/* ===================================
   CSS VARIABLES & THEME SYSTEM
   =================================== */

:root {
    /* Dark Theme Colors */
    --bg-primary: #0a0e27;
    --bg-secondary: #151a35;
    --bg-tertiary: #1e2542;
    --bg-hover: #252d4f;
    
    /* Accent Colors */
    --accent-primary: #6366f1;
    --accent-secondary: #8b5cf6;
    --accent-gradient: linear-gradient(135deg, #6366f1 0%, #8b5cf6 100%);
    
    /* Text Colors */
    --text-primary: #ffffff;
    --text-secondary: #a8b2d1;
    --text-muted: #64748b;
    
    /* Status Colors */
    --success: #10b981;
    --error: #ef4444;
    --warning: #f59e0b;
    --info: #3b82f6;
    
    /* Borders & Shadows */
    --border-color: rgba(148, 163, 184, 0.1);
    --shadow-sm: 0 2px 8px rgba(0, 0, 0, 0.3);
    --shadow-md: 0 4px 16px rgba(0, 0, 0, 0.4);
    --shadow-lg: 0 8px 32px rgba(0, 0, 0, 0.5);
    --shadow-glow: 0 0 30px rgba(99, 102, 241, 0.3);
    
    /* Spacing */
    --spacing-xs: 0.5rem;
    --spacing-sm: 1rem;
    --spacing-md: 1.5rem;
    --spacing-lg: 2rem;
    --spacing-xl: 3rem;
    
    /* Border Radius */
    --radius-sm: 0.5rem;
    --radius-md: 1rem;
    --radius-lg: 1.5rem;
    --radius-xl: 2rem;
    
    /* Transitions */
    --transition-fast: 0.2s ease;
    --transition-normal: 0.3s ease;
    --transition-slow: 0.5s ease;
}

[data-theme="light"] {
    --bg-primary: #ffffff;
    --bg-secondary: #f8fafc;
    --bg-tertiary: #f1f5f9;
    --bg-hover: #e2e8f0;
    
    --text-primary: #0f172a;
    --text-secondary: #475569;
    --text-muted: #94a3b8;
    
    --border-color: rgba(15, 23, 42, 0.1);
    --shadow-sm: 0 2px 8px rgba(0, 0, 0, 0.05);
    --shadow-md: 0 4px 16px rgba(0, 0, 0, 0.08);
    --shadow-lg: 0 8px 32px rgba(0, 0, 0, 0.1);
    --shadow-glow: 0 0 30px rgba(99, 102, 241, 0.15);
}

/* ===================================
   RESET & BASE STYLES
   =================================== */

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

html {
    scroll-behavior: smooth;
}

body {
    font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, 'Helvetica Neue', Arial, sans-serif;
    background-color: var(--bg-primary);
    color: var(--text-primary);
    line-height: 1.6;
    overflow-x: hidden;
    transition: background-color var(--transition-normal);
}

/* ===================================
   ANIMATED BACKGROUND
   =================================== */

.bg-animation {
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    z-index: -1;
    overflow: hidden;
    pointer-events: none;
}

.gradient-orb {
    position: absolute;
    border-radius: 50%;
    filter: blur(80px);
    opacity: 0.3;
    animation: float 20s ease-in-out infinite;
}

.orb-1 {
    width: 600px;
    height: 600px;
    top: -300px;
    right: -200px;
    background: radial-gradient(circle, #6366f1, transparent);
    animation-delay: 0s;
}

.orb-2 {
    width: 500px;
    height: 500px;
    bottom: -250px;
    left: -150px;
    background: radial-gradient(circle, #8b5cf6, transparent);
    animation-delay: 5s;
}

.orb-3 {
    width: 400px;
    height: 400px;
    top: 50%;
    left: 50%;
    transform: translate(-50%, -50%);
    background: radial-gradient(circle, #06b6d4, transparent);
    animation-delay: 10s;
}

@keyframes float {
    0%, 100% {
        transform: translate(0, 0) scale(1);
    }
    33% {
        transform: translate(30px, -30px) scale(1.1);
    }
    66% {
        transform: translate(-20px, 20px) scale(0.9);
    }
}

/* ===================================
   CONTAINER & LAYOUT
   =================================== */

.container {
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 var(--spacing-md);
}

/* ===================================
   HEADER
   =================================== */

.header {
    position: sticky;
    top: 0;
    z-index: 100;
    background: rgba(10, 14, 39, 0.8);
    backdrop-filter: blur(20px);
    border-bottom: 1px solid var(--border-color);
    padding: var(--spacing-md) 0;
    animation: slideDown 0.5s ease;
}

[data-theme="light"] .header {
    background: rgba(255, 255, 255, 0.8);
}

@keyframes slideDown {
    from {
        transform: translateY(-100%);
        opacity: 0;
    }
    to {
        transform: translateY(0);
        opacity: 1;
    }
}

.header .container {
    display: flex;
    justify-content: space-between;
    align-items: center;
}

.logo {
    display: flex;
    align-items: center;
    gap: var(--spacing-sm);
    font-size: 1.5rem;
    font-weight: 700;
    color: var(--text-primary);
}

.logo-icon {
    width: 32px;
    height: 32px;
    stroke-width: 2;
    stroke: var(--accent-primary);
    animation: pulse 2s ease-in-out infinite;
}

@keyframes pulse {
    0%, 100% { transform: scale(1); }
    50% { transform: scale(1.1); }
}

.theme-toggle {
    background: var(--bg-secondary);
    border: 1px solid var(--border-color);
    border-radius: var(--radius-md);
    padding: var(--spacing-xs);
    cursor: pointer;
    display: flex;
    align-items: center;
    justify-content: center;
    transition: all var(--transition-fast);
}

.theme-toggle:hover {
    background: var(--bg-hover);
    border-color: var(--accent-primary);
    box-shadow: var(--shadow-glow);
}

.theme-toggle svg {
    width: 24px;
    height: 24px;
    stroke: var(--text-primary);
    fill: none;
    stroke-width: 2;
}

/* ===================================
   HERO SECTION
   =================================== */

.hero {
    text-align: center;
    padding: var(--spacing-xl) 0;
    animation: fadeIn 0.8s ease;
}

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

.hero-title {
    font-size: clamp(2rem, 5vw, 4rem);
    font-weight: 800;
    line-height: 1.2;
    margin-bottom: var(--spacing-md);
}

.gradient-text {
    background: var(--accent-gradient);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
    animation: gradientShift 3s ease infinite;
}

@keyframes gradientShift {
    0%, 100% { filter: hue-rotate(0deg); }
    50% { filter: hue-rotate(20deg); }
}

.hero-subtitle {
    font-size: clamp(1rem, 0.5vw, 1.25rem);
    color: var(--text-secondary);
    max-width: 600px;
    margin: 0 auto;
}

/* ===================================
   TOOLS GRID
   =================================== */

.tools-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
    gap: var(--spacing-md);
    padding: var(--spacing-lg) 0;
}

.tool-card {
    background: var(--bg-secondary);
    border: 1px solid var(--border-color);
    border-radius: var(--radius-lg);
    padding: var(--spacing-lg);
    cursor: pointer;
    transition: all var(--transition-normal);
    position: relative;
    overflow: hidden;
    animation: cardFadeIn 0.6s ease backwards;
}

@keyframes cardFadeIn {
    from {
        opacity: 0;
        transform: translateY(30px);
    }
    to {
        opacity: 1;
        transform: translateY(0);
    }
}

.tool-card:nth-child(1) { animation-delay: 0.1s; }
.tool-card:nth-child(2) { animation-delay: 0.2s; }
.tool-card:nth-child(3) { animation-delay: 0.3s; }
.tool-card:nth-child(4) { animation-delay: 0.4s; }
.tool-card:nth-child(5) { animation-delay: 0.5s; }
.tool-card:nth-child(6) { animation-delay: 0.6s; }
.tool-card:nth-child(7) { animation-delay: 0.7s; }
.tool-card:nth-child(8) { animation-delay: 0.8s; }
.tool-card:nth-child(9) { animation-delay: 0.9s; }

.tool-card::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    height: 2px;
    background: var(--accent-gradient);
    transform: scaleX(0);
    transition: transform var(--transition-normal);
}

.tool-card:hover {
    transform: translateY(-8px);
    box-shadow: var(--shadow-lg), var(--shadow-glow);
    border-color: var(--accent-primary);
}

.tool-card:hover::before {
    transform: scaleX(1);
}

.tool-icon {
    width: 48px;
    height: 48px;
    margin-bottom: var(--spacing-md);
    padding: var(--spacing-sm);
    background: var(--accent-gradient);
    border-radius: var(--radius-md);
    display: flex;
    align-items: center;
    justify-content: center;
    transition: transform var(--transition-normal);
}

.tool-card:hover .tool-icon {
    transform: rotateY(360deg);
}

.tool-icon svg {
    width: 100%;
    height: 100%;
    stroke: white;
    fill: none;
    stroke-width: 2;
}

.tool-card h3 {
    font-size: 1.25rem;
    font-weight: 700;
    margin-bottom: var(--spacing-xs);
}

.tool-card p {
    color: var(--text-secondary);
    font-size: 0.95rem;
}

/* ===================================
   MODAL
   =================================== */

.modal {
    display: none;
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    background: rgba(0, 0, 0, 0.8);
    backdrop-filter: blur(10px);
    z-index: 1000;
    animation: modalFadeIn 0.3s ease;
    overflow-y: auto;
}

.modal.active {
    display: flex;
    align-items: center;
    justify-content: center;
    padding: var(--spacing-md);
}

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

.modal-content {
    background: var(--bg-secondary);
    border-radius: var(--radius-xl);
    width: 100%;
    max-width: 700px;
    max-height: 90vh;
    overflow-y: auto;
    box-shadow: var(--shadow-lg);
    animation: modalSlideUp 0.3s ease;
    position: relative;
}

@keyframes modalSlideUp {
    from {
        transform: translateY(50px);
        opacity: 0;
    }
    to {
        transform: translateY(0);
        opacity: 1;
    }
}

.modal-close {
    position: absolute;
    top: var(--spacing-md);
    right: var(--spacing-md);
    background: var(--bg-tertiary);
    border: 1px solid var(--border-color);
    border-radius: var(--radius-md);
    padding: var(--spacing-xs);
    cursor: pointer;
    transition: all var(--transition-fast);
    z-index: 10;
}

.modal-close:hover {
    background: var(--bg-hover);
    border-color: var(--accent-primary);
    transform: rotate(90deg);
}

.modal-close svg {
    width: 20px;
    height: 20px;
    stroke: var(--text-primary);
    stroke-width: 2;
}

.modal-header {
    padding: var(--spacing-lg);
    border-bottom: 1px solid var(--border-color);
}

.modal-header h2 {
    font-size: 1.75rem;
    font-weight: 700;
    margin-bottom: var(--spacing-xs);
}

.modal-header p {
    color: var(--text-secondary);
}

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

/* ===================================
   UPLOAD AREA
   =================================== */

.upload-area {
    border: 2px dashed var(--border-color);
    border-radius: var(--radius-lg);
    padding: var(--spacing-xl);
    text-align: center;
    cursor: pointer;
    transition: all var(--transition-normal);
    background: var(--bg-tertiary);
}

.upload-area:hover,
.upload-area:focus,
.upload-area.dragover {
    border-color: var(--accent-primary);
    background: var(--bg-hover);
    box-shadow: var(--shadow-glow);
    outline: none;
}

.upload-icon {
    width: 64px;
    height: 64px;
    margin: 0 auto var(--spacing-md);
    stroke: var(--accent-primary);
    stroke-width: 2;
    fill: none;
    animation: bounce 2s ease-in-out infinite;
}

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

.upload-text {
    font-size: 1.1rem;
    font-weight: 600;
    margin-bottom: var(--spacing-xs);
}

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

/* ===================================
   FILE LIST
   =================================== */

.file-list {
    margin-top: var(--spacing-md);
}

.file-item {
    display: flex;
    align-items: center;
    justify-content: space-between;
    background: var(--bg-tertiary);
    border: 1px solid var(--border-color);
    border-radius: var(--radius-md);
    padding: var(--spacing-md);
    margin-bottom: var(--spacing-sm);
    animation: slideIn 0.3s ease;
}

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

.file-info {
    display: flex;
    align-items: center;
    gap: var(--spacing-sm);
    flex: 1;
    min-width: 0;
}

.file-icon {
    width: 40px;
    height: 40px;
    background: var(--accent-gradient);
    border-radius: var(--radius-sm);
    display: flex;
    align-items: center;
    justify-content: center;
    flex-shrink: 0;
}

.file-icon svg {
    width: 24px;
    height: 24px;
    stroke: white;
    fill: none;
    stroke-width: 2;
}

.file-details {
    min-width: 0;
    flex: 1;
}

.file-details h4 {
    font-size: 0.95rem;
    font-weight: 600;
    margin-bottom: 2px;
    overflow: hidden;
    text-overflow: ellipsis;
    white-space: nowrap;
}

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

.file-remove {
    background: transparent;
    border: none;
    cursor: pointer;
    padding: var(--spacing-xs);
    color: var(--text-muted);
    transition: color var(--transition-fast);
    flex-shrink: 0;
}

.file-remove:hover {
    color: var(--error);
}

/* ===================================
   TOOL OPTIONS
   =================================== */

.tool-options {
    margin-top: var(--spacing-lg);
}

.option-group {
    margin-bottom: var(--spacing-md);
}

.option-group label {
    display: block;
    font-weight: 600;
    margin-bottom: var(--spacing-xs);
    color: var(--text-primary);
}

.option-group input,
.option-group select,
.option-group textarea {
    width: 100%;
    background: var(--bg-tertiary);
    border: 1px solid var(--border-color);
    border-radius: var(--radius-md);
    padding: var(--spacing-sm);
    color: var(--text-primary);
    font-size: 1rem;
    font-family: inherit;
    transition: all var(--transition-fast);
}

.option-group textarea {
    min-height: 120px;
    resize: vertical;
}

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

.option-group input[type="color"] {
    height: 48px;
    cursor: pointer;
}

/* ===================================
   RESULTS DISPLAY
   =================================== */

.results-display {
    margin-top: var(--spacing-lg);
    background: var(--bg-tertiary);
    border: 1px solid var(--border-color);
    border-radius: var(--radius-lg);
    padding: var(--spacing-lg);
}

.results-display h3 {
    font-size: 1.25rem;
    font-weight: 700;
    margin-bottom: var(--spacing-md);
    color: var(--accent-primary);
}

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

.stat-card {
    background: var(--bg-secondary);
    border: 1px solid var(--border-color);
    border-radius: var(--radius-md);
    padding: var(--spacing-md);
    text-align: center;
}

.stat-card .stat-value {
    font-size: 2rem;
    font-weight: 800;
    color: var(--accent-primary);
    display: block;
    margin-bottom: var(--spacing-xs);
}

.stat-card .stat-label {
    font-size: 0.9rem;
    color: var(--text-secondary);
}

.keyword-list {
    margin-bottom: var(--spacing-lg);
}

.keyword-item {
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: var(--spacing-sm);
    background: var(--bg-secondary);
    border-radius: var(--radius-sm);
    margin-bottom: var(--spacing-xs);
}

.keyword-item .keyword {
    font-weight: 600;
}

.keyword-item .count {
    background: var(--accent-gradient);
    color: white;
    padding: 2px 8px;
    border-radius: 999px;
    font-size: 0.85rem;
    font-weight: 600;
}

.typo-list {
    margin-top: var(--spacing-md);
}


.typo-item {
    background: var(--bg-secondary);
    border-radius: var(--radius-sm);
    padding: var(--spacing-sm);
    margin-bottom: var(--spacing-xs);
}

.typo-item .incorrect {
    color: var(--error);
    font-weight: 600;
    display: block;
    margin-bottom: 4px;
}

.typo-item .suggestions {
    color: var(--text-secondary);
    font-size: 0.9rem;
}

/* ===================================
   PROGRESS BAR
   =================================== */

.progress-container {
    margin: var(--spacing-lg) 0;
}

.progress-bar {
    height: 8px;
    background: var(--bg-tertiary);
    border-radius: 999px;
    overflow: hidden;
}

.progress-fill {
    height: 100%;
    background: var(--accent-gradient);
    border-radius: 999px;
    transition: width 0.3s ease;
    width: 0;
}

.progress-fill.indeterminate {
    width: 30%;
    animation: indeterminate 1.5s ease-in-out infinite;
}

@keyframes indeterminate {
    0% {
        transform: translateX(-100%);
    }
    100% {
        transform: translateX(400%);
    }
}

.progress-text {
    text-align: center;
    margin-top: var(--spacing-sm);
    color: var(--text-secondary);
    font-weight: 600;
}

/* ===================================
   BUTTONS
   =================================== */

.btn-primary {
    width: 100%;
    background: var(--accent-gradient);
    border: none;
    border-radius: var(--radius-md);
    padding: var(--spacing-md);
    color: white;
    font-size: 1rem;
    font-weight: 600;
    cursor: pointer;
    display: flex;
    align-items: center;
    justify-content: center;
    gap: var(--spacing-xs);
    transition: all var(--transition-normal);
    margin-top: var(--spacing-lg);
}

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

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

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

.btn-primary svg {
    width: 20px;
    height: 20px;
    stroke: white;
    fill: none;
    stroke-width: 2;
}

/* ===================================
   TOAST NOTIFICATIONS
   =================================== */

.toast-container {
    position: fixed;
    top: var(--spacing-lg);
    right: var(--spacing-lg);
    z-index: 2000;
    display: flex;
    flex-direction: column;
    gap: var(--spacing-sm);
}

.toast {
    background: var(--bg-secondary);
    border: 1px solid var(--border-color);
    border-radius: var(--radius-md);
    padding: var(--spacing-md);
    min-width: 300px;
    max-width: 400px;
    box-shadow: var(--shadow-lg);
    display: flex;
    align-items: flex-start;
    gap: var(--spacing-sm);
    animation: toastSlideIn 0.3s ease;
}

@keyframes toastSlideIn {
    from {
        transform: translateX(400px);
        opacity: 0;
    }
    to {
        transform: translateX(0);
        opacity: 1;
    }
}

.toast.success {
    border-left: 4px solid var(--success);
}

.toast.error {
    border-left: 4px solid var(--error);
}

.toast.info {
    border-left: 4px solid var(--info);
}

.toast.warning {
    border-left: 4px solid var(--warning);
}

.toast-icon {
    flex-shrink: 0;
    width: 20px;
    height: 20px;
}

.toast-content {
    flex: 1;
}

.toast-title {
    font-weight: 600;
    margin-bottom: 2px;
}

.toast-message {
    font-size: 0.9rem;
    color: var(--text-secondary);
}

/* ===================================
   RESPONSIVE DESIGN
   =================================== */

/* Tablet */
@media (max-width: 768px) {
    .tools-grid {
        grid-template-columns: repeat(auto-fit, minmax(240px, 1fr));
        gap: var(--spacing-sm);
    }
    
    .hero-title {
        font-size: 2.5rem;
    }
    
    .modal-content {
        max-width: 95%;
    }
    
    .toast-container {
        right: var(--spacing-sm);
        left: var(--spacing-sm);
    }
    
    .toast {
        min-width: unset;
        max-width: unset;
    }

    .stat-grid {
        grid-template-columns: repeat(2, 1fr);
    }
}

/* Mobile */
@media (max-width: 480px) {
    .container {
        padding: 0 var(--spacing-sm);
    }
    
    .tools-grid {
        grid-template-columns: 1fr;
    }
    
    .hero {
        padding: var(--spacing-lg) 0;
    }
    
    .hero-title {
        font-size: 2rem;
    }
    
    .upload-area {
        padding: var(--spacing-lg);
    }
    
    .modal-body {
        padding: var(--spacing-md);
    }
    
    .modal-header {
        padding: var(--spacing-md);
    }
    
    .orb-1, .orb-2, .orb-3 {
        width: 300px;
        height: 300px;
    }

    .stat-grid {
        grid-template-columns: 1fr;
    }

    .logo {
        font-size: 1.25rem;
    }

    .logo-icon {
        width: 28px;
        height: 28px;
    }
}

/* ===================================
   SCROLLBAR STYLING
   =================================== */

::-webkit-scrollbar {
    width: 10px;
}

::-webkit-scrollbar-track {
    background: var(--bg-primary);
}

::-webkit-scrollbar-thumb {
    background: var(--bg-tertiary);
    border-radius: 999px;
}

::-webkit-scrollbar-thumb:hover {
    background: var(--accent-primary);
}

/* For modal content */
.modal-content::-webkit-scrollbar {
    width: 8px;
}

/* ===================================
   UTILITY CLASSES
   =================================== */

.hidden {
    display: none !important;
}

.loading {
    pointer-events: none;
    opacity: 0.6;
}

.text-center {
    text-align: center;
}

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

.mt-lg {
    margin-top: var(--spacing-lg);
}

.mb-lg {
    margin-bottom: var(--spacing-lg);
}

/* ===================================
   ACCESSIBILITY
   =================================== */

.visually-hidden {
    position: absolute;
    width: 1px;
    height: 1px;
    padding: 0;
    margin: -1px;
    overflow: hidden;
    clip: rect(0, 0, 0, 0);
    white-space: nowrap;
    border-width: 0;
}

/* Focus states for keyboard navigation */
button:focus-visible,
a:focus-visible,
input:focus-visible,
select:focus-visible,
textarea:focus-visible,
.upload-area:focus-visible {
    outline: 2px solid var(--accent-primary);
    outline-offset: 2px;
}

/* Reduced motion */
@media (prefers-reduced-motion: reduce) {
    *,
    *::before,
    *::after {
        animation-duration: 0.01ms !important;
        animation-iteration-count: 1 !important;
        transition-duration: 0.01ms !important;
    }
}