:root {
    /* Light theme variables */
    --bg-primary: #ffffff;
    --bg-secondary: #f0f4f8;
    --bg-tertiary: #e2e8f0;
    --text-primary: #1e293b;
    --text-secondary: #64748b;
    --border-color: #cbd5e1;
    --btn-primary: #4f46e5;
    --btn-primary-hover: #4338ca;
    --btn-secondary: #94a3b8;
    --btn-secondary-hover: #64748b;
    --card-shadow: 0 10px 30px rgba(0,0,0,0.08);
    --input-focus: #4f46e5;
    --transition-speed: 0.3s;
}

/* Scoping the Dark Theme Styles to the wrapper */
.modern-word-counter-wrapper[data-theme="dark"] {
    /* Dark theme variables */
    --bg-primary: #1e293b;
    --bg-secondary: #334155;
    --bg-tertiary: #475569;
    --text-primary: #f1f5f9;
    --text-secondary: #cbd5e1;
    --border-color: #475569;
    --btn-primary: #818cf8;
    --btn-primary-hover: #6366f1;
    --btn-secondary: #94a3b8;
    --btn-secondary-hover: #cbd5e1;
    --card-shadow: 0 10px 30px rgba(0,0,0,0.3);
    --input-focus: #818cf8;
}

.word-counter-app {
    width: 100%;
    max-width: 900px;
    margin: 2rem auto; 
    padding: 2rem;
    border-radius: 20px;
    background: var(--bg-primary);
    box-shadow: var(--card-shadow);
    transition: box-shadow var(--transition-speed), background var(--transition-speed);
}

/* Header and Theme Toggle */
.app-header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    margin-bottom: 2rem;
    border-bottom: 1px solid var(--border-color);
    padding-bottom: 1rem;
}

.app-header h1 {
    font-size: 2rem;
    font-weight: 700;
    margin: 0;
    color: var(--text-primary);
}

.theme-toggle-btn {
    background: var(--bg-tertiary);
    border: none;
    border-radius: 50%;
    width: 40px;
    height: 40px;
    cursor: pointer;
    color: var(--text-primary);
    display: flex;
    align-items: center;
    justify-content: center;
    transition: background var(--transition-speed), transform 0.1s ease-in-out;
}

.theme-toggle-btn:hover {
    background: var(--border-color);
    transform: scale(1.05);
}

.sun-icon, .moon-icon {
    display: none;
}

/* Target icons based on the wrapper's theme attribute */
.modern-word-counter-wrapper[data-theme="light"] .sun-icon,
.modern-word-counter-wrapper[data-theme="dark"] .moon-icon { 
    display: block; 
}

/* Textarea */
#text-input {
    width: 100%;
    min-height: 250px;
    padding: 1.5rem;
    border: 2px solid var(--border-color);
    border-radius: 12px;
    font-size: 1rem;
    line-height: 1.6;
    resize: vertical;
    background: var(--bg-secondary);
    color: var(--text-primary);
    transition: border-color var(--transition-speed), box-shadow var(--transition-speed);
}

#text-input:focus {
    outline: none;
    border-color: var(--input-focus);
    box-shadow: 0 0 0 4px rgba(79, 70, 229, 0.2);
}

/* Stats Grid */
.stats-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(150px, 1fr));
    gap: 1.5rem;
    margin-top: 1.5rem;
    margin-bottom: 2rem;
}

.stat-card {
    background: var(--bg-tertiary);
    border-radius: 12px;
    padding: 1.2rem;
    text-align: center;
    box-shadow: 0 4px 8px rgba(0,0,0,0.05);
    transition: background var(--transition-speed), transform 0.1s ease-in-out;
    cursor: default;
}

.stat-card:hover {
    transform: translateY(-2px);
}

.stat-label {
    display: block;
    font-size: 0.9rem;
    font-weight: 500;
    color: var(--text-secondary);
    margin-bottom: 0.5rem;
}

.stat-value {
    font-size: 2rem;
    font-weight: 800;
    color: var(--text-primary);
    display: block;
}

/* Action Buttons */
.actions-container {
    display: flex;
    gap: 1rem;
    justify-content: center;
}

.btn {
    display: flex;
    align-items: center;
    gap: 0.5rem;
    padding: 0.75rem 1.5rem;
    border: none;
    border-radius: 10px;
    font-weight: 600;
    cursor: pointer;
    transition: all 0.2s ease;
    box-shadow: 0 2px 6px rgba(0,0,0,0.1);
}

.btn-primary {
    background: var(--btn-primary);
    color: white;
    box-shadow: 0 4px 10px rgba(79, 70, 229, 0.3);
}

.btn-primary:hover {
    background: var(--btn-primary-hover);
    transform: translateY(-1px);
}

.btn-secondary {
    background: var(--bg-tertiary);
    color: var(--text-primary);
}

.btn-secondary:hover {
    background: var(--border-color);
    transform: translateY(-1px);
}

/* Responsive */
@media (max-width: 600px) {
    .word-counter-app {
        padding: 1rem;
    }
    .app-header {
        flex-direction: column;
        align-items: flex-start;
    }
    .stats-grid {
        grid-template-columns: 1fr 1fr;
    }
    .actions-container {
        flex-direction: column;
        gap: 0.75rem;
    }
    .btn {
        width: 100%;
        justify-content: center;
    }
}