/* ========================================
   CSS Variables & Root Styles
   ======================================== */

:root {
    /* Dark Theme Colors */
    --bg-primary: #0f0f1a;
    --bg-secondary: #1a1a2e;
    --bg-card: #16213e;
    --bg-input: #1a1a3e;
    --bg-hover: #1f2849;
    
    /* Accent Colors */
    --accent-primary: #00d9ff;
    --accent-secondary: #4ecca3;
    --accent-gradient: linear-gradient(135deg, #00d9ff 0%, #4ecca3 100%);
    
    /* Text Colors */
    --text-primary: #ffffff;
    --text-secondary: #b0b0b0;
    --text-muted: #6b6b8a;
    
    /* Status Colors */
    --success: #4ecca3;
    --error: #ff6b6b;
    --warning: #ffd93d;
    --info: #00d9ff;
    
    /* 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: 6px;
    --radius-md: 10px;
    --radius-lg: 16px;
    --radius-xl: 24px;
    
    /* Shadows */
    --shadow-sm: 0 2px 4px rgba(0, 0, 0, 0.2);
    --shadow-md: 0 4px 12px rgba(0, 0, 0, 0.3);
    --shadow-lg: 0 8px 24px rgba(0, 0, 0, 0.4);
    --shadow-glow: 0 0 20px rgba(0, 217, 255, 0.3);
    
    /* Transitions */
    --transition-fast: 150ms ease;
    --transition-normal: 250ms ease;
    --transition-slow: 350ms ease;
    
    /* Fonts */
    --font-mono: 'Fira Code', 'Consolas', 'Monaco', monospace;
    --font-sans: 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', sans-serif;
}

/* Light Theme */
[data-theme="light"] {
    --bg-primary: #f5f5f7;
    --bg-secondary: #ffffff;
    --bg-card: #ffffff;
    --bg-input: #f0f0f5;
    --bg-hover: #e8e8ed;
    --text-primary: #1a1a2e;
    --text-secondary: #4a4a6a;
    --text-muted: #8a8a9a;
    --shadow-sm: 0 2px 4px rgba(0, 0, 0, 0.08);
    --shadow-md: 0 4px 12px rgba(0, 0, 0, 0.12);
    --shadow-lg: 0 8px 24px rgba(0, 0, 0, 0.16);
}

/* ========================================
   Reset & Base Styles
   ======================================== */

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

html {
    font-size: 16px;
    scroll-behavior: smooth;
}

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

/* ========================================
   Binary Rain Background Effect
   ======================================== */

.binary-rain {
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    pointer-events: none;
    z-index: 0;
    opacity: 0.03;
    overflow: hidden;
}

.binary-rain .binary-column {
    position: absolute;
    top: -100%;
    font-family: var(--font-mono);
    font-size: 14px;
    color: var(--accent-primary);
    writing-mode: vertical-rl;
    text-orientation: upright;
    animation: rain-fall linear infinite;
    opacity: 0.7;
}

@keyframes rain-fall {
    0% {
        transform: translateY(-100%);
    }
    100% {
        transform: translateY(calc(100vh + 100%));
    }
}

/* ========================================
   Container & Layout
   ======================================== */

.container {
    position: relative;
    z-index: 1;
    max-width: 1400px;
    margin: 0 auto;
    padding: var(--spacing-lg);
}

/* ========================================
   Header Styles
   ======================================== */

.header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: var(--spacing-lg) 0;
    margin-bottom: var(--spacing-xl);
    border-bottom: 1px solid rgba(255, 255, 255, 0.1);
}

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

.logo-icon {
    font-family: var(--font-mono);
    font-size: 1.5rem;
    font-weight: 600;
    background: var(--accent-gradient);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
    padding: var(--spacing-sm) var(--spacing-md);
    border: 2px solid var(--accent-primary);
    border-radius: var(--radius-md);
}

.logo-text h1 {
    font-size: 1.75rem;
    font-weight: 700;
    background: var(--accent-gradient);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
}

.subtitle {
    color: var(--text-secondary);
    font-size: 0.9rem;
    margin-top: var(--spacing-xs);
}

.theme-toggle {
    background: var(--bg-card);
    border: 1px solid rgba(255, 255, 255, 0.1);
    border-radius: var(--radius-md);
    padding: var(--spacing-sm) var(--spacing-md);
    cursor: pointer;
    transition: all var(--transition-normal);
}

.theme-toggle:hover {
    background: var(--bg-hover);
    transform: scale(1.05);
}

.theme-icon {
    font-size: 1.25rem;
}

/* ========================================
   Main Content & Converters Grid
   ======================================== */

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

.converters-grid {
    display: grid;
    grid-template-columns: repeat(2, 1fr);
    gap: var(--spacing-xl);
}

@media (max-width: 1024px) {
    .converters-grid {
        grid-template-columns: 1fr;
    }
}

/* ========================================
   Converter Card Styles
   ======================================== */

.converter-card {
    background: var(--bg-card);
    border-radius: var(--radius-lg);
    padding: var(--spacing-xl);
    box-shadow: var(--shadow-md);
    border: 1px solid rgba(255, 255, 255, 0.05);
    transition: all var(--transition-normal);
}

.converter-card:hover {
    box-shadow: var(--shadow-lg);
    border-color: rgba(0, 217, 255, 0.2);
}

.card-header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    margin-bottom: var(--spacing-lg);
    padding-bottom: var(--spacing-md);
    border-bottom: 1px solid rgba(255, 255, 255, 0.1);
}

.card-header h2 {
    display: flex;
    align-items: center;
    gap: var(--spacing-sm);
    font-size: 1.25rem;
    font-weight: 600;
}

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

/* ========================================
   Real-time Toggle Switch
   ======================================== */

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

.toggle-switch {
    position: relative;
    display: inline-block;
    width: 44px;
    height: 24px;
}

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

.toggle-slider {
    position: absolute;
    cursor: pointer;
    inset: 0;
    background-color: var(--bg-input);
    border-radius: 24px;
    transition: var(--transition-normal);
}

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

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

.toggle-switch input:checked + .toggle-slider::before {
    transform: translateX(20px);
    background-color: white;
}

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

/* ========================================
   Input Group Styles
   ======================================== */

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

.input-group label {
    display: block;
    font-size: 0.9rem;
    font-weight: 500;
    color: var(--text-secondary);
    margin-bottom: var(--spacing-sm);
}

.input-textarea {
    width: 100%;
    padding: var(--spacing-md);
    background: var(--bg-input);
    border: 2px solid rgba(255, 255, 255, 0.1);
    border-radius: var(--radius-md);
    color: var(--text-primary);
    font-family: var(--font-sans);
    font-size: 1rem;
    resize: vertical;
    min-height: 100px;
    transition: all var(--transition-normal);
}

.input-textarea.binary-input {
    font-family: var(--font-mono);
    letter-spacing: 1px;
}

.input-textarea:focus {
    outline: none;
    border-color: var(--accent-primary);
    box-shadow: 0 0 0 3px rgba(0, 217, 255, 0.15);
}

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

.input-info {
    display: flex;
    justify-content: space-between;
    align-items: center;
    margin-top: var(--spacing-sm);
}

.char-count, .bit-count {
    font-size: 0.8rem;
    color: var(--text-muted);
    font-family: var(--font-mono);
}

.clear-btn {
    background: transparent;
    border: none;
    color: var(--text-secondary);
    font-size: 0.8rem;
    cursor: pointer;
    padding: var(--spacing-xs) var(--spacing-sm);
    border-radius: var(--radius-sm);
    transition: all var(--transition-fast);
}

.clear-btn:hover {
    color: var(--error);
    background: rgba(255, 107, 107, 0.1);
}

/* ========================================
   Format Selector
   ======================================== */

.format-selector {
    display: flex;
    align-items: center;
    gap: var(--spacing-md);
    margin-bottom: var(--spacing-md);
}

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

.format-dropdown {
    flex: 1;
    padding: var(--spacing-sm) var(--spacing-md);
    background: var(--bg-input);
    border: 2px solid rgba(255, 255, 255, 0.1);
    border-radius: var(--radius-md);
    color: var(--text-primary);
    font-size: 0.9rem;
    cursor: pointer;
    transition: all var(--transition-normal);
}

.format-dropdown:focus {
    outline: none;
    border-color: var(--accent-primary);
}

.format-dropdown option {
    background: var(--bg-card);
    color: var(--text-primary);
}

/* ========================================
   Convert Button
   ======================================== */

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

.convert-btn:hover {
    transform: translateY(-2px);
    box-shadow: var(--shadow-glow);
}

.convert-btn:active {
    transform: translateY(0);
}

.btn-icon {
    font-size: 1.1rem;
}

/* ========================================
   Output Group Styles
   ======================================== */

.output-group {
    background: var(--bg-input);
    border-radius: var(--radius-md);
    padding: var(--spacing-lg);
    border: 1px solid rgba(255, 255, 255, 0.05);
}

.output-group label {
    display: block;
    font-size: 0.9rem;
    font-weight: 500;
    color: var(--text-secondary);
    margin-bottom: var(--spacing-sm);
}

.output-display {
    background: var(--bg-primary);
    padding: var(--spacing-md);
    border-radius: var(--radius-md);
    min-height: 80px;
    font-family: var(--font-mono);
    font-size: 0.95rem;
    line-height: 1.8;
    word-break: break-all;
    color: var(--accent-primary);
    border: 1px solid rgba(255, 255, 255, 0.05);
}

.output-display.text-output {
    font-family: var(--font-sans);
    color: var(--accent-secondary);
}

.placeholder-text {
    color: var(--text-muted);
    font-style: italic;
}

.output-info {
    margin-top: var(--spacing-sm);
    display: flex;
    justify-content: flex-end;
}

/* ========================================
   Breakdown Section
   ======================================== */

.breakdown-section {
    margin-top: var(--spacing-md);
}

.breakdown-toggle {
    display: flex;
    align-items: center;
    gap: var(--spacing-sm);
    width: 100%;
    padding: var(--spacing-sm);
    background: transparent;
    border: none;
    color: var(--text-secondary);
    font-size: 0.9rem;
    cursor: pointer;
    transition: all var(--transition-fast);
    border-radius: var(--radius-sm);
}

.breakdown-toggle:hover {
    color: var(--accent-primary);
    background: rgba(0, 217, 255, 0.05);
}

.toggle-arrow {
    transition: transform var(--transition-normal);
    font-size: 0.8rem;
}

.breakdown-toggle[aria-expanded="true"] .toggle-arrow {
    transform: rotate(90deg);
}

.breakdown-content {
    margin-top: var(--spacing-md);
    overflow-x: auto;
}

.breakdown-table {
    width: 100%;
    border-collapse: collapse;
    font-size: 0.85rem;
}

.breakdown-table th,
.breakdown-table td {
    padding: var(--spacing-sm) var(--spacing-md);
    text-align: left;
    border-bottom: 1px solid rgba(255, 255, 255, 0.1);
}

.breakdown-table th {
    background: var(--bg-primary);
    color: var(--text-secondary);
    font-weight: 500;
    text-transform: uppercase;
    font-size: 0.75rem;
    letter-spacing: 0.5px;
}

.breakdown-table td {
    font-family: var(--font-mono);
    color: var(--text-primary);
}

.breakdown-table tr:hover td {
    background: rgba(0, 217, 255, 0.05);
}

/* ========================================
   Action Buttons
   ======================================== */

.action-buttons {
    display: flex;
    gap: var(--spacing-sm);
    margin-top: var(--spacing-md);
    flex-wrap: wrap;
}

.action-btn {
    display: flex;
    align-items: center;
    gap: var(--spacing-xs);
    padding: var(--spacing-sm) var(--spacing-md);
    background: var(--bg-secondary);
    border: 1px solid rgba(255, 255, 255, 0.1);
    border-radius: var(--radius-sm);
    color: var(--text-secondary);
    font-size: 0.85rem;
    cursor: pointer;
    transition: all var(--transition-normal);
}

.action-btn:hover:not(:disabled) {
    background: var(--bg-hover);
    color: var(--text-primary);
    border-color: rgba(255, 255, 255, 0.2);
}

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

.action-btn.copy-btn:hover:not(:disabled) {
    border-color: var(--accent-primary);
    color: var(--accent-primary);
}

.action-btn.download-btn:hover:not(:disabled) {
    border-color: var(--accent-secondary);
    color: var(--accent-secondary);
}

.action-btn.reset-btn:hover:not(:disabled) {
    border-color: var(--warning);
    color: var(--warning);
}

/* ========================================
   Upload Section
   ======================================== */

.upload-section {
    background: var(--bg-card);
    border-radius: var(--radius-lg);
    padding: var(--spacing-xl);
    box-shadow: var(--shadow-md);
    border: 1px solid rgba(255, 255, 255, 0.05);
}

.upload-section h2 {
    display: flex;
    align-items: center;
    gap: var(--spacing-sm);
    font-size: 1.25rem;
    font-weight: 600;
    margin-bottom: var(--spacing-lg);
}

.upload-zone {
    position: relative;
    display: flex;
    flex-direction: column;
    align-items: center;
    justify-content: center;
    padding: var(--spacing-2xl);
    background: var(--bg-input);
    border: 2px dashed rgba(255, 255, 255, 0.2);
    border-radius: var(--radius-lg);
    cursor: pointer;
    transition: all var(--transition-normal);
}

.upload-zone:hover,
.upload-zone.drag-over {
    border-color: var(--accent-primary);
    background: rgba(0, 217, 255, 0.05);
}

.upload-zone.drag-over {
    transform: scale(1.01);
}

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

.upload-text {
    font-size: 1.1rem;
    font-weight: 500;
    color: var(--text-primary);
}

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

.file-type-badge {
    position: absolute;
    bottom: var(--spacing-md);
    right: var(--spacing-md);
    background: var(--bg-primary);
    color: var(--text-secondary);
    padding: var(--spacing-xs) var(--spacing-sm);
    border-radius: var(--radius-sm);
    font-size: 0.75rem;
    font-family: var(--font-mono);
}

.upload-status {
    margin-top: var(--spacing-md);
    text-align: center;
    font-size: 0.9rem;
    min-height: 24px;
}

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

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

/* ========================================
   Reference Section
   ======================================== */

.reference-section {
    background: var(--bg-card);
    border-radius: var(--radius-lg);
    padding: var(--spacing-lg);
    box-shadow: var(--shadow-md);
    border: 1px solid rgba(255, 255, 255, 0.05);
}

.reference-toggle {
    display: flex;
    align-items: center;
    gap: var(--spacing-sm);
    width: 100%;
    padding: var(--spacing-sm);
    background: transparent;
    border: none;
    color: var(--text-primary);
    font-size: 1rem;
    font-weight: 500;
    cursor: pointer;
    transition: all var(--transition-fast);
    border-radius: var(--radius-sm);
}

.reference-toggle:hover {
    color: var(--accent-primary);
}

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

.reference-grid {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(100px, 1fr));
    gap: var(--spacing-sm);
}

.reference-item {
    background: var(--bg-input);
    padding: var(--spacing-sm);
    border-radius: var(--radius-sm);
    text-align: center;
    font-family: var(--font-mono);
    font-size: 0.75rem;
    transition: all var(--transition-fast);
}

.reference-item:hover {
    background: var(--bg-hover);
    transform: scale(1.05);
}

.reference-item .char {
    display: block;
    font-size: 1rem;
    font-weight: 600;
    color: var(--accent-primary);
    margin-bottom: var(--spacing-xs);
}

.reference-item .ascii {
    color: var(--text-secondary);
}

.reference-item .binary {
    color: var(--text-muted);
    font-size: 0.65rem;
}

/* ========================================
   Footer Styles
   ======================================== */

.footer {
    margin-top: var(--spacing-2xl);
    padding-top: var(--spacing-xl);
    border-top: 1px solid rgba(255, 255, 255, 0.1);
}

.footer-content {
    display: grid;
    grid-template-columns: repeat(2, 1fr);
    gap: var(--spacing-xl);
}

@media (max-width: 768px) {
    .footer-content {
        grid-template-columns: 1fr;
    }
}

.footer h3 {
    font-size: 1rem;
    font-weight: 600;
    color: var(--text-primary);
    margin-bottom: var(--spacing-md);
}

.footer ul {
    list-style: none;
}

.footer li {
    font-size: 0.9rem;
    color: var(--text-secondary);
    margin-bottom: var(--spacing-sm);
    line-height: 1.5;
}

.footer li strong {
    color: var(--accent-primary);
}

kbd {
    display: inline-block;
    padding: var(--spacing-xs) var(--spacing-sm);
    background: var(--bg-input);
    border: 1px solid rgba(255, 255, 255, 0.1);
    border-radius: var(--radius-sm);
    font-family: var(--font-mono);
    font-size: 0.75rem;
    color: var(--text-primary);
    margin: 0 2px;
}

.footer-bottom {
    margin-top: var(--spacing-xl);
    padding-top: var(--spacing-lg);
    text-align: center;
    border-top: 1px solid rgba(255, 255, 255, 0.05);
}

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

/* ========================================
   Toast Notifications
   ======================================== */

.toast-container {
    position: fixed;
    bottom: var(--spacing-xl);
    right: var(--spacing-xl);
    z-index: 1000;
    display: flex;
    flex-direction: column;
    gap: var(--spacing-sm);
}

.toast {
    display: flex;
    align-items: center;
    gap: var(--spacing-md);
    padding: var(--spacing-md) var(--spacing-lg);
    background: var(--bg-card);
    border-radius: var(--radius-md);
    box-shadow: var(--shadow-lg);
    border-left: 4px solid var(--accent-primary);
    animation: toast-slide-in 0.3s ease;
    max-width: 350px;
}

.toast.success {
    border-left-color: var(--success);
}

.toast.error {
    border-left-color: var(--error);
}

.toast.warning {
    border-left-color: var(--warning);
}

.toast-icon {
    font-size: 1.25rem;
}

.toast-message {
    flex: 1;
    font-size: 0.9rem;
    color: var(--text-primary);
}

.toast-close {
    background: transparent;
    border: none;
    color: var(--text-muted);
    cursor: pointer;
    font-size: 1.25rem;
    padding: 0;
    line-height: 1;
}

.toast-close:hover {
    color: var(--text-primary);
}

@keyframes toast-slide-in {
    from {
        transform: translateX(100%);
        opacity: 0;
    }
    to {
        transform: translateX(0);
        opacity: 1;
    }
}

@keyframes toast-slide-out {
    from {
        transform: translateX(0);
        opacity: 1;
    }
    to {
        transform: translateX(100%);
        opacity: 0;
    }
}

.toast.removing {
    animation: toast-slide-out 0.3s ease forwards;
}

/* ========================================
   Responsive Styles
   ======================================== */

@media (max-width: 768px) {
    .container {
        padding: var(--spacing-md);
    }
    
    .header {
        flex-direction: column;
        text-align: center;
        gap: var(--spacing-md);
    }
    
    .logo {
        flex-direction: column;
    }
    
    .logo-text h1 {
        font-size: 1.5rem;
    }
    
    .converter-card {
        padding: var(--spacing-lg);
    }
    
    .card-header {
        flex-direction: column;
        align-items: flex-start;
        gap: var(--spacing-sm);
    }
    
    .action-buttons {
        flex-direction: column;
    }
    
    .action-btn {
        width: 100%;
        justify-content: center;
    }
    
    .toast-container {
        left: var(--spacing-md);
        right: var(--spacing-md);
        bottom: var(--spacing-md);
    }
    
    .toast {
        max-width: 100%;
    }
}

/* ========================================
   Focus Styles for Accessibility
   ======================================== */

:focus-visible {
    outline: 2px solid var(--accent-primary);
    outline-offset: 2px;
}

button:focus-visible,
input:focus-visible,
textarea:focus-visible,
select:focus-visible {
    outline: 2px solid var(--accent-primary);
    outline-offset: 2px;
}

/* ========================================
   Utility Classes
   ======================================== */

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

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

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

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

::-webkit-scrollbar-thumb:hover {
    background: var(--text-muted);
}

/* Selection Styles */
::selection {
    background: var(--accent-primary);
    color: var(--bg-primary);
}