/* FileConverter - Clean, Minimal CSS */

/* ===== CSS Variables ===== */
:root {
    /* Colors */
    --color-bg: #0a0a0b;
    --color-bg-elevated: #141416;
    --color-bg-hover: #1a1a1d;
    --color-surface: #1e1e21;
    --color-border: #2a2a2e;
    --color-border-hover: #3a3a3f;
    
    --color-text-primary: #fafafa;
    --color-text-secondary: #a1a1a6;
    --color-text-muted: #6b6b70;
    
    --color-accent: #6366f1;
    --color-accent-hover: #818cf8;
    --color-accent-muted: rgba(99, 102, 241, 0.15);
    
    --color-success: #22c55e;
    --color-success-muted: rgba(34, 197, 94, 0.15);
    --color-error: #ef4444;
    --color-error-muted: rgba(239, 68, 68, 0.15);
    --color-warning: #f59e0b;
    
    /* Typography */
    --font-sans: 'DM Sans', -apple-system, BlinkMacSystemFont, 'Segoe UI', sans-serif;
    --font-mono: 'JetBrains Mono', 'SF Mono', Monaco, monospace;
    
    /* Spacing */
    --space-xs: 0.25rem;
    --space-sm: 0.5rem;
    --space-md: 1rem;
    --space-lg: 1.5rem;
    --space-xl: 2rem;
    --space-2xl: 3rem;
    --space-3xl: 4rem;
    
    /* Border Radius */
    --radius-sm: 0.375rem;
    --radius-md: 0.5rem;
    --radius-lg: 0.75rem;
    --radius-xl: 1rem;
    --radius-full: 9999px;
    
    /* Shadows */
    --shadow-sm: 0 1px 2px rgba(0, 0, 0, 0.3);
    --shadow-md: 0 4px 6px rgba(0, 0, 0, 0.4);
    --shadow-lg: 0 10px 15px rgba(0, 0, 0, 0.5);
    --shadow-glow: 0 0 20px rgba(99, 102, 241, 0.3);
    
    /* Transitions */
    --transition-fast: 150ms ease;
    --transition-normal: 250ms ease;
    --transition-slow: 350ms ease;
    
    /* Container */
    --container-max: 720px;
    --header-height: 64px;
}

/* ===== Reset & Base ===== */
*, *::before, *::after {
    box-sizing: border-box;
    margin: 0;
    padding: 0;
}

html {
    font-size: 16px;
    -webkit-font-smoothing: antialiased;
    -moz-osx-font-smoothing: grayscale;
}

body {
    font-family: var(--font-sans);
    background-color: var(--color-bg);
    color: var(--color-text-primary);
    line-height: 1.6;
    min-height: 100vh;
    display: flex;
    flex-direction: column;
}

a {
    color: var(--color-accent);
    text-decoration: none;
    transition: color var(--transition-fast);
}

a:hover {
    color: var(--color-accent-hover);
}

/* ===== Header ===== */
.header {
    position: sticky;
    top: 0;
    z-index: 100;
    background: rgba(10, 10, 11, 0.8);
    backdrop-filter: blur(12px);
    -webkit-backdrop-filter: blur(12px);
    border-bottom: 1px solid var(--color-border);
    height: var(--header-height);
}

.header-content {
    max-width: var(--container-max);
    margin: 0 auto;
    padding: 0 var(--space-lg);
    height: 100%;
    display: flex;
    align-items: center;
    justify-content: space-between;
}

.logo {
    display: flex;
    align-items: center;
    gap: var(--space-sm);
    color: var(--color-text-primary);
    font-weight: 600;
    font-size: 1.125rem;
}

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

.logo-icon {
    width: 24px;
    height: 24px;
    color: var(--color-accent);
}

.nav-status {
    font-size: 0.875rem;
    color: var(--color-text-muted);
    padding: var(--space-xs) var(--space-md);
    background: var(--color-bg-elevated);
    border-radius: var(--radius-full);
    border: 1px solid var(--color-border);
}

/* ===== Main Content ===== */
.main {
    flex: 1;
    padding: var(--space-2xl) var(--space-lg);
}

.container {
    max-width: var(--container-max);
    margin: 0 auto;
}

/* ===== Hero Section ===== */
.hero {
    text-align: center;
    margin-bottom: var(--space-2xl);
}

.hero-title {
    font-size: clamp(2rem, 5vw, 2.75rem);
    font-weight: 700;
    letter-spacing: -0.02em;
    margin-bottom: var(--space-md);
    background: linear-gradient(135deg, var(--color-text-primary) 0%, var(--color-text-secondary) 100%);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
}

.hero-subtitle {
    font-size: 1.125rem;
    color: var(--color-text-secondary);
    max-width: 500px;
    margin: 0 auto;
}

/* ===== Upload Section ===== */
.upload-section {
    margin-bottom: var(--space-2xl);
}

.upload-form {
    display: flex;
    flex-direction: column;
    gap: var(--space-lg);
}

/* Drop Zone */
.dropzone {
    position: relative;
    border: 2px dashed var(--color-border);
    border-radius: var(--radius-xl);
    padding: var(--space-3xl) var(--space-xl);
    text-align: center;
    cursor: pointer;
    transition: all var(--transition-normal);
    background: var(--color-bg-elevated);
}

.dropzone:hover,
.dropzone.dragover {
    border-color: var(--color-accent);
    background: var(--color-accent-muted);
}

.dropzone-content {
    pointer-events: none;
}

.dropzone-icon {
    width: 48px;
    height: 48px;
    color: var(--color-text-muted);
    margin-bottom: var(--space-md);
}

.dropzone:hover .dropzone-icon,
.dropzone.dragover .dropzone-icon {
    color: var(--color-accent);
}

.dropzone-text {
    font-size: 1rem;
    color: var(--color-text-secondary);
    margin-bottom: var(--space-sm);
}

.dropzone-browse {
    color: var(--color-accent);
    font-weight: 500;
}

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

.file-input {
    position: absolute;
    inset: 0;
    opacity: 0;
    cursor: pointer;
    pointer-events: none; /* Prevent capturing clicks - we trigger it via JS */
}

/* File Preview */
.file-preview {
    background: var(--color-surface);
    border: 1px solid var(--color-border);
    border-radius: var(--radius-lg);
    padding: var(--space-md);
}

.file-info {
    display: flex;
    align-items: center;
    gap: var(--space-md);
}

.file-icon {
    width: 48px;
    height: 48px;
    display: flex;
    align-items: center;
    justify-content: center;
    background: var(--color-accent-muted);
    border-radius: var(--radius-md);
    color: var(--color-accent);
    flex-shrink: 0;
}

.file-icon svg {
    width: 24px;
    height: 24px;
}

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

.file-name {
    font-weight: 500;
    color: var(--color-text-primary);
    white-space: nowrap;
    overflow: hidden;
    text-overflow: ellipsis;
}

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

.file-remove {
    width: 36px;
    height: 36px;
    display: flex;
    align-items: center;
    justify-content: center;
    background: transparent;
    border: 1px solid var(--color-border);
    border-radius: var(--radius-md);
    color: var(--color-text-muted);
    cursor: pointer;
    transition: all var(--transition-fast);
}

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

.file-remove svg {
    width: 18px;
    height: 18px;
}

/* Options Section */
.options-section {
    display: flex;
    flex-direction: column;
    gap: var(--space-lg);
}

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

.option-label {
    font-size: 0.875rem;
    font-weight: 500;
    color: var(--color-text-secondary);
}

/* Format Grid */
.format-grid {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(70px, 1fr));
    gap: var(--space-sm);
}

.format-btn {
    padding: var(--space-sm) var(--space-md);
    background: var(--color-bg-elevated);
    border: 1px solid var(--color-border);
    border-radius: var(--radius-md);
    color: var(--color-text-secondary);
    font-size: 0.875rem;
    font-weight: 500;
    text-transform: uppercase;
    cursor: pointer;
    transition: all var(--transition-fast);
    text-align: center;
}

.format-btn:hover {
    border-color: var(--color-border-hover);
    background: var(--color-bg-hover);
}

.format-btn.active {
    background: var(--color-accent);
    border-color: var(--color-accent);
    color: white;
}

/* Options Toggle */
.options-toggle {
    display: flex;
    align-items: center;
    justify-content: center;
    gap: var(--space-sm);
    padding: var(--space-sm);
    background: transparent;
    border: none;
    color: var(--color-text-muted);
    font-size: 0.875rem;
    cursor: pointer;
    transition: color var(--transition-fast);
}

.options-toggle:hover {
    color: var(--color-text-secondary);
}

.toggle-icon {
    width: 16px;
    height: 16px;
    transition: transform var(--transition-fast);
}

.options-toggle.active .toggle-icon {
    transform: rotate(180deg);
}

/* Advanced Options */
.advanced-options {
    background: var(--color-surface);
    border: 1px solid var(--color-border);
    border-radius: var(--radius-lg);
    padding: var(--space-lg);
}

.options-grid {
    display: grid;
    grid-template-columns: repeat(2, 1fr);
    gap: var(--space-md);
}

@media (max-width: 480px) {
    .options-grid {
        grid-template-columns: 1fr;
    }
}

.option-item {
    display: flex;
    flex-direction: column;
    gap: var(--space-xs);
}

.option-input,
.option-select {
    padding: var(--space-sm) var(--space-md);
    background: var(--color-bg-elevated);
    border: 1px solid var(--color-border);
    border-radius: var(--radius-md);
    color: var(--color-text-primary);
    font-size: 0.875rem;
    font-family: inherit;
    transition: border-color var(--transition-fast);
}

.option-input:focus,
.option-select:focus {
    outline: none;
    border-color: var(--color-accent);
}

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

/* Range Input */
.range-container {
    display: flex;
    align-items: center;
    gap: var(--space-md);
}

.option-range {
    flex: 1;
    -webkit-appearance: none;
    appearance: none;
    height: 6px;
    background: var(--color-bg-elevated);
    border-radius: var(--radius-full);
    cursor: pointer;
}

.option-range::-webkit-slider-thumb {
    -webkit-appearance: none;
    width: 18px;
    height: 18px;
    background: var(--color-accent);
    border-radius: 50%;
    cursor: pointer;
    transition: transform var(--transition-fast);
}

.option-range::-webkit-slider-thumb:hover {
    transform: scale(1.1);
}

.range-value {
    font-size: 0.875rem;
    font-family: var(--font-mono);
    color: var(--color-text-secondary);
    min-width: 40px;
}

/* Color Input */
.color-input-wrapper {
    display: flex;
    gap: var(--space-sm);
}

.color-input {
    width: 44px;
    height: 38px;
    padding: 2px;
    border: 1px solid var(--color-border);
    border-radius: var(--radius-md);
    cursor: pointer;
    background: transparent;
}

.color-input::-webkit-color-swatch-wrapper {
    padding: 0;
}

.color-input::-webkit-color-swatch {
    border: none;
    border-radius: var(--radius-sm);
}

.color-text {
    flex: 1;
    font-family: var(--font-mono);
    text-transform: uppercase;
}

/* Convert Button */
.convert-btn {
    width: 100%;
    padding: var(--space-md) var(--space-xl);
    background: var(--color-accent);
    border: none;
    border-radius: var(--radius-lg);
    color: white;
    font-size: 1rem;
    font-weight: 600;
    cursor: pointer;
    transition: all var(--transition-fast);
    display: flex;
    align-items: center;
    justify-content: center;
    gap: var(--space-sm);
    min-height: 52px;
}

.convert-btn:hover:not(:disabled) {
    background: var(--color-accent-hover);
    box-shadow: var(--shadow-glow);
}

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

.btn-loader {
    display: flex;
    align-items: center;
    gap: var(--space-sm);
}

.spinner {
    width: 20px;
    height: 20px;
    animation: spin 1s linear infinite;
}

.spinner-circle {
    stroke-dasharray: 45;
    stroke-dashoffset: 45;
    animation: dash 1.5s ease-in-out infinite;
}

@keyframes spin {
    100% { transform: rotate(360deg); }
}

@keyframes dash {
    0% { stroke-dashoffset: 45; }
    50% { stroke-dashoffset: 0; }
    100% { stroke-dashoffset: -45; }
}

/* ===== Result Section ===== */
.result-section {
    margin-bottom: var(--space-2xl);
}

.result-card {
    background: var(--color-surface);
    border: 1px solid var(--color-border);
    border-radius: var(--radius-xl);
    padding: var(--space-2xl);
    text-align: center;
}

.result-icon {
    width: 64px;
    height: 64px;
    margin: 0 auto var(--space-md);
    display: flex;
    align-items: center;
    justify-content: center;
    border-radius: 50%;
}

.result-icon.success {
    background: var(--color-success-muted);
    color: var(--color-success);
}

.result-icon.error {
    background: var(--color-error-muted);
    color: var(--color-error);
}

.result-icon svg {
    width: 32px;
    height: 32px;
}

.result-title {
    font-size: 1.5rem;
    font-weight: 600;
    margin-bottom: var(--space-sm);
}

.result-message {
    color: var(--color-text-secondary);
    margin-bottom: var(--space-xl);
}

.result-actions {
    display: flex;
    flex-direction: column;
    gap: var(--space-md);
}

.download-btn {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    gap: var(--space-sm);
    padding: var(--space-md) var(--space-xl);
    background: var(--color-success);
    border-radius: var(--radius-lg);
    color: white;
    font-weight: 600;
    transition: all var(--transition-fast);
}

.download-btn:hover {
    background: #16a34a;
    color: white;
}

.download-btn svg {
    width: 20px;
    height: 20px;
}

.new-conversion-btn {
    padding: var(--space-md) var(--space-xl);
    background: transparent;
    border: 1px solid var(--color-border);
    border-radius: var(--radius-lg);
    color: var(--color-text-secondary);
    font-size: 1rem;
    cursor: pointer;
    transition: all var(--transition-fast);
}

.new-conversion-btn:hover {
    border-color: var(--color-border-hover);
    color: var(--color-text-primary);
}

/* ===== Formats Info ===== */
.formats-info {
    text-align: center;
}

.formats-title {
    font-size: 1.25rem;
    font-weight: 600;
    margin-bottom: var(--space-lg);
    color: var(--color-text-secondary);
}

.formats-grid {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: var(--space-md);
}

@media (max-width: 600px) {
    .formats-grid {
        grid-template-columns: 1fr;
    }
}

.format-category {
    padding: var(--space-lg);
    background: var(--color-bg-elevated);
    border: 1px solid var(--color-border);
    border-radius: var(--radius-lg);
}

.format-category h3 {
    font-size: 0.875rem;
    font-weight: 600;
    color: var(--color-accent);
    margin-bottom: var(--space-sm);
    text-transform: uppercase;
    letter-spacing: 0.05em;
}

.format-category p {
    font-size: 0.875rem;
    color: var(--color-text-muted);
}

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

.footer {
    background: var(--color-bg-elevated);
    border-top: 1px solid var(--color-border);
    padding: var(--space-xl) var(--space-lg);
    margin-top: auto;
}

.footer-content {
    max-width: var(--container-max);
    margin: 0 auto;
    text-align: center;
}

.footer-links {
    display: flex;
    justify-content: center;
    gap: var(--space-lg);
    margin-bottom: var(--space-md);
    flex-wrap: wrap;
}

.footer-links a {
    font-size: 0.875rem;
    color: var(--color-text-muted);
    transition: color var(--transition-fast);
}

.footer-links a:hover {
    color: var(--color-text-primary);
}

.footer-copyright {
    font-size: 0.75rem;
    color: var(--color-text-muted);
}

/* ===== Error Pages ===== */
.error-page {
    min-height: 100vh;
    display: flex;
    align-items: center;
    justify-content: center;
    text-align: center;
    padding: var(--space-xl);
}

.error-code {
    font-size: 6rem;
    font-weight: 700;
    color: var(--color-accent);
    line-height: 1;
}

.error-message {
    font-size: 1.25rem;
    color: var(--color-text-secondary);
    margin: var(--space-md) 0 var(--space-xl);
}

.error-back {
    display: inline-flex;
    align-items: center;
    gap: var(--space-sm);
    padding: var(--space-md) var(--space-xl);
    background: var(--color-accent);
    border-radius: var(--radius-lg);
    color: white;
    font-weight: 500;
}

/* ===== Utilities ===== */
.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;
}

/* Size Info Styles */
.size-info {
    text-align: center;
    padding: var(--space-md);
}

.size-info p {
    margin: var(--space-sm) 0;
}

.size-comparison {
    display: flex;
    align-items: center;
    justify-content: center;
    gap: var(--space-md);
    margin: var(--space-md) 0;
    flex-wrap: wrap;
}

.size-item {
    display: flex;
    flex-direction: column;
    align-items: center;
    gap: var(--space-xs);
}

.size-label {
    font-size: 0.75rem;
    color: var(--color-text-muted);
    text-transform: uppercase;
    letter-spacing: 0.05em;
}

.size-value {
    font-size: 1.25rem;
    font-weight: 600;
    color: var(--color-text-primary);
}

.size-value.size-reduced {
    color: var(--color-success);
}

.size-value.size-increased {
    color: var(--color-warning);
}

.size-arrow {
    font-size: 1.5rem;
    color: var(--color-text-muted);
}

.size-change {
    display: inline-block;
    padding: var(--space-xs) var(--space-sm);
    border-radius: var(--radius-full);
    font-size: 0.875rem;
    font-weight: 500;
}

.size-change.positive {
    background: var(--color-success-muted);
    color: var(--color-success);
}

.size-change.negative {
    background: rgba(245, 158, 11, 0.15);
    color: var(--color-warning);
}

.size-hint {
    margin-top: var(--space-md);
    padding: var(--space-sm) var(--space-md);
    background: var(--color-accent-muted);
    border-radius: var(--radius-md);
    font-size: 0.875rem;
    color: var(--color-text-secondary);
}

.size-hint strong {
    color: var(--color-accent);
}