:root {
    --primary: #2563eb;
    --primary-hover: #1d4ed8;
    --bg: #f8fafc;
    --card-bg: #ffffff;
    --text: #1e293b;
    --text-muted: #64748b;
    --border: #e2e8f0;
}

body {
    font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, Helvetica, Arial, sans-serif;
    background-color: var(--bg);
    color: var(--text);
    margin: 0;
    padding: 0;
    line-height: 1.5;
}

.container {
    max-width: 800px;
    margin: 0 auto;
    padding: 2rem 1rem;
}

header {
    text-align: center;
    margin-bottom: 3rem;
}

header h1 {
    font-size: 2.5rem;
    font-weight: 800;
    margin-bottom: 0.5rem;
    color: var(--primary);
}

header p {
    color: var(--text-muted);
}

main {
    display: grid;
    gap: 2rem;
}

.card {
    background: var(--card-bg);
    border: 1px solid var(--border);
    border-radius: 0.75rem;
    padding: 1.5rem;
    box-shadow: 0 1px 3px rgba(0,0,0,0.1);
}

.card h2 {
    margin-top: 0;
    font-size: 1.25rem;
    margin-bottom: 1.5rem;
}

.input-group {
    margin-bottom: 1.25rem;
}

.input-group label {
    display: block;
    font-size: 0.875rem;
    font-weight: 500;
    margin-bottom: 0.5rem;
}

input[type="file"], select {
    width: 100%;
    padding: 0.5rem;
    border: 1px solid var(--border);
    border-radius: 0.375rem;
    box-sizing: border-box;
}

button {
    width: 100%;
    padding: 0.75rem;
    background-color: var(--primary);
    color: white;
    border: none;
    border-radius: 0.375rem;
    font-weight: 600;
    cursor: pointer;
    transition: background-color 0.2s;
}

button:hover:not(:disabled) {
    background-color: var(--primary-hover);
}

button:disabled {
    opacity: 0.5;
    cursor: not-allowed;
}

.result-area {
    margin-top: 1.5rem;
    text-align: center;
}

canvas {
    display: block;
    max-width: 100%;
    height: auto;
    border: 1px solid var(--border);
    border-radius: 0.375rem;
    margin: 1rem auto;
}

.success-box {
    background-color: #f0fdf4;
    border: 1px solid #bbf7d0;
    padding: 1rem;
    border-radius: 0.375rem;
}

.download-link {
    display: block;
    margin: 1rem auto;
    color: var(--primary);
    text-decoration: none;
    font-weight: 600;
}

.download-link:hover {
    text-decoration: underline;
}

audio {
    width: 100%;
    margin-top: 1rem;
}

footer {
    text-align: center;
    margin-top: 4rem;
    color: var(--text-muted);
    font-size: 0.875rem;
}

footer a {
    color: var(--primary);
    text-decoration: none;
}

.error {
    color: #dc2626;
    font-size: 0.875rem;
}