* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
    font-family: Arial, sans-serif;
}

body {
    background: #0d0d0d;
    color: #e6e6e6;
}

#app {
    display: flex;
    height: 100vh;
}

/* SIDEBAR */
.sidebar {
    width: 260px;
    background: #111;
    padding: 20px;
    border-right: 1px solid #222;
    overflow-y: auto;
}

.logo {
    font-size: 20px;
    font-weight: bold;
    margin-bottom: 25px;
    color: #4da6ff;
}

.nav h3 {
    margin: 20px 0 10px;
    font-size: 14px;
    color: #999;
    text-transform: uppercase;
}

.nav a {
    display: block;
    padding: 8px 0;
    color: #ccc;
    text-decoration: none;
    font-size: 15px;
    transition: 0.2s;
}

.nav a:hover {
    color: #4da6ff;
}

/* MAIN CONTENT */
.content {
    flex: 1;
    padding: 40px;
    overflow-y: auto;
}

#tool-container {
    max-width: 900px;
}

.signature-wrapper {
    border: 1px solid #333;
    background: #1a1a1a;
    margin: 20px 0;
    height: 200px;
    position: relative;
}

#signatureCanvas {
    width: 100%;
    height: 100%;
    display: block;
}

.signature-actions button {
    margin-right: 10px;
    margin-top: 10px;
}

.tool textarea {
    width: 100%;
    min-height: 120px;
    margin: 10px 0;
    padding: 10px;
    background: #111;
    color: #eee;
    border: 1px solid #333;
    resize: vertical;
}

.tool-desc {
    margin-bottom: 15px;
    opacity: 0.85;
}

.file-label {
    display: block;
    margin-bottom: 6px;
    font-weight: 600;
}

.file-input {
    margin-bottom: 15px;
}

.status {
    margin-top: 10px;
    font-size: 0.9rem;
    opacity: 0.8;
}

.preview-box {
    background: #111;
    padding: 12px;
    border-radius: 6px;
    max-height: 260px;
    overflow: auto;
    margin-bottom: 15px;
    border: 1px solid #222;
}