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

:root {
    --bg-primary: #f5f5f5;
    --bg-secondary: white;
    --text-primary: #333;
    --text-secondary: #7f8c8d;
    --text-heading: #2c3e50;
    --text-label: #34495e;
    --border-color: #ddd;
    --border-light: #ecf0f1;
    --shadow: rgba(0,0,0,0.1);
    --preview-bg: #f8f9fa;
    --preview-border: #dee2e6;
}

/* Dark theme - applies when system prefers dark OR when manually set */
@media (prefers-color-scheme: dark) {
    :root:not([data-theme="light"]) {
        --bg-primary: #1a1a1a;
        --bg-secondary: #2d2d2d;
        --text-primary: #e0e0e0;
        --text-secondary: #a0a0a0;
        --text-heading: #f0f0f0;
        --text-label: #d0d0d0;
        --border-color: #444;
        --border-light: #3a3a3a;
        --shadow: rgba(0,0,0,0.3);
        --preview-bg: #252525;
        --preview-border: #444;
    }
}

/* Explicit dark theme override */
[data-theme="dark"] {
    --bg-primary: #1a1a1a;
    --bg-secondary: #2d2d2d;
    --text-primary: #e0e0e0;
    --text-secondary: #a0a0a0;
    --text-heading: #f0f0f0;
    --text-label: #d0d0d0;
    --border-color: #444;
    --border-light: #3a3a3a;
    --shadow: rgba(0,0,0,0.3);
    --preview-bg: #252525;
    --preview-border: #444;
}

body {
    font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, 'Helvetica Neue', Arial, sans-serif;
    line-height: 1.6;
    color: var(--text-primary);
    background-color: var(--bg-primary);
    transition: background-color 0.3s, color 0.3s;
}

.container {
    max-width: 1400px;
    margin: 0 auto;
    padding: 20px;
}

header {
    background: var(--bg-secondary);
    padding: 30px;
    margin-bottom: 30px;
    border-radius: 8px;
    box-shadow: 0 2px 4px var(--shadow);
    text-align: center;
    transition: background-color 0.3s;
}

header h1 {
    color: var(--text-heading);
    margin-bottom: 10px;
    font-size: 2.5em;
}

header p {
    color: var(--text-secondary);
    font-size: 1.1em;
}

main {
    display: grid;
    grid-template-columns: 400px 1fr;
    gap: 30px;
    align-items: start;
}

.form-section, .preview-section {
    background: var(--bg-secondary);
    padding: 30px;
    border-radius: 8px;
    box-shadow: 0 2px 4px var(--shadow);
    transition: background-color 0.3s;
}

.form-section h2, .preview-section h2 {
    color: var(--text-heading);
    margin-bottom: 25px;
    padding-bottom: 10px;
    border-bottom: 2px solid var(--border-light);
    transition: color 0.3s, border-color 0.3s;
}

.form-group {
    margin-bottom: 20px;
}

.form-group label {
    display: block;
    margin-bottom: 5px;
    color: var(--text-label);
    font-weight: 500;
}

.form-group input,
.form-group select {
    width: 100%;
    padding: 10px 12px;
    border: 1px solid var(--border-color);
    border-radius: 4px;
    font-size: 14px;
    background: var(--bg-secondary);
    color: var(--text-primary);
    transition: border-color 0.3s, background-color 0.3s;
}

.form-group input:focus,
.form-group select:focus {
    outline: none;
    border-color: #3498db;
}

.help-text {
    display: block;
    margin-top: 5px;
    font-size: 12px;
    color: var(--text-secondary);
}

#recommendedLevel {
    color: #27ae60;
    font-weight: 500;
}

.button-group {
    display: flex;
    gap: 10px;
    margin-top: 25px;
}

.btn {
    padding: 12px 24px;
    border: none;
    border-radius: 4px;
    font-size: 16px;
    font-weight: 500;
    cursor: pointer;
    transition: all 0.3s;
}

.btn-primary {
    background: #3498db;
    color: white;
    flex: 1;
}

.btn-primary:hover {
    background: #2980b9;
}

.btn-secondary {
    background: #95a5a6;
    color: white;
}

.btn-secondary:hover {
    background: #7f8c8d;
}

.preview-container {
    position: relative;
    background: var(--preview-bg);
    border: 2px dashed var(--preview-border);
    border-radius: 8px;
    padding: 20px;
    min-height: 440px;
    display: flex;
    align-items: center;
    justify-content: center;
    transition: background-color 0.3s, border-color 0.3s;
}

#signCanvas {
    display: none;
    width: 100%;
    aspect-ratio: 2 / 1;
    background: white !important; /* Always white for the sign */
    box-shadow: 0 4px 6px rgba(0,0,0,0.1);
}

.placeholder {
    text-align: center;
    color: var(--text-secondary);
}

.placeholder p {
    font-size: 18px;
}

.action-buttons {
    margin-top: 20px;
    display: flex;
    gap: 10px;
    justify-content: center;
}

.btn-action {
    background: #27ae60;
    color: white;
    display: flex;
    align-items: center;
    gap: 8px;
}

.btn-action:hover {
    background: #229954;
}

.btn-action .icon {
    font-size: 18px;
}

/* Theme Toggle Button */
.theme-toggle {
    position: fixed;
    top: 20px;
    right: 20px;
    background: var(--bg-secondary);
    border: 2px solid var(--border-color);
    border-radius: 50%;
    width: 50px;
    height: 50px;
    display: flex;
    align-items: center;
    justify-content: center;
    cursor: pointer;
    transition: all 0.3s;
    box-shadow: 0 2px 8px var(--shadow);
    z-index: 1000;
}

.theme-toggle:hover {
    transform: scale(1.1);
}

.theme-toggle svg {
    width: 24px;
    height: 24px;
    fill: var(--text-primary);
    transition: fill 0.3s;
}

/* Default: show moon icon (to switch to dark) */
.theme-toggle .sun-icon {
    display: none;
}

.theme-toggle .moon-icon {
    display: block;
}

/* When dark theme is active (either by system preference or manual setting) */
@media (prefers-color-scheme: dark) {
    :root:not([data-theme="light"]) .theme-toggle .sun-icon {
        display: block;
    }
    
    :root:not([data-theme="light"]) .theme-toggle .moon-icon {
        display: none;
    }
}

[data-theme="dark"] .theme-toggle .sun-icon {
    display: block;
}

[data-theme="dark"] .theme-toggle .moon-icon {
    display: none;
}

[data-theme="light"] .theme-toggle .sun-icon {
    display: none;
}

[data-theme="light"] .theme-toggle .moon-icon {
    display: block;
}

@media (max-width: 768px) {
    main {
        grid-template-columns: 1fr;
    }
    
    header h1 {
        font-size: 2em;
    }
    
    .action-buttons {
        flex-direction: column;
    }
    
    .btn-action {
        width: 100%;
        justify-content: center;
    }
}

@media print {
    @page {
        size: landscape;
        margin: 0;
    }

    body {
        background: white;
    }

    .container {
        padding: 0;
        max-width: none;
    }

    header,
    .form-section,
    .preview-section h2,
    .action-buttons,
    .placeholder,
    .theme-toggle {
        display: none !important;
    }

    main {
        display: block;
    }

    .preview-section {
        box-shadow: none;
        padding: 0;
    }

    .preview-container {
        border: none;
        padding: 0;
        background: white;
        display: flex;
        justify-content: center;
        align-items: center;
        height: 100vh;
        min-height: none;
        max-height: none;
    }

    #signCanvas {
        display: block !important;
        width: 98vw !important;
        height: 49vw !important; /* Maintain 2:1 aspect ratio */
        max-height: 98vh !important;
        max-width: 196vh !important; /* 98vh * 2 for aspect ratio */
        box-shadow: none;
        object-fit: contain;
    }
}