:root {
    --ink: #17202a;
    --paper: #ffffff;
    --navy: #1e3a8a;
    --cyan: #06b6d4;
    --border: #e2e8f0;
    --mark-color: rgba(225, 29, 72, 0.5); /* Transparent red for marking */
}

body {
    font-family: system-ui, -apple-system, sans-serif;
    background-color: var(--paper);
    color: var(--ink);
    margin: 0;
    line-height: 1.6;
    padding-bottom: 3rem;
}

.container {
    max-width: 600px;
    margin: 0 auto;
    padding: 0 1rem;
}

header {
    padding: 1.5rem 0;
    border-bottom: 1px solid var(--border);
    margin-bottom: 2rem;
}

header h1 {
    margin: 0 0 0.25rem 0;
    font-size: 1.5rem;
    color: var(--navy);
}

header p {
    margin: 0;
    color: var(--ink);
    opacity: 0.7;
    font-size: 0.9rem;
    text-transform: uppercase;
    letter-spacing: 0.05em;
}

.instructions {
    margin-bottom: 2rem;
}

.instructions h2 {
    font-size: 1.25rem;
    margin-bottom: 1rem;
}

.disclaimer {
    background: rgba(30, 58, 138, 0.05);
    border-left: 4px solid var(--navy);
    padding: 1rem;
    font-size: 0.9rem;
    margin-bottom: 1.5rem;
}

ol {
    padding-left: 1.25rem;
}

ol li {
    margin-bottom: 0.5rem;
}

.test-area {
    margin-bottom: 2rem;
}

.canvas-header {
    display: flex;
    justify-content: flex-end;
    margin-bottom: 0.5rem;
}

.btn {
    padding: 0.5rem 1rem;
    font-size: 0.9rem;
    font-weight: 600;
    border-radius: 4px;
    cursor: pointer;
    border: none;
    transition: opacity 0.2s;
}

.btn:hover {
    opacity: 0.9;
}

.btn-clear {
    background: transparent;
    border: 1px solid var(--border);
    color: var(--ink);
}

.btn-primary {
    background: var(--navy);
    color: #ffffff;
    display: block;
    width: 100%;
    padding: 1rem;
    font-size: 1.1rem;
    margin-top: 1.5rem;
}

.canvas-container {
    width: 100%;
    aspect-ratio: 1 / 1;
    border: 1px solid var(--ink); /* Black border */
    background: #ffffff; /* Explicit pure white background */
    touch-action: none;
}

canvas {
    display: block;
    width: 100%;
    height: 100%;
    cursor: crosshair;
}

.results {
    background: #ffffff;
    border: 1px solid var(--border);
    border-radius: 8px;
    padding: 1.5rem;
    text-align: center;
}

.results h2 {
    font-size: 1.25rem;
    margin-top: 0;
    color: var(--navy);
}

.results p {
    margin: 0;
}

/* --- CSS DE REFERÊNCIAS --- */
.references { margin-top: 2rem; padding: 1.5rem; background: rgba(15,23,42,0.05); border-radius: 8px; font-size: 0.9rem; text-align: left; }
.references h3 { margin-top: 0; font-size: 1rem; color: var(--text-primary, #17202a); margin-bottom: 0.5rem; }
.references p { margin-bottom: 1rem; color: var(--text-secondary, #475569); }
.references ol { padding-left: 1.5rem; margin-bottom: 1rem; }
.references li { margin-bottom: 0.5rem; color: var(--text-secondary, #475569); }
.references a { color: #0ea5e9; text-decoration: none; font-weight: bold; }
.references .disclaimer { margin-top: 1rem; font-style: italic; color: #64748b; font-size: 0.85rem; border-top: 1px solid rgba(0,0,0,0.1); padding-top: 0.8rem; }