/* ===== RESET & BASE STYLES ===== */
* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}

:root {
    /* Color Palette */
    --primary: #2563eb;
    --primary-dark: #1d4ed8;
    --primary-light: #3b82f6;
    --secondary: #64748b;
    --success: #10b981;
    --warning: #f59e0b;
    --error: #ef4444;
    --background: #f8fafc;
    --surface: #ffffff;
    --border: #e2e8f0;
    --text-primary: #1e293b;
    --text-secondary: #64748b;
    --text-muted: #94a3b8;
    
    /* Typography */
    --font-family: 'Source Serif Pro', Georgia, serif;
    --font-size-xs: 0.75rem;
    --font-size-sm: 0.875rem;
    --font-size-base: 1rem;
    --font-size-lg: 1.125rem;
    --font-size-xl: 1.25rem;
    --font-size-2xl: 1.5rem;
    --font-size-3xl: 1.875rem;
    
    /* Spacing */
    --spacing-xs: 0.25rem;
    --spacing-sm: 0.5rem;
    --spacing-md: 1rem;
    --spacing-lg: 1.5rem;
    --spacing-xl: 2rem;
    --spacing-2xl: 3rem;
    
    /* Border Radius */
    --radius-sm: 0.375rem;
    --radius-md: 0.5rem;
    --radius-lg: 0.75rem;
    --radius-xl: 1rem;
    --radius-2xl: 1.5rem;
    
    /* Shadows */
    --shadow-sm: 0 1px 2px 0 rgba(0, 0, 0, 0.05);
    --shadow-md: 0 4px 6px -1px rgba(0, 0, 0, 0.1);
    --shadow-lg: 0 10px 15px -3px rgba(0, 0, 0, 0.1);
    --shadow-xl: 0 20px 25px -5px rgba(0, 0, 0, 0.1);
    
    /* Transitions */
    --transition-fast: 150ms ease;
    --transition-normal: 250ms ease;
    --transition-slow: 350ms ease;
}

body {
    font-family: var(--font-family);
    background: var(--background);
    color: var(--text-primary);
    line-height: 1.6;
    min-height: 100vh;
}

/* ===== APP LAYOUT ===== */
.app-container {
    min-height: 100vh;
    display: flex;
    flex-direction: column;
}

.app-header {
    background: var(--surface);
    border-bottom: 1px solid var(--border);
    padding: var(--spacing-md) var(--spacing-xl);
    box-shadow: var(--shadow-sm);
}

.header-content {
    display: flex;
    align-items: center;
    justify-content: space-between;
    max-width: 1400px;
    margin: 0 auto;
}

.logo-section {
    display: flex;
    align-items: center;
    gap: var(--spacing-md);
}

.logo-icon {
    width: 48px;
    height: 48px;
    background: linear-gradient(135deg, var(--primary), var(--primary-dark));
    border-radius: var(--radius-lg);
    display: flex;
    align-items: center;
    justify-content: center;
    color: white;
    font-size: var(--font-size-xl);
}

.logo-text h1 {
    font-size: var(--font-size-2xl);
    font-weight: 700;
    color: var(--text-primary);
    margin-bottom: var(--spacing-xs);
}

.subtitle {
    color: var(--text-secondary);
    font-size: var(--font-size-sm);
}

.header-actions {
    display: flex;
    gap: var(--spacing-sm);
}

.btn-help {
    background: none;
    border: none;
    color: var(--text-secondary);
    font-size: var(--font-size-lg);
    cursor: pointer;
    padding: var(--spacing-sm);
    border-radius: var(--radius-md);
    transition: var(--transition-fast);
}

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

.app-main {
    flex: 1;
    padding: var(--spacing-xl);
    margin-left: 60px; /* Space for collapsed sidebar */
    transition: margin-left var(--transition-normal);
}

.app-main.sidebar-expanded {
    margin-left: 320px; /* Space for expanded sidebar */
}

/* ===== SIDEBAR STYLES ===== */
.app-sidebar {
    position: fixed;
    top: 0;
    left: 0;
    height: 100vh;
    width: 60px;
    background: var(--surface);
    border-right: 1px solid var(--border);
    box-shadow: var(--shadow-md);
    z-index: 1000;
    transition: width var(--transition-normal);
    overflow: hidden;
}

.app-sidebar:hover,
.app-sidebar.sidebar-expanded {
    width: 320px;
}

.sidebar-header {
    padding: var(--spacing-md);
    border-bottom: 1px solid var(--border);
    display: flex;
    align-items: center;
    gap: var(--spacing-sm);
    min-height: 60px;
}

.sidebar-toggle {
    background: none;
    border: none;
    color: var(--text-secondary);
    font-size: var(--font-size-lg);
    cursor: pointer;
    padding: var(--spacing-sm);
    border-radius: var(--radius-md);
    transition: var(--transition-fast);
}

.sidebar-toggle:hover {
    background: var(--background);
    color: var(--primary);
}

.sidebar-header h3 {
    font-size: var(--font-size-lg);
    font-weight: 600;
    color: var(--text-primary);
    white-space: nowrap;
    opacity: 0;
    transition: opacity var(--transition-normal);
}

.app-sidebar:hover .sidebar-header h3,
.app-sidebar.sidebar-expanded .sidebar-header h3 {
    opacity: 1;
}

.sidebar-content {
    padding: var(--spacing-md);
    height: calc(100vh - 80px);
    overflow-y: auto;
}

.sidebar-content .settings-accordion {
    opacity: 0;
    transition: opacity var(--transition-normal);
}

.app-sidebar:hover .sidebar-content .settings-accordion,
.app-sidebar.sidebar-expanded .sidebar-content .settings-accordion {
    opacity: 1;
}

/* Adjust main content layout for sidebar */
.main-grid {
    display: grid;
    grid-template-columns: 1fr;
    gap: var(--spacing-xl);
    max-width: 1400px;
    margin: 0 auto;
}

.left-column {
    display: flex;
    flex-direction: column;
    gap: var(--spacing-xl);
}

.right-column {
    display: none; /* Hide the old right column since we have sidebar now */
}

/* ===== CARDS ===== */
.card {
    background: var(--surface);
    border-radius: var(--radius-xl);
    box-shadow: var(--shadow-md);
    border: 1px solid var(--border);
    overflow: hidden;
}

.card-header {
    padding: var(--spacing-lg) var(--spacing-lg) 0;
    display: flex;
    align-items: center;
    gap: var(--spacing-sm);
    margin-bottom: var(--spacing-md);
}

.card-header i {
    color: var(--primary);
    font-size: var(--font-size-lg);
}

.card-header h2 {
    font-size: var(--font-size-xl);
    font-weight: 600;
    color: var(--text-primary);
}

.card-body {
    padding: 0 var(--spacing-lg) var(--spacing-lg);
}

/* ===== UPLOAD CARD ===== */
.upload-container {
    display: flex;
    flex-direction: column;
    gap: var(--spacing-md);
}

.drop-zone {
    border: 2px dashed var(--border);
    border-radius: var(--radius-lg);
    padding: var(--spacing-2xl);
    text-align: center;
    cursor: pointer;
    transition: all var(--transition-normal);
    position: relative;
}

.drop-zone:hover {
    border-color: var(--primary-light);
    background: rgba(59, 130, 246, 0.05);
}

.drop-zone.dragover {
    border-color: var(--primary);
    background: rgba(37, 99, 235, 0.1);
    transform: scale(1.02);
}

.drop-content i {
    font-size: 3rem;
    color: var(--text-muted);
    margin-bottom: var(--spacing-md);
}

.drop-content h3 {
    font-size: var(--font-size-lg);
    font-weight: 600;
    margin-bottom: var(--spacing-xs);
    color: var(--text-primary);
}

.drop-content p {
    color: var(--text-secondary);
    margin-bottom: var(--spacing-sm);
}

.file-types {
    font-size: var(--font-size-xs);
    color: var(--text-muted);
    background: var(--background);
    padding: var(--spacing-xs) var(--spacing-sm);
    border-radius: var(--radius-md);
}

.file-input {
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    opacity: 0;
    cursor: pointer;
}

.file-preview {
    display: none;
    animation: slideUp var(--transition-normal);
}

.file-preview.visible {
    display: block;
}

.file-info {
    display: flex;
    align-items: center;
    gap: var(--spacing-md);
    padding: var(--spacing-md);
    background: var(--background);
    border-radius: var(--radius-lg);
    border: 1px solid var(--border);
}

.file-info i {
    color: var(--primary);
    font-size: var(--font-size-xl);
}

.file-details {
    flex: 1;
    display: flex;
    flex-direction: column;
    gap: var(--spacing-xs);
}

.file-name {
    font-weight: 600;
    color: var(--text-primary);
}

.file-size {
    font-size: var(--font-size-sm);
    color: var(--text-secondary);
}

.btn-remove {
    background: none;
    border: none;
    color: var(--text-muted);
    cursor: pointer;
    padding: var(--spacing-sm);
    border-radius: var(--radius-md);
    transition: var(--transition-fast);
}

.btn-remove:hover {
    color: var(--error);
    background: rgba(239, 68, 68, 0.1);
}

/* ===== ACTION CARD ===== */
.btn-process {
    width: 100%;
    background: linear-gradient(135deg, var(--primary), var(--primary-dark));
    color: white;
    border: none;
    padding: var(--spacing-lg) var(--spacing-xl);
    border-radius: var(--radius-lg);
    font-size: var(--font-size-lg);
    font-weight: 600;
    cursor: pointer;
    transition: all var(--transition-normal);
    display: flex;
    align-items: center;
    justify-content: center;
    gap: var(--spacing-md);
    position: relative;
    overflow: hidden;
}

.btn-process:not(:disabled):hover {
    transform: translateY(-2px);
    box-shadow: var(--shadow-lg);
}

.btn-process:disabled {
    opacity: 0.6;
    cursor: not-allowed;
    transform: none !important;
}

.btn-icon {
    font-size: var(--font-size-xl);
}

.btn-loading {
    display: none;
}

.btn-process.loading .btn-text,
.btn-process.loading .btn-icon {
    display: none;
}

.btn-process.loading .btn-loading {
    display: flex;
    align-items: center;
    gap: var(--spacing-sm);
}

.process-status {
    margin-top: var(--spacing-md);
    padding: var(--spacing-md);
    background: var(--background);
    border-radius: var(--radius-lg);
    border: 1px solid var(--border);
}

.status-item {
    display: flex;
    align-items: center;
    gap: var(--spacing-sm);
    font-size: var(--font-size-sm);
}

.status-success {
    color: var(--success);
}

.status-warning {
    color: var(--warning);
}

.status-error {
    color: var(--error);
}

/* ===== RESULTS CARD ===== */
.results-content {
    text-align: center;
}

.results-placeholder {
    padding: var(--spacing-2xl) var(--spacing-lg);
    color: var(--text-muted);
}

.results-placeholder i {
    font-size: 3rem;
    margin-bottom: var(--spacing-md);
    opacity: 0.5;
}

.results-success {
    padding: var(--spacing-xl) var(--spacing-lg);
}

.success-icon {
    font-size: 4rem;
    color: var(--success);
    margin-bottom: var(--spacing-md);
}

.results-success h3 {
    font-size: var(--font-size-xl);
    font-weight: 600;
    margin-bottom: var(--spacing-sm);
    color: var(--text-primary);
}

.results-success p {
    color: var(--text-secondary);
    margin-bottom: var(--spacing-lg);
}

.btn-download-result {
    display: inline-flex;
    align-items: center;
    gap: var(--spacing-sm);
    background: var(--success);
    color: white;
    padding: var(--spacing-md) var(--spacing-lg);
    border-radius: var(--radius-lg);
    text-decoration: none;
    font-weight: 600;
    transition: var(--transition-normal);
}

.btn-download-result:hover {
    background: #0da271;
    transform: translateY(-1px);
}

/* ===== SETTINGS ACCORDION ===== */
.settings-accordion {
    display: flex;
    flex-direction: column;
    gap: var(--spacing-sm);
}

.accordion-item {
    background: var(--surface);
    border-radius: var(--radius-lg);
    border: 1px solid var(--border);
    overflow: hidden;
}

.accordion-header {
    padding: var(--spacing-lg);
    display: flex;
    align-items: center;
    gap: var(--spacing-md);
    cursor: pointer;
    transition: var(--transition-normal);
    user-select: none;
}

.accordion-header:hover {
    background: var(--background);
}

.accordion-header i:first-child {
    color: var(--primary);
    font-size: var(--font-size-lg);
}

.accordion-header h3 {
    flex: 1;
    font-size: var(--font-size-lg);
    font-weight: 600;
    color: var(--text-primary);
}

.accordion-arrow {
    transition: transform var(--transition-normal);
    color: var(--text-muted);
}

.accordion-header.active .accordion-arrow {
    transform: rotate(180deg);
}

.accordion-content {
    max-height: 0;
    overflow: hidden;
    transition: max-height var(--transition-normal);
}

.accordion-content.active {
    max-height: 1000px;
}

.accordion-content > div {
    padding: 0 var(--spacing-lg) var(--spacing-lg);
}

/* ===== SETTINGS STYLES ===== */
.setting-group {
    margin-bottom: var(--spacing-lg);
}

.setting-group:last-child {
    margin-bottom: 0;
}

.switch-label {
    display: flex;
    align-items: center;
    justify-content: space-between;
    margin-bottom: var(--spacing-xs);
}

.label-text {
    font-weight: 500;
    color: var(--text-primary);
}

.setting-description {
    font-size: var(--font-size-sm);
    color: var(--text-secondary);
    margin-top: var(--spacing-xs);
}

.switch {
    position: relative;
    display: inline-block;
    width: 50px;
    height: 24px;
}

.switch input {
    opacity: 0;
    width: 0;
    height: 0;
}

.slider {
    position: absolute;
    cursor: pointer;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    background: var(--border);
    transition: var(--transition-normal);
    border-radius: 34px;
}

.slider:before {
    position: absolute;
    content: "";
    height: 18px;
    width: 18px;
    left: 3px;
    bottom: 3px;
    background: white;
    transition: var(--transition-normal);
    border-radius: 50%;
}

input:checked + .slider {
    background: var(--primary);
}

input:checked + .slider:before {
    transform: translateX(26px);
}

/* Form Elements */
.form-grid {
    display: grid;
    gap: var(--spacing-lg);
}

.form-group {
    display: flex;
    flex-direction: column;
    gap: var(--spacing-sm);
}

.form-group label {
    font-weight: 500;
    color: var(--text-primary);
    font-size: var(--font-size-sm);
}

.form-select {
    padding: var(--spacing-sm) var(--spacing-md);
    border: 1px solid var(--border);
    border-radius: var(--radius-md);
    background: var(--surface);
    font-size: var(--font-size-sm);
    transition: var(--transition-fast);
}

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

.slider-container {
    display: flex;
    align-items: center;
    gap: var(--spacing-md);
}

.form-slider {
    flex: 1;
    height: 4px;
    background: var(--border);
    border-radius: 2px;
    outline: none;
    -webkit-appearance: none;
}

.form-slider::-webkit-slider-thumb {
    -webkit-appearance: none;
    width: 18px;
    height: 18px;
    background: var(--primary);
    border-radius: 50%;
    cursor: pointer;
    border: 2px solid white;
    box-shadow: var(--shadow-md);
}

.form-slider::-moz-range-thumb {
    width: 18px;
    height: 18px;
    background: var(--primary);
    border-radius: 50%;
    cursor: pointer;
    border: 2px solid white;
    box-shadow: var(--shadow-md);
}

.slider-value {
    min-width: 60px;
    text-align: right;
    font-size: var(--font-size-sm);
    color: var(--text-secondary);
    font-weight: 500;
}

/* Academic & Custom Options */
.academic-options,
.custom-options {
    margin-top: var(--spacing-lg);
    padding-top: var(--spacing-lg);
    border-top: 1px solid var(--border);
}

/* ===== FOOTER ===== */
.app-footer {
    background: var(--surface);
    border-top: 1px solid var(--border);
    padding: var(--spacing-lg) var(--spacing-xl);
    margin-top: auto;
}

.footer-content {
    display: flex;
    align-items: center;
    justify-content: space-between;
    max-width: 1400px;
    margin: 0 auto;
}

.footer-content p {
    color: var(--text-secondary);
    font-size: var(--font-size-sm);
}

.footer-links {
    display: flex;
    gap: var(--spacing-lg);
}

.footer-link {
    color: var(--text-secondary);
    text-decoration: none;
    font-size: var(--font-size-sm);
    transition: var(--transition-fast);
}

.footer-link:hover {
    color: var(--primary);
}

/* ===== ANIMATIONS ===== */
@keyframes slideUp {
    from {
        opacity: 0;
        transform: translateY(10px);
    }
    to {
        opacity: 1;
        transform: translateY(0);
    }
}

@keyframes spin {
    from {
        transform: rotate(0deg);
    }
    to {
        transform: rotate(360deg);
    }
}

/* ===== MODAL STYLES ===== */
.modal {
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    background: rgba(0, 0, 0, 0.5);
    display: flex;
    align-items: center;
    justify-content: center;
    z-index: 2000;
    animation: fadeIn 0.3s ease;
}

.modal-content {
    background: var(--surface);
    border-radius: var(--radius-xl);
    box-shadow: var(--shadow-xl);
    max-width: 500px;
    width: 90%;
    max-height: 80vh;
    overflow-y: auto;
    animation: slideUp 0.3s ease;
}

.modal-header {
    padding: var(--spacing-lg);
    border-bottom: 1px solid var(--border);
    display: flex;
    align-items: center;
    justify-content: space-between;
}

.modal-header h2 {
    font-size: var(--font-size-xl);
    font-weight: 600;
    color: var(--text-primary);
}

.modal-close {
    background: none;
    border: none;
    font-size: var(--font-size-2xl);
    color: var(--text-muted);
    cursor: pointer;
    padding: var(--spacing-xs);
    border-radius: var(--radius-sm);
    transition: var(--transition-fast);
}

.modal-close:hover {
    color: var(--error);
    background: rgba(239, 68, 68, 0.1);
}

.modal-body {
    padding: var(--spacing-lg);
}

.guide-step {
    margin-bottom: var(--spacing-lg);
    padding-bottom: var(--spacing-lg);
    border-bottom: 1px solid var(--border);
}

.guide-step:last-child {
    margin-bottom: 0;
    padding-bottom: 0;
    border-bottom: none;
}

.guide-step h3 {
    font-size: var(--font-size-lg);
    font-weight: 600;
    color: var(--primary);
    margin-bottom: var(--spacing-sm);
}

.guide-step p {
    color: var(--text-secondary);
    line-height: 1.6;
}

@keyframes fadeIn {
    from { opacity: 0; }
    to { opacity: 1; }
}

/* ===== RESPONSIVE DESIGN ===== */
@media (max-width: 1024px) {
    .main-grid {
        grid-template-columns: 1fr;
        gap: var(--spacing-lg);
    }
    
    .right-column {
        position: static;
        max-height: none;
    }
}

@media (max-width: 768px) {
    .app-main {
        padding: var(--spacing-md);
    }
    
    .header-content {
        flex-direction: column;
        gap: var(--spacing-md);
        text-align: center;
    }
    
    .footer-content {
        flex-direction: column;
        gap: var(--spacing-md);
        text-align: center;
    }
    
    .footer-links {
        justify-content: center;
    }
    
    .drop-zone {
        padding: var(--spacing-xl);
    }
    
    .card-header {
        padding: var(--spacing-md) var(--spacing-md) 0;
    }
    
    .card-body {
        padding: 0 var(--spacing-md) var(--spacing-md);
    }
}

@media (max-width: 480px) {
    .logo-section {
        flex-direction: column;
        text-align: center;
        gap: var(--spacing-sm);
    }
    
    .logo-icon {
        width: 40px;
        height: 40px;
        font-size: var(--font-size-lg);
    }
    
    .logo-text h1 {
        font-size: var(--font-size-xl);
    }
    
    .drop-content i {
        font-size: 2.5rem;
    }
    
    .drop-content h3 {
        font-size: var(--font-size-lg);
    }
    
    .btn-process {
        padding: var(--spacing-md) var(--spacing-lg);
        font-size: var(--font-size-base);
    }
}