/* CSS Reset and Base Styles */
*,
*::before,
*::after {
    box-sizing: border-box;
    margin: 0;
    padding: 0;
}

:root {
    --primary-color: #4f46e5;
    --primary-hover: #4338ca;
    --secondary-color: #6b7280;
    --secondary-hover: #4b5563;
    --background-color: #f8fafc;
    --card-background: #ffffff;
    --text-primary: #1e293b;
    --text-secondary: #64748b;
    --border-color: #e2e8f0;
    --success-color: #10b981;
    --warning-color: #f59e0b;
    --error-color: #ef4444;
    --shadow-sm: 0 1px 2px 0 rgb(0 0 0 / 0.05);
    --shadow-md: 0 4px 6px -1px rgb(0 0 0 / 0.1), 0 2px 4px -2px rgb(0 0 0 / 0.1);
    --shadow-lg: 0 10px 15px -3px rgb(0 0 0 / 0.1), 0 4px 6px -4px rgb(0 0 0 / 0.1);
    --radius-sm: 0.375rem;
    --radius-md: 0.5rem;
    --radius-lg: 0.75rem;
    --transition: all 0.2s ease-in-out;
}

body {
    font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, Oxygen, Ubuntu, Cantarell, sans-serif;
    background-color: var(--background-color);
    color: var(--text-primary);
    line-height: 1.6;
    min-height: 100vh;
}

.container {
    max-width: 900px;
    margin: 0 auto;
    padding: 2rem 1rem;
    min-height: 100vh;
    display: flex;
    flex-direction: column;
}

/* Header Styles */
header {
    text-align: center;
    margin-bottom: 2rem;
}

header h1 {
    font-size: 2.5rem;
    font-weight: 700;
    color: var(--text-primary);
    margin-bottom: 0.5rem;
}

.subtitle {
    color: var(--text-secondary);
    font-size: 1.1rem;
}

/* Main Content */
main {
    flex: 1;
}

/* Input Section */
.input-section {
    background: var(--card-background);
    padding: 1.5rem;
    border-radius: var(--radius-lg);
    box-shadow: var(--shadow-md);
    margin-bottom: 1.5rem;
}

.input-section label {
    display: block;
    font-weight: 600;
    margin-bottom: 0.75rem;
    color: var(--text-primary);
}

textarea {
    width: 100%;
    padding: 1rem;
    border: 2px solid var(--border-color);
    border-radius: var(--radius-md);
    font-size: 1rem;
    font-family: inherit;
    resize: vertical;
    transition: var(--transition);
    min-height: 200px;
}

textarea:focus {
    outline: none;
    border-color: var(--primary-color);
    box-shadow: 0 0 0 3px rgba(79, 70, 229, 0.1);
}

textarea::placeholder {
    color: var(--text-secondary);
}

.input-actions {
    display: flex;
    gap: 1rem;
    margin-top: 1rem;
    justify-content: flex-end;
}

/* Button Styles */
.btn {
    padding: 0.75rem 1.5rem;
    border: none;
    border-radius: var(--radius-md);
    font-size: 1rem;
    font-weight: 600;
    cursor: pointer;
    transition: var(--transition);
    display: inline-flex;
    align-items: center;
    gap: 0.5rem;
}

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

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

.btn-secondary {
    background-color: var(--card-background);
    color: var(--secondary-color);
    border: 2px solid var(--border-color);
}

.btn-secondary:hover {
    background-color: var(--background-color);
    border-color: var(--secondary-color);
}

/* Settings Section */
.settings-section {
    background: var(--card-background);
    padding: 1.5rem;
    border-radius: var(--radius-lg);
    box-shadow: var(--shadow-md);
    margin-bottom: 1.5rem;
}

.settings-section h2 {
    font-size: 1.25rem;
    margin-bottom: 1rem;
    color: var(--text-primary);
}

.setting-item {
    margin-bottom: 1rem;
}

.setting-item label {
    display: block;
    font-weight: 500;
    margin-bottom: 0.5rem;
    color: var(--text-primary);
}

#wpm-value {
    color: var(--primary-color);
    font-weight: 700;
}

input[type="range"] {
    width: 100%;
    height: 8px;
    border-radius: 4px;
    background: var(--border-color);
    appearance: none;
    cursor: pointer;
}

input[type="range"]::-webkit-slider-thumb {
    appearance: none;
    width: 20px;
    height: 20px;
    border-radius: 50%;
    background: var(--primary-color);
    cursor: pointer;
    transition: var(--transition);
}

input[type="range"]::-webkit-slider-thumb:hover {
    transform: scale(1.1);
    box-shadow: var(--shadow-md);
}

input[type="range"]::-moz-range-thumb {
    width: 20px;
    height: 20px;
    border-radius: 50%;
    background: var(--primary-color);
    cursor: pointer;
    border: none;
}

.wpm-labels {
    display: flex;
    justify-content: space-between;
    font-size: 0.75rem;
    color: var(--text-secondary);
    margin-top: 0.5rem;
}

/* Results Section */
.results-section {
    background: var(--card-background);
    padding: 1.5rem;
    border-radius: var(--radius-lg);
    box-shadow: var(--shadow-md);
    margin-bottom: 1.5rem;
}

.results-section h2 {
    font-size: 1.25rem;
    margin-bottom: 1.5rem;
    color: var(--text-primary);
}

.results-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(200px, 1fr));
    gap: 1rem;
    margin-bottom: 2rem;
}

.result-card {
    background: var(--background-color);
    padding: 1.25rem;
    border-radius: var(--radius-md);
    display: flex;
    align-items: flex-start;
    gap: 1rem;
    transition: var(--transition);
}

.result-card:hover {
    transform: translateY(-2px);
    box-shadow: var(--shadow-sm);
}

.result-card.time-card {
    background: linear-gradient(135deg, #4f46e5 0%, #7c3aed 100%);
    color: white;
}

.result-card.time-card .result-note {
    color: rgba(255, 255, 255, 0.8);
}

.card-icon {
    font-size: 1.75rem;
    line-height: 1;
}

.card-content h3 {
    font-size: 0.875rem;
    font-weight: 500;
    opacity: 0.9;
    margin-bottom: 0.25rem;
}

.result-value {
    font-size: 1.5rem;
    font-weight: 700;
    line-height: 1.2;
}

.result-note {
    font-size: 0.75rem;
    color: var(--text-secondary);
    margin-top: 0.25rem;
}

/* Reading Level Section */
.reading-level-section {
    border-top: 1px solid var(--border-color);
    padding-top: 1.5rem;
}

.reading-level-section h3 {
    font-size: 1.1rem;
    margin-bottom: 1rem;
    color: var(--text-primary);
}

.level-results {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
    gap: 0.75rem;
    margin-bottom: 1.5rem;
}

.level-item {
    display: flex;
    flex-wrap: wrap;
    align-items: baseline;
    gap: 0.5rem;
    padding: 0.75rem;
    background: var(--background-color);
    border-radius: var(--radius-sm);
}

.level-label {
    color: var(--text-secondary);
    font-size: 0.875rem;
}

.level-value {
    font-weight: 700;
    color: var(--primary-color);
}

.level-description {
    font-size: 0.8rem;
    color: var(--text-secondary);
    font-style: italic;
    width: 100%;
}

/* Difficulty Meter */
.level-meter {
    margin-top: 1rem;
}

.meter-labels {
    display: flex;
    justify-content: space-between;
    font-size: 0.7rem;
    color: var(--text-secondary);
    margin-bottom: 0.5rem;
}

.meter-bar {
    height: 12px;
    background: linear-gradient(to right,
        #10b981 0%,
        #84cc16 25%,
        #eab308 50%,
        #f97316 75%,
        #ef4444 100%
    );
    border-radius: 6px;
    position: relative;
}

.meter-marker {
    position: absolute;
    top: -4px;
    width: 20px;
    height: 20px;
    background: white;
    border: 3px solid var(--text-primary);
    border-radius: 50%;
    transform: translateX(-50%);
    transition: left 0.3s ease;
    left: 50%;
    box-shadow: var(--shadow-md);
}

/* Footer */
footer {
    text-align: center;
    padding: 2rem 1rem;
    margin-top: auto;
    border-top: 1px solid var(--border-color);
}

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

footer a {
    color: var(--primary-color);
    text-decoration: none;
    font-weight: 600;
    transition: var(--transition);
}

footer a:hover {
    color: var(--primary-hover);
    text-decoration: underline;
}

/* Responsive Design */
@media (max-width: 768px) {
    .container {
        padding: 1rem;
    }

    header h1 {
        font-size: 1.75rem;
    }

    .subtitle {
        font-size: 1rem;
    }

    .input-section,
    .settings-section,
    .results-section {
        padding: 1rem;
    }

    .input-actions {
        flex-direction: column;
    }

    .btn {
        width: 100%;
        justify-content: center;
    }

    .results-grid {
        grid-template-columns: 1fr 1fr;
    }

    .result-card {
        padding: 1rem;
    }

    .result-value {
        font-size: 1.25rem;
    }

    .level-results {
        grid-template-columns: 1fr;
    }

    .meter-labels {
        font-size: 0.6rem;
    }
}

@media (max-width: 480px) {
    header h1 {
        font-size: 1.5rem;
    }

    .results-grid {
        grid-template-columns: 1fr;
    }

    .result-card {
        flex-direction: column;
        text-align: center;
    }

    .card-icon {
        font-size: 2rem;
    }
}

/* Animation for results appearing */
@keyframes fadeIn {
    from {
        opacity: 0;
        transform: translateY(10px);
    }
    to {
        opacity: 1;
        transform: translateY(0);
    }
}

.results-section.show {
    animation: fadeIn 0.3s ease-out;
}

/* Custom scrollbar */
textarea::-webkit-scrollbar {
    width: 8px;
}

textarea::-webkit-scrollbar-track {
    background: var(--background-color);
    border-radius: 4px;
}

textarea::-webkit-scrollbar-thumb {
    background: var(--border-color);
    border-radius: 4px;
}

textarea::-webkit-scrollbar-thumb:hover {
    background: var(--secondary-color);
}