:root {
    --bg-dark: #0F172A;
    --surface: #1E293B;
    --surface-glass: rgba(30, 41, 59, 0.7);
    --border: #334155;
    
    --primary: #6366F1;
    --primary-hover: #4F46E5;
    --accent: #22D3EE;
    --secondary: #94A3B8;
    
    --text-main: #F8FAFC;
    --text-muted: #CBD5E1;
    
    --radius-lg: 12px;
    --radius-md: 8px;
    --transition: 250ms ease;
    --header-height: 60px;
    --sub-header-height: 48px;
}

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

body {
    font-family: 'Inter', system-ui, sans-serif;
    background-color: var(--bg-dark);
    color: var(--text-main);
    overflow: hidden; /* Stop page level scrolling, workspace handles it */
    display: flex;
    flex-direction: column;
    height: 100vh;
}

/* Header */
.top-nav {
    height: var(--header-height);
    background: var(--surface-glass);
    backdrop-filter: blur(12px);
    -webkit-backdrop-filter: blur(12px);
    border-bottom: 1px solid var(--border);
    display: flex;
    align-items: center;
    justify-content: space-between;
    padding: 0 1.5rem;
    z-index: 100;
}

.logo {
    display: flex;
    align-items: center;
    gap: 0.5rem;
}

.logo h1 {
    font-size: 1.25rem;
    font-weight: 700;
    letter-spacing: -0.02em;
}

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

.url-bar {
    flex: 1;
    max-width: 600px;
    display: flex;
    gap: 0.5rem;
    margin: 0 2rem;
}

.url-bar input {
    flex: 1;
    background: rgba(0,0,0,0.2);
    border: 1px solid var(--border);
    border-radius: var(--radius-md);
    padding: 0.5rem 1rem;
    color: var(--text-main);
    font-family: inherit;
    font-size: 0.95rem;
    transition: var(--transition);
}

.url-bar input:focus {
    outline: none;
    border-color: var(--primary);
    background: rgba(0,0,0,0.4);
}

.nav-actions {
    display: flex;
    gap: 0.5rem;
}

/* Sub Toolbar */
.sub-toolbar {
    height: var(--sub-header-height);
    background: var(--surface);
    border-bottom: 1px solid var(--border);
    display: flex;
    align-items: center;
    justify-content: space-between;
    padding: 0 1.5rem;
    font-size: 0.875rem;
    color: var(--text-muted);
}

.zoom-controls {
    display: flex;
    align-items: center;
    gap: 1rem;
}

.pixel-density label {
    cursor: pointer;
    display: flex;
    align-items: center;
    gap: 0.5rem;
}

/* Workspace */
.workspace {
    flex: 1;
    overflow: auto;
    padding: 2rem;
    display: flex;
    align-items: flex-start;
    gap: 2rem;
    background-image: 
        linear-gradient(rgba(255,255,255,0.03) 1px, transparent 1px),
        linear-gradient(90deg, rgba(255,255,255,0.03) 1px, transparent 1px);
    background-size: 20px 20px;
    transform-origin: 0 0;
    transition: transform var(--transition);
}

/* Device Frame */
.device-container {
    background: var(--surface);
    border-radius: var(--radius-lg);
    border: 1px solid var(--border);
    display: flex;
    flex-direction: column;
    box-shadow: 0 10px 30px rgba(0,0,0,0.3);
    overflow: hidden;
    flex-shrink: 0;
    transition: box-shadow var(--transition);
}

.device-container:hover {
    box-shadow: 0 10px 40px rgba(99, 102, 241, 0.2);
    border-color: rgba(99, 102, 241, 0.5);
}

.device-header {
    height: 40px;
    background: rgba(0,0,0,0.2);
    border-bottom: 1px solid var(--border);
    display: flex;
    align-items: center;
    justify-content: space-between;
    padding: 0 1rem;
}

.device-info {
    display: flex;
    flex-direction: column;
}

.device-name {
    font-size: 0.8rem;
    font-weight: 600;
    color: var(--text-main);
}

.device-size {
    font-size: 0.7rem;
    color: var(--secondary);
}

.device-actions {
    display: flex;
    gap: 0.25rem;
}

.icon-btn {
    background: transparent;
    border: none;
    color: var(--secondary);
    padding: 4px;
    border-radius: 4px;
    cursor: pointer;
    transition: var(--transition);
    display: flex;
    align-items: center;
    justify-content: center;
}

.icon-btn:hover {
    background: rgba(255,255,255,0.1);
    color: var(--text-main);
}

.btn-remove:hover {
    color: #ef4444;
    background: rgba(239, 68, 68, 0.1);
}

.device-screen-wrapper {
    background: #fff; /* Iframe renders over white */
    position: relative;
    /* dimensions set via JS */
}

.device-iframe {
    width: 100%;
    height: 100%;
    border: none;
    display: block;
    background-color: transparent; /* so it reflects site's bg */
}

/* Buttons */
.btn {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    gap: 0.5rem;
    padding: 0.5rem 1rem;
    border-radius: var(--radius-md);
    font-family: inherit;
    font-size: 0.875rem;
    font-weight: 500;
    cursor: pointer;
    transition: var(--transition);
    border: 1px solid transparent;
}

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

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

.btn-outline {
    background: transparent;
    color: var(--text-main);
    border-color: var(--border);
}

.btn-outline:hover {
    background: rgba(255,255,255,0.05);
}

/* Modals */
.modal-overlay {
    position: fixed;
    top: 0; left: 0; right: 0; bottom: 0;
    background: rgba(0,0,0,0.6);
    backdrop-filter: blur(4px);
    -webkit-backdrop-filter: blur(4px);
    z-index: 1000;
    display: flex;
    align-items: center;
    justify-content: center;
    opacity: 0;
    pointer-events: none;
    transition: opacity var(--transition);
}

.modal-overlay.active {
    opacity: 1;
    pointer-events: auto;
}

.modal-content {
    background: var(--surface);
    border: 1px solid var(--border);
    border-radius: var(--radius-lg);
    width: 90%;
    max-width: 480px;
    box-shadow: 0 20px 40px rgba(0,0,0,0.5);
    transform: translateY(20px);
    transition: transform var(--transition);
}

.modal-overlay.active .modal-content {
    transform: translateY(0);
}

.modal-header {
    padding: 1.25rem 1.5rem;
    border-bottom: 1px solid var(--border);
    display: flex;
    justify-content: space-between;
    align-items: center;
}

.modal-header h2 {
    font-size: 1.1rem;
    font-weight: 600;
}

.close-btn {
    background: transparent;
    border: none;
    color: var(--secondary);
    font-size: 1.5rem;
    cursor: pointer;
    line-height: 1;
}

.close-btn:hover {
    color: var(--text-main);
}

.modal-body {
    padding: 1.5rem;
}

.preset-list {
    display: grid;
    grid-template-columns: repeat(2, 1fr);
    gap: 0.5rem;
}

.preset-btn {
    background: rgba(0,0,0,0.2);
    border: 1px solid var(--border);
    padding: 0.75rem;
    border-radius: var(--radius-md);
    color: var(--text-main);
    cursor: pointer;
    text-align: left;
    transition: var(--transition);
}

.preset-btn:hover {
    background: rgba(99, 102, 241, 0.1);
    border-color: var(--primary);
}

.preset-btn strong {
    display: block;
    font-size: 0.875rem;
    margin-bottom: 0.25rem;
}

.preset-btn span {
    font-size: 0.75rem;
    color: var(--secondary);
}

.divider {
    border: none;
    border-top: 1px solid var(--border);
    margin: 1.5rem 0;
}

.custom-device-form h3 {
    font-size: 0.95rem;
    margin-bottom: 0.75rem;
}

.custom-device-form input,
.modal-body textarea {
    width: 100%;
    background: rgba(0,0,0,0.2);
    border: 1px solid var(--border);
    border-radius: var(--radius-md);
    padding: 0.75rem;
    color: var(--text-main);
    font-family: inherit;
    margin-bottom: 0.75rem;
}

.custom-device-form input:focus,
.modal-body textarea:focus {
    outline: none;
    border-color: var(--primary);
}

.size-inputs {
    display: flex;
    align-items: center;
    gap: 0.5rem;
}

.size-inputs span {
    color: var(--secondary);
}

.desc {
    font-size: 0.875rem;
    color: var(--text-muted);
    margin-bottom: 1rem;
}

.batch-list {
    display: flex;
    flex-direction: column;
    gap: 0.25rem;
    margin-top: 1rem;
}

.batch-item {
    background: rgba(0,0,0,0.2);
    border-radius: 4px;
    padding: 0.5rem;
    font-size: 0.8rem;
    cursor: pointer;
    text-overflow: ellipsis;
    overflow: hidden;
    white-space: nowrap;
}

.batch-item:hover {
    background: rgba(255,255,255,0.05);
}