:root {
    --bg-color: #f8fafc;
    --card-bg: #ffffff;
    --text-main: #0f172a;
    --text-muted: #64748b;
    --primary: #0284c7;
    --primary-hover: #0369a1;
    --border: #e2e8f0;
    --font-ui: 'Inter', sans-serif;
    --font-code: 'JetBrains Mono', monospace;
}

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

body {
    background-color: var(--bg-color);
    color: var(--text-main);
    font-family: var(--font-ui);
    line-height: 1.5;
}

.navbar {
    background: var(--card-bg);
    padding: 1rem 2rem;
    display: flex;
    justify-content: space-between;
    align-items: center;
    border-bottom: 1px solid var(--border);
}
.logo { display: flex; align-items: center; gap: 0.75rem; color: var(--primary); }
.logo h1 { font-size: 1.25rem; font-weight: 600; color: var(--text-main); }
.nav-links { color: var(--text-muted); font-size: 0.875rem; font-weight: 500; }

.container {
    max-width: 1400px;
    margin: 2rem auto;
    padding: 0 2rem;
    display: grid;
    grid-template-columns: 320px 1fr;
    gap: 2rem;
}

/* Sidebar Presets */
.sidebar h3 { font-size: 1.1rem; margin-bottom: 0.5rem; }
.text-sm { font-size: 0.85rem; color: var(--text-muted); margin-bottom: 1.5rem; }
.preset-list { display: flex; flex-direction: column; gap: 0.75rem; }

.preset-btn {
    background: var(--card-bg);
    border: 1px solid var(--border);
    padding: 1rem;
    border-radius: 8px;
    text-align: left;
    cursor: pointer;
    transition: all 0.2s;
}
.preset-btn:hover, .preset-btn.active {
    border-color: var(--primary);
    box-shadow: 0 4px 6px -1px rgba(0,0,0,0.05);
}
.preset-btn strong { display: block; font-size: 0.95rem; margin-bottom: 0.25rem; color: var(--text-main); }
.preset-btn span { display: block; font-size: 0.8rem; color: var(--text-muted); }

/* Main Cards */
.card {
    background: var(--card-bg);
    border: 1px solid var(--border);
    border-radius: 10px;
    margin-bottom: 1.5rem;
    overflow: hidden;
}
.card-header {
    padding: 1rem 1.5rem;
    border-bottom: 1px solid var(--border);
    display: flex;
    justify-content: space-between;
    align-items: center;
    background: #fcfcfc;
}
.card-header h2 { font-size: 1.1rem; }
.card-header span { color: var(--text-muted); font-size: 0.9rem; font-weight: 400; }

/* Radio Tabs */
.mode-tabs { display: flex; gap: 1rem; font-size: 0.875rem; }
.mode-tabs label { cursor: pointer; display: flex; align-items: center; gap: 0.25rem; color: var(--text-muted); }
.mode-tabs input:checked + label { color: var(--primary); font-weight: 500; }

.card-body { padding: 1.5rem; }

/* Inputs */
.input-panel { display: none; }
.input-panel.active { display: block; }

textarea {
    width: 100%;
    height: 350px;
    background: #1e1e1e;
    color: #d4d4d4;
    font-family: var(--font-code);
    font-size: 0.875rem;
    padding: 1rem;
    border-radius: 6px;
    border: 1px solid var(--border);
    resize: vertical;
}
.sm-textarea { height: 120px; }

.text-input, .select-input {
    width: 100%;
    padding: 0.75rem 1rem;
    border: 1px solid var(--border);
    border-radius: 6px;
    font-family: var(--font-ui);
    font-size: 0.9rem;
}
.file-input {
    border: 2px dashed var(--border);
    padding: 2rem;
    width: 100%;
    text-align: center;
    border-radius: 6px;
    color: var(--text-muted);
}
.hidden { display: none; }
.mt-2 { margin-top: 0.75rem; }

/* Footer / Settings */
.settings-grid { display: grid; grid-template-columns: 1fr auto; gap: 2rem; align-items: end; }
.setting-title { display: block; font-size: 0.9rem; font-weight: 500; margin-bottom: 0.5rem; }

.btn-primary {
    display: flex;
    align-items: center;
    gap: 0.5rem;
    background: var(--primary);
    color: white;
    border: none;
    padding: 0.75rem 1.5rem;
    font-size: 1rem;
    font-weight: 500;
    border-radius: 6px;
    cursor: pointer;
    transition: background 0.2s;
}
.btn-primary:hover { background: var(--primary-hover); }

@media (max-width: 900px) {
    .container { grid-template-columns: 1fr; }
    .settings-grid { grid-template-columns: 1fr; }
}