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

body {
    font-family: 'Segoe UI', system-ui, sans-serif;
    background: #0a0a0f;
    color: #e0e0e0;
    overflow: hidden;
    height: 100vh;
}

/* ==================== Toolbar ==================== */
#toolbar {
    position: fixed;
    top: 0; left: 0; right: 0;
    height: 48px;
    background: #12121a;
    border-bottom: 1px solid #2a2a3a;
    display: flex;
    align-items: center;
    padding: 0 12px;
    gap: 6px;
    z-index: 100;
}

#toolbar .logo {
    font-weight: 700;
    font-size: 15px;
    color: #00e599;
    margin-right: 12px;
}

.gate-btn {
    padding: 5px 12px;
    background: #1a1a2e;
    border: 1px solid #2a2a3a;
    border-radius: 6px;
    color: #ccc;
    cursor: pointer;
    font-size: 12px;
    font-weight: 600;
    transition: all 0.15s;
    user-select: none;
}
.gate-btn:hover { background: #252540; border-color: #00e599; color: #fff; }
.gate-btn.input-btn { border-color: #3388ff; }
.gate-btn.input-btn:hover { border-color: #55aaff; }
.gate-btn.clock-btn { border-color: #ff44aa; }
.gate-btn.clock-btn:hover { border-color: #ff66cc; }
.gate-btn.output-btn { border-color: #ff8833; }
.gate-btn.output-btn:hover { border-color: #ffaa55; }

.separator { width: 1px; height: 24px; background: #2a2a3a; margin: 0 6px; }
.toolbar-right { margin-left: auto; display: flex; gap: 6px; align-items: center; }

.action-btn {
    padding: 5px 10px;
    background: transparent;
    border: 1px solid #333;
    border-radius: 6px;
    color: #888;
    cursor: pointer;
    font-size: 11px;
    transition: all 0.15s;
}
.action-btn:hover { border-color: #ff4444; color: #ff4444; }
.action-btn.help-btn:hover { border-color: #00e599; color: #00e599; }
.action-btn.sim-btn { border-color: #ff44aa; color: #ff44aa; }
.action-btn.sim-btn:hover { background: #ff44aa22; }
.action-btn.sim-btn.active { background: #ff44aa33; border-color: #ff66cc; color: #ff66cc; }

/* ==================== Canvas ==================== */
#canvas {
    position: fixed;
    top: 48px; left: 0; right: 0; bottom: 0;
    cursor: default;
}

/* ==================== Waveform Panel ==================== */
#waveform-panel {
    display: none;
    position: fixed;
    left: 0; right: 0; bottom: 0;
    height: 220px;
    background: #0c0c14;
    border-top: 2px solid #00e599;
    z-index: 90;
    flex-direction: column;
}
#waveform-panel.visible { display: flex; }

#wave-toolbar {
    display: flex;
    align-items: center;
    padding: 4px 12px;
    gap: 8px;
    background: #10101a;
    border-bottom: 1px solid #1a1a2a;
    height: 32px;
    flex-shrink: 0;
}

#wave-toolbar span.wave-title {
    font-size: 12px;
    font-weight: 700;
    color: #00e599;
    margin-right: 8px;
}

.wave-btn {
    padding: 3px 10px;
    background: #1a1a2e;
    border: 1px solid #2a2a3a;
    border-radius: 4px;
    color: #aaa;
    cursor: pointer;
    font-size: 11px;
    font-weight: 600;
    transition: all 0.15s;
}
.wave-btn:hover { border-color: #00e599; color: #fff; }
.wave-btn.active { background: #00e59933; border-color: #00e599; color: #00e599; }
.wave-btn.record { border-color: #ff4444; }
.wave-btn.record.active { background: #ff444433; border-color: #ff4444; color: #ff4444; }

.wave-info { margin-left: auto; font-size: 11px; color: #555; }

#wave-container { display: flex; flex: 1; overflow: hidden; }

#wave-labels {
    width: 100px;
    flex-shrink: 0;
    overflow-y: auto;
    background: #0e0e18;
    border-right: 1px solid #1a1a2a;
}

.wave-label {
    height: 30px;
    display: flex;
    align-items: center;
    padding: 0 8px;
    font-size: 11px;
    font-weight: 600;
    border-bottom: 1px solid #111;
    color: #888;
    white-space: nowrap;
    overflow: hidden;
    text-overflow: ellipsis;
}
.wave-label.input-label { color: #3388ff; }
.wave-label.output-label { color: #ff8833; }
.wave-label.gate-label { color: #00e599; }

#wave-canvas { flex: 1; cursor: crosshair; }

/* ==================== Help Modal ==================== */
#help-modal {
    display: none;
    position: fixed;
    top: 0; left: 0; right: 0; bottom: 0;
    background: rgba(0,0,0,0.7);
    z-index: 200;
    justify-content: center;
    align-items: center;
}
#help-modal.visible { display: flex; }

#help-content {
    background: #12121a;
    border: 1px solid #2a2a3a;
    border-radius: 12px;
    padding: 24px;
    max-width: 520px;
    width: 90%;
    max-height: 80vh;
    overflow-y: auto;
}
#help-content h2 { color: #00e599; margin-bottom: 12px; font-size: 18px; }
#help-content h3 { color: #ff44aa; margin: 12px 0 8px; font-size: 14px; }
#help-content p, #help-content li { color: #aaa; font-size: 13px; line-height: 1.5; margin-bottom: 6px; }
#help-content ul { padding-left: 20px; }
#help-content kbd {
    background: #1a1a2e;
    border: 1px solid #333;
    border-radius: 4px;
    padding: 1px 5px;
    font-size: 11px;
    color: #ddd;
}
#help-close {
    margin-top: 12px;
    padding: 6px 18px;
    background: #00e599;
    border: none;
    border-radius: 6px;
    color: #000;
    font-weight: 600;
    cursor: pointer;
}

/* ==================== Resize Handle ==================== */
#wave-resize {
    position: absolute;
    top: -4px; left: 0; right: 0;
    height: 8px;
    cursor: ns-resize;
    z-index: 91;
}