/* ==========================================
   VARIABLES & RESET
   ========================================== */
:root {
    /* Colors */
    --primary: #6366f1;
    --primary-dark: #4f46e5;
    --secondary: #8b5cf6;
    --success: #10b981;
    --warning: #f59e0b;
    --error: #ef4444;
    
    --bg-primary: #ffffff;
    --bg-secondary: #f9fafb;
    --bg-tertiary: #f3f4f6;
    
    --text-primary: #111827;
    --text-secondary: #6b7280;
    --text-tertiary: #9ca3af;
    
    --border: #e5e7eb;
    --border-hover: #d1d5db;
    
    /* 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);
    
    /* Spacing */
    --spacing-xs: 0.5rem;
    --spacing-sm: 0.75rem;
    --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;
    
    /* Transitions */
    --transition: all 0.2s ease;
}

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

body {
    font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', 'Roboto', 
                 'Oxygen', 'Ubuntu', 'Cantarell', 'Fira Sans', 'Droid Sans', 
                 'Helvetica Neue', sans-serif;
    -webkit-font-smoothing: antialiased;
    -moz-osx-font-smoothing: grayscale;
    background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    min-height: 100vh;
    color: var(--text-primary);
    line-height: 1.6;
}

/* ==========================================
   CONTAINER & LAYOUT
   ========================================== */
.container {
    max-width: 900px;
    margin: 0 auto;
    padding: var(--spacing-xl) var(--spacing-md);
    min-height: 100vh;
    display: flex;
    flex-direction: column;
}

/* ==========================================
   HEADER
   ========================================== */
.header {
    text-align: center;
    margin-bottom: var(--spacing-2xl);
    animation: fadeInDown 0.6s ease;
}

.logo {
    display: flex;
    align-items: center;
    justify-content: center;
    gap: var(--spacing-sm);
    margin-bottom: var(--spacing-sm);
}

.logo .icon {
    font-size: 3rem;
    animation: pulse 2s ease-in-out infinite;
}

.logo h1 {
    font-size: 2.5rem;
    font-weight: 800;
    color: var(--bg-primary);
    text-shadow: 0 2px 10px rgba(0, 0, 0, 0.2);
}

.tagline {
    font-size: 1.125rem;
    color: rgba(255, 255, 255, 0.9);
    font-weight: 300;
}

/* ==========================================
   CARDS
   ========================================== */
.card {
    background: var(--bg-primary);
    border-radius: var(--radius-xl);
    padding: var(--spacing-xl);
    box-shadow: var(--shadow-xl);
    margin-bottom: var(--spacing-lg);
    animation: fadeInUp 0.6s ease;
}

.card h2 {
    font-size: 1.5rem;
    margin-bottom: var(--spacing-lg);
    color: var(--text-primary);
}

/* ==========================================
   DROPZONE
   ========================================== */
.dropzone {
    border: 2px dashed var(--border);
    border-radius: var(--radius-lg);
    padding: var(--spacing-2xl);
    text-align: center;
    background: var(--bg-secondary);
    transition: var(--transition);
    cursor: pointer;
    margin-bottom: var(--spacing-lg);
}

.dropzone:hover,
.dropzone.dragover {
    border-color: var(--primary);
    background: var(--bg-tertiary);
    transform: scale(1.01);
}

.dropzone-content {
    display: flex;
    flex-direction: column;
    align-items: center;
    gap: var(--spacing-sm);
}

.upload-icon {
    font-size: 3rem;
    opacity: 0.7;
}

.dropzone-text {
    font-size: 1.125rem;
    font-weight: 500;
    color: var(--text-primary);
}

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

.file-info {
    font-size: 0.75rem;
    color: var(--text-tertiary);
    margin-top: var(--spacing-sm);
}

/* ==========================================
   FILE SELECTED
   ========================================== */
.file-selected {
    margin-bottom: var(--spacing-lg);
    animation: fadeIn 0.3s ease;
}

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

.file-icon {
    font-size: 2rem;
}

.file-details {
    flex: 1;
}

.file-name {
    font-weight: 600;
    color: var(--text-primary);
    margin-bottom: 0.25rem;
}

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

/* ==========================================
   BUTTONS
   ========================================== */
.btn {
    padding: 0.75rem 1.5rem;
    border: none;
    border-radius: var(--radius-md);
    font-size: 1rem;
    font-weight: 600;
    cursor: pointer;
    transition: var(--transition);
    display: inline-flex;
    align-items: center;
    gap: var(--spacing-sm);
    justify-content: center;
}

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

.btn-primary:hover:not(:disabled) {
    background: var(--primary-dark);
    transform: translateY(-2px);
    box-shadow: var(--shadow-md);
}

.btn-secondary {
    background: var(--bg-tertiary);
    color: var(--text-primary);
}

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

.btn-analyze {
    width: 100%;
    padding: 1rem 2rem;
    font-size: 1.125rem;
    background: linear-gradient(135deg, var(--primary), var(--secondary));
    color: white;
    margin-top: var(--spacing-lg);
}

.btn-analyze:hover:not(:disabled) {
    transform: scale(1.02);
    box-shadow: var(--shadow-lg);
}

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

.btn-icon {
    background: transparent;
    border: none;
    color: var(--text-secondary);
    cursor: pointer;
    font-size: 1.25rem;
    padding: 0.25rem;
    transition: var(--transition);
}

.btn-icon:hover {
    color: var(--error);
}

/* ==========================================
   SELECT INPUT
   ========================================== */
.analysis-type-section {
    margin-bottom: var(--spacing-lg);
}

.analysis-type-section label {
    display: block;
    margin-bottom: var(--spacing-sm);
    color: var(--text-primary);
}

.select-input {
    width: 100%;
    padding: 0.75rem;
    border: 1px solid var(--border);
    border-radius: var(--radius-md);
    font-size: 1rem;
    background: white;
    cursor: pointer;
    transition: var(--transition);
}

.select-input:hover {
    border-color: var(--border-hover);
}

.select-input:focus {
    outline: none;
    border-color: var(--primary);
    box-shadow: 0 0 0 3px rgba(99, 102, 241, 0.1);
}

.type-description {
    margin-top: var(--spacing-xs);
    font-size: 0.875rem;
    color: var(--text-secondary);
}

/* ==========================================
   EXAMPLES
   ========================================== */
.examples-section {
    margin-top: var(--spacing-xl);
    text-align: center;
}

.examples-title {
    color: var(--text-secondary);
    margin-bottom: var(--spacing-md);
    font-size: 0.875rem;
}

.examples-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(150px, 1fr));
    gap: var(--spacing-md);
}

.example-btn {
    padding: var(--spacing-md);
    background: var(--bg-secondary);
    border: 1px solid var(--border);
    border-radius: var(--radius-md);
    cursor: pointer;
    transition: var(--transition);
    display: flex;
    flex-direction: column;
    align-items: center;
    gap: var(--spacing-xs);
}

.example-btn:hover {
    background: var(--bg-tertiary);
    border-color: var(--primary);
    transform: translateY(-2px);
    box-shadow: var(--shadow-sm);
}

.example-icon {
    font-size: 2rem;
}

.example-text {
    font-size: 0.875rem;
    font-weight: 500;
    color: var(--text-primary);
}

/* ==========================================
   LOADING
   ========================================== */
.loading-card {
    text-align: center;
}

.spinner {
    width: 60px;
    height: 60px;
    margin: 0 auto var(--spacing-lg);
    border: 4px solid var(--bg-tertiary);
    border-top-color: var(--primary);
    border-radius: 50%;
    animation: spin 1s linear infinite;
}

.loading-text {
    color: var(--text-secondary);
    margin-bottom: var(--spacing-xl);
}

.loading-steps {
    display: flex;
    justify-content: space-between;
    gap: var(--spacing-sm);
}

.step {
    flex: 1;
    display: flex;
    flex-direction: column;
    align-items: center;
    gap: var(--spacing-xs);
    padding: var(--spacing-sm);
    border-radius: var(--radius-md);
    opacity: 0.4;
    transition: var(--transition);
}

.step.active {
    opacity: 1;
    background: var(--bg-secondary);
}

.step-icon {
    font-size: 1.5rem;
}

.step span:last-child {
    font-size: 0.75rem;
    font-weight: 500;
}

/* ==========================================
   RESULTS
   ========================================== */
.results-header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    margin-bottom: var(--spacing-lg);
}

.results-header h2 {
    color: white;
    font-size: 1.75rem;
}

.result-card {
    animation: fadeInUp 0.6s ease backwards;
}

.result-card:nth-child(1) { animation-delay: 0.1s; }
.result-card:nth-child(2) { animation-delay: 0.2s; }
.result-card:nth-child(3) { animation-delay: 0.3s; }
.result-card:nth-child(4) { animation-delay: 0.4s; }

.card-header {
    display: flex;
    align-items: center;
    gap: var(--spacing-sm);
    margin-bottom: var(--spacing-md);
    padding-bottom: var(--spacing-md);
    border-bottom: 2px solid var(--bg-secondary);
}

.card-icon {
    font-size: 1.75rem;
}

.card-header h3 {
    font-size: 1.25rem;
    font-weight: 700;
}

.card-content {
    color: var(--text-secondary);
    line-height: 1.8;
    white-space: pre-wrap;
}

.actions-list {
    list-style-position: inside;
    color: var(--text-secondary);
}

.actions-list li {
    padding: var(--spacing-sm) 0;
    border-bottom: 1px solid var(--bg-secondary);
}

.actions-list li:last-child {
    border-bottom: none;
}

/* ==========================================
   ERROR
   ========================================== */
.error-card {
    text-align: center;
    border: 2px solid var(--error);
}

.error-icon {
    font-size: 3rem;
    margin-bottom: var(--spacing-md);
}

.error-message {
    color: var(--error);
    margin-bottom: var(--spacing-lg);
}

/* ==========================================
   FOOTER
   ========================================== */
.footer {
    margin-top: auto;
    padding-top: var(--spacing-xl);
    text-align: center;
    color: rgba(255, 255, 255, 0.8);
    font-size: 0.875rem;
}

/* ==========================================
   ANIMATIONS
   ========================================== */
@keyframes fadeIn {
    from { opacity: 0; }
    to { opacity: 1; }
}

@keyframes fadeInUp {
    from {
        opacity: 0;
        transform: translateY(20px);
    }
    to {
        opacity: 1;
        transform: translateY(0);
    }
}

@keyframes fadeInDown {
    from {
        opacity: 0;
        transform: translateY(-20px);
    }
    to {
        opacity: 1;
        transform: translateY(0);
    }
}

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

@keyframes pulse {
    0%, 100% { transform: scale(1); }
    50% { transform: scale(1.05); }
}

/* ==========================================
   RESPONSIVE
   ========================================== */
@media (max-width: 768px) {
    .container {
        padding: var(--spacing-md);
    }
    
    .logo h1 {
        font-size: 2rem;
    }
    
    .results-header {
        flex-direction: column;
        gap: var(--spacing-md);
    }
    
    .loading-steps {
        flex-wrap: wrap;
    }
    
    .step span:last-child {
        font-size: 0.625rem;
    }
}