:root {
    --primary-color: #6366f1;
    --primary-hover: #4f46e5;
    --success-color: #22c55e;
    --success-hover: #16a34a;
    --error-color: #ef4444;
    --error-hover: #dc2626;
    --warning-color: #f59e0b;
    --warning-hover: #d97706;
    
    /* Light Theme (Default in variables, but we'll override for dark) */
    --bg-color: #f8fafc;
    --text-color: #1e293b;
    --text-muted: #64748b;
    --card-bg: #ffffff;
    --shadow: 0 4px 6px -1px rgb(0 0 0 / 0.1), 0 2px 4px -2px rgb(0 0 0 / 0.1);
    
    --theme-color: var(--primary-color);
    --theme-hover: var(--primary-hover);
}

body.dark-theme {
    --bg-color: #0f172a;
    --text-color: #f8fafc;
    --text-muted: #94a3b8;
    --card-bg: #1e293b;
    --shadow: 0 10px 15px -3px rgba(0, 0, 0, 0.3);
}

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

body {
    font-family: 'Inter', -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, sans-serif;
    background-color: var(--bg-color);
    color: var(--text-color);
    line-height: 1.5;
    display: flex;
    justify-content: center;
    align-items: center;
    min-height: 100vh;
}

#app {
    width: 100%;
    max-width: 600px;
    padding: 2rem;
    text-align: center;
    position: relative;
}

header h1 {
    font-size: 3.5rem;
    font-weight: 800;
    color: var(--theme-color);
    margin: 0.5rem 0 0.5rem;
    transition: color 0.3s ease;
}

.stats-container {
    display: flex;
    justify-content: center;
    align-items: center;
    gap: 0.5rem;
    margin-top: 1rem;
}

.btn-small {
    background: var(--card-bg);
    border: 2px solid var(--theme-color);
    border-radius: 50%;
    width: 2.5rem;
    height: 2.5rem;
    cursor: pointer;
    font-size: 1.1rem;
    display: flex;
    align-items: center;
    justify-content: center;
    box-shadow: var(--shadow);
    transition: all 0.2s ease;
}

.btn-small:hover {
    transform: scale(1.1);
    border-color: var(--error-color);
}

.btn-small:active {
    transform: scale(0.95);
}

#score-display {
    background: var(--card-bg);
    color: var(--text-color);
    padding: 0.5rem 1.5rem;
    border-radius: 2rem;
    font-weight: 700;
    font-size: 1.1rem;
    box-shadow: var(--shadow);
    border: 2px solid var(--theme-color);
    transition: all 0.3s ease;
}

#score-value {
    color: var(--theme-color);
    font-size: 1.3rem;
    margin-left: 0.2rem;
}

header p {
    color: var(--text-muted);
    margin-bottom: 2rem;
}

.hidden-seo {
    position: absolute;
    width: 1px;
    height: 1px;
    padding: 0;
    margin: -1px;
    overflow: hidden;
    clip: rect(0, 0, 0, 0);
    white-space: nowrap;
    border: 0;
}

.theme-toggle-container {
    position: absolute;
    top: 1rem;
    right: 1rem;
}

.btn-theme {
    background: var(--card-bg);
    border: 1px solid var(--text-muted);
    color: var(--text-color);
    padding: 0.5rem;
    border-radius: 50%;
    width: 40px;
    height: 40px;
    cursor: pointer;
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 1.2rem;
    transition: all 0.2s;
    box-shadow: var(--shadow);
}

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

#game-container {
    background: var(--card-bg);
    padding: 2rem;
    border-radius: 1rem;
    box-shadow: var(--shadow);
}

h2, h3 {
    margin-bottom: 1.5rem;
}

.button-group {
    display: flex;
    flex-direction: column;
    gap: 1rem;
    margin-bottom: 1.5rem;
}

.difficulty-grid {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: 1.5rem;
    margin-bottom: 1.5rem;
}

.btn {
    padding: 1rem 2rem;
    font-size: 1.125rem;
    font-weight: 600;
    border: none;
    border-radius: 0.5rem;
    background-color: var(--theme-color);
    color: white;
    cursor: pointer;
    transition: all 0.2s;
    display: flex;
    flex-direction: column;
    align-items: center;
    justify-content: center;
    gap: 0.5rem;
}

.btn-diff {
    aspect-ratio: 1 / 1;
    padding: 1rem;
    text-align: center;
    min-height: 140px;
    height: 100%;
}

.btn-diff .title {
    font-size: 1.5rem;
    font-weight: 800;
}

.btn-diff .desc {
    font-size: 0.8rem;
    font-weight: 400;
    line-height: 1.2;
}

/* Difficulty Buttons with Hover */
.btn-green { background-color: var(--success-color); }
.btn-green:hover { background-color: var(--success-hover) !important; transform: translateY(-3px); box-shadow: 0 10px 15px -3px rgba(34, 197, 94, 0.4); }

.btn-yellow { background-color: var(--warning-color); }
.btn-yellow:hover { background-color: var(--warning-hover) !important; transform: translateY(-3px); box-shadow: 0 10px 15px -3px rgba(245, 158, 11, 0.4); }

.btn-red { background-color: var(--error-color); }
.btn-red:hover { background-color: var(--error-hover) !important; transform: translateY(-3px); box-shadow: 0 10px 15px -3px rgba(239, 68, 68, 0.4); }

.btn:hover {
    background-color: var(--theme-hover);
    transform: translateY(-2px);
}

.btn-icon {
    padding: 0.75rem 1.5rem;
    font-size: 1rem;
    border: 2px solid var(--theme-color);
    background: transparent;
    color: var(--theme-color);
    border-radius: 0.5rem;
    cursor: pointer;
    margin-bottom: 1rem;
    transition: all 0.2s;
}

.btn-icon:hover {
    background: var(--theme-color);
    color: white;
}

.btn-main {
    font-size: 1.25rem;
    padding: 1rem 2rem;
}

.btn-secondary {
    background: transparent;
    color: var(--text-muted);
    border: none;
    text-decoration: underline;
    cursor: pointer;
}

.hidden {
    display: none;
}

/* Feedback animations */
#feedback {
    margin-bottom: 1rem;
    padding: 1rem;
    border-radius: 0.5rem;
    font-weight: 700;
    opacity: 0;
    min-height: 4rem;
    display: flex;
    align-items: center;
    justify-content: center;
    transition: opacity 0.3s;
    visibility: hidden; /* Garantir que comece escondido e não interativo */
}

.show-feedback {
    opacity: 1 !important;
    visibility: visible !important;
}

.success {
    background-color: #dcfce7;
    color: var(--success-color);
    animation: bounce 0.5s ease;
}

.error {
    background-color: #fee2e2;
    color: var(--error-color);
    animation: shake 0.5s ease;
}

@keyframes bounce {
    0%, 100% { transform: scale(1); }
    50% { transform: scale(1.1); }
}

@keyframes shake {
    0%, 100% { transform: translateX(0); }
    25% { transform: translateX(-10px); }
    75% { transform: translateX(10px); }
}

#options-container {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(120px, 1fr));
    gap: 1.5rem;
    justify-content: center;
}

@media (max-width: 600px) {
    header h1 {
        font-size: 2.5rem;
    }
    .difficulty-grid {
        grid-template-columns: 1fr;
    }
    .btn-diff {
        aspect-ratio: auto;
        min-height: 100px;
    }
}

@media (max-width: 400px) {
    #options-container {
        grid-template-columns: 1fr;
    }
    header h1 {
        font-size: 2rem;
    }
}

/* Footer Styles */
footer {
    margin-top: 3rem;
    padding-top: 1.5rem;
    border-top: 1px solid var(--text-muted);
    opacity: 0.8;
}

.footer-content {
    display: flex;
    flex-direction: column;
    align-items: center;
    gap: 0.75rem;
}

.github-link {
    display: flex;
    align-items: center;
    gap: 0.5rem;
    color: var(--text-color);
    text-decoration: none;
    font-weight: 500;
    transition: color 0.2s;
}

.github-link:hover {
    color: var(--theme-color);
}

footer p {
    font-size: 0.9rem;
    color: var(--text-muted);
}