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

:root {
    /* Modern Color Palette */
    --primary-gradient: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    --accent-gradient: linear-gradient(135deg, #f093fb 0%, #f5576c 100%);
    --success-gradient: linear-gradient(135deg, #4facfe 0%, #00f2fe 100%);
    
    /* Neutral Colors */
    --bg-dark: #0f0f23;
    --bg-card: rgba(255, 255, 255, 0.05);
    --bg-hover: rgba(255, 255, 255, 0.1);
    --text-primary: #ffffff;
    --text-secondary: rgba(255, 255, 255, 0.7);
    --text-muted: rgba(255, 255, 255, 0.5);
    
    /* Shadows */
    --shadow-sm: 0 2px 8px rgba(0, 0, 0, 0.1);
    --shadow-md: 0 4px 16px rgba(0, 0, 0, 0.2);
    --shadow-lg: 0 8px 32px rgba(0, 0, 0, 0.3);
    --shadow-glow: 0 0 40px rgba(102, 126, 234, 0.3);
    
    /* Spacing */
    --spacing-xs: 0.5rem;
    --spacing-sm: 1rem;
    --spacing-md: 1.5rem;
    --spacing-lg: 2rem;
    --spacing-xl: 3rem;
}

body {
    font-family: 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', sans-serif;
    background: var(--bg-dark);
    background-image: 
        radial-gradient(circle at 20% 50%, rgba(102, 126, 234, 0.1) 0%, transparent 50%),
        radial-gradient(circle at 80% 80%, rgba(118, 75, 162, 0.1) 0%, transparent 50%);
    color: var(--text-primary);
    min-height: 100vh;
    display: flex;
    align-items: center;
    justify-content: center;
    padding: var(--spacing-md);
    line-height: 1.6;
}

/* Container */
.container {
    width: 100%;
    max-width: 640px;
    animation: fadeIn 0.6s ease-out;
}

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

/* Header */
.header {
    text-align: center;
    margin-bottom: var(--spacing-xl);
}

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

.logo h1 {
    font-size: 2rem;
    font-weight: 700;
    background: var(--primary-gradient);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
}

.subtitle {
    font-size: 0.95rem;
    color: var(--text-secondary);
    font-weight: 400;
}

/* Main Card with Glassmorphism */
.main-card {
    background: var(--bg-card);
    backdrop-filter: blur(20px);
    -webkit-backdrop-filter: blur(20px);
    border: 1px solid rgba(255, 255, 255, 0.1);
    border-radius: 24px;
    padding: var(--spacing-xl);
    box-shadow: var(--shadow-lg), var(--shadow-glow);
    transition: all 0.3s ease;
}

.main-card:hover {
    box-shadow: var(--shadow-lg), 0 0 60px rgba(102, 126, 234, 0.4);
}

.card-title {
    font-size: 1.75rem;
    font-weight: 600;
    margin-bottom: var(--spacing-xs);
    text-align: center;
}

.card-description {
    text-align: center;
    color: var(--text-secondary);
    margin-bottom: var(--spacing-lg);
    font-size: 0.95rem;
}

/* Upload Zone */
.upload-zone {
    border: 2px dashed rgba(255, 255, 255, 0.2);
    border-radius: 16px;
    padding: var(--spacing-xl);
    text-align: center;
    cursor: pointer;
    transition: all 0.3s ease;
    background: rgba(255, 255, 255, 0.02);
    margin-bottom: var(--spacing-lg);
}

.upload-zone:hover {
    border-color: rgba(102, 126, 234, 0.6);
    background: rgba(102, 126, 234, 0.05);
    transform: translateY(-2px);
}

.upload-zone.drag-over {
    border-color: #667eea;
    background: rgba(102, 126, 234, 0.1);
    transform: scale(1.02);
}

.upload-icon {
    margin-bottom: var(--spacing-sm);
    animation: float 3s ease-in-out infinite;
}

@keyframes float {
    0%, 100% { transform: translateY(0px); }
    50% { transform: translateY(-10px); }
}

.upload-text {
    display: flex;
    flex-direction: column;
    gap: var(--spacing-xs);
}

.upload-text strong {
    font-size: 1.1rem;
    color: var(--text-primary);
}

.upload-text span {
    font-size: 0.9rem;
    color: var(--text-muted);
}

/* File Info */
.file-info {
    display: flex;
    align-items: center;
    gap: var(--spacing-sm);
    padding: var(--spacing-md);
    background: rgba(255, 255, 255, 0.05);
    border-radius: 12px;
    margin-bottom: var(--spacing-lg);
    border: 1px solid rgba(255, 255, 255, 0.1);
    animation: slideIn 0.3s ease-out;
}

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

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

.file-details {
    flex: 1;
}

.file-name {
    font-weight: 500;
    margin-bottom: 4px;
}

.file-size {
    font-size: 0.85rem;
    color: var(--text-secondary);
}

.btn-remove {
    background: rgba(245, 87, 108, 0.2);
    color: #f5576c;
    border: none;
    width: 32px;
    height: 32px;
    border-radius: 8px;
    cursor: pointer;
    font-size: 1.2rem;
    transition: all 0.2s ease;
}

.btn-remove:hover {
    background: rgba(245, 87, 108, 0.3);
    transform: scale(1.1);
}

/* Format Selection */
.format-section {
    margin-bottom: var(--spacing-lg);
}

.section-label {
    display: block;
    font-weight: 500;
    margin-bottom: var(--spacing-sm);
    font-size: 0.95rem;
}

.format-options {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: var(--spacing-sm);
}

.format-option {
    cursor: pointer;
}

.format-option input[type="radio"] {
    display: none;
}

.option-content {
    padding: var(--spacing-md);
    border: 2px solid rgba(255, 255, 255, 0.1);
    border-radius: 12px;
    background: rgba(255, 255, 255, 0.03);
    transition: all 0.3s ease;
    text-align: center;
}

.format-option:hover .option-content {
    border-color: rgba(102, 126, 234, 0.4);
    background: rgba(102, 126, 234, 0.05);
    transform: translateY(-2px);
}

.format-option input:checked + .option-content {
    border-color: #667eea;
    background: rgba(102, 126, 234, 0.1);
    box-shadow: 0 0 20px rgba(102, 126, 234, 0.3);
}

.option-icon {
    font-size: 2rem;
    margin-bottom: var(--spacing-xs);
}

.option-label {
    font-weight: 600;
    margin-bottom: 4px;
    font-size: 0.95rem;
}

.option-desc {
    font-size: 0.8rem;
    color: var(--text-muted);
}

/* AI Enhancement Toggle */
.ai-section {
    margin-bottom: var(--spacing-lg);
    padding: var(--spacing-md);
    background: rgba(240, 147, 251, 0.05);
    border-radius: 12px;
    border: 1px solid rgba(240, 147, 251, 0.2);
}

.toggle-label {
    display: flex;
    align-items: center;
    gap: var(--spacing-sm);
    cursor: pointer;
}

.toggle-input {
    display: none;
}

.toggle-switch {
    position: relative;
    width: 48px;
    height: 26px;
    background: rgba(255, 255, 255, 0.2);
    border-radius: 13px;
    transition: all 0.3s ease;
    flex-shrink: 0;
}

.toggle-switch::before {
    content: '';
    position: absolute;
    top: 3px;
    left: 3px;
    width: 20px;
    height: 20px;
    background: white;
    border-radius: 50%;
    transition: all 0.3s ease;
    box-shadow: 0 2px 4px rgba(0, 0, 0, 0.2);
}

.toggle-input:checked + .toggle-switch {
    background: var(--accent-gradient);
}

.toggle-input:checked + .toggle-switch::before {
    transform: translateX(22px);
}

.toggle-text {
    display: flex;
    flex-direction: column;
    gap: 4px;
}

.toggle-text strong {
    font-size: 0.95rem;
}

.toggle-text small {
    font-size: 0.8rem;
    color: var(--text-secondary);
}

/* Convert Button */
.btn-convert {
    width: 100%;
    padding: var(--spacing-md) var(--spacing-lg);
    background: var(--primary-gradient);
    color: white;
    border: none;
    border-radius: 12px;
    font-size: 1.05rem;
    font-weight: 600;
    cursor: pointer;
    transition: all 0.3s ease;
    display: flex;
    align-items: center;
    justify-content: center;
    gap: var(--spacing-xs);
    box-shadow: 0 4px 15px rgba(102, 126, 234, 0.4);
}

.btn-convert:hover:not(:disabled) {
    transform: translateY(-2px);
    box-shadow: 0 6px 20px rgba(102, 126, 234, 0.5);
}

.btn-convert:active:not(:disabled) {
    transform: translateY(0);
}

.btn-convert:disabled {
    background: rgba(255, 255, 255, 0.1);
    cursor: not-allowed;
    box-shadow: none;
}

.btn-icon {
    transition: transform 0.3s ease;
}

.btn-convert:hover:not(:disabled) .btn-icon {
    transform: translateX(4px);
}

/* Progress */
.progress-container {
    margin-bottom: var(--spacing-md);
    animation: slideIn 0.3s ease-out;
}

.progress-bar {
    height: 8px;
    background: rgba(255, 255, 255, 0.1);
    border-radius: 4px;
    overflow: hidden;
    margin-bottom: var(--spacing-xs);
}

.progress-fill {
    height: 100%;
    background: var(--success-gradient);
    width: 0%;
    transition: width 0.3s ease;
    animation: shimmer 1.5s infinite;
}

@keyframes shimmer {
    0% { opacity: 0.6; }
    50% { opacity: 1; }
    100% { opacity: 0.6; }
}

.progress-text {
    text-align: center;
    font-size: 0.9rem;
    color: var(--text-secondary);
}

/* Error Message */
.error-message {
    margin-top: var(--spacing-md);
    padding: var(--spacing-md);
    background: rgba(245, 87, 108, 0.1);
    border: 1px solid rgba(245, 87, 108, 0.3);
    border-radius: 12px;
    color: #f5576c;
    font-size: 0.9rem;
    animation: shake 0.5s ease-out, slideIn 0.3s ease-out;
    white-space: pre-line;
    line-height: 1.6;
}

@keyframes shake {
    0%, 100% { transform: translateX(0); }
    25% { transform: translateX(-10px); }
    75% { transform: translateX(10px); }
}

/* Footer */
.footer {
    text-align: center;
    margin-top: var(--spacing-xl);
    padding: var(--spacing-lg) 0;
    color: var(--text-muted);
    font-size: 0.85rem;
}

.footer p {
    margin-bottom: var(--spacing-xs);
}

.footer strong {
    background: var(--accent-gradient);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
}

.footer-note {
    font-size: 0.75rem;
    opacity: 0.6;
}

/* Responsive Design */
@media (max-width: 640px) {
    .container {
        padding: var(--spacing-sm);
    }
    
    .main-card {
        padding: var(--spacing-lg);
        border-radius: 20px;
    }
    
    .card-title {
        font-size: 1.5rem;
    }
    
    .format-options {
        grid-template-columns: 1fr;
    }
    
    .upload-zone {
        padding: var(--spacing-lg);
    }
}

/* Loading Spinner */
.spinner {
    display: inline-block;
    width: 20px;
    height: 20px;
    border: 3px solid rgba(255, 255, 255, 0.3);
    border-top-color: white;
    border-radius: 50%;
    animation: spin 0.8s linear infinite;
}

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

/* Token Section */
.token-section {
    margin-bottom: var(--spacing-lg);
}

.token-input-wrapper {
    display: flex;
    gap: var(--spacing-xs);
}

.token-input {
    flex: 1;
    padding: var(--spacing-sm) var(--spacing-md);
    background: rgba(255, 255, 255, 0.05);
    border: 1px solid rgba(255, 255, 255, 0.1);
    border-radius: 8px;
    color: var(--text-primary);
    font-size: 0.9rem;
    font-family: 'Monaco', 'Consolas', monospace;
    transition: all 0.3s ease;
}

.token-input:focus {
    outline: none;
    border-color: rgba(102, 126, 234, 0.6);
    background: rgba(102, 126, 234, 0.05);
}

.token-input::placeholder {
    color: var(--text-muted);
}

.token-toggle {
    padding: var(--spacing-sm);
    background: rgba(255, 255, 255, 0.05);
    border: 1px solid rgba(255, 255, 255, 0.1);
    border-radius: 8px;
    color: var(--text-secondary);
    cursor: pointer;
    transition: all 0.3s ease;
    display: flex;
    align-items: center;
    justify-content: center;
}

.token-toggle:hover {
    background: rgba(255, 255, 255, 0.1);
    color: var(--text-primary);
}

.token-hint {
    display: block;
    margin-top: var(--spacing-xs);
    font-size: 0.8rem;
    color: var(--text-muted);
}

/* Converter Section */
.converter-section {
    margin-bottom: var(--spacing-lg);
}

.converter-select {
    width: 100%;
    padding: var(--spacing-sm) var(--spacing-md);
    background: rgba(255, 255, 255, 0.05);
    border: 1px solid rgba(255, 255, 255, 0.1);
    border-radius: 8px;
    color: var(--text-primary);
    font-size: 0.9rem;
    cursor: pointer;
    transition: all 0.3s ease;
    appearance: none;
    background-image: url("data:image/svg+xml,%3Csvg xmlns='http://www.w3.org/2000/svg' width='12' height='12' viewBox='0 0 12 12'%3E%3Cpath fill='rgba(255,255,255,0.5)' d='M6 8L2 4h8z'/%3E%3C/svg%3E");
    background-repeat: no-repeat;
    background-position: right 12px center;
}

.converter-select:focus {
    outline: none;
    border-color: rgba(102, 126, 234, 0.6);
    background-color: rgba(102, 126, 234, 0.05);
}

.converter-select option {
    background: #1a1a2e;
    color: var(--text-primary);
    padding: var(--spacing-sm);
}