: none;
    border-color: var(--primary);
    box-shadow: 0 0 0 3px var(--primary-bg);
}

.input::placeholder {
    color: var(--gray-400);
}

/* ===========================
   FD Container
   =========================== */
.fd-container {
    background: var(--gray-50);
    border-radius: var(--radius-md);
    padding: 16px;
    border: 1px solid var(--gray-200);
}

.fd-list {
    min-height: 60px;
    margin-bottom: 16px;
}

.fd-item {
    display: flex;
    align-items: center;
    justify-content: space-between;
    background: var(--white);
    padding: 12px 16px;
    border-radius: var(--radius);
    margin-bottom: 8px;
    border: 1px solid var(--gray-200);
    transition: var(--transition);
}

.fd-item:hover {
    border-color: var(--primary-bg);
    background: var(--primary-bg);
}

.fd-text {
    font-family: 'Fira Code', monospace;
    font-size: 0.9rem;
    color: var(--gray-800);
}

.fd-delete {
    background: none;
    border: none;
    color: var(--gray-400);
    cursor: pointer;
    padding: 4px 8px;
    border-radius: var(--radius);
    transition: var(--transition);
}

.fd-delete:hover {
    background: var(--danger-bg);
    color: var(--danger);
}

.fd-input-row {
    display: flex;
    gap: 12px;
    align-items: center;
}

.fd-input-row .input {
    flex: 1;
}

.fd-input-row .arrow {
    font-size: 1.25rem;
    color: var(--primary);
    font-weight: bold;
}

.empty-state {
    text-align: center;
    color: var(--gray-400);
    font-style: italic;
    padding: 20px;
}

/* ===========================
   Checkbox Group
   =========================== */
.checkbox-group {
    display: flex;
    flex-wrap: wrap;
    gap: 10px;
    margin-bottom: 16px;
}

.attr-checkbox {
    display: flex;
    align-items: center;
    gap: 8px;
    padding: 10px 16px;
    background: var(--gray-100);
    border: 2px solid transparent;
    border-radius: var(--radius);
    cursor: pointer;
    transition: var(--transition);
    font-size: 0.9rem;
    font-weight: 500;
}

.attr-checkbox:hover {
    background: var(--primary-bg);
}

.attr-checkbox.selected {
    background: var(--primary-bg);
    border-color: var(--primary);
    color: var(--primary);
}

.attr-checkbox input {
    display: none;
}

/* ===========================
   Result Box
   =========================== */
.result-box {
    margin-top: 16px;
    padding: 16px;
    background: var(--gray-50);
    border-radius: var(--radius-md);
    border: 1px solid var(--gray-200);
}

.result-box:empty {
    display: none;
}

.closure-formula {
    font-family: 'Fira Code', monospace;
    font-size: 1.1rem;
    color: var(--primary);
    text-align: center;
    padding: 16px;
    background: var(--primary-bg);
    border-radius: var(--radius);
}

/* ===========================
   Keys Display
   =========================== */
.keys-display {
    display: flex;
    flex-wrap: wrap;
    gap: 12px;
}

.key-item {
    display: flex;
    align-items: center;
    gap: 8px;
    padding: 12px 20px;
    background: linear-gradient(135deg, var(--warning-bg), rgba(245, 158, 11, 0.2));
    border: 1px solid rgba(245, 158, 11, 0.3);
    border-radius: var(--radius);
    font-family: 'Fira Code', monospace;
    font-size: 0.9rem;
    color: var(--gray-800);
}

.key-item i {
    color: var(--warning);
}

/* ===========================
   Normalization Steps
   =========================== */
.norm-steps {
    display: flex;
    flex-direction: column;
    gap: 16px;
}

.norm-step {
    background: var(--gray-50);
    border: 1px solid var(--gray-200);
    border-radius: var(--radius-md);
    padding: 20px;
    transition: var(--transition);
}

.norm-header {
    display: flex;
    align-items: center;
    gap: 16px;
    margin-bottom: 12px;
    flex-wrap: wrap;
}

.norm-badge {
    background: linear-gradient(135deg, var(--primary), var(--primary-dark));
    color: var(--white);
    padding: 6px 14px;
    border-radius: var(--radius);
    font-weight: 700;
    font-size: 0.85rem;
}

.norm-header h3 {
    flex: 1;
    font-size: 1rem;
    font-weight: 600;
    color: var(--gray-800);
}

.norm-status {
    display: flex;
    align-items: center;
    gap: 6px;
    padding: 6px 12px;
    border-radius: var(--radius);
    font-size: 0.85rem;
    font-weight: 600;
}

.norm-status.pending {
    background: var(--gray-100);
    color: var(--gray-500);
}

.norm-status.pass {
    background: var(--success-bg);
    color: var(--success);
}

.norm-status.fail {
    background: var(--danger-bg);
    color: var(--danger);
}

.norm-rule {
    font-size: 0.9rem;
    color: var(--gray-600);
    font-style: italic;
    margin-bottom: 12px;
}

.norm-result {
    margin-top: 12px;
}

.violation-item {
    background: var(--danger-bg);
    border-left: 4px solid var(--danger);
    padding: 12px 16px;
    border-radius: 0 var(--radius) var(--radius) 0;
    margin-bottom: 8px;
}

.violation-item h4 {
    font-size: 0.9rem;
    color: var(--danger);
    margin-bottom: 4px;
    display: flex;
    align-items: center;
    gap: 8px;
}

.violation-item p {
    font-size: 0.85rem;
    color: var(--gray-700);
}

.success-item {
    background: var(--success-bg);
    border-left: 4px solid var(--success);
    padding: 12px 16px;
    border-radius: 0 var(--radius) var(--radius) 0;
}

.success-item h4 {
    font-size: 0.9rem;
    color: var(--success);
    display: flex;
    align-items: center;
    gap: 8px;
}

/* ===========================
   Decomposition
   =========================== */
.decomposed-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
    gap: 16px;
    margin-bottom: 24px;
}

.decomposed-table {
    background: var(--gray-50);
    border: 1px solid var(--gray-200);
    border-radius: var(--radius-md);
    overflow: hidden;
}

.decomposed-table-header {
    display: flex;
    align-items: center;
    gap: 10px;
    padding: 14px 16px;
    background: linear-gradient(135deg, var(--primary-bg), rgba(139, 92, 246, 0.1));
    border-bottom: 1px solid var(--gray-200);
}

.decomposed-table-header i {
    color: var(--primary);
}

.decomposed-table-header h4 {
    font-size: 1rem;
    font-weight: 600;
    color: var(--gray-800);
}

.decomposed-table-content {
    padding: 16px;
}

.attribute-list {
    display: flex;
    flex-wrap: wrap;
    gap: 8px;
    margin-bottom: 12px;
}

.attr-tag {
    padding: 6px 12px;
    background: var(--gray-100);
    border-radius: var(--radius);
    font-family: 'Fira Code', monospace;
    font-size: 0.85rem;
    color: var(--gray-700);
}

.attr-tag.key {
    background: var(--warning-bg);
    color: var(--gray-800);
    border: 1px solid rgba(245, 158, 11, 0.3);
}

.fd-in-table {
    font-size: 0.8rem;
    color: var(--gray-500);
    font-family: 'Fira Code', monospace;
}

/* ===========================
   Verification Box
   =========================== */
.verification-box {
    background: var(--gray-50);
    border: 1px solid var(--gray-200);
    border-radius: var(--radius-md);
    padding: 20px;
}

.verification-box h3 {
    font-size: 1rem;
    font-weight: 600;
    color: var(--gray-800);
    margin-bottom: 16px;
    display: flex;
    align-items: center;
    gap: 8px;
}

.verification-box h3 i {
    color: var(--primary);
}

.verification-items {
    display: flex;
    gap: 16px;
    flex-wrap: wrap;
}

.check-item {
    display: flex;
    align-items: center;
    gap: 10px;
    padding: 12px 20px;
    border-radius: var(--radius);
    font-size: 0.9rem;
    font-weight: 500;
}

.check-item.pending {
    background: var(--gray-100);
    color: var(--gray-500);
}

.check-item.pass {
    background: var(--success-bg);
    color: var(--success);
}

.check-item.fail {
    background: var(--danger-bg);
    color: var(--danger);
}

/* ===========================
   Modal
   =========================== */
.modal {
    position: fixed;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    background: rgba(0, 0, 0, 0.5);
    backdrop-filter: blur(4px);
    display: flex;
    align-items: center;
    justify-content: center;
    z-index: 1000;
    opacity: 0;
    visibility: hidden;
    transition: var(--transition);
    padding: 20px;
}

.modal.show {
    opacity: 1;
    visibility: visible;
}

.modal-content {
    background: var(--white);
    border-radius: var(--radius-lg);
    width: 100%;
    max-width: 600px;
    max-height: 80vh;
    overflow: hidden;
    box-shadow: var(--shadow-xl);
    transform: translateY(20px);
    transition: var(--transition);
}

.modal.show .modal-content {
    transform: translateY(0);
}

.modal-header {
    display: flex;
    align-items: center;
    justify-content: space-between;
    padding: 20px 24px;
    border-bottom: 1px solid var(--gray-200);
    background: var(--gray-50);
}

.modal-header h2 {
    font-size: 1.15rem;
    font-weight: 600;
    color: var(--gray-900);
    display: flex;
    align-items: center;
    gap: 10px;
}

.modal-header h2 i {
    color: var(--primary);
}

.modal-close {
    background: none;
    border: none;
    font-size: 1.25rem;
    color: var(--gray-400);
    cursor: pointer;
    padding: 4px;
    transition: var(--transition);
}

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

.modal-body {
    padding: 24px;
    max-height: 60vh;
    overflow-y: auto;
}

/* ===========================
   Tutorial Styles
   =========================== */
.tutorial-section {
    margin-bottom: 24px;
}

.tutorial-section:last-child {
    margin-bottom: 0;
}

.tutorial-section h3 {
    font-size: 1.05rem;
    font-weight: 600;
    color: var(--gray-800);
    margin-bottom: 12px;
}

.tutorial-section p {
    color: var(--gray-600);
    font-size: 0.95rem;
    line-height: 1.7;
}

.tutorial-section ul,
.tutorial-section ol {
    color: var(--gray-600);
    padding-left: 20px;
    line-height: 1.8;
}

.tutorial-section li {
    margin-bottom: 8px;
}

.nf-cards {
    display: grid;
    grid-template-columns: repeat(2, 1fr);
    gap: 12px;
}

.nf-card {
    background: var(--gray-50);
    padding: 16px;
    border-radius: var(--radius);
    border: 1px solid var(--gray-200);
}

.nf-card .nf-badge {
    display: inline-block;
    background: var(--primary);
    color: var(--white);
    padding: 4px 10px;
    border-radius: var(--radius);
    font-weight: 700;
    font-size: 0.8rem;
    margin-bottom: 8px;
}

.nf-card p {
    font-size: 0.85rem;
    color: var(--gray-600);
}

/* ===========================
   Responsive Design
   =========================== */
@media (max-width: 1024px) {
    .main-content {
        padding: 20px;
    }
    
    .card {
        margin-bottom: 20px;
    }
}

@media (max-width: 768px) {
    .header {
        flex-direction: column;
        gap: 16px;
        padding: 16px;
    }
    
    .header-left {
        width: 100%;
        justify-content: center;
    }
    
    .header-right {
        width: 100%;
        justify-content: center;
        flex-wrap: wrap;
    }
    
    .header-right .btn span {
        display: none;
    }
    
    .main-content {
        padding: 16px;
    }
    
    .fd-input-row {
        flex-wrap: wrap;
    }
    
    .fd-input-row .input {
        min-width: 100px;
    }
    
    .nf-cards {
        grid-template-columns: 1fr;
    }
    
    .verification-items {
        flex-direction: column;
    }
    
    .card-header {
        flex-direction: column;
        align-items: flex-start;
        gap: 10px;
    }
    
    .decomposition-tables {
        grid-template-columns: 1fr;
    }
}

@media (max-width: 600px) {
    .header {
        padding: 12px;
    }
    
    .logo h1 {
        font-size: 1.2rem;
    }
    
    .btn {
        padding: 10px 14px;
        font-size: 13px;
    }
    
    .card-body {
        padding: 16px;
    }
    
    .input {
        font-size: 14px;
        padding: 10px 12px;
    }
    
    .table-cell {
        padding: 8px 10px;
        font-size: 13px;
    }
}

@media (max-width: 480px) {
    .logo h1 {
        font-size: 1.1rem;
    }
    
    .card-body {
        padding: 12px;
    }
    
    .norm-header {
        flex-direction: column;
        align-items: flex-start;
    }
    
    .header-right {
        gap: 8px;
        flex-wrap: wrap;
        width: 100%;
    }
    
    .header-right .btn {
        flex: 1;
        min-width: 45%;
        justify-content: center;
        text-align: center;
    }
    
    .btn {
        padding: 10px 12px;
        font-size: 12px;
    }
    
    .fd-input-row {
        gap: 8px;
        flex-direction: column;
    }
    
    .fd-input-row .btn {
        width: 100%;
    }
    
    .nf-badge {
        padding: 4px 10px;
        font-size: 11px;
    }
    
    .card-actions {
        flex-direction: column;
        gap: 8px;
    }
    
    .card-actions .btn {
        width: 100%;
    }
}

@media (max-width: 360px) {
    .header {
        padding: 10px;
    }
    
    .main-content {
        padding: 10px;
    }
    
    .card {
        border-radius: 8px;
    }
    
    .card-body {
        padding: 10px;
    }
}

/* Touch device optimizations */
@media (hover: none) and (pointer: coarse) {
    .btn {
        min-height: 44px;
    }
    
    .input {
        min-height: 44px;
    }
    
    .table-cell {
        padding: 12px;
    }
    
    .fd-item {
        padding: 12px;
    }
}

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

::-webkit-scrollbar-track {
    background: var(--gray-100);
}

::-webkit-scrollbar-thumb {
    background: var(--gray-300);
    border-radius: 4px;
}

::-webkit-scrollbar-thumb:hover {
    background: var(--gray-400);
}