:root {
    --bg-app: #f8fafc;
    --bg-panel: #ffffff;
    --bg-canvas: #e2e8f0;
    --bg-dots: #cbd5e1;
    --text-main: #1e293b;
    --text-muted: #64748b;
    --primary: #3b82f6;
    --primary-hover: #2563eb;
    --border: #e2e8f0;
    --bg-input: #ffffff;
    --overlay-bg: rgba(255, 255, 255, 0.9);
}

[data-theme="dark"] {
    --bg-app: #0f172a;
    --bg-panel: #1e293b;
    --bg-canvas: #020617;
    --bg-dots: #1e293b;
    --text-main: #f1f5f9;
    --text-muted: #94a3b8;
    --primary: #60a5fa;
    --primary-hover: #3b82f6;
    --border: #334155;
    --bg-input: #0f172a;
    --overlay-bg: rgba(15, 23, 42, 0.9);
}

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

body {
    font-family: 'Inter', sans-serif;
    background-color: var(--bg-app);
    color: var(--text-main);
    height: 100vh;
    overflow: hidden;
}

.app-container {
    display: flex;
    flex-direction: column;
    height: 100%;
}

/* Header */
header {
    height: 120px;
    background-color: #0f172a;
    border-bottom: 1px solid var(--border);
    display: flex;
    align-items: center;
    justify-content: flex-start;
    padding: 0 20px;
    flex-shrink: 0;
    z-index: 20;
}

.logo-container {
    display: flex;
    flex-direction: column;
    align-items: center;
    gap: 5px;
}

.app-logo {
    width: 48px;
    height: 48px;
}

.logo-text {
    font-weight: 700;
    font-size: 1.2rem;
    color: #ffffff;
}

h1 {
    font-size: 3rem;
    font-weight: 700;
    color: #ffffff;
    margin-left: 40px;
}

.theme-btn {
    margin-left: auto;
    background: transparent;
    border: 1px solid #334155;
    padding: 8px;
    border-radius: 50%;
    cursor: pointer;
    color: #ffffff;
    display: flex;
    align-items: center;
    justify-content: center;
    width: 36px;
    height: 36px;
    transition: all 0.2s;
}

.theme-btn:hover {
    background-color: var(--bg-app);
}

/* Main Layout */
main {
    flex: 1;
    display: flex;
    overflow: hidden;
}

/* Sidebar (Controls) */
.controls {
    width: 400px;
    background-color: var(--bg-panel);
    border-right: 1px solid var(--border);
    display: flex;
    flex-direction: column;
    padding: 20px;
    gap: 15px;
    z-index: 10;
    overflow-y: auto;
    order: -1; /* Sidebar on Left */
    box-shadow: 2px 0 10px rgba(0,0,0,0.05);
}

/* Compact Layout Helpers */
.compact-row {
    display: flex;
    gap: 10px;
    align-items: center;
}

.compact-row > * {
    flex: 1;
    min-width: 0; /* Allow shrinking */
}

.compact-grid {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: 8px;
}

.compact-grid .input-col {
    display: flex;
    flex-direction: column;
    gap: 2px;
}

.compact-grid .input-col span {
    font-size: 0.75rem;
    color: var(--text-muted);
}

.compact-grid input {
    padding: 6px 8px; /* Smaller padding */
}


/* Tabs */
.tabs {
    display: flex;
    gap: 5px;
    background: var(--bg-app);
    padding: 4px;
    border-radius: 8px;
    flex-shrink: 0;
}

.tab-btn {
    flex: 1;
    padding: 8px;
    border: none;
    background: transparent;
    color: var(--text-muted);
    font-weight: 600;
    cursor: pointer;
    border-radius: 6px;
    transition: all 0.2s;
    font-size: 0.8rem;
}

.tab-btn.active {
    background: var(--bg-panel);
    color: var(--primary);
    box-shadow: 0 1px 3px rgba(0,0,0,0.1);
}

/* Controls Content */
.tab-content {
    display: flex;
    flex-direction: column;
    gap: 20px;
}

.control-group {
    display: flex;
    flex-direction: column;
    gap: 8px;
}

.control-group label {
    font-size: 0.85rem;
    font-weight: 600;
    color: var(--text-muted);
}

select, input[type="range"] {
    width: 100%;
}

input[type="number"],
input[type="text"],
select {
    width: 100%;
    padding: 10px 12px;
    border-radius: 6px;
    border: 1px solid var(--border);
    background-color: var(--bg-input);
    color: var(--text-main);
    font-size: 0.9rem;
    transition: border-color 0.2s;
}

input:focus, select:focus {
    outline: none;
    border-color: var(--primary);
    background-color: var(--bg-panel);
}

/* Dual Input for Keychain */
.dual-input {
    display: flex;
    gap: 10px;
}

.input-col {
    flex: 1;
    display: flex;
    flex-direction: column;
    gap: 4px;
}

.input-col span {
    font-size: 0.75rem;
    color: var(--text-muted);
}

/* Thickness Options */
.thickness-options {
    display: flex;
    gap: 5px;
    background: var(--bg-app);
    padding: 4px;
    border-radius: 8px;
}

.thick-btn, .eyelet-btn {
    flex: 1;
    padding: 8px;
    border: none;
    background-color: transparent;
    color: var(--text-muted);
    font-size: 0.85rem;
    font-weight: 600;
    cursor: pointer;
    border-radius: 6px;
    transition: all 0.2s;
}

.thick-btn.active, .eyelet-btn.active {
    background-color: var(--bg-panel);
    color: var(--primary);
    box-shadow: 0 1px 2px rgba(0,0,0,0.1);
}

/* Buttons */
.button-group {
    display: flex;
    flex-direction: column;
    gap: 10px;
    margin-top: 10px;
}

.download-btn, .action-btn {
    width: 100%;
    padding: 12px;
    border: none;
    border-radius: 8px;
    font-weight: 600;
    cursor: pointer;
    transition: all 0.2s;
    display: flex;
    align-items: center;
    justify-content: center;
    gap: 8px;
}

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

.download-btn.primary:hover, .action-btn.primary:hover {
    background-color: var(--primary-hover);
}

.download-btn.secondary, .action-btn.secondary {
    background-color: var(--bg-panel);
    color: var(--text-main);
    border: 1px solid var(--border);
}

.download-btn.secondary:hover, .action-btn.secondary:hover {
    background-color: var(--bg-app);
}

.download-btn:disabled {
    opacity: 0.7;
    cursor: not-allowed;
}

.hidden {
    display: none !important;
}

/* Copyright */
.copyright {
    margin-top: auto;
    font-size: 0.75rem;
    color: var(--text-muted);
    text-align: right;
    padding-top: 10px;
    opacity: 0.7;
}

/* Canvas Area */
.canvas-container {
    flex: 1;
    position: relative;
    display: flex;
    justify-content: center;
    align-items: center;
    background-color: var(--bg-canvas);
    background-image: radial-gradient(var(--bg-dots) 1px, transparent 1px);
    background-size: 20px 20px;
    overflow: hidden;
    cursor: move;
}

canvas {
    display: block;
    max-width: 100%;
    max-height: 100%;
}

.canvas-instructions {
    position: absolute;
    bottom: 20px;
    left: 50%;
    transform: translateX(-50%);
    background: var(--bg-panel);
    padding: 8px 16px;
    border-radius: 20px;
    font-size: 0.85rem;
    color: var(--text-muted);
    box-shadow: 0 4px 6px rgba(0,0,0,0.1);
    pointer-events: none;
    border: 1px solid var(--border);
    z-index: 5;
}

/* Action Overlay */
.action-overlay {
    position: absolute;
    bottom: 60px; /* Above instructions */
    left: 50%;
    transform: translateX(-50%);
    display: flex;
    gap: 10px;
    z-index: 20;
}

/* Upload Overlay */
.upload-overlay {
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    background-color: var(--overlay-bg);
    display: flex;
    flex-direction: column;
    justify-content: center;
    align-items: center;
    gap: 20px;
    z-index: 30;
}

.upload-btn {
    padding: 12px 24px;
    background-color: var(--primary);
    color: white;
    border-radius: 8px;
    font-weight: 600;
    cursor: pointer;
    transition: background-color 0.2s;
}

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

.loading-indicator {
    position: absolute;
    top: 50%;
    left: 50%;
    transform: translate(-50%, -50%);
    background: var(--bg-panel);
    padding: 20px;
    border-radius: 12px;
    box-shadow: 0 10px 25px rgba(0,0,0,0.1);
    border: 1px solid var(--border);
    z-index: 40;
    font-weight: 600;
}